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Squashed 'src/secp256k1/' changes from 22f60a6..2bfb82b

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2bfb82b Merge pull request 
06aeea5 Turn secp256k1_ec_pubkey_serialize outlen to in/out
970164d Merge pull request 
6466625 Improvements for coordinate decompression
e2100ad Merge pull request 
8e48787 Change secp256k1_ec_pubkey_combine's count argument to size_t.
c69dea0 Clear output in more cases for pubkey_combine, adds tests.
269d422 Comment copyediting.
b4d17da Merge pull request 
4709265 Merge pull request 
26abce7 Adds 32 static test vectors for scalar mul, sqr, inv.
5b71a3f Better error case handling for pubkey_create & pubkey_serialize, more tests.
3b7bc69 Merge pull request 
eed87af Change contrib/laxder from headers-only to files compilable as standalone C
d7eb1ae Merge pull request 
7914a6e Make lax_der_privatekey_parsing.h not depend on internal code
73f64ff Merge pull request 
9234391 Overhaul flags handling
1a36898 Make flags more explicit, add runtime checks.
1a3e03a Merge pull request 
96be204 Add additional tests for eckey and arg-checks.
bb5aa4d Make the tweak function zeroize-output-on-fail behavior consistent.
4a243da Move secp256k1_ec_privkey_import/export to contrib.
1b3efc1 Move secp256k1_ecdsa_sig_recover into the recovery module.
e3cd679 Eliminate all side-effects from VERIFY_CHECK() usage.
b30fc85 Avoid nonce_function_rfc6979 algo16 argument emulation.
70d4640 Make secp256k1_ec_pubkey_create skip processing invalid secret keys.
6c476a8 Minor comment improvements.
131afe5 Merge pull request 
0c6ab2f Introduce explicit lower-S normalization
fea19e7 Add contrib/lax_der_parsing.h
3bb9c44 Rewrite ECDSA signature parsing code
fa57f1b Use secp256k1_rand_int and secp256k1_rand_bits more
49b3749 Add new tests for the extra testrand functions
f684d7d Faster secp256k1_rand_int implementation
251b1a6 Improve testrand: add extra random functions
31994c8 Merge pull request 
f79aa88 Bugfix: swap arguments to noncefp
c98df26 Merge pull request 
67f7da4 Extensive interface and operations tests for secp256k1_ec_pubkey_parse.
ee2cb40 Add ARG_CHECKs to secp256k1_ec_pubkey_parse/secp256k1_ec_pubkey_serialize
7450ef1 Merge pull request 
68a3c76 Merge pull request 
98135ee Merge pull request 
37100d7 improve ECDH header-doc
b13d749 Fix couple of typos in API comments
7c823e3 travis: fixup module configs
cc3141a Merge pull request 
ee58fae Merge pull request 
213aa67 Do not force benchmarks to be statically linked.
338fc8b Add API exports to secp256k1_nonce_function_default and secp256k1_nonce_function_rfc6979.
52fd03f Merge pull request 
9f6993f Remove some dead code.
357f8cd Merge pull request 
118cd82 Use explicit symbol visibility.
4e64608 Include public module headers when compiling modules.
1f41437 Merge pull request 
fe0d463 Merge pull request 
cfe0ed9 Fix miscellaneous style nits that irritate overactive static analysis.
2b199de Use the explicit NULL macro for pointer comparisons.
9e90516 Merge pull request 
dd891e0 Get rid of _t as it is POSIX reserved
201819b Merge pull request 
912f203 Eliminate a few unbraced statements that crept into the code.
eeab823 Merge pull request 
486b9bb Use a flags bitfield for compressed option to secp256k1_ec_pubkey_serialize and secp256k1_ec_privkey_export
05732c5 Callback data: Accept pointers to either const or non-const data
1973c73 Bugfix: Reinitialise buffer lengths that have been used as outputs
788038d Use size_t for lengths (at least in external API)
c9d7c2a secp256k1_context_set_{error,illegal}_callback: Restore default handler by passing NULL as function argument
9aac008 secp256k1_context_destroy: Allow NULL argument as a no-op
64b730b secp256k1_context_create: Use unsigned type for flags bitfield
cb04ab5 Merge pull request 
a551669 Merge pull request 
81e45ff Update group_impl.h
85e3a2c Merge pull request 
b2eb63b Merge pull request 
dc0ce9f [API BREAK] Change argument order to out/outin/in
6d947ca Merge pull request 
c822693 Merge pull request 
6d04350 Merge pull request 
7ab311c Merge pull request 
5fb3229 Fixes a bug where bench_sign would fail due to passing in too small a buffer.
263dcbc remove unused assignment
b183b41 bugfix: "ARG_CHECK(ctx != NULL)" makes no sense
6da1446 build: fix parallel build
5eb4356 Merge pull request 
c996d53 Print success
9f443be Move pubkey recovery code to separate module
d49abbd Separate ECDSA recovery tests
439d34a Separate recoverable and normal signatures
a7b046e Merge pull request 
f66907f Improve/reformat API documentation secp256k1.h
2f77487 Add context building benchmarks
cc623d5 Merge pull request 
de7e398 small typo fix
9d96e36 Merge pull request 
432e1ce Merge pull request 
14727fd Use correct name in gitignore
356b0e9 Actually test static precomputation in Travis
ff3a5df Merge pull request 
2587208 Merge pull request 
a5a66c7 Add support for custom EC-Schnorr-SHA256 signatures
d84a378 Merge pull request 
72ae443 Improve perf. of cmov-based table lookup
92e53fc Implement endomorphism optimization for secp256k1_ecmult_const
ed35d43 Make `secp256k1_scalar_add_bit` conditional; make `secp256k1_scalar_split_lambda_var` constant time
91c0ce9 Add benchmarks for ECDH and const-time multiplication
0739bbb Add ECDH module which works by hashing the output of ecmult_const
4401500 Add constant-time multiply `secp256k1_ecmult_const` for ECDH
e4ce393 build: fix hard-coded usage of "gen_context"
b8e39ac build: don't use BUILT_SOURCES for the static context header
baa75da tests: add a couple tests
ae4f0c6 Merge pull request 
995c548 Introduce callback functions for dealing with errors.
c333074 Merge pull request 
18c329c Remove the internal secp256k1_ecdsa_sig_t type
74a2acd Add a secp256k1_ecdsa_signature_t type
23cfa91 Introduce secp256k1_pubkey_t type
4c63780 Merge pull request 
3e6f1e2 Change rfc6979 implementation to be a generic PRNG
ed5334a Update configure.ac to make it build on OpenBSD
1b68366 Merge pull request 
a83bb48 Make ecmult static precomputation default
166b32f Merge pull request 
c37812f Add gen_context src/ecmult_static_context.h to CLEANFILES to fix distclean.
125c15d Merge pull request 
76f6769 Fix build with static ecmult altroot and make dist.
5133f78 Merge pull request 
b0a60e6 Merge pull request 
733c1e6 Add travis build to test the static context.
fbecc38 Add ability to use a statically generated ecmult context.
4fb174d Merge pull request 
4ab8990 Merge pull request 
bdf0e0c Merge pull request 
31d0c1f Merge pull request 
eb2c8ff Add missing casts to SECP256K1_FE_CONST_INNER
55399c2 Further performance improvements to _ecmult_wnaf
99fd963 Add secp256k1_ec_pubkey_compress(), with test similar to the related decompress() function.
145cc6e Improve performance of _ecmult_wnaf
36b305a Verify the result of GMP modular inverse using non-GMP code
0cbc860 Merge pull request 
06ff7fe Merge pull request 
5a43124 Save 1 _fe_negate since s1 == -s2
a5d796e Update code comments
3f3964e Add specific VERIFY tests for _fe_cmov
7d054cd Refactor to save a _fe_negate
b28d02a Refactor to remove a local var
55e7fc3 Perf. improvement in _gej_add_ge
a0601cd Fix VERIFY calculations in _fe_cmov methods
17f7148 Merge pull request 
7657420 Add tests for adding P+Q with P.x!=Q.x and P.y=-Q.y
8c5d5f7 tests: Add failing unit test for  (bad addition formula)
5de4c5d gej_add_ge: fix degenerate case when computing P + (-lambda)P
bcf2fcf gej_add_ge: rearrange algebra
e2a07c7 Fix compilation with C++
873a453 Merge pull request 
91eb0da Merge pull request 
210ffed Use separate in and out pointers in `secp256k1_ec_pubkey_decompress`
a1d5ae1 Tiny optimization
729badf Merge pull request 
2d5a186 Apply effective-affine trick to precomp
4f9791a Effective affine addition in EC multiplication
2b4cf41 Use pkg-config always when possible, with failover to manual checks for libcrypto

git-subtree-dir: src/secp256k1
git-subtree-split: 2bfb82b10edf0f0b0e366a12f94c8b21a914159d
This commit is contained in:
Pieter Wuille 2015-11-13 00:12:43 +01:00
parent a591d98c32
commit 1d84107924
68 changed files with 7769 additions and 1957 deletions

4
.gitignore vendored
View file

@ -1,9 +1,12 @@
bench_inv
bench_ecdh
bench_sign
bench_verify
bench_schnorr_verify
bench_recover
bench_internal
tests
gen_context
*.exe
*.so
*.a
@ -28,6 +31,7 @@ build-aux/
*~
src/libsecp256k1-config.h
src/libsecp256k1-config.h.in
src/ecmult_static_context.h
m4/libtool.m4
m4/ltoptions.m4
m4/ltsugar.m4

18
.travis.yml
View file

@ -8,20 +8,24 @@ compiler:
- gcc
env:
global:
- FIELD=auto BIGNUM=auto SCALAR=auto ENDOMORPHISM=no ASM=no BUILD=check EXTRAFLAGS= HOST=
- FIELD=auto BIGNUM=auto SCALAR=auto ENDOMORPHISM=no STATICPRECOMPUTATION=yes ASM=no BUILD=check EXTRAFLAGS= HOST= ECDH=no schnorr=no RECOVERY=no
matrix:
- SCALAR=32bit
- SCALAR=32bit RECOVERY=yes
- SCALAR=32bit FIELD=32bit ECDH=yes
- SCALAR=64bit
- FIELD=64bit
- FIELD=64bit RECOVERY=yes
- FIELD=64bit ENDOMORPHISM=yes
- FIELD=64bit ENDOMORPHISM=yes ECDH=yes
- FIELD=64bit ASM=x86_64
- FIELD=64bit ENDOMORPHISM=yes ASM=x86_64
- FIELD=32bit
- FIELD=32bit SCHNORR=yes
- FIELD=32bit ENDOMORPHISM=yes
- BIGNUM=no
- BIGNUM=no ENDOMORPHISM=yes
- BIGNUM=no ENDOMORPHISM=yes SCHNORR=yes RECOVERY=yes
- BIGNUM=no STATICPRECOMPUTATION=no
- BUILD=distcheck
- EXTRAFLAGS=CFLAGS=-DDETERMINISTIC
- EXTRAFLAGS=CPPFLAGS=-DDETERMINISTIC
- EXTRAFLAGS=CFLAGS=-O0
matrix:
fast_finish: true
include:
@ -55,5 +59,5 @@ before_script: ./autogen.sh
script:
- if [ -n "$HOST" ]; then export USE_HOST="--host=$HOST"; fi
- if [ "x$HOST" = "xi686-linux-gnu" ]; then export CC="$CC -m32"; fi
- ./configure --enable-endomorphism=$ENDOMORPHISM --with-field=$FIELD --with-bignum=$BIGNUM --with-scalar=$SCALAR $EXTRAFLAGS $USE_HOST && make -j2 $BUILD
- ./configure --enable-endomorphism=$ENDOMORPHISM --with-field=$FIELD --with-bignum=$BIGNUM --with-scalar=$SCALAR --enable-ecmult-static-precomputation=$STATICPRECOMPUTATION --enable-module-ecdh=$ECDH --enable-module-schnorr=$SCHNORR --enable-module-recovery=$RECOVERY $EXTRAFLAGS $USE_HOST && make -j2 $BUILD
os: linux

54
Makefile.am
View file

@ -19,6 +19,8 @@ noinst_HEADERS += src/eckey.h
noinst_HEADERS += src/eckey_impl.h
noinst_HEADERS += src/ecmult.h
noinst_HEADERS += src/ecmult_impl.h
noinst_HEADERS += src/ecmult_const.h
noinst_HEADERS += src/ecmult_const_impl.h
noinst_HEADERS += src/ecmult_gen.h
noinst_HEADERS += src/ecmult_gen_impl.h
noinst_HEADERS += src/num.h
@ -38,40 +40,72 @@ noinst_HEADERS += src/hash_impl.h
noinst_HEADERS += src/field.h
noinst_HEADERS += src/field_impl.h
noinst_HEADERS += src/bench.h
noinst_HEADERS += contrib/lax_der_parsing.h
noinst_HEADERS += contrib/lax_der_parsing.c
noinst_HEADERS += contrib/lax_der_privatekey_parsing.h
noinst_HEADERS += contrib/lax_der_privatekey_parsing.c
pkgconfigdir = $(libdir)/pkgconfig
pkgconfig_DATA = libsecp256k1.pc
libsecp256k1_la_SOURCES = src/secp256k1.c
libsecp256k1_la_CPPFLAGS = -I$(top_srcdir)/include $(SECP_INCLUDES)
libsecp256k1_la_CPPFLAGS = -I$(top_srcdir)/include -I$(top_srcdir)/src $(SECP_INCLUDES)
libsecp256k1_la_LIBADD = $(SECP_LIBS)
noinst_PROGRAMS =
if USE_BENCHMARK
noinst_PROGRAMS += bench_verify bench_recover bench_sign bench_internal
noinst_PROGRAMS += bench_verify bench_sign bench_internal
bench_verify_SOURCES = src/bench_verify.c
bench_verify_LDADD = libsecp256k1.la $(SECP_LIBS)
bench_verify_LDFLAGS = -static
bench_recover_SOURCES = src/bench_recover.c
bench_recover_LDADD = libsecp256k1.la $(SECP_LIBS)
bench_recover_LDFLAGS = -static
bench_sign_SOURCES = src/bench_sign.c
bench_sign_LDADD = libsecp256k1.la $(SECP_LIBS)
bench_sign_LDFLAGS = -static
bench_internal_SOURCES = src/bench_internal.c
bench_internal_LDADD = $(SECP_LIBS)
bench_internal_LDFLAGS = -static
bench_internal_CPPFLAGS = $(SECP_INCLUDES)
endif
if USE_TESTS
noinst_PROGRAMS += tests
tests_SOURCES = src/tests.c
tests_CPPFLAGS = -DVERIFY $(SECP_INCLUDES) $(SECP_TEST_INCLUDES)
tests_CPPFLAGS = -DVERIFY -I$(top_srcdir)/src -I$(top_srcdir)/include $(SECP_INCLUDES) $(SECP_TEST_INCLUDES)
tests_LDADD = $(SECP_LIBS) $(SECP_TEST_LIBS)
tests_LDFLAGS = -static
TESTS = tests
endif
EXTRA_DIST = autogen.sh
if USE_ECMULT_STATIC_PRECOMPUTATION
CPPFLAGS_FOR_BUILD +=-I$(top_srcdir)/
CFLAGS_FOR_BUILD += -Wall -Wextra -Wno-unused-function
gen_context_OBJECTS = gen_context.o
gen_context_BIN = gen_context$(BUILD_EXEEXT)
gen_%.o: src/gen_%.c
$(CC_FOR_BUILD) $(CPPFLAGS_FOR_BUILD) $(CFLAGS_FOR_BUILD) -c $< -o $@
$(gen_context_BIN): $(gen_context_OBJECTS)
$(CC_FOR_BUILD) $^ -o $@
$(libsecp256k1_la_OBJECTS): src/ecmult_static_context.h
$(tests_OBJECTS): src/ecmult_static_context.h
$(bench_internal_OBJECTS): src/ecmult_static_context.h
src/ecmult_static_context.h: $(gen_context_BIN)
./$(gen_context_BIN)
CLEANFILES = $(gen_context_BIN) src/ecmult_static_context.h
endif
EXTRA_DIST = autogen.sh src/gen_context.c src/basic-config.h
if ENABLE_MODULE_ECDH
include src/modules/ecdh/Makefile.am.include
endif
if ENABLE_MODULE_SCHNORR
include src/modules/schnorr/Makefile.am.include
endif
if ENABLE_MODULE_RECOVERY
include src/modules/recovery/Makefile.am.include
endif

125
build-aux/m4/ax_prog_cc_for_build.m4 Normal file
View file

@ -0,0 +1,125 @@
# ===========================================================================
# http://www.gnu.org/software/autoconf-archive/ax_prog_cc_for_build.html
# ===========================================================================
#
# SYNOPSIS
#
# AX_PROG_CC_FOR_BUILD
#
# DESCRIPTION
#
# This macro searches for a C compiler that generates native executables,
# that is a C compiler that surely is not a cross-compiler. This can be
# useful if you have to generate source code at compile-time like for
# example GCC does.
#
# The macro sets the CC_FOR_BUILD and CPP_FOR_BUILD macros to anything
# needed to compile or link (CC_FOR_BUILD) and preprocess (CPP_FOR_BUILD).
# The value of these variables can be overridden by the user by specifying
# a compiler with an environment variable (like you do for standard CC).
#
# It also sets BUILD_EXEEXT and BUILD_OBJEXT to the executable and object
# file extensions for the build platform, and GCC_FOR_BUILD to `yes' if
# the compiler we found is GCC. All these variables but GCC_FOR_BUILD are
# substituted in the Makefile.
#
# LICENSE
#
# Copyright (c) 2008 Paolo Bonzini <bonzini@gnu.org>
#
# Copying and distribution of this file, with or without modification, are
# permitted in any medium without royalty provided the copyright notice
# and this notice are preserved. This file is offered as-is, without any
# warranty.
#serial 8
AU_ALIAS([AC_PROG_CC_FOR_BUILD], [AX_PROG_CC_FOR_BUILD])
AC_DEFUN([AX_PROG_CC_FOR_BUILD], [dnl
AC_REQUIRE([AC_PROG_CC])dnl
AC_REQUIRE([AC_PROG_CPP])dnl
AC_REQUIRE([AC_EXEEXT])dnl
AC_REQUIRE([AC_CANONICAL_HOST])dnl
dnl Use the standard macros, but make them use other variable names
dnl
pushdef([ac_cv_prog_CPP], ac_cv_build_prog_CPP)dnl
pushdef([ac_cv_prog_gcc], ac_cv_build_prog_gcc)dnl
pushdef([ac_cv_prog_cc_works], ac_cv_build_prog_cc_works)dnl
pushdef([ac_cv_prog_cc_cross], ac_cv_build_prog_cc_cross)dnl
pushdef([ac_cv_prog_cc_g], ac_cv_build_prog_cc_g)dnl
pushdef([ac_cv_exeext], ac_cv_build_exeext)dnl
pushdef([ac_cv_objext], ac_cv_build_objext)dnl
pushdef([ac_exeext], ac_build_exeext)dnl
pushdef([ac_objext], ac_build_objext)dnl
pushdef([CC], CC_FOR_BUILD)dnl
pushdef([CPP], CPP_FOR_BUILD)dnl
pushdef([CFLAGS], CFLAGS_FOR_BUILD)dnl
pushdef([CPPFLAGS], CPPFLAGS_FOR_BUILD)dnl
pushdef([LDFLAGS], LDFLAGS_FOR_BUILD)dnl
pushdef([host], build)dnl
pushdef([host_alias], build_alias)dnl
pushdef([host_cpu], build_cpu)dnl
pushdef([host_vendor], build_vendor)dnl
pushdef([host_os], build_os)dnl
pushdef([ac_cv_host], ac_cv_build)dnl
pushdef([ac_cv_host_alias], ac_cv_build_alias)dnl
pushdef([ac_cv_host_cpu], ac_cv_build_cpu)dnl
pushdef([ac_cv_host_vendor], ac_cv_build_vendor)dnl
pushdef([ac_cv_host_os], ac_cv_build_os)dnl
pushdef([ac_cpp], ac_build_cpp)dnl
pushdef([ac_compile], ac_build_compile)dnl
pushdef([ac_link], ac_build_link)dnl
save_cross_compiling=$cross_compiling
save_ac_tool_prefix=$ac_tool_prefix
cross_compiling=no
ac_tool_prefix=
AC_PROG_CC
AC_PROG_CPP
AC_EXEEXT
ac_tool_prefix=$save_ac_tool_prefix
cross_compiling=$save_cross_compiling
dnl Restore the old definitions
dnl
popdef([ac_link])dnl
popdef([ac_compile])dnl
popdef([ac_cpp])dnl
popdef([ac_cv_host_os])dnl
popdef([ac_cv_host_vendor])dnl
popdef([ac_cv_host_cpu])dnl
popdef([ac_cv_host_alias])dnl
popdef([ac_cv_host])dnl
popdef([host_os])dnl
popdef([host_vendor])dnl
popdef([host_cpu])dnl
popdef([host_alias])dnl
popdef([host])dnl
popdef([LDFLAGS])dnl
popdef([CPPFLAGS])dnl
popdef([CFLAGS])dnl
popdef([CPP])dnl
popdef([CC])dnl
popdef([ac_objext])dnl
popdef([ac_exeext])dnl
popdef([ac_cv_objext])dnl
popdef([ac_cv_exeext])dnl
popdef([ac_cv_prog_cc_g])dnl
popdef([ac_cv_prog_cc_cross])dnl
popdef([ac_cv_prog_cc_works])dnl
popdef([ac_cv_prog_gcc])dnl
popdef([ac_cv_prog_CPP])dnl
dnl Finally, set Makefile variables
dnl
BUILD_EXEEXT=$ac_build_exeext
BUILD_OBJEXT=$ac_build_objext
AC_SUBST(BUILD_EXEEXT)dnl
AC_SUBST(BUILD_OBJEXT)dnl
AC_SUBST([CFLAGS_FOR_BUILD])dnl
AC_SUBST([CPPFLAGS_FOR_BUILD])dnl
AC_SUBST([LDFLAGS_FOR_BUILD])dnl
])

18
build-aux/m4/bitcoin_secp.m4
View file

@ -16,8 +16,7 @@ AC_MSG_RESULT([$has_64bit_asm])
dnl
AC_DEFUN([SECP_OPENSSL_CHECK],[
if test x"$use_pkgconfig" = x"yes"; then
: #NOP
has_libcrypto=no
m4_ifdef([PKG_CHECK_MODULES],[
PKG_CHECK_MODULES([CRYPTO], [libcrypto], [has_libcrypto=yes],[has_libcrypto=no])
if test x"$has_libcrypto" = x"yes"; then
@ -27,11 +26,16 @@ if test x"$use_pkgconfig" = x"yes"; then
LIBS="$TEMP_LIBS"
fi
])
else
AC_CHECK_HEADER(openssl/crypto.h,[AC_CHECK_LIB(crypto, main,[has_libcrypto=yes; CRYPTO_LIBS=-lcrypto; AC_DEFINE(HAVE_LIBCRYPTO,1,[Define this symbol if libcrypto is installed])]
)])
LIBS=
fi
if test x$has_libcrypto = xno; then
AC_CHECK_HEADER(openssl/crypto.h,[
AC_CHECK_LIB(crypto, main,[
has_libcrypto=yes
CRYPTO_LIBS=-lcrypto
AC_DEFINE(HAVE_LIBCRYPTO,1,[Define this symbol if libcrypto is installed])
])
])
LIBS=
fi
if test x"$has_libcrypto" = x"yes" && test x"$has_openssl_ec" = x; then
AC_MSG_CHECKING(for EC functions in libcrypto)
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[

64
configure.ac
View file

@ -17,25 +17,19 @@ PKG_PROG_PKG_CONFIG
AC_PATH_TOOL(AR, ar)
AC_PATH_TOOL(RANLIB, ranlib)
AC_PATH_TOOL(STRIP, strip)
AX_PROG_CC_FOR_BUILD
if test "x$CFLAGS" = "x"; then
CFLAGS="-O3 -g"
fi
AM_PROG_CC_C_O
AC_PROG_CC_C89
if test x"$ac_cv_prog_cc_c89" = x"no"; then
AC_MSG_ERROR([c89 compiler support required])
fi
case $host in
*mingw*)
use_pkgconfig=no
;;
*)
use_pkgconfig=yes
;;
esac
case $host_os in
*darwin*)
if test x$cross_compiling != xyes; then
@ -80,6 +74,14 @@ AC_COMPILE_IFELSE([AC_LANG_SOURCE([[char foo;]])],
CFLAGS="$saved_CFLAGS"
])
saved_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -fvisibility=hidden"
AC_MSG_CHECKING([if ${CC} supports -fvisibility=hidden])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[char foo;]])],
[ AC_MSG_RESULT([yes]) ],
[ AC_MSG_RESULT([no])
CFLAGS="$saved_CFLAGS"
])
AC_ARG_ENABLE(benchmark,
AS_HELP_STRING([--enable-benchmark],[compile benchmark (default is no)]),
@ -95,6 +97,26 @@ AC_ARG_ENABLE(endomorphism,
AS_HELP_STRING([--enable-endomorphism],[enable endomorphism (default is no)]),
[use_endomorphism=$enableval],
[use_endomorphism=no])
AC_ARG_ENABLE(ecmult_static_precomputation,
AS_HELP_STRING([--enable-ecmult-static-precomputation],[enable precomputed ecmult table for signing (default is yes)]),
[use_ecmult_static_precomputation=$enableval],
[use_ecmult_static_precomputation=yes])
AC_ARG_ENABLE(module_ecdh,
AS_HELP_STRING([--enable-module-ecdh],[enable ECDH shared secret computation (default is no)]),
[enable_module_ecdh=$enableval],
[enable_module_ecdh=no])
AC_ARG_ENABLE(module_schnorr,
AS_HELP_STRING([--enable-module-schnorr],[enable Schnorr signature module (default is no)]),
[enable_module_schnorr=$enableval],
[enable_module_schnorr=no])
AC_ARG_ENABLE(module_recovery,
AS_HELP_STRING([--enable-module-recovery],[enable ECDSA pubkey recovery module (default is no)]),
[enable_module_recovery=$enableval],
[enable_module_recovery=no])
AC_ARG_WITH([field], [AS_HELP_STRING([--with-field=64bit|32bit|auto],
[Specify Field Implementation. Default is auto])],[req_field=$withval], [req_field=auto])
@ -305,6 +327,22 @@ if test x"$use_endomorphism" = x"yes"; then
AC_DEFINE(USE_ENDOMORPHISM, 1, [Define this symbol to use endomorphism optimization])
fi
if test x"$use_ecmult_static_precomputation" = x"yes"; then
AC_DEFINE(USE_ECMULT_STATIC_PRECOMPUTATION, 1, [Define this symbol to use a statically generated ecmult table])
fi
if test x"$enable_module_ecdh" = x"yes"; then
AC_DEFINE(ENABLE_MODULE_ECDH, 1, [Define this symbol to enable the ECDH module])
fi
if test x"$enable_module_schnorr" = x"yes"; then
AC_DEFINE(ENABLE_MODULE_SCHNORR, 1, [Define this symbol to enable the Schnorr signature module])
fi
if test x"$enable_module_recovery" = x"yes"; then
AC_DEFINE(ENABLE_MODULE_RECOVERY, 1, [Define this symbol to enable the ECDSA pubkey recovery module])
fi
AC_C_BIGENDIAN()
AC_MSG_NOTICE([Using assembly optimizations: $set_asm])
@ -312,6 +350,10 @@ AC_MSG_NOTICE([Using field implementation: $set_field])
AC_MSG_NOTICE([Using bignum implementation: $set_bignum])
AC_MSG_NOTICE([Using scalar implementation: $set_scalar])
AC_MSG_NOTICE([Using endomorphism optimizations: $use_endomorphism])
AC_MSG_NOTICE([Building ECDH module: $enable_module_ecdh])
AC_MSG_NOTICE([Building Schnorr signatures module: $enable_module_schnorr])
AC_MSG_NOTICE([Building ECDSA pubkey recovery module: $enable_module_recovery])
AC_CONFIG_HEADERS([src/libsecp256k1-config.h])
AC_CONFIG_FILES([Makefile libsecp256k1.pc])
@ -321,6 +363,10 @@ AC_SUBST(SECP_TEST_LIBS)
AC_SUBST(SECP_TEST_INCLUDES)
AM_CONDITIONAL([USE_TESTS], [test x"$use_tests" != x"no"])
AM_CONDITIONAL([USE_BENCHMARK], [test x"$use_benchmark" = x"yes"])
AM_CONDITIONAL([USE_ECMULT_STATIC_PRECOMPUTATION], [test x"$use_ecmult_static_precomputation" = x"yes"])
AM_CONDITIONAL([ENABLE_MODULE_ECDH], [test x"$enable_module_ecdh" = x"yes"])
AM_CONDITIONAL([ENABLE_MODULE_SCHNORR], [test x"$enable_module_schnorr" = x"yes"])
AM_CONDITIONAL([ENABLE_MODULE_RECOVERY], [test x"$enable_module_recovery" = x"yes"])
dnl make sure nothing new is exported so that we don't break the cache
PKGCONFIG_PATH_TEMP="$PKG_CONFIG_PATH"

150
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@ -0,0 +1,150 @@
/**********************************************************************
* Copyright (c) 2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#include <string.h>
#include <secp256k1.h>
#include "lax_der_parsing.h"
int ecdsa_signature_parse_der_lax(const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input, size_t inputlen) {
size_t rpos, rlen, spos, slen;
size_t pos = 0;
size_t lenbyte;
unsigned char tmpsig[64] = {0};
int overflow = 0;
/* Hack to initialize sig with a correctly-parsed but invalid signature. */
secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig);
/* Sequence tag byte */
if (pos == inputlen || input[pos] != 0x30) {
return 0;
}
pos++;
/* Sequence length bytes */
if (pos == inputlen) {
return 0;
}
lenbyte = input[pos++];
if (lenbyte & 0x80) {
lenbyte -= 0x80;
if (pos + lenbyte > inputlen) {
return 0;
}
pos += lenbyte;
}
/* Integer tag byte for R */
if (pos == inputlen || input[pos] != 0x02) {
return 0;
}
pos++;
/* Integer length for R */
if (pos == inputlen) {
return 0;
}
lenbyte = input[pos++];
if (lenbyte & 0x80) {
lenbyte -= 0x80;
if (pos + lenbyte > inputlen) {
return 0;
}
while (lenbyte > 0 && input[pos] == 0) {
pos++;
lenbyte--;
}
if (lenbyte >= sizeof(size_t)) {
return 0;
}
rlen = 0;
while (lenbyte > 0) {
rlen = (rlen << 8) + input[pos];
pos++;
lenbyte--;
}
} else {
rlen = lenbyte;
}
if (rlen > inputlen - pos) {
return 0;
}
rpos = pos;
pos += rlen;
/* Integer tag byte for S */
if (pos == inputlen || input[pos] != 0x02) {
return 0;
}
pos++;
/* Integer length for S */
if (pos == inputlen) {
return 0;
}
lenbyte = input[pos++];
if (lenbyte & 0x80) {
lenbyte -= 0x80;
if (pos + lenbyte > inputlen) {
return 0;
}
while (lenbyte > 0 && input[pos] == 0) {
pos++;
lenbyte--;
}
if (lenbyte >= sizeof(size_t)) {
return 0;
}
slen = 0;
while (lenbyte > 0) {
slen = (slen << 8) + input[pos];
pos++;
lenbyte--;
}
} else {
slen = lenbyte;
}
if (slen > inputlen - pos) {
return 0;
}
spos = pos;
pos += slen;
/* Ignore leading zeroes in R */
while (rlen > 0 && input[rpos] == 0) {
rlen--;
rpos++;
}
/* Copy R value */
if (rlen > 32) {
overflow = 1;
} else {
memcpy(tmpsig + 32 - rlen, input + rpos, rlen);
}
/* Ignore leading zeroes in S */
while (slen > 0 && input[spos] == 0) {
slen--;
spos++;
}
/* Copy S value */
if (slen > 32) {
overflow = 1;
} else {
memcpy(tmpsig + 64 - slen, input + spos, slen);
}
if (!overflow) {
overflow = !secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig);
}
if (overflow) {
memset(tmpsig, 0, 64);
secp256k1_ecdsa_signature_parse_compact(ctx, sig, tmpsig);
}
return 1;
}

91
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@ -0,0 +1,91 @@
/**********************************************************************
* Copyright (c) 2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
/****
* Please do not link this file directly. It is not part of the libsecp256k1
* project and does not promise any stability in its API, functionality or
* presence. Projects which use this code should instead copy this header
* and its accompanying .c file directly into their codebase.
****/
/* This file defines a function that parses DER with various errors and
* violations. This is not a part of the library itself, because the allowed
* violations are chosen arbitrarily and do not follow or establish any
* standard.
*
* In many places it matters that different implementations do not only accept
* the same set of valid signatures, but also reject the same set of signatures.
* The only means to accomplish that is by strictly obeying a standard, and not
* accepting anything else.
*
* Nonetheless, sometimes there is a need for compatibility with systems that
* use signatures which do not strictly obey DER. The snippet below shows how
* certain violations are easily supported. You may need to adapt it.
*
* Do not use this for new systems. Use well-defined DER or compact signatures
* instead if you have the choice (see secp256k1_ecdsa_signature_parse_der and
* secp256k1_ecdsa_signature_parse_compact).
*
* The supported violations are:
* - All numbers are parsed as nonnegative integers, even though X.609-0207
* section 8.3.3 specifies that integers are always encoded as two's
* complement.
* - Integers can have length 0, even though section 8.3.1 says they can't.
* - Integers with overly long padding are accepted, violation section
* 8.3.2.
* - 127-byte long length descriptors are accepted, even though section
* 8.1.3.5.c says that they are not.
* - Trailing garbage data inside or after the signature is ignored.
* - The length descriptor of the sequence is ignored.
*
* Compared to for example OpenSSL, many violations are NOT supported:
* - Using overly long tag descriptors for the sequence or integers inside,
* violating section 8.1.2.2.
* - Encoding primitive integers as constructed values, violating section
* 8.3.1.
*/
#ifndef _SECP256K1_CONTRIB_LAX_DER_PARSING_H_
#define _SECP256K1_CONTRIB_LAX_DER_PARSING_H_
#include <secp256k1.h>
# ifdef __cplusplus
extern "C" {
# endif
/** Parse a signature in "lax DER" format
*
* Returns: 1 when the signature could be parsed, 0 otherwise.
* Args: ctx: a secp256k1 context object
* Out: sig: a pointer to a signature object
* In: input: a pointer to the signature to be parsed
* inputlen: the length of the array pointed to be input
*
* This function will accept any valid DER encoded signature, even if the
* encoded numbers are out of range. In addition, it will accept signatures
* which violate the DER spec in various ways. Its purpose is to allow
* validation of the Bitcoin blockchain, which includes non-DER signatures
* from before the network rules were updated to enforce DER. Note that
* the set of supported violations is a strict subset of what OpenSSL will
* accept.
*
* After the call, sig will always be initialized. If parsing failed or the
* encoded numbers are out of range, signature validation with it is
* guaranteed to fail for every message and public key.
*/
int ecdsa_signature_parse_der_lax(
const secp256k1_context* ctx,
secp256k1_ecdsa_signature* sig,
const unsigned char *input,
size_t inputlen
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
#ifdef __cplusplus
}
#endif
#endif

113
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@ -0,0 +1,113 @@
/**********************************************************************
* Copyright (c) 2014, 2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#include <string.h>
#include <secp256k1.h>
#include "lax_der_privatekey_parsing.h"
int ec_privkey_import_der(const secp256k1_context* ctx, unsigned char *out32, const unsigned char *privkey, size_t privkeylen) {
const unsigned char *end = privkey + privkeylen;
int lenb = 0;
int len = 0;
memset(out32, 0, 32);
/* sequence header */
if (end < privkey+1 || *privkey != 0x30) {
return 0;
}
privkey++;
/* sequence length constructor */
if (end < privkey+1 || !(*privkey & 0x80)) {
return 0;
}
lenb = *privkey & ~0x80; privkey++;
if (lenb < 1 || lenb > 2) {
return 0;
}
if (end < privkey+lenb) {
return 0;
}
/* sequence length */
len = privkey[lenb-1] | (lenb > 1 ? privkey[lenb-2] << 8 : 0);
privkey += lenb;
if (end < privkey+len) {
return 0;
}
/* sequence element 0: version number (=1) */
if (end < privkey+3 || privkey[0] != 0x02 || privkey[1] != 0x01 || privkey[2] != 0x01) {
return 0;
}
privkey += 3;
/* sequence element 1: octet string, up to 32 bytes */
if (end < privkey+2 || privkey[0] != 0x04 || privkey[1] > 0x20 || end < privkey+2+privkey[1]) {
return 0;
}
memcpy(out32 + 32 - privkey[1], privkey + 2, privkey[1]);
if (!secp256k1_ec_seckey_verify(ctx, out32)) {
memset(out32, 0, 32);
return 0;
}
return 1;
}
int ec_privkey_export_der(const secp256k1_context *ctx, unsigned char *privkey, size_t *privkeylen, const unsigned char *key32, int compressed) {
secp256k1_pubkey pubkey;
size_t pubkeylen = 0;
if (!secp256k1_ec_pubkey_create(ctx, &pubkey, key32)) {
*privkeylen = 0;
return 0;
}
if (compressed) {
static const unsigned char begin[] = {
0x30,0x81,0xD3,0x02,0x01,0x01,0x04,0x20
};
static const unsigned char middle[] = {
0xA0,0x81,0x85,0x30,0x81,0x82,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
0x21,0x02,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
0x17,0x98,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x24,0x03,0x22,0x00
};
unsigned char *ptr = privkey;
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
memcpy(ptr, key32, 32); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
pubkeylen = 33;
secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED);
ptr += pubkeylen;
*privkeylen = ptr - privkey;
} else {
static const unsigned char begin[] = {
0x30,0x82,0x01,0x13,0x02,0x01,0x01,0x04,0x20
};
static const unsigned char middle[] = {
0xA0,0x81,0xA5,0x30,0x81,0xA2,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
0x41,0x04,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
0x17,0x98,0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65,0x5D,0xA4,0xFB,0xFC,0x0E,0x11,
0x08,0xA8,0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19,0x9C,0x47,0xD0,0x8F,0xFB,0x10,
0xD4,0xB8,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x44,0x03,0x42,0x00
};
unsigned char *ptr = privkey;
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
memcpy(ptr, key32, 32); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
pubkeylen = 65;
secp256k1_ec_pubkey_serialize(ctx, ptr, &pubkeylen, &pubkey, SECP256K1_EC_UNCOMPRESSED);
ptr += pubkeylen;
*privkeylen = ptr - privkey;
}
return 1;
}

90
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@ -0,0 +1,90 @@
/**********************************************************************
* Copyright (c) 2014, 2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
/****
* Please do not link this file directly. It is not part of the libsecp256k1
* project and does not promise any stability in its API, functionality or
* presence. Projects which use this code should instead copy this header
* and its accompanying .c file directly into their codebase.
****/
/* This file contains code snippets that parse DER private keys with
* various errors and violations. This is not a part of the library
* itself, because the allowed violations are chosen arbitrarily and
* do not follow or establish any standard.
*
* It also contains code to serialize private keys in a compatible
* manner.
*
* These functions are meant for compatibility with applications
* that require BER encoded keys. When working with secp256k1-specific
* code, the simple 32-byte private keys normally used by the
* library are sufficient.
*/
#ifndef _SECP256K1_CONTRIB_BER_PRIVATEKEY_H_
#define _SECP256K1_CONTRIB_BER_PRIVATEKEY_H_
#include <secp256k1.h>
# ifdef __cplusplus
extern "C" {
# endif
/** Export a private key in DER format.
*
* Returns: 1 if the private key was valid.
* Args: ctx: pointer to a context object, initialized for signing (cannot
* be NULL)
* Out: privkey: pointer to an array for storing the private key in BER.
* Should have space for 279 bytes, and cannot be NULL.
* privkeylen: Pointer to an int where the length of the private key in
* privkey will be stored.
* In: seckey: pointer to a 32-byte secret key to export.
* compressed: 1 if the key should be exported in
* compressed format, 0 otherwise
*
* This function is purely meant for compatibility with applications that
* require BER encoded keys. When working with secp256k1-specific code, the
* simple 32-byte private keys are sufficient.
*
* Note that this function does not guarantee correct DER output. It is
* guaranteed to be parsable by secp256k1_ec_privkey_import_der
*/
SECP256K1_WARN_UNUSED_RESULT int ec_privkey_export_der(
const secp256k1_context* ctx,
unsigned char *privkey,
size_t *privkeylen,
const unsigned char *seckey,
int compressed
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Import a private key in DER format.
* Returns: 1 if a private key was extracted.
* Args: ctx: pointer to a context object (cannot be NULL).
* Out: seckey: pointer to a 32-byte array for storing the private key.
* (cannot be NULL).
* In: privkey: pointer to a private key in DER format (cannot be NULL).
* privkeylen: length of the DER private key pointed to be privkey.
*
* This function will accept more than just strict DER, and even allow some BER
* violations. The public key stored inside the DER-encoded private key is not
* verified for correctness, nor are the curve parameters. Use this function
* only if you know in advance it is supposed to contain a secp256k1 private
* key.
*/
SECP256K1_WARN_UNUSED_RESULT int ec_privkey_import_der(
const secp256k1_context* ctx,
unsigned char *seckey,
const unsigned char *privkey,
size_t privkeylen
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
#ifdef __cplusplus
}
#endif
#endif

704
include/secp256k1.h
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@ -5,6 +5,99 @@
extern "C" {
# endif
#include <stddef.h>
/* These rules specify the order of arguments in API calls:
*
* 1. Context pointers go first, followed by output arguments, combined
* output/input arguments, and finally input-only arguments.
* 2. Array lengths always immediately the follow the argument whose length
* they describe, even if this violates rule 1.
* 3. Within the OUT/OUTIN/IN groups, pointers to data that is typically generated
* later go first. This means: signatures, public nonces, private nonces,
* messages, public keys, secret keys, tweaks.
* 4. Arguments that are not data pointers go last, from more complex to less
* complex: function pointers, algorithm names, messages, void pointers,
* counts, flags, booleans.
* 5. Opaque data pointers follow the function pointer they are to be passed to.
*/
/** Opaque data structure that holds context information (precomputed tables etc.).
*
* The purpose of context structures is to cache large precomputed data tables
* that are expensive to construct, and also to maintain the randomization data
* for blinding.
*
* Do not create a new context object for each operation, as construction is
* far slower than all other API calls (~100 times slower than an ECDSA
* verification).
*
* A constructed context can safely be used from multiple threads
* simultaneously, but API call that take a non-const pointer to a context
* need exclusive access to it. In particular this is the case for
* secp256k1_context_destroy and secp256k1_context_randomize.
*
* Regarding randomization, either do it once at creation time (in which case
* you do not need any locking for the other calls), or use a read-write lock.
*/
typedef struct secp256k1_context_struct secp256k1_context;
/** Opaque data structure that holds a parsed and valid public key.
*
* The exact representation of data inside is implementation defined and not
* guaranteed to be portable between different platforms or versions. It is
* however guaranteed to be 64 bytes in size, and can be safely copied/moved.
* If you need to convert to a format suitable for storage or transmission, use
* secp256k1_ec_pubkey_serialize and secp256k1_ec_pubkey_parse.
*
* Furthermore, it is guaranteed that identical public keys (ignoring
* compression) will have identical representation, so they can be memcmp'ed.
*/
typedef struct {
unsigned char data[64];
} secp256k1_pubkey;
/** Opaque data structured that holds a parsed ECDSA signature.
*
* The exact representation of data inside is implementation defined and not
* guaranteed to be portable between different platforms or versions. It is
* however guaranteed to be 64 bytes in size, and can be safely copied/moved.
* If you need to convert to a format suitable for storage or transmission, use
* the secp256k1_ecdsa_signature_serialize_* and
* secp256k1_ecdsa_signature_serialize_* functions.
*
* Furthermore, it is guaranteed to identical signatures will have identical
* representation, so they can be memcmp'ed.
*/
typedef struct {
unsigned char data[64];
} secp256k1_ecdsa_signature;
/** A pointer to a function to deterministically generate a nonce.
*
* Returns: 1 if a nonce was successfully generated. 0 will cause signing to fail.
* Out: nonce32: pointer to a 32-byte array to be filled by the function.
* In: msg32: the 32-byte message hash being verified (will not be NULL)
* key32: pointer to a 32-byte secret key (will not be NULL)
* algo16: pointer to a 16-byte array describing the signature
* algorithm (will be NULL for ECDSA for compatibility).
* data: Arbitrary data pointer that is passed through.
* attempt: how many iterations we have tried to find a nonce.
* This will almost always be 0, but different attempt values
* are required to result in a different nonce.
*
* Except for test cases, this function should compute some cryptographic hash of
* the message, the algorithm, the key and the attempt.
*/
typedef int (*secp256k1_nonce_function)(
unsigned char *nonce32,
const unsigned char *msg32,
const unsigned char *key32,
const unsigned char *algo16,
void *data,
unsigned int attempt
);
# if !defined(SECP256K1_GNUC_PREREQ)
# if defined(__GNUC__)&&defined(__GNUC_MINOR__)
# define SECP256K1_GNUC_PREREQ(_maj,_min) \
@ -26,6 +119,20 @@ extern "C" {
# define SECP256K1_INLINE inline
# endif
#ifndef SECP256K1_API
# if defined(_WIN32)
# ifdef SECP256K1_BUILD
# define SECP256K1_API __declspec(dllexport)
# else
# define SECP256K1_API
# endif
# elif defined(__GNUC__) && defined(SECP256K1_BUILD)
# define SECP256K1_API __attribute__ ((visibility ("default")))
# else
# define SECP256K1_API
# endif
#endif
/**Warning attributes
* NONNULL is not used if SECP256K1_BUILD is set to avoid the compiler optimizing out
* some paranoid null checks. */
@ -40,305 +147,434 @@ extern "C" {
# define SECP256K1_ARG_NONNULL(_x)
# endif
/** Opaque data structure that holds context information (precomputed tables etc.).
* Only functions that take a pointer to a non-const context require exclusive
* access to it. Multiple functions that take a pointer to a const context may
* run simultaneously.
*/
typedef struct secp256k1_context_struct secp256k1_context_t;
/** All flags' lower 8 bits indicate what they're for. Do not use directly. */
#define SECP256K1_FLAGS_TYPE_MASK ((1 << 8) - 1)
#define SECP256K1_FLAGS_TYPE_CONTEXT (1 << 0)
#define SECP256K1_FLAGS_TYPE_COMPRESSION (1 << 1)
/** The higher bits contain the actual data. Do not use directly. */
#define SECP256K1_FLAGS_BIT_CONTEXT_VERIFY (1 << 8)
#define SECP256K1_FLAGS_BIT_CONTEXT_SIGN (1 << 9)
#define SECP256K1_FLAGS_BIT_COMPRESSION (1 << 8)
/** Flags to pass to secp256k1_context_create. */
# define SECP256K1_CONTEXT_VERIFY (1 << 0)
# define SECP256K1_CONTEXT_SIGN (1 << 1)
#define SECP256K1_CONTEXT_VERIFY (SECP256K1_FLAGS_TYPE_CONTEXT | SECP256K1_FLAGS_BIT_CONTEXT_VERIFY)
#define SECP256K1_CONTEXT_SIGN (SECP256K1_FLAGS_TYPE_CONTEXT | SECP256K1_FLAGS_BIT_CONTEXT_SIGN)
#define SECP256K1_CONTEXT_NONE (SECP256K1_FLAGS_TYPE_CONTEXT)
/** Flag to pass to secp256k1_ec_pubkey_serialize and secp256k1_ec_privkey_export. */
#define SECP256K1_EC_COMPRESSED (SECP256K1_FLAGS_TYPE_COMPRESSION | SECP256K1_FLAGS_BIT_COMPRESSION)
#define SECP256K1_EC_UNCOMPRESSED (SECP256K1_FLAGS_TYPE_COMPRESSION)
/** Create a secp256k1 context object.
*
* Returns: a newly created context object.
* In: flags: which parts of the context to initialize.
*/
secp256k1_context_t* secp256k1_context_create(
int flags
SECP256K1_API secp256k1_context* secp256k1_context_create(
unsigned int flags
) SECP256K1_WARN_UNUSED_RESULT;
/** Copies a secp256k1 context object.
*
* Returns: a newly created context object.
* In: ctx: an existing context to copy
* Args: ctx: an existing context to copy (cannot be NULL)
*/
secp256k1_context_t* secp256k1_context_clone(
const secp256k1_context_t* ctx
) SECP256K1_WARN_UNUSED_RESULT;
SECP256K1_API secp256k1_context* secp256k1_context_clone(
const secp256k1_context* ctx
) SECP256K1_ARG_NONNULL(1) SECP256K1_WARN_UNUSED_RESULT;
/** Destroy a secp256k1 context object.
*
* The context pointer may not be used afterwards.
* Args: ctx: an existing context to destroy (cannot be NULL)
*/
void secp256k1_context_destroy(
secp256k1_context_t* ctx
SECP256K1_API void secp256k1_context_destroy(
secp256k1_context* ctx
);
/** Set a callback function to be called when an illegal argument is passed to
* an API call. It will only trigger for violations that are mentioned
* explicitly in the header.
*
* The philosophy is that these shouldn't be dealt with through a
* specific return value, as calling code should not have branches to deal with
* the case that this code itself is broken.
*
* On the other hand, during debug stage, one would want to be informed about
* such mistakes, and the default (crashing) may be inadvisable.
* When this callback is triggered, the API function called is guaranteed not
* to cause a crash, though its return value and output arguments are
* undefined.
*
* Args: ctx: an existing context object (cannot be NULL)
* In: fun: a pointer to a function to call when an illegal argument is
* passed to the API, taking a message and an opaque pointer
* (NULL restores a default handler that calls abort).
* data: the opaque pointer to pass to fun above.
*/
SECP256K1_API void secp256k1_context_set_illegal_callback(
secp256k1_context* ctx,
void (*fun)(const char* message, void* data),
const void* data
) SECP256K1_ARG_NONNULL(1);
/** Verify an ECDSA signature.
* Returns: 1: correct signature
* 0: incorrect signature
* -1: invalid public key
* -2: invalid signature
* In: ctx: a secp256k1 context object, initialized for verification.
* msg32: the 32-byte message hash being verified (cannot be NULL)
* sig: the signature being verified (cannot be NULL)
* siglen: the length of the signature
* pubkey: the public key to verify with (cannot be NULL)
* pubkeylen: the length of pubkey
/** Set a callback function to be called when an internal consistency check
* fails. The default is crashing.
*
* This can only trigger in case of a hardware failure, miscompilation,
* memory corruption, serious bug in the library, or other error would can
* otherwise result in undefined behaviour. It will not trigger due to mere
* incorrect usage of the API (see secp256k1_context_set_illegal_callback
* for that). After this callback returns, anything may happen, including
* crashing.
*
* Args: ctx: an existing context object (cannot be NULL)
* In: fun: a pointer to a function to call when an internal error occurs,
* taking a message and an opaque pointer (NULL restores a default
* handler that calls abort).
* data: the opaque pointer to pass to fun above.
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_verify(
const secp256k1_context_t* ctx,
const unsigned char *msg32,
const unsigned char *sig,
int siglen,
const unsigned char *pubkey,
int pubkeylen
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(5);
SECP256K1_API void secp256k1_context_set_error_callback(
secp256k1_context* ctx,
void (*fun)(const char* message, void* data),
const void* data
) SECP256K1_ARG_NONNULL(1);
/** A pointer to a function to deterministically generate a nonce.
* Returns: 1 if a nonce was successfully generated. 0 will cause signing to fail.
* In: msg32: the 32-byte message hash being verified (will not be NULL)
* key32: pointer to a 32-byte secret key (will not be NULL)
* attempt: how many iterations we have tried to find a nonce.
* This will almost always be 0, but different attempt values
* are required to result in a different nonce.
* data: Arbitrary data pointer that is passed through.
* Out: nonce32: pointer to a 32-byte array to be filled by the function.
* Except for test cases, this function should compute some cryptographic hash of
* the message, the key and the attempt.
/** Parse a variable-length public key into the pubkey object.
*
* Returns: 1 if the public key was fully valid.
* 0 if the public key could not be parsed or is invalid.
* Args: ctx: a secp256k1 context object.
* Out: pubkey: pointer to a pubkey object. If 1 is returned, it is set to a
* parsed version of input. If not, its value is undefined.
* In: input: pointer to a serialized public key
* inputlen: length of the array pointed to by input
*
* This function supports parsing compressed (33 bytes, header byte 0x02 or
* 0x03), uncompressed (65 bytes, header byte 0x04), or hybrid (65 bytes, header
* byte 0x06 or 0x07) format public keys.
*/
typedef int (*secp256k1_nonce_function_t)(
unsigned char *nonce32,
const unsigned char *msg32,
const unsigned char *key32,
unsigned int attempt,
const void *data
);
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_parse(
const secp256k1_context* ctx,
secp256k1_pubkey* pubkey,
const unsigned char *input,
size_t inputlen
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Serialize a pubkey object into a serialized byte sequence.
*
* Returns: 1 always.
* Args: ctx: a secp256k1 context object.
* Out: output: a pointer to a 65-byte (if compressed==0) or 33-byte (if
* compressed==1) byte array to place the serialized key
* in.
* In/Out: outputlen: a pointer to an integer which is initially set to the
* size of output, and is overwritten with the written
* size.
* In: pubkey: a pointer to a secp256k1_pubkey containing an
* initialized public key.
* flags: SECP256K1_EC_COMPRESSED if serialization should be in
* compressed format, otherwise SECP256K1_EC_UNCOMPRESSED.
*/
SECP256K1_API int secp256k1_ec_pubkey_serialize(
const secp256k1_context* ctx,
unsigned char *output,
size_t *outputlen,
const secp256k1_pubkey* pubkey,
unsigned int flags
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Parse an ECDSA signature in compact (64 bytes) format.
*
* Returns: 1 when the signature could be parsed, 0 otherwise.
* Args: ctx: a secp256k1 context object
* Out: sig: a pointer to a signature object
* In: input64: a pointer to the 64-byte array to parse
*
* The signature must consist of a 32-byte big endian R value, followed by a
* 32-byte big endian S value. If R or S fall outside of [0..order-1], the
* encoding is invalid. R and S with value 0 are allowed in the encoding.
*
* After the call, sig will always be initialized. If parsing failed or R or
* S are zero, the resulting sig value is guaranteed to fail validation for any
* message and public key.
*/
SECP256K1_API int secp256k1_ecdsa_signature_parse_compact(
const secp256k1_context* ctx,
secp256k1_ecdsa_signature* sig,
const unsigned char *input64
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Parse a DER ECDSA signature.
*
* Returns: 1 when the signature could be parsed, 0 otherwise.
* Args: ctx: a secp256k1 context object
* Out: sig: a pointer to a signature object
* In: input: a pointer to the signature to be parsed
* inputlen: the length of the array pointed to be input
*
* This function will accept any valid DER encoded signature, even if the
* encoded numbers are out of range.
*
* After the call, sig will always be initialized. If parsing failed or the
* encoded numbers are out of range, signature validation with it is
* guaranteed to fail for every message and public key.
*/
SECP256K1_API int secp256k1_ecdsa_signature_parse_der(
const secp256k1_context* ctx,
secp256k1_ecdsa_signature* sig,
const unsigned char *input,
size_t inputlen
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Serialize an ECDSA signature in DER format.
*
* Returns: 1 if enough space was available to serialize, 0 otherwise
* Args: ctx: a secp256k1 context object
* Out: output: a pointer to an array to store the DER serialization
* In/Out: outputlen: a pointer to a length integer. Initially, this integer
* should be set to the length of output. After the call
* it will be set to the length of the serialization (even
* if 0 was returned).
* In: sig: a pointer to an initialized signature object
*/
SECP256K1_API int secp256k1_ecdsa_signature_serialize_der(
const secp256k1_context* ctx,
unsigned char *output,
size_t *outputlen,
const secp256k1_ecdsa_signature* sig
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Serialize an ECDSA signature in compact (64 byte) format.
*
* Returns: 1
* Args: ctx: a secp256k1 context object
* Out: output64: a pointer to a 64-byte array to store the compact serialization
* In: sig: a pointer to an initialized signature object
*
* See secp256k1_ecdsa_signature_parse_compact for details about the encoding.
*/
SECP256K1_API int secp256k1_ecdsa_signature_serialize_compact(
const secp256k1_context* ctx,
unsigned char *output64,
const secp256k1_ecdsa_signature* sig
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Verify an ECDSA signature.
*
* Returns: 1: correct signature
* 0: incorrect or unparseable signature
* Args: ctx: a secp256k1 context object, initialized for verification.
* In: sig: the signature being verified (cannot be NULL)
* msg32: the 32-byte message hash being verified (cannot be NULL)
* pubkey: pointer to an initialized public key to verify with (cannot be NULL)
*
* To avoid accepting malleable signatures, only ECDSA signatures in lower-S
* form are accepted.
*
* If you need to accept ECDSA signatures from sources that do not obey this
* rule, apply secp256k1_ecdsa_signature_normalize to the signature prior to
* validation, but be aware that doing so results in malleable signatures.
*
* For details, see the comments for that function.
*/
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_verify(
const secp256k1_context* ctx,
const secp256k1_ecdsa_signature *sig,
const unsigned char *msg32,
const secp256k1_pubkey *pubkey
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Convert a signature to a normalized lower-S form.
*
* Returns: 1 if sigin was not normalized, 0 if it already was.
* Args: ctx: a secp256k1 context object
* Out: sigout: a pointer to a signature to fill with the normalized form,
* or copy if the input was already normalized. (can be NULL if
* you're only interested in whether the input was already
* normalized).
* In: sigin: a pointer to a signature to check/normalize (cannot be NULL,
* can be identical to sigout)
*
* With ECDSA a third-party can forge a second distinct signature of the same
* message, given a single initial signature, but without knowing the key. This
* is done by negating the S value modulo the order of the curve, 'flipping'
* the sign of the random point R which is not included in the signature.
*
* Forgery of the same message isn't universally problematic, but in systems
* where message malleability or uniqueness of signatures is important this can
* cause issues. This forgery can be blocked by all verifiers forcing signers
* to use a normalized form.
*
* The lower-S form reduces the size of signatures slightly on average when
* variable length encodings (such as DER) are used and is cheap to verify,
* making it a good choice. Security of always using lower-S is assured because
* anyone can trivially modify a signature after the fact to enforce this
* property anyway.
*
* The lower S value is always between 0x1 and
* 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0,
* inclusive.
*
* No other forms of ECDSA malleability are known and none seem likely, but
* there is no formal proof that ECDSA, even with this additional restriction,
* is free of other malleability. Commonly used serialization schemes will also
* accept various non-unique encodings, so care should be taken when this
* property is required for an application.
*
* The secp256k1_ecdsa_sign function will by default create signatures in the
* lower-S form, and secp256k1_ecdsa_verify will not accept others. In case
* signatures come from a system that cannot enforce this property,
* secp256k1_ecdsa_signature_normalize must be called before verification.
*/
SECP256K1_API int secp256k1_ecdsa_signature_normalize(
const secp256k1_context* ctx,
secp256k1_ecdsa_signature *sigout,
const secp256k1_ecdsa_signature *sigin
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(3);
/** An implementation of RFC6979 (using HMAC-SHA256) as nonce generation function.
* If a data pointer is passed, it is assumed to be a pointer to 32 bytes of
* extra entropy.
*/
extern const secp256k1_nonce_function_t secp256k1_nonce_function_rfc6979;
SECP256K1_API extern const secp256k1_nonce_function secp256k1_nonce_function_rfc6979;
/** A default safe nonce generation function (currently equal to secp256k1_nonce_function_rfc6979). */
extern const secp256k1_nonce_function_t secp256k1_nonce_function_default;
SECP256K1_API extern const secp256k1_nonce_function secp256k1_nonce_function_default;
/** Create an ECDSA signature.
* Returns: 1: signature created
* 0: the nonce generation function failed, the private key was invalid, or there is not
* enough space in the signature (as indicated by siglen).
* In: ctx: pointer to a context object, initialized for signing (cannot be NULL)
* msg32: the 32-byte message hash being signed (cannot be NULL)
* seckey: pointer to a 32-byte secret key (cannot be NULL)
* noncefp:pointer to a nonce generation function. If NULL, secp256k1_nonce_function_default is used
* ndata: pointer to arbitrary data used by the nonce generation function (can be NULL)
* Out: sig: pointer to an array where the signature will be placed (cannot be NULL)
* In/Out: siglen: pointer to an int with the length of sig, which will be updated
* to contain the actual signature length (<=72).
*
* The sig always has an s value in the lower half of the range (From 0x1
* to 0x7FFFFFFFFFFFFFFFFFFFFFFFFFFFFFFF5D576E7357A4501DDFE92F46681B20A0,
* inclusive), unlike many other implementations.
* With ECDSA a third-party can can forge a second distinct signature
* of the same message given a single initial signature without knowing
* the key by setting s to its additive inverse mod-order, 'flipping' the
* sign of the random point R which is not included in the signature.
* Since the forgery is of the same message this isn't universally
* problematic, but in systems where message malleability or uniqueness
* of signatures is important this can cause issues. This forgery can be
* blocked by all verifiers forcing signers to use a canonical form. The
* lower-S form reduces the size of signatures slightly on average when
* variable length encodings (such as DER) are used and is cheap to
* verify, making it a good choice. Security of always using lower-S is
* assured because anyone can trivially modify a signature after the
* fact to enforce this property. Adjusting it inside the signing
* function avoids the need to re-serialize or have curve specific
* constants outside of the library. By always using a canonical form
* even in applications where it isn't needed it becomes possible to
* impose a requirement later if a need is discovered.
* No other forms of ECDSA malleability are known and none seem likely,
* but there is no formal proof that ECDSA, even with this additional
* restriction, is free of other malleability. Commonly used serialization
* schemes will also accept various non-unique encodings, so care should
* be taken when this property is required for an application.
*/
int secp256k1_ecdsa_sign(
const secp256k1_context_t* ctx,
const unsigned char *msg32,
unsigned char *sig,
int *siglen,
const unsigned char *seckey,
secp256k1_nonce_function_t noncefp,
const void *ndata
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4) SECP256K1_ARG_NONNULL(5);
/** Create a compact ECDSA signature (64 byte + recovery id).
* Returns: 1: signature created
* 0: the nonce generation function failed, or the secret key was invalid.
* In: ctx: pointer to a context object, initialized for signing (cannot be NULL)
* msg32: the 32-byte message hash being signed (cannot be NULL)
* 0: the nonce generation function failed, or the private key was invalid.
* Args: ctx: pointer to a context object, initialized for signing (cannot be NULL)
* Out: sig: pointer to an array where the signature will be placed (cannot be NULL)
* In: msg32: the 32-byte message hash being signed (cannot be NULL)
* seckey: pointer to a 32-byte secret key (cannot be NULL)
* noncefp:pointer to a nonce generation function. If NULL, secp256k1_nonce_function_default is used
* ndata: pointer to arbitrary data used by the nonce generation function (can be NULL)
* Out: sig: pointer to a 64-byte array where the signature will be placed (cannot be NULL)
* In case 0 is returned, the returned signature length will be zero.
* recid: pointer to an int, which will be updated to contain the recovery id (can be NULL)
*
* The created signature is always in lower-S form. See
* secp256k1_ecdsa_signature_normalize for more details.
*/
int secp256k1_ecdsa_sign_compact(
const secp256k1_context_t* ctx,
const unsigned char *msg32,
unsigned char *sig64,
const unsigned char *seckey,
secp256k1_nonce_function_t noncefp,
const void *ndata,
int *recid
SECP256K1_API int secp256k1_ecdsa_sign(
const secp256k1_context* ctx,
secp256k1_ecdsa_signature *sig,
const unsigned char *msg32,
const unsigned char *seckey,
secp256k1_nonce_function noncefp,
const void *ndata
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Recover an ECDSA public key from a compact signature.
* Returns: 1: public key successfully recovered (which guarantees a correct signature).
* 0: otherwise.
* In: ctx: pointer to a context object, initialized for verification (cannot be NULL)
* msg32: the 32-byte message hash assumed to be signed (cannot be NULL)
* sig64: signature as 64 byte array (cannot be NULL)
* compressed: whether to recover a compressed or uncompressed pubkey
* recid: the recovery id (0-3, as returned by ecdsa_sign_compact)
* Out: pubkey: pointer to a 33 or 65 byte array to put the pubkey (cannot be NULL)
* pubkeylen: pointer to an int that will contain the pubkey length (cannot be NULL)
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_recover_compact(
const secp256k1_context_t* ctx,
const unsigned char *msg32,
const unsigned char *sig64,
unsigned char *pubkey,
int *pubkeylen,
int compressed,
int recid
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4) SECP256K1_ARG_NONNULL(5);
/** Verify an ECDSA secret key.
*
* Returns: 1: secret key is valid
* 0: secret key is invalid
* In: ctx: pointer to a context object (cannot be NULL)
* seckey: pointer to a 32-byte secret key (cannot be NULL)
* Args: ctx: pointer to a context object (cannot be NULL)
* In: seckey: pointer to a 32-byte secret key (cannot be NULL)
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_verify(
const secp256k1_context_t* ctx,
const unsigned char *seckey
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);
/** Just validate a public key.
* Returns: 1: public key is valid
* 0: public key is invalid
* In: ctx: pointer to a context object (cannot be NULL)
* pubkey: pointer to a 33-byte or 65-byte public key (cannot be NULL).
* pubkeylen: length of pubkey
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_verify(
const secp256k1_context_t* ctx,
const unsigned char *pubkey,
int pubkeylen
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_seckey_verify(
const secp256k1_context* ctx,
const unsigned char *seckey
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2);
/** Compute the public key for a secret key.
* In: ctx: pointer to a context object, initialized for signing (cannot be NULL)
* compressed: whether the computed public key should be compressed
* seckey: pointer to a 32-byte private key (cannot be NULL)
* Out: pubkey: pointer to a 33-byte (if compressed) or 65-byte (if uncompressed)
* area to store the public key (cannot be NULL)
* pubkeylen: pointer to int that will be updated to contains the pubkey's
* length (cannot be NULL)
*
* Returns: 1: secret was valid, public key stores
* 0: secret was invalid, try again
* Args: ctx: pointer to a context object, initialized for signing (cannot be NULL)
* Out: pubkey: pointer to the created public key (cannot be NULL)
* In: seckey: pointer to a 32-byte private key (cannot be NULL)
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_create(
const secp256k1_context_t* ctx,
unsigned char *pubkey,
int *pubkeylen,
const unsigned char *seckey,
int compressed
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Decompress a public key.
* In: ctx: pointer to a context object (cannot be NULL)
* In/Out: pubkey: pointer to a 65-byte array to put the decompressed public key.
* It must contain a 33-byte or 65-byte public key already (cannot be NULL)
* pubkeylen: pointer to the size of the public key pointed to by pubkey (cannot be NULL)
* It will be updated to reflect the new size.
* Returns: 0: pubkey was invalid
* 1: pubkey was valid, and was replaced with its decompressed version
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_decompress(
const secp256k1_context_t* ctx,
unsigned char *pubkey,
int *pubkeylen
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_create(
const secp256k1_context* ctx,
secp256k1_pubkey *pubkey,
const unsigned char *seckey
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Export a private key in DER format.
* In: ctx: pointer to a context object, initialized for signing (cannot be NULL)
/** Tweak a private key by adding tweak to it.
* Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for
* uniformly random 32-byte arrays, or if the resulting private key
* would be invalid (only when the tweak is the complement of the
* private key). 1 otherwise.
* Args: ctx: pointer to a context object (cannot be NULL).
* In/Out: seckey: pointer to a 32-byte private key.
* In: tweak: pointer to a 32-byte tweak.
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_export(
const secp256k1_context_t* ctx,
const unsigned char *seckey,
unsigned char *privkey,
int *privkeylen,
int compressed
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Import a private key in DER format. */
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_import(
const secp256k1_context_t* ctx,
unsigned char *seckey,
const unsigned char *privkey,
int privkeylen
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Tweak a private key by adding tweak to it. */
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_add(
const secp256k1_context_t* ctx,
unsigned char *seckey,
const unsigned char *tweak
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_add(
const secp256k1_context* ctx,
unsigned char *seckey,
const unsigned char *tweak
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Tweak a public key by adding tweak times the generator to it.
* In: ctx: pointer to a context object, initialized for verification (cannot be NULL)
* Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for
* uniformly random 32-byte arrays, or if the resulting public key
* would be invalid (only when the tweak is the complement of the
* corresponding private key). 1 otherwise.
* Args: ctx: pointer to a context object initialized for validation
* (cannot be NULL).
* In/Out: pubkey: pointer to a public key object.
* In: tweak: pointer to a 32-byte tweak.
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add(
const secp256k1_context_t* ctx,
unsigned char *pubkey,
int pubkeylen,
const unsigned char *tweak
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4);
/** Tweak a private key by multiplying it with tweak. */
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_mul(
const secp256k1_context_t* ctx,
unsigned char *seckey,
const unsigned char *tweak
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_add(
const secp256k1_context* ctx,
secp256k1_pubkey *pubkey,
const unsigned char *tweak
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Tweak a public key by multiplying it with tweak.
* In: ctx: pointer to a context object, initialized for verification (cannot be NULL)
/** Tweak a private key by multiplying it by a tweak.
* Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for
* uniformly random 32-byte arrays, or equal to zero. 1 otherwise.
* Args: ctx: pointer to a context object (cannot be NULL).
* In/Out: seckey: pointer to a 32-byte private key.
* In: tweak: pointer to a 32-byte tweak.
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul(
const secp256k1_context_t* ctx,
unsigned char *pubkey,
int pubkeylen,
const unsigned char *tweak
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(4);
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_privkey_tweak_mul(
const secp256k1_context* ctx,
unsigned char *seckey,
const unsigned char *tweak
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Tweak a public key by multiplying it by a tweak value.
* Returns: 0 if the tweak was out of range (chance of around 1 in 2^128 for
* uniformly random 32-byte arrays, or equal to zero. 1 otherwise.
* Args: ctx: pointer to a context object initialized for validation
* (cannot be NULL).
* In/Out: pubkey: pointer to a public key obkect.
* In: tweak: pointer to a 32-byte tweak.
*/
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_tweak_mul(
const secp256k1_context* ctx,
secp256k1_pubkey *pubkey,
const unsigned char *tweak
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Updates the context randomization.
* Returns: 1: randomization successfully updated
* 0: error
* In: ctx: pointer to a context object (cannot be NULL)
* seed32: pointer to a 32-byte random seed (NULL resets to initial state)
* Args: ctx: pointer to a context object (cannot be NULL)
* In: seed32: pointer to a 32-byte random seed (NULL resets to initial state)
*/
SECP256K1_WARN_UNUSED_RESULT int secp256k1_context_randomize(
secp256k1_context_t* ctx,
const unsigned char *seed32
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_context_randomize(
secp256k1_context* ctx,
const unsigned char *seed32
) SECP256K1_ARG_NONNULL(1);
/** Add a number of public keys together.
* Returns: 1: the sum of the public keys is valid.
* 0: the sum of the public keys is not valid.
* Args: ctx: pointer to a context object
* Out: out: pointer to a public key object for placing the resulting public key
* (cannot be NULL)
* In: ins: pointer to array of pointers to public keys (cannot be NULL)
* n: the number of public keys to add together (must be at least 1)
*/
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ec_pubkey_combine(
const secp256k1_context* ctx,
secp256k1_pubkey *out,
const secp256k1_pubkey * const * ins,
size_t n
) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
# ifdef __cplusplus
}

31
include/secp256k1_ecdh.h Normal file
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@ -0,0 +1,31 @@
#ifndef _SECP256K1_ECDH_
# define _SECP256K1_ECDH_
# include "secp256k1.h"
# ifdef __cplusplus
extern "C" {
# endif
/** Compute an EC Diffie-Hellman secret in constant time
* Returns: 1: exponentiation was successful
* 0: scalar was invalid (zero or overflow)
* Args: ctx: pointer to a context object (cannot be NULL)
* Out: result: a 32-byte array which will be populated by an ECDH
* secret computed from the point and scalar
* In: pubkey: a pointer to a secp256k1_pubkey containing an
* initialized public key
* privkey: a 32-byte scalar with which to multiply the point
*/
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdh(
const secp256k1_context* ctx,
unsigned char *result,
const secp256k1_pubkey *pubkey,
const unsigned char *privkey
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
# ifdef __cplusplus
}
# endif
#endif

110
include/secp256k1_recovery.h Normal file
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@ -0,0 +1,110 @@
#ifndef _SECP256K1_RECOVERY_
# define _SECP256K1_RECOVERY_
# include "secp256k1.h"
# ifdef __cplusplus
extern "C" {
# endif
/** Opaque data structured that holds a parsed ECDSA signature,
* supporting pubkey recovery.
*
* The exact representation of data inside is implementation defined and not
* guaranteed to be portable between different platforms or versions. It is
* however guaranteed to be 65 bytes in size, and can be safely copied/moved.
* If you need to convert to a format suitable for storage or transmission, use
* the secp256k1_ecdsa_signature_serialize_* and
* secp256k1_ecdsa_signature_parse_* functions.
*
* Furthermore, it is guaranteed that identical signatures (including their
* recoverability) will have identical representation, so they can be
* memcmp'ed.
*/
typedef struct {
unsigned char data[65];
} secp256k1_ecdsa_recoverable_signature;
/** Parse a compact ECDSA signature (64 bytes + recovery id).
*
* Returns: 1 when the signature could be parsed, 0 otherwise
* Args: ctx: a secp256k1 context object
* Out: sig: a pointer to a signature object
* In: input64: a pointer to a 64-byte compact signature
* recid: the recovery id (0, 1, 2 or 3)
*/
SECP256K1_API int secp256k1_ecdsa_recoverable_signature_parse_compact(
const secp256k1_context* ctx,
secp256k1_ecdsa_recoverable_signature* sig,
const unsigned char *input64,
int recid
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Convert a recoverable signature into a normal signature.
*
* Returns: 1
* Out: sig: a pointer to a normal signature (cannot be NULL).
* In: sigin: a pointer to a recoverable signature (cannot be NULL).
*/
SECP256K1_API int secp256k1_ecdsa_recoverable_signature_convert(
const secp256k1_context* ctx,
secp256k1_ecdsa_signature* sig,
const secp256k1_ecdsa_recoverable_signature* sigin
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Serialize an ECDSA signature in compact format (64 bytes + recovery id).
*
* Returns: 1
* Args: ctx: a secp256k1 context object
* Out: output64: a pointer to a 64-byte array of the compact signature (cannot be NULL)
* recid: a pointer to an integer to hold the recovery id (can be NULL).
* In: sig: a pointer to an initialized signature object (cannot be NULL)
*/
SECP256K1_API int secp256k1_ecdsa_recoverable_signature_serialize_compact(
const secp256k1_context* ctx,
unsigned char *output64,
int *recid,
const secp256k1_ecdsa_recoverable_signature* sig
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Create a recoverable ECDSA signature.
*
* Returns: 1: signature created
* 0: the nonce generation function failed, or the private key was invalid.
* Args: ctx: pointer to a context object, initialized for signing (cannot be NULL)
* Out: sig: pointer to an array where the signature will be placed (cannot be NULL)
* In: msg32: the 32-byte message hash being signed (cannot be NULL)
* seckey: pointer to a 32-byte secret key (cannot be NULL)
* noncefp:pointer to a nonce generation function. If NULL, secp256k1_nonce_function_default is used
* ndata: pointer to arbitrary data used by the nonce generation function (can be NULL)
*/
SECP256K1_API int secp256k1_ecdsa_sign_recoverable(
const secp256k1_context* ctx,
secp256k1_ecdsa_recoverable_signature *sig,
const unsigned char *msg32,
const unsigned char *seckey,
secp256k1_nonce_function noncefp,
const void *ndata
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Recover an ECDSA public key from a signature.
*
* Returns: 1: public key successfully recovered (which guarantees a correct signature).
* 0: otherwise.
* Args: ctx: pointer to a context object, initialized for verification (cannot be NULL)
* Out: pubkey: pointer to the recovered public key (cannot be NULL)
* In: sig: pointer to initialized signature that supports pubkey recovery (cannot be NULL)
* msg32: the 32-byte message hash assumed to be signed (cannot be NULL)
*/
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_ecdsa_recover(
const secp256k1_context* ctx,
secp256k1_pubkey *pubkey,
const secp256k1_ecdsa_recoverable_signature *sig,
const unsigned char *msg32
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
# ifdef __cplusplus
}
# endif
#endif

173
include/secp256k1_schnorr.h Normal file
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@ -0,0 +1,173 @@
#ifndef _SECP256K1_SCHNORR_
# define _SECP256K1_SCHNORR_
# include "secp256k1.h"
# ifdef __cplusplus
extern "C" {
# endif
/** Create a signature using a custom EC-Schnorr-SHA256 construction. It
* produces non-malleable 64-byte signatures which support public key recovery
* batch validation, and multiparty signing.
* Returns: 1: signature created
* 0: the nonce generation function failed, or the private key was
* invalid.
* Args: ctx: pointer to a context object, initialized for signing
* (cannot be NULL)
* Out: sig64: pointer to a 64-byte array where the signature will be
* placed (cannot be NULL)
* In: msg32: the 32-byte message hash being signed (cannot be NULL)
* seckey: pointer to a 32-byte secret key (cannot be NULL)
* noncefp:pointer to a nonce generation function. If NULL,
* secp256k1_nonce_function_default is used
* ndata: pointer to arbitrary data used by the nonce generation
* function (can be NULL)
*/
SECP256K1_API int secp256k1_schnorr_sign(
const secp256k1_context* ctx,
unsigned char *sig64,
const unsigned char *msg32,
const unsigned char *seckey,
secp256k1_nonce_function noncefp,
const void *ndata
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Verify a signature created by secp256k1_schnorr_sign.
* Returns: 1: correct signature
* 0: incorrect signature
* Args: ctx: a secp256k1 context object, initialized for verification.
* In: sig64: the 64-byte signature being verified (cannot be NULL)
* msg32: the 32-byte message hash being verified (cannot be NULL)
* pubkey: the public key to verify with (cannot be NULL)
*/
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_schnorr_verify(
const secp256k1_context* ctx,
const unsigned char *sig64,
const unsigned char *msg32,
const secp256k1_pubkey *pubkey
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Recover an EC public key from a Schnorr signature created using
* secp256k1_schnorr_sign.
* Returns: 1: public key successfully recovered (which guarantees a correct
* signature).
* 0: otherwise.
* Args: ctx: pointer to a context object, initialized for
* verification (cannot be NULL)
* Out: pubkey: pointer to a pubkey to set to the recovered public key
* (cannot be NULL).
* In: sig64: signature as 64 byte array (cannot be NULL)
* msg32: the 32-byte message hash assumed to be signed (cannot
* be NULL)
*/
SECP256K1_API int secp256k1_schnorr_recover(
const secp256k1_context* ctx,
secp256k1_pubkey *pubkey,
const unsigned char *sig64,
const unsigned char *msg32
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4);
/** Generate a nonce pair deterministically for use with
* secp256k1_schnorr_partial_sign.
* Returns: 1: valid nonce pair was generated.
* 0: otherwise (nonce generation function failed)
* Args: ctx: pointer to a context object, initialized for signing
* (cannot be NULL)
* Out: pubnonce: public side of the nonce (cannot be NULL)
* privnonce32: private side of the nonce (32 byte) (cannot be NULL)
* In: msg32: the 32-byte message hash assumed to be signed (cannot
* be NULL)
* sec32: the 32-byte private key (cannot be NULL)
* noncefp: pointer to a nonce generation function. If NULL,
* secp256k1_nonce_function_default is used
* noncedata: pointer to arbitrary data used by the nonce generation
* function (can be NULL)
*
* Do not use the output as a private/public key pair for signing/validation.
*/
SECP256K1_API int secp256k1_schnorr_generate_nonce_pair(
const secp256k1_context* ctx,
secp256k1_pubkey *pubnonce,
unsigned char *privnonce32,
const unsigned char *msg32,
const unsigned char *sec32,
secp256k1_nonce_function noncefp,
const void* noncedata
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
/** Produce a partial Schnorr signature, which can be combined using
* secp256k1_schnorr_partial_combine, to end up with a full signature that is
* verifiable using secp256k1_schnorr_verify.
* Returns: 1: signature created successfully.
* 0: no valid signature exists with this combination of keys, nonces
* and message (chance around 1 in 2^128)
* -1: invalid private key, nonce, or public nonces.
* Args: ctx: pointer to context object, initialized for signing (cannot
* be NULL)
* Out: sig64: pointer to 64-byte array to put partial signature in
* In: msg32: pointer to 32-byte message to sign
* sec32: pointer to 32-byte private key
* pubnonce_others: pointer to pubkey containing the sum of the other's
* nonces (see secp256k1_ec_pubkey_combine)
* secnonce32: pointer to 32-byte array containing our nonce
*
* The intended procedure for creating a multiparty signature is:
* - Each signer S[i] with private key x[i] and public key Q[i] runs
* secp256k1_schnorr_generate_nonce_pair to produce a pair (k[i],R[i]) of
* private/public nonces.
* - All signers communicate their public nonces to each other (revealing your
* private nonce can lead to discovery of your private key, so it should be
* considered secret).
* - All signers combine all the public nonces they received (excluding their
* own) using secp256k1_ec_pubkey_combine to obtain an
* Rall[i] = sum(R[0..i-1,i+1..n]).
* - All signers produce a partial signature using
* secp256k1_schnorr_partial_sign, passing in their own private key x[i],
* their own private nonce k[i], and the sum of the others' public nonces
* Rall[i].
* - All signers communicate their partial signatures to each other.
* - Someone combines all partial signatures using
* secp256k1_schnorr_partial_combine, to obtain a full signature.
* - The resulting signature is validatable using secp256k1_schnorr_verify, with
* public key equal to the result of secp256k1_ec_pubkey_combine of the
* signers' public keys (sum(Q[0..n])).
*
* Note that secp256k1_schnorr_partial_combine and secp256k1_ec_pubkey_combine
* function take their arguments in any order, and it is possible to
* pre-combine several inputs already with one call, and add more inputs later
* by calling the function again (they are commutative and associative).
*/
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_schnorr_partial_sign(
const secp256k1_context* ctx,
unsigned char *sig64,
const unsigned char *msg32,
const unsigned char *sec32,
const secp256k1_pubkey *pubnonce_others,
const unsigned char *secnonce32
) SECP256K1_ARG_NONNULL(1) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3) SECP256K1_ARG_NONNULL(4) SECP256K1_ARG_NONNULL(5) SECP256K1_ARG_NONNULL(6);
/** Combine multiple Schnorr partial signatures.
* Returns: 1: the passed signatures were successfully combined.
* 0: the resulting signature is not valid (chance of 1 in 2^256)
* -1: some inputs were invalid, or the signatures were not created
* using the same set of nonces
* Args: ctx: pointer to a context object
* Out: sig64: pointer to a 64-byte array to place the combined signature
* (cannot be NULL)
* In: sig64sin: pointer to an array of n pointers to 64-byte input
* signatures
* n: the number of signatures to combine (at least 1)
*/
SECP256K1_API SECP256K1_WARN_UNUSED_RESULT int secp256k1_schnorr_partial_combine(
const secp256k1_context* ctx,
unsigned char *sig64,
const unsigned char * const * sig64sin,
size_t n
) SECP256K1_ARG_NONNULL(2) SECP256K1_ARG_NONNULL(3);
# ifdef __cplusplus
}
# endif
#endif

32
src/basic-config.h Normal file
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@ -0,0 +1,32 @@
/**********************************************************************
* Copyright (c) 2013, 2014 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_BASIC_CONFIG_
#define _SECP256K1_BASIC_CONFIG_
#ifdef USE_BASIC_CONFIG
#undef USE_ASM_X86_64
#undef USE_ENDOMORPHISM
#undef USE_FIELD_10X26
#undef USE_FIELD_5X52
#undef USE_FIELD_INV_BUILTIN
#undef USE_FIELD_INV_NUM
#undef USE_NUM_GMP
#undef USE_NUM_NONE
#undef USE_SCALAR_4X64
#undef USE_SCALAR_8X32
#undef USE_SCALAR_INV_BUILTIN
#undef USE_SCALAR_INV_NUM
#define USE_NUM_NONE 1
#define USE_FIELD_INV_BUILTIN 1
#define USE_SCALAR_INV_BUILTIN 1
#define USE_FIELD_10X26 1
#define USE_SCALAR_8X32 1
#endif // USE_BASIC_CONFIG
#endif // _SECP256K1_BASIC_CONFIG_

20
src/bench.h
View file

@ -20,7 +20,9 @@ static double gettimedouble(void) {
void print_number(double x) {
double y = x;
int c = 0;
if (y < 0.0) y = -y;
if (y < 0.0) {
y = -y;
}
while (y < 100.0) {
y *= 10.0;
c++;
@ -35,13 +37,21 @@ void run_benchmark(char *name, void (*benchmark)(void*), void (*setup)(void*), v
double max = 0.0;
for (i = 0; i < count; i++) {
double begin, total;
if (setup) setup(data);
if (setup != NULL) {
setup(data);
}
begin = gettimedouble();
benchmark(data);
total = gettimedouble() - begin;
if (teardown) teardown(data);
if (total < min) min = total;
if (total > max) max = total;
if (teardown != NULL) {
teardown(data);
}
if (total < min) {
min = total;
}
if (total > max) {
max = total;
}
sum += total;
}
printf("%s: min ", name);

53
src/bench_ecdh.c Normal file
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@ -0,0 +1,53 @@
/**********************************************************************
* Copyright (c) 2015 Pieter Wuille, Andrew Poelstra *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#include <string.h>
#include "include/secp256k1.h"
#include "include/secp256k1_ecdh.h"
#include "util.h"
#include "bench.h"
typedef struct {
secp256k1_context *ctx;
secp256k1_pubkey point;
unsigned char scalar[32];
} bench_ecdh_t;
static void bench_ecdh_setup(void* arg) {
int i;
bench_ecdh_t *data = (bench_ecdh_t*)arg;
const unsigned char point[] = {
0x03,
0x54, 0x94, 0xc1, 0x5d, 0x32, 0x09, 0x97, 0x06,
0xc2, 0x39, 0x5f, 0x94, 0x34, 0x87, 0x45, 0xfd,
0x75, 0x7c, 0xe3, 0x0e, 0x4e, 0x8c, 0x90, 0xfb,
0xa2, 0xba, 0xd1, 0x84, 0xf8, 0x83, 0xc6, 0x9f
};
data->ctx = secp256k1_context_create(0);
for (i = 0; i < 32; i++) {
data->scalar[i] = i + 1;
}
CHECK(secp256k1_ec_pubkey_parse(data->ctx, &data->point, point, sizeof(point)) == 1);
}
static void bench_ecdh(void* arg) {
int i;
unsigned char res[32];
bench_ecdh_t *data = (bench_ecdh_t*)arg;
for (i = 0; i < 20000; i++) {
CHECK(secp256k1_ecdh(data->ctx, res, &data->point, data->scalar) == 1);
}
}
int main(void) {
bench_ecdh_t data;
run_benchmark("ecdh", bench_ecdh, bench_ecdh_setup, NULL, &data, 10, 20000);
return 0;
}

62
src/bench_internal.c
View file

@ -13,15 +13,17 @@
#include "field_impl.h"
#include "group_impl.h"
#include "scalar_impl.h"
#include "ecmult_const_impl.h"
#include "ecmult_impl.h"
#include "bench.h"
#include "secp256k1.c"
typedef struct {
secp256k1_scalar_t scalar_x, scalar_y;
secp256k1_fe_t fe_x, fe_y;
secp256k1_ge_t ge_x, ge_y;
secp256k1_gej_t gej_x, gej_y;
unsigned char data[32];
secp256k1_scalar scalar_x, scalar_y;
secp256k1_fe fe_x, fe_y;
secp256k1_ge ge_x, ge_y;
secp256k1_gej gej_x, gej_y;
unsigned char data[64];
int wnaf[256];
} bench_inv_t;
@ -51,6 +53,7 @@ void bench_setup(void* arg) {
secp256k1_gej_set_ge(&data->gej_x, &data->ge_x);
secp256k1_gej_set_ge(&data->gej_y, &data->ge_y);
memcpy(data->data, init_x, 32);
memcpy(data->data + 32, init_y, 32);
}
void bench_scalar_add(void* arg) {
@ -95,8 +98,8 @@ void bench_scalar_split(void* arg) {
bench_inv_t *data = (bench_inv_t*)arg;
for (i = 0; i < 20000; i++) {
secp256k1_scalar_t l, r;
secp256k1_scalar_split_lambda_var(&l, &r, &data->scalar_x);
secp256k1_scalar l, r;
secp256k1_scalar_split_lambda(&l, &r, &data->scalar_x);
secp256k1_scalar_add(&data->scalar_x, &data->scalar_x, &data->scalar_y);
}
}
@ -193,7 +196,7 @@ void bench_group_double_var(void* arg) {
bench_inv_t *data = (bench_inv_t*)arg;
for (i = 0; i < 200000; i++) {
secp256k1_gej_double_var(&data->gej_x, &data->gej_x);
secp256k1_gej_double_var(&data->gej_x, &data->gej_x, NULL);
}
}
@ -202,7 +205,7 @@ void bench_group_add_var(void* arg) {
bench_inv_t *data = (bench_inv_t*)arg;
for (i = 0; i < 200000; i++) {
secp256k1_gej_add_var(&data->gej_x, &data->gej_x, &data->gej_y);
secp256k1_gej_add_var(&data->gej_x, &data->gej_x, &data->gej_y, NULL);
}
}
@ -220,7 +223,7 @@ void bench_group_add_affine_var(void* arg) {
bench_inv_t *data = (bench_inv_t*)arg;
for (i = 0; i < 200000; i++) {
secp256k1_gej_add_ge_var(&data->gej_x, &data->gej_x, &data->ge_y);
secp256k1_gej_add_ge_var(&data->gej_x, &data->gej_x, &data->ge_y, NULL);
}
}
@ -229,7 +232,17 @@ void bench_ecmult_wnaf(void* arg) {
bench_inv_t *data = (bench_inv_t*)arg;
for (i = 0; i < 20000; i++) {
secp256k1_ecmult_wnaf(data->wnaf, &data->scalar_x, WINDOW_A);
secp256k1_ecmult_wnaf(data->wnaf, 256, &data->scalar_x, WINDOW_A);
secp256k1_scalar_add(&data->scalar_x, &data->scalar_x, &data->scalar_y);
}
}
void bench_wnaf_const(void* arg) {
int i;
bench_inv_t *data = (bench_inv_t*)arg;
for (i = 0; i < 20000; i++) {
secp256k1_wnaf_const(data->wnaf, data->scalar_x, WINDOW_A);
secp256k1_scalar_add(&data->scalar_x, &data->scalar_x, &data->scalar_y);
}
}
@ -265,11 +278,27 @@ void bench_rfc6979_hmac_sha256(void* arg) {
secp256k1_rfc6979_hmac_sha256_t rng;
for (i = 0; i < 20000; i++) {
secp256k1_rfc6979_hmac_sha256_initialize(&rng, data->data, 32, data->data, 32, NULL, 0);
secp256k1_rfc6979_hmac_sha256_initialize(&rng, data->data, 64);
secp256k1_rfc6979_hmac_sha256_generate(&rng, data->data, 32);
}
}
void bench_context_verify(void* arg) {
int i;
(void)arg;
for (i = 0; i < 20; i++) {
secp256k1_context_destroy(secp256k1_context_create(SECP256K1_CONTEXT_VERIFY));
}
}
void bench_context_sign(void* arg) {
int i;
(void)arg;
for (i = 0; i < 200; i++) {
secp256k1_context_destroy(secp256k1_context_create(SECP256K1_CONTEXT_SIGN));
}
}
int have_flag(int argc, char** argv, char *flag) {
char** argm = argv + argc;
@ -278,7 +307,9 @@ int have_flag(int argc, char** argv, char *flag) {
return 1;
}
while (argv != NULL && argv != argm) {
if (strcmp(*argv, flag) == 0) return 1;
if (strcmp(*argv, flag) == 0) {
return 1;
}
argv++;
}
return 0;
@ -309,10 +340,15 @@ int main(int argc, char **argv) {
if (have_flag(argc, argv, "group") || have_flag(argc, argv, "add")) run_benchmark("group_add_affine", bench_group_add_affine, bench_setup, NULL, &data, 10, 200000);
if (have_flag(argc, argv, "group") || have_flag(argc, argv, "add")) run_benchmark("group_add_affine_var", bench_group_add_affine_var, bench_setup, NULL, &data, 10, 200000);
if (have_flag(argc, argv, "ecmult") || have_flag(argc, argv, "wnaf")) run_benchmark("wnaf_const", bench_wnaf_const, bench_setup, NULL, &data, 10, 20000);
if (have_flag(argc, argv, "ecmult") || have_flag(argc, argv, "wnaf")) run_benchmark("ecmult_wnaf", bench_ecmult_wnaf, bench_setup, NULL, &data, 10, 20000);
if (have_flag(argc, argv, "hash") || have_flag(argc, argv, "sha256")) run_benchmark("hash_sha256", bench_sha256, bench_setup, NULL, &data, 10, 20000);
if (have_flag(argc, argv, "hash") || have_flag(argc, argv, "hmac")) run_benchmark("hash_hmac_sha256", bench_hmac_sha256, bench_setup, NULL, &data, 10, 20000);
if (have_flag(argc, argv, "hash") || have_flag(argc, argv, "rng6979")) run_benchmark("hash_rfc6979_hmac_sha256", bench_rfc6979_hmac_sha256, bench_setup, NULL, &data, 10, 20000);
if (have_flag(argc, argv, "context") || have_flag(argc, argv, "verify")) run_benchmark("context_verify", bench_context_verify, bench_setup, NULL, &data, 10, 20);
if (have_flag(argc, argv, "context") || have_flag(argc, argv, "sign")) run_benchmark("context_sign", bench_context_sign, bench_setup, NULL, &data, 10, 200);
return 0;
}

25
src/bench_recover.c
View file

@ -1,15 +1,16 @@
/**********************************************************************
* Copyright (c) 2014 Pieter Wuille *
* Copyright (c) 2014-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#include "include/secp256k1.h"
#include "include/secp256k1_recovery.h"
#include "util.h"
#include "bench.h"
typedef struct {
secp256k1_context_t *ctx;
secp256k1_context *ctx;
unsigned char msg[32];
unsigned char sig[64];
} bench_recover_t;
@ -17,16 +18,20 @@ typedef struct {
void bench_recover(void* arg) {
int i;
bench_recover_t *data = (bench_recover_t*)arg;
unsigned char pubkey[33];
secp256k1_pubkey pubkey;
unsigned char pubkeyc[33];
for (i = 0; i < 20000; i++) {
int j;
int pubkeylen = 33;
CHECK(secp256k1_ecdsa_recover_compact(data->ctx, data->msg, data->sig, pubkey, &pubkeylen, 1, i % 2));
size_t pubkeylen = 33;
secp256k1_ecdsa_recoverable_signature sig;
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(data->ctx, &sig, data->sig, i % 2));
CHECK(secp256k1_ecdsa_recover(data->ctx, &pubkey, &sig, data->msg));
CHECK(secp256k1_ec_pubkey_serialize(data->ctx, pubkeyc, &pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED));
for (j = 0; j < 32; j++) {
data->sig[j + 32] = data->msg[j]; /* Move former message to S. */
data->msg[j] = data->sig[j]; /* Move former R to message. */
data->sig[j] = pubkey[j + 1]; /* Move recovered pubkey X coordinate to R (which must be a valid X coordinate). */
data->sig[j] = pubkeyc[j + 1]; /* Move recovered pubkey X coordinate to R (which must be a valid X coordinate). */
}
}
}
@ -35,8 +40,12 @@ void bench_recover_setup(void* arg) {
int i;
bench_recover_t *data = (bench_recover_t*)arg;
for (i = 0; i < 32; i++) data->msg[i] = 1 + i;
for (i = 0; i < 64; i++) data->sig[i] = 65 + i;
for (i = 0; i < 32; i++) {
data->msg[i] = 1 + i;
}
for (i = 0; i < 64; i++) {
data->sig[i] = 65 + i;
}
}
int main(void) {

73
src/bench_schnorr_verify.c Normal file
View file

@ -0,0 +1,73 @@
/**********************************************************************
* Copyright (c) 2014 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#include <stdio.h>
#include <string.h>
#include "include/secp256k1.h"
#include "include/secp256k1_schnorr.h"
#include "util.h"
#include "bench.h"
typedef struct {
unsigned char key[32];
unsigned char sig[64];
unsigned char pubkey[33];
size_t pubkeylen;
} benchmark_schnorr_sig_t;
typedef struct {
secp256k1_context *ctx;
unsigned char msg[32];
benchmark_schnorr_sig_t sigs[64];
int numsigs;
} benchmark_schnorr_verify_t;
static void benchmark_schnorr_init(void* arg) {
int i, k;
benchmark_schnorr_verify_t* data = (benchmark_schnorr_verify_t*)arg;
for (i = 0; i < 32; i++) {
data->msg[i] = 1 + i;
}
for (k = 0; k < data->numsigs; k++) {
secp256k1_pubkey pubkey;
for (i = 0; i < 32; i++) {
data->sigs[k].key[i] = 33 + i + k;
}
secp256k1_schnorr_sign(data->ctx, data->sigs[k].sig, data->msg, data->sigs[k].key, NULL, NULL);
data->sigs[k].pubkeylen = 33;
CHECK(secp256k1_ec_pubkey_create(data->ctx, &pubkey, data->sigs[k].key));
CHECK(secp256k1_ec_pubkey_serialize(data->ctx, data->sigs[k].pubkey, &data->sigs[k].pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED));
}
}
static void benchmark_schnorr_verify(void* arg) {
int i;
benchmark_schnorr_verify_t* data = (benchmark_schnorr_verify_t*)arg;
for (i = 0; i < 20000 / data->numsigs; i++) {
secp256k1_pubkey pubkey;
data->sigs[0].sig[(i >> 8) % 64] ^= (i & 0xFF);
CHECK(secp256k1_ec_pubkey_parse(data->ctx, &pubkey, data->sigs[0].pubkey, data->sigs[0].pubkeylen));
CHECK(secp256k1_schnorr_verify(data->ctx, data->sigs[0].sig, data->msg, &pubkey) == ((i & 0xFF) == 0));
data->sigs[0].sig[(i >> 8) % 64] ^= (i & 0xFF);
}
}
int main(void) {
benchmark_schnorr_verify_t data;
data.ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY);
data.numsigs = 1;
run_benchmark("schnorr_verify", benchmark_schnorr_verify, benchmark_schnorr_init, NULL, &data, 10, 20000);
secp256k1_context_destroy(data.ctx);
return 0;
}

22
src/bench_sign.c
View file

@ -9,7 +9,7 @@
#include "bench.h"
typedef struct {
secp256k1_context_t* ctx;
secp256k1_context* ctx;
unsigned char msg[32];
unsigned char key[32];
} bench_sign_t;
@ -18,22 +18,28 @@ static void bench_sign_setup(void* arg) {
int i;
bench_sign_t *data = (bench_sign_t*)arg;
for (i = 0; i < 32; i++) data->msg[i] = i + 1;
for (i = 0; i < 32; i++) data->key[i] = i + 65;
for (i = 0; i < 32; i++) {
data->msg[i] = i + 1;
}
for (i = 0; i < 32; i++) {
data->key[i] = i + 65;
}
}
static void bench_sign(void* arg) {
int i;
bench_sign_t *data = (bench_sign_t*)arg;
unsigned char sig[64];
unsigned char sig[74];
for (i = 0; i < 20000; i++) {
size_t siglen = 74;
int j;
int recid = 0;
CHECK(secp256k1_ecdsa_sign_compact(data->ctx, data->msg, sig, data->key, NULL, NULL, &recid));
secp256k1_ecdsa_signature signature;
CHECK(secp256k1_ecdsa_sign(data->ctx, &signature, data->msg, data->key, NULL, NULL));
CHECK(secp256k1_ecdsa_signature_serialize_der(data->ctx, sig, &siglen, &signature));
for (j = 0; j < 32; j++) {
data->msg[j] = sig[j]; /* Move former R to message. */
data->key[j] = sig[j + 32]; /* Move former S to key. */
data->msg[j] = sig[j];
data->key[j] = sig[j + 32];
}
}
}

28
src/bench_verify.c
View file

@ -12,13 +12,13 @@
#include "bench.h"
typedef struct {
secp256k1_context_t *ctx;
secp256k1_context *ctx;
unsigned char msg[32];
unsigned char key[32];
unsigned char sig[72];
int siglen;
size_t siglen;
unsigned char pubkey[33];
int pubkeylen;
size_t pubkeylen;
} benchmark_verify_t;
static void benchmark_verify(void* arg) {
@ -26,10 +26,14 @@ static void benchmark_verify(void* arg) {
benchmark_verify_t* data = (benchmark_verify_t*)arg;
for (i = 0; i < 20000; i++) {
secp256k1_pubkey pubkey;
secp256k1_ecdsa_signature sig;
data->sig[data->siglen - 1] ^= (i & 0xFF);
data->sig[data->siglen - 2] ^= ((i >> 8) & 0xFF);
data->sig[data->siglen - 3] ^= ((i >> 16) & 0xFF);
CHECK(secp256k1_ecdsa_verify(data->ctx, data->msg, data->sig, data->siglen, data->pubkey, data->pubkeylen) == (i == 0));
CHECK(secp256k1_ec_pubkey_parse(data->ctx, &pubkey, data->pubkey, data->pubkeylen) == 1);
CHECK(secp256k1_ecdsa_signature_parse_der(data->ctx, &sig, data->sig, data->siglen) == 1);
CHECK(secp256k1_ecdsa_verify(data->ctx, &sig, data->msg, &pubkey) == (i == 0));
data->sig[data->siglen - 1] ^= (i & 0xFF);
data->sig[data->siglen - 2] ^= ((i >> 8) & 0xFF);
data->sig[data->siglen - 3] ^= ((i >> 16) & 0xFF);
@ -38,16 +42,24 @@ static void benchmark_verify(void* arg) {
int main(void) {
int i;
secp256k1_pubkey pubkey;
secp256k1_ecdsa_signature sig;
benchmark_verify_t data;
data.ctx = secp256k1_context_create(SECP256K1_CONTEXT_SIGN | SECP256K1_CONTEXT_VERIFY);
for (i = 0; i < 32; i++) data.msg[i] = 1 + i;
for (i = 0; i < 32; i++) data.key[i] = 33 + i;
for (i = 0; i < 32; i++) {
data.msg[i] = 1 + i;
}
for (i = 0; i < 32; i++) {
data.key[i] = 33 + i;
}
data.siglen = 72;
secp256k1_ecdsa_sign(data.ctx, data.msg, data.sig, &data.siglen, data.key, NULL, NULL);
CHECK(secp256k1_ecdsa_sign(data.ctx, &sig, data.msg, data.key, NULL, NULL));
CHECK(secp256k1_ecdsa_signature_serialize_der(data.ctx, data.sig, &data.siglen, &sig));
CHECK(secp256k1_ec_pubkey_create(data.ctx, &pubkey, data.key));
data.pubkeylen = 33;
CHECK(secp256k1_ec_pubkey_create(data.ctx, data.pubkey, &data.pubkeylen, data.key, 1));
CHECK(secp256k1_ec_pubkey_serialize(data.ctx, data.pubkey, &data.pubkeylen, &pubkey, SECP256K1_EC_COMPRESSED) == 1);
run_benchmark("ecdsa_verify", benchmark_verify, NULL, NULL, &data, 10, 20000);

15
src/ecdsa.h
View file

@ -7,18 +7,15 @@
#ifndef _SECP256K1_ECDSA_
#define _SECP256K1_ECDSA_
#include <stddef.h>
#include "scalar.h"
#include "group.h"
#include "ecmult.h"
typedef struct {
secp256k1_scalar_t r, s;
} secp256k1_ecdsa_sig_t;
static int secp256k1_ecdsa_sig_parse(secp256k1_ecdsa_sig_t *r, const unsigned char *sig, int size);
static int secp256k1_ecdsa_sig_serialize(unsigned char *sig, int *size, const secp256k1_ecdsa_sig_t *a);
static int secp256k1_ecdsa_sig_verify(const secp256k1_ecmult_context_t *ctx, const secp256k1_ecdsa_sig_t *sig, const secp256k1_ge_t *pubkey, const secp256k1_scalar_t *message);
static int secp256k1_ecdsa_sig_sign(const secp256k1_ecmult_gen_context_t *ctx, secp256k1_ecdsa_sig_t *sig, const secp256k1_scalar_t *seckey, const secp256k1_scalar_t *message, const secp256k1_scalar_t *nonce, int *recid);
static int secp256k1_ecdsa_sig_recover(const secp256k1_ecmult_context_t *ctx, const secp256k1_ecdsa_sig_t *sig, secp256k1_ge_t *pubkey, const secp256k1_scalar_t *message, int recid);
static int secp256k1_ecdsa_sig_parse(secp256k1_scalar *r, secp256k1_scalar *s, const unsigned char *sig, size_t size);
static int secp256k1_ecdsa_sig_serialize(unsigned char *sig, size_t *size, const secp256k1_scalar *r, const secp256k1_scalar *s);
static int secp256k1_ecdsa_sig_verify(const secp256k1_ecmult_context *ctx, const secp256k1_scalar* r, const secp256k1_scalar* s, const secp256k1_ge *pubkey, const secp256k1_scalar *message);
static int secp256k1_ecdsa_sig_sign(const secp256k1_ecmult_gen_context *ctx, secp256k1_scalar* r, secp256k1_scalar* s, const secp256k1_scalar *seckey, const secp256k1_scalar *message, const secp256k1_scalar *nonce, int *recid);
#endif

260
src/ecdsa_impl.h
View file

@ -1,5 +1,5 @@
/**********************************************************************
* Copyright (c) 2013, 2014 Pieter Wuille *
* Copyright (c) 2013-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
@ -28,7 +28,7 @@
* sage: '%x' % (EllipticCurve ([F (a), F (b)]).order())
* 'fffffffffffffffffffffffffffffffebaaedce6af48a03bbfd25e8cd0364141'
*/
static const secp256k1_fe_t secp256k1_ecdsa_const_order_as_fe = SECP256K1_FE_CONST(
static const secp256k1_fe secp256k1_ecdsa_const_order_as_fe = SECP256K1_FE_CONST(
0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFEUL,
0xBAAEDCE6UL, 0xAF48A03BUL, 0xBFD25E8CUL, 0xD0364141UL
);
@ -42,82 +42,150 @@ static const secp256k1_fe_t secp256k1_ecdsa_const_order_as_fe = SECP256K1_FE_CON
* sage: '%x' % (p - EllipticCurve ([F (a), F (b)]).order())
* '14551231950b75fc4402da1722fc9baee'
*/
static const secp256k1_fe_t secp256k1_ecdsa_const_p_minus_order = SECP256K1_FE_CONST(
static const secp256k1_fe secp256k1_ecdsa_const_p_minus_order = SECP256K1_FE_CONST(
0, 0, 0, 1, 0x45512319UL, 0x50B75FC4UL, 0x402DA172UL, 0x2FC9BAEEUL
);
static int secp256k1_ecdsa_sig_parse(secp256k1_ecdsa_sig_t *r, const unsigned char *sig, int size) {
unsigned char ra[32] = {0}, sa[32] = {0};
const unsigned char *rp;
const unsigned char *sp;
int lenr;
int lens;
int overflow;
if (sig[0] != 0x30) {
static int secp256k1_der_read_len(const unsigned char **sigp, const unsigned char *sigend) {
int lenleft, b1;
size_t ret = 0;
if (*sigp >= sigend) {
return -1;
}
b1 = *((*sigp)++);
if (b1 == 0xFF) {
/* X.690-0207 8.1.3.5.c the value 0xFF shall not be used. */
return -1;
}
if ((b1 & 0x80) == 0) {
/* X.690-0207 8.1.3.4 short form length octets */
return b1;
}
if (b1 == 0x80) {
/* Indefinite length is not allowed in DER. */
return -1;
}
/* X.690-207 8.1.3.5 long form length octets */
lenleft = b1 & 0x7F;
if (lenleft > sigend - *sigp) {
return -1;
}
if (**sigp == 0) {
/* Not the shortest possible length encoding. */
return -1;
}
if ((size_t)lenleft > sizeof(size_t)) {
/* The resulting length would exceed the range of a size_t, so
* certainly longer than the passed array size.
*/
return -1;
}
while (lenleft > 0) {
if ((ret >> ((sizeof(size_t) - 1) * 8)) != 0) {
}
ret = (ret << 8) | **sigp;
if (ret + lenleft > (size_t)(sigend - *sigp)) {
/* Result exceeds the length of the passed array. */
return -1;
}
(*sigp)++;
lenleft--;
}
if (ret < 128) {
/* Not the shortest possible length encoding. */
return -1;
}
return ret;
}
static int secp256k1_der_parse_integer(secp256k1_scalar *r, const unsigned char **sig, const unsigned char *sigend) {
int overflow = 0;
unsigned char ra[32] = {0};
int rlen;
if (*sig == sigend || **sig != 0x02) {
/* Not a primitive integer (X.690-0207 8.3.1). */
return 0;
}
lenr = sig[3];
if (5+lenr >= size) {
(*sig)++;
rlen = secp256k1_der_read_len(sig, sigend);
if (rlen <= 0 || (*sig) + rlen > sigend) {
/* Exceeds bounds or not at least length 1 (X.690-0207 8.3.1). */
return 0;
}
lens = sig[lenr+5];
if (sig[1] != lenr+lens+4) {
if (**sig == 0x00 && rlen > 1 && (((*sig)[1]) & 0x80) == 0x00) {
/* Excessive 0x00 padding. */
return 0;
}
if (lenr+lens+6 > size) {
if (**sig == 0xFF && rlen > 1 && (((*sig)[1]) & 0x80) == 0x80) {
/* Excessive 0xFF padding. */
return 0;
}
if (sig[2] != 0x02) {
return 0;
if ((**sig & 0x80) == 0x80) {
/* Negative. */
overflow = 1;
}
if (lenr == 0) {
return 0;
while (rlen > 0 && **sig == 0) {
/* Skip leading zero bytes */
rlen--;
(*sig)++;
}
if (sig[lenr+4] != 0x02) {
return 0;
if (rlen > 32) {
overflow = 1;
}
if (lens == 0) {
return 0;
if (!overflow) {
memcpy(ra + 32 - rlen, *sig, rlen);
secp256k1_scalar_set_b32(r, ra, &overflow);
}
sp = sig + 6 + lenr;
while (lens > 0 && sp[0] == 0) {
lens--;
sp++;
}
if (lens > 32) {
return 0;
}
rp = sig + 4;
while (lenr > 0 && rp[0] == 0) {
lenr--;
rp++;
}
if (lenr > 32) {
return 0;
}
memcpy(ra + 32 - lenr, rp, lenr);
memcpy(sa + 32 - lens, sp, lens);
overflow = 0;
secp256k1_scalar_set_b32(&r->r, ra, &overflow);
if (overflow) {
return 0;
}
secp256k1_scalar_set_b32(&r->s, sa, &overflow);
if (overflow) {
return 0;
secp256k1_scalar_set_int(r, 0);
}
(*sig) += rlen;
return 1;
}
static int secp256k1_ecdsa_sig_serialize(unsigned char *sig, int *size, const secp256k1_ecdsa_sig_t *a) {
static int secp256k1_ecdsa_sig_parse(secp256k1_scalar *rr, secp256k1_scalar *rs, const unsigned char *sig, size_t size) {
const unsigned char *sigend = sig + size;
int rlen;
if (sig == sigend || *(sig++) != 0x30) {
/* The encoding doesn't start with a constructed sequence (X.690-0207 8.9.1). */
return 0;
}
rlen = secp256k1_der_read_len(&sig, sigend);
if (rlen < 0 || sig + rlen > sigend) {
/* Tuple exceeds bounds */
return 0;
}
if (sig + rlen != sigend) {
/* Garbage after tuple. */
return 0;
}
if (!secp256k1_der_parse_integer(rr, &sig, sigend)) {
return 0;
}
if (!secp256k1_der_parse_integer(rs, &sig, sigend)) {
return 0;
}
if (sig != sigend) {
/* Trailing garbage inside tuple. */
return 0;
}
return 1;
}
static int secp256k1_ecdsa_sig_serialize(unsigned char *sig, size_t *size, const secp256k1_scalar* ar, const secp256k1_scalar* as) {
unsigned char r[33] = {0}, s[33] = {0};
unsigned char *rp = r, *sp = s;
int lenR = 33, lenS = 33;
secp256k1_scalar_get_b32(&r[1], &a->r);
secp256k1_scalar_get_b32(&s[1], &a->s);
size_t lenR = 33, lenS = 33;
secp256k1_scalar_get_b32(&r[1], ar);
secp256k1_scalar_get_b32(&s[1], as);
while (lenR > 1 && rp[0] == 0 && rp[1] < 0x80) { lenR--; rp++; }
while (lenS > 1 && sp[0] == 0 && sp[1] < 0x80) { lenS--; sp++; }
if (*size < 6+lenS+lenR) {
*size = 6 + lenS + lenR;
return 0;
}
*size = 6 + lenS + lenR;
@ -132,26 +200,26 @@ static int secp256k1_ecdsa_sig_serialize(unsigned char *sig, int *size, const se
return 1;
}
static int secp256k1_ecdsa_sig_verify(const secp256k1_ecmult_context_t *ctx, const secp256k1_ecdsa_sig_t *sig, const secp256k1_ge_t *pubkey, const secp256k1_scalar_t *message) {
static int secp256k1_ecdsa_sig_verify(const secp256k1_ecmult_context *ctx, const secp256k1_scalar *sigr, const secp256k1_scalar *sigs, const secp256k1_ge *pubkey, const secp256k1_scalar *message) {
unsigned char c[32];
secp256k1_scalar_t sn, u1, u2;
secp256k1_fe_t xr;
secp256k1_gej_t pubkeyj;
secp256k1_gej_t pr;
secp256k1_scalar sn, u1, u2;
secp256k1_fe xr;
secp256k1_gej pubkeyj;
secp256k1_gej pr;
if (secp256k1_scalar_is_zero(&sig->r) || secp256k1_scalar_is_zero(&sig->s)) {
if (secp256k1_scalar_is_zero(sigr) || secp256k1_scalar_is_zero(sigs)) {
return 0;
}
secp256k1_scalar_inverse_var(&sn, &sig->s);
secp256k1_scalar_inverse_var(&sn, sigs);
secp256k1_scalar_mul(&u1, &sn, message);
secp256k1_scalar_mul(&u2, &sn, &sig->r);
secp256k1_scalar_mul(&u2, &sn, sigr);
secp256k1_gej_set_ge(&pubkeyj, pubkey);
secp256k1_ecmult(ctx, &pr, &pubkeyj, &u2, &u1);
if (secp256k1_gej_is_infinity(&pr)) {
return 0;
}
secp256k1_scalar_get_b32(c, &sig->r);
secp256k1_scalar_get_b32(c, sigr);
secp256k1_fe_set_b32(&xr, c);
/** We now have the recomputed R point in pr, and its claimed x coordinate (modulo n)
@ -171,11 +239,11 @@ static int secp256k1_ecdsa_sig_verify(const secp256k1_ecmult_context_t *ctx, con
* secp256k1_gej_eq_x implements the (xr * pr.z^2 mod p == pr.x) test.
*/
if (secp256k1_gej_eq_x_var(&xr, &pr)) {
/* xr.x == xr * xr.z^2 mod p, so the signature is valid. */
/* xr * pr.z^2 mod p == pr.x, so the signature is valid. */
return 1;
}
if (secp256k1_fe_cmp_var(&xr, &secp256k1_ecdsa_const_p_minus_order) >= 0) {
/* xr + p >= n, so we can skip testing the second case. */
/* xr + n >= p, so we can skip testing the second case. */
return 0;
}
secp256k1_fe_add(&xr, &secp256k1_ecdsa_const_order_as_fe);
@ -186,44 +254,11 @@ static int secp256k1_ecdsa_sig_verify(const secp256k1_ecmult_context_t *ctx, con
return 0;
}
static int secp256k1_ecdsa_sig_recover(const secp256k1_ecmult_context_t *ctx, const secp256k1_ecdsa_sig_t *sig, secp256k1_ge_t *pubkey, const secp256k1_scalar_t *message, int recid) {
unsigned char brx[32];
secp256k1_fe_t fx;
secp256k1_ge_t x;
secp256k1_gej_t xj;
secp256k1_scalar_t rn, u1, u2;
secp256k1_gej_t qj;
if (secp256k1_scalar_is_zero(&sig->r) || secp256k1_scalar_is_zero(&sig->s)) {
return 0;
}
secp256k1_scalar_get_b32(brx, &sig->r);
VERIFY_CHECK(secp256k1_fe_set_b32(&fx, brx)); /* brx comes from a scalar, so is less than the order; certainly less than p */
if (recid & 2) {
if (secp256k1_fe_cmp_var(&fx, &secp256k1_ecdsa_const_p_minus_order) >= 0) {
return 0;
}
secp256k1_fe_add(&fx, &secp256k1_ecdsa_const_order_as_fe);
}
if (!secp256k1_ge_set_xo_var(&x, &fx, recid & 1)) {
return 0;
}
secp256k1_gej_set_ge(&xj, &x);
secp256k1_scalar_inverse_var(&rn, &sig->r);
secp256k1_scalar_mul(&u1, &rn, message);
secp256k1_scalar_negate(&u1, &u1);
secp256k1_scalar_mul(&u2, &rn, &sig->s);
secp256k1_ecmult(ctx, &qj, &xj, &u2, &u1);
secp256k1_ge_set_gej_var(pubkey, &qj);
return !secp256k1_gej_is_infinity(&qj);
}
static int secp256k1_ecdsa_sig_sign(const secp256k1_ecmult_gen_context_t *ctx, secp256k1_ecdsa_sig_t *sig, const secp256k1_scalar_t *seckey, const secp256k1_scalar_t *message, const secp256k1_scalar_t *nonce, int *recid) {
static int secp256k1_ecdsa_sig_sign(const secp256k1_ecmult_gen_context *ctx, secp256k1_scalar *sigr, secp256k1_scalar *sigs, const secp256k1_scalar *seckey, const secp256k1_scalar *message, const secp256k1_scalar *nonce, int *recid) {
unsigned char b[32];
secp256k1_gej_t rp;
secp256k1_ge_t r;
secp256k1_scalar_t n;
secp256k1_gej rp;
secp256k1_ge r;
secp256k1_scalar n;
int overflow = 0;
secp256k1_ecmult_gen(ctx, &rp, nonce);
@ -231,28 +266,33 @@ static int secp256k1_ecdsa_sig_sign(const secp256k1_ecmult_gen_context_t *ctx, s
secp256k1_fe_normalize(&r.x);
secp256k1_fe_normalize(&r.y);
secp256k1_fe_get_b32(b, &r.x);
secp256k1_scalar_set_b32(&sig->r, b, &overflow);
if (secp256k1_scalar_is_zero(&sig->r)) {
/* P.x = order is on the curve, so technically sig->r could end up zero, which would be an invalid signature. */
secp256k1_scalar_set_b32(sigr, b, &overflow);
if (secp256k1_scalar_is_zero(sigr)) {
/* P.x = order is on the curve, so technically sig->r could end up zero, which would be an invalid signature.
* This branch is cryptographically unreachable as hitting it requires finding the discrete log of P.x = N.
*/
secp256k1_gej_clear(&rp);
secp256k1_ge_clear(&r);
return 0;
}
if (recid) {
/* The overflow condition is cryptographically unreachable as hitting it requires finding the discrete log
* of some P where P.x >= order, and only 1 in about 2^127 points meet this criteria.
*/
*recid = (overflow ? 2 : 0) | (secp256k1_fe_is_odd(&r.y) ? 1 : 0);
}
secp256k1_scalar_mul(&n, &sig->r, seckey);
secp256k1_scalar_mul(&n, sigr, seckey);
secp256k1_scalar_add(&n, &n, message);
secp256k1_scalar_inverse(&sig->s, nonce);
secp256k1_scalar_mul(&sig->s, &sig->s, &n);
secp256k1_scalar_inverse(sigs, nonce);
secp256k1_scalar_mul(sigs, sigs, &n);
secp256k1_scalar_clear(&n);
secp256k1_gej_clear(&rp);
secp256k1_ge_clear(&r);
if (secp256k1_scalar_is_zero(&sig->s)) {
if (secp256k1_scalar_is_zero(sigs)) {
return 0;
}
if (secp256k1_scalar_is_high(&sig->s)) {
secp256k1_scalar_negate(&sig->s, &sig->s);
if (secp256k1_scalar_is_high(sigs)) {
secp256k1_scalar_negate(sigs, sigs);
if (recid) {
*recid ^= 1;
}

17
src/eckey.h
View file

@ -7,20 +7,19 @@
#ifndef _SECP256K1_ECKEY_
#define _SECP256K1_ECKEY_
#include <stddef.h>
#include "group.h"
#include "scalar.h"
#include "ecmult.h"
#include "ecmult_gen.h"
static int secp256k1_eckey_pubkey_parse(secp256k1_ge_t *elem, const unsigned char *pub, int size);
static int secp256k1_eckey_pubkey_serialize(secp256k1_ge_t *elem, unsigned char *pub, int *size, int compressed);
static int secp256k1_eckey_pubkey_parse(secp256k1_ge *elem, const unsigned char *pub, size_t size);
static int secp256k1_eckey_pubkey_serialize(secp256k1_ge *elem, unsigned char *pub, size_t *size, int compressed);
static int secp256k1_eckey_privkey_parse(secp256k1_scalar_t *key, const unsigned char *privkey, int privkeylen);
static int secp256k1_eckey_privkey_serialize(const secp256k1_ecmult_gen_context_t *ctx, unsigned char *privkey, int *privkeylen, const secp256k1_scalar_t *key, int compressed);
static int secp256k1_eckey_privkey_tweak_add(secp256k1_scalar_t *key, const secp256k1_scalar_t *tweak);
static int secp256k1_eckey_pubkey_tweak_add(const secp256k1_ecmult_context_t *ctx, secp256k1_ge_t *key, const secp256k1_scalar_t *tweak);
static int secp256k1_eckey_privkey_tweak_mul(secp256k1_scalar_t *key, const secp256k1_scalar_t *tweak);
static int secp256k1_eckey_pubkey_tweak_mul(const secp256k1_ecmult_context_t *ctx, secp256k1_ge_t *key, const secp256k1_scalar_t *tweak);
static int secp256k1_eckey_privkey_tweak_add(secp256k1_scalar *key, const secp256k1_scalar *tweak);
static int secp256k1_eckey_pubkey_tweak_add(const secp256k1_ecmult_context *ctx, secp256k1_ge *key, const secp256k1_scalar *tweak);
static int secp256k1_eckey_privkey_tweak_mul(secp256k1_scalar *key, const secp256k1_scalar *tweak);
static int secp256k1_eckey_pubkey_tweak_mul(const secp256k1_ecmult_context *ctx, secp256k1_ge *key, const secp256k1_scalar *tweak);
#endif

127
src/eckey_impl.h
View file

@ -14,12 +14,12 @@
#include "group.h"
#include "ecmult_gen.h"
static int secp256k1_eckey_pubkey_parse(secp256k1_ge_t *elem, const unsigned char *pub, int size) {
static int secp256k1_eckey_pubkey_parse(secp256k1_ge *elem, const unsigned char *pub, size_t size) {
if (size == 33 && (pub[0] == 0x02 || pub[0] == 0x03)) {
secp256k1_fe_t x;
secp256k1_fe x;
return secp256k1_fe_set_b32(&x, pub+1) && secp256k1_ge_set_xo_var(elem, &x, pub[0] == 0x03);
} else if (size == 65 && (pub[0] == 0x04 || pub[0] == 0x06 || pub[0] == 0x07)) {
secp256k1_fe_t x, y;
secp256k1_fe x, y;
if (!secp256k1_fe_set_b32(&x, pub+1) || !secp256k1_fe_set_b32(&y, pub+33)) {
return 0;
}
@ -33,7 +33,7 @@ static int secp256k1_eckey_pubkey_parse(secp256k1_ge_t *elem, const unsigned cha
}
}
static int secp256k1_eckey_pubkey_serialize(secp256k1_ge_t *elem, unsigned char *pub, int *size, int compressed) {
static int secp256k1_eckey_pubkey_serialize(secp256k1_ge *elem, unsigned char *pub, size_t *size, int compressed) {
if (secp256k1_ge_is_infinity(elem)) {
return 0;
}
@ -51,110 +51,7 @@ static int secp256k1_eckey_pubkey_serialize(secp256k1_ge_t *elem, unsigned char
return 1;
}
static int secp256k1_eckey_privkey_parse(secp256k1_scalar_t *key, const unsigned char *privkey, int privkeylen) {
unsigned char c[32] = {0};
const unsigned char *end = privkey + privkeylen;
int lenb = 0;
int len = 0;
int overflow = 0;
/* sequence header */
if (end < privkey+1 || *privkey != 0x30) {
return 0;
}
privkey++;
/* sequence length constructor */
if (end < privkey+1 || !(*privkey & 0x80)) {
return 0;
}
lenb = *privkey & ~0x80; privkey++;
if (lenb < 1 || lenb > 2) {
return 0;
}
if (end < privkey+lenb) {
return 0;
}
/* sequence length */
len = privkey[lenb-1] | (lenb > 1 ? privkey[lenb-2] << 8 : 0);
privkey += lenb;
if (end < privkey+len) {
return 0;
}
/* sequence element 0: version number (=1) */
if (end < privkey+3 || privkey[0] != 0x02 || privkey[1] != 0x01 || privkey[2] != 0x01) {
return 0;
}
privkey += 3;
/* sequence element 1: octet string, up to 32 bytes */
if (end < privkey+2 || privkey[0] != 0x04 || privkey[1] > 0x20 || end < privkey+2+privkey[1]) {
return 0;
}
memcpy(c + 32 - privkey[1], privkey + 2, privkey[1]);
secp256k1_scalar_set_b32(key, c, &overflow);
memset(c, 0, 32);
return !overflow;
}
static int secp256k1_eckey_privkey_serialize(const secp256k1_ecmult_gen_context_t *ctx, unsigned char *privkey, int *privkeylen, const secp256k1_scalar_t *key, int compressed) {
secp256k1_gej_t rp;
secp256k1_ge_t r;
int pubkeylen = 0;
secp256k1_ecmult_gen(ctx, &rp, key);
secp256k1_ge_set_gej(&r, &rp);
if (compressed) {
static const unsigned char begin[] = {
0x30,0x81,0xD3,0x02,0x01,0x01,0x04,0x20
};
static const unsigned char middle[] = {
0xA0,0x81,0x85,0x30,0x81,0x82,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
0x21,0x02,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
0x17,0x98,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x24,0x03,0x22,0x00
};
unsigned char *ptr = privkey;
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
secp256k1_scalar_get_b32(ptr, key); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
if (!secp256k1_eckey_pubkey_serialize(&r, ptr, &pubkeylen, 1)) {
return 0;
}
ptr += pubkeylen;
*privkeylen = ptr - privkey;
} else {
static const unsigned char begin[] = {
0x30,0x82,0x01,0x13,0x02,0x01,0x01,0x04,0x20
};
static const unsigned char middle[] = {
0xA0,0x81,0xA5,0x30,0x81,0xA2,0x02,0x01,0x01,0x30,0x2C,0x06,0x07,0x2A,0x86,0x48,
0xCE,0x3D,0x01,0x01,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F,0x30,0x06,0x04,0x01,0x00,0x04,0x01,0x07,0x04,
0x41,0x04,0x79,0xBE,0x66,0x7E,0xF9,0xDC,0xBB,0xAC,0x55,0xA0,0x62,0x95,0xCE,0x87,
0x0B,0x07,0x02,0x9B,0xFC,0xDB,0x2D,0xCE,0x28,0xD9,0x59,0xF2,0x81,0x5B,0x16,0xF8,
0x17,0x98,0x48,0x3A,0xDA,0x77,0x26,0xA3,0xC4,0x65,0x5D,0xA4,0xFB,0xFC,0x0E,0x11,
0x08,0xA8,0xFD,0x17,0xB4,0x48,0xA6,0x85,0x54,0x19,0x9C,0x47,0xD0,0x8F,0xFB,0x10,
0xD4,0xB8,0x02,0x21,0x00,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFE,0xBA,0xAE,0xDC,0xE6,0xAF,0x48,0xA0,0x3B,0xBF,0xD2,0x5E,
0x8C,0xD0,0x36,0x41,0x41,0x02,0x01,0x01,0xA1,0x44,0x03,0x42,0x00
};
unsigned char *ptr = privkey;
memcpy(ptr, begin, sizeof(begin)); ptr += sizeof(begin);
secp256k1_scalar_get_b32(ptr, key); ptr += 32;
memcpy(ptr, middle, sizeof(middle)); ptr += sizeof(middle);
if (!secp256k1_eckey_pubkey_serialize(&r, ptr, &pubkeylen, 0)) {
return 0;
}
ptr += pubkeylen;
*privkeylen = ptr - privkey;
}
return 1;
}
static int secp256k1_eckey_privkey_tweak_add(secp256k1_scalar_t *key, const secp256k1_scalar_t *tweak) {
static int secp256k1_eckey_privkey_tweak_add(secp256k1_scalar *key, const secp256k1_scalar *tweak) {
secp256k1_scalar_add(key, key, tweak);
if (secp256k1_scalar_is_zero(key)) {
return 0;
@ -162,9 +59,9 @@ static int secp256k1_eckey_privkey_tweak_add(secp256k1_scalar_t *key, const secp
return 1;
}
static int secp256k1_eckey_pubkey_tweak_add(const secp256k1_ecmult_context_t *ctx, secp256k1_ge_t *key, const secp256k1_scalar_t *tweak) {
secp256k1_gej_t pt;
secp256k1_scalar_t one;
static int secp256k1_eckey_pubkey_tweak_add(const secp256k1_ecmult_context *ctx, secp256k1_ge *key, const secp256k1_scalar *tweak) {
secp256k1_gej pt;
secp256k1_scalar one;
secp256k1_gej_set_ge(&pt, key);
secp256k1_scalar_set_int(&one, 1);
secp256k1_ecmult(ctx, &pt, &pt, &one, tweak);
@ -176,7 +73,7 @@ static int secp256k1_eckey_pubkey_tweak_add(const secp256k1_ecmult_context_t *ct
return 1;
}
static int secp256k1_eckey_privkey_tweak_mul(secp256k1_scalar_t *key, const secp256k1_scalar_t *tweak) {
static int secp256k1_eckey_privkey_tweak_mul(secp256k1_scalar *key, const secp256k1_scalar *tweak) {
if (secp256k1_scalar_is_zero(tweak)) {
return 0;
}
@ -185,9 +82,9 @@ static int secp256k1_eckey_privkey_tweak_mul(secp256k1_scalar_t *key, const secp
return 1;
}
static int secp256k1_eckey_pubkey_tweak_mul(const secp256k1_ecmult_context_t *ctx, secp256k1_ge_t *key, const secp256k1_scalar_t *tweak) {
secp256k1_scalar_t zero;
secp256k1_gej_t pt;
static int secp256k1_eckey_pubkey_tweak_mul(const secp256k1_ecmult_context *ctx, secp256k1_ge *key, const secp256k1_scalar *tweak) {
secp256k1_scalar zero;
secp256k1_gej pt;
if (secp256k1_scalar_is_zero(tweak)) {
return 0;
}

20
src/ecmult.h
View file

@ -12,20 +12,20 @@
typedef struct {
/* For accelerating the computation of a*P + b*G: */
secp256k1_ge_storage_t (*pre_g)[]; /* odd multiples of the generator */
secp256k1_ge_storage (*pre_g)[]; /* odd multiples of the generator */
#ifdef USE_ENDOMORPHISM
secp256k1_ge_storage_t (*pre_g_128)[]; /* odd multiples of 2^128*generator */
secp256k1_ge_storage (*pre_g_128)[]; /* odd multiples of 2^128*generator */
#endif
} secp256k1_ecmult_context_t;
} secp256k1_ecmult_context;
static void secp256k1_ecmult_context_init(secp256k1_ecmult_context_t *ctx);
static void secp256k1_ecmult_context_build(secp256k1_ecmult_context_t *ctx);
static void secp256k1_ecmult_context_clone(secp256k1_ecmult_context_t *dst,
const secp256k1_ecmult_context_t *src);
static void secp256k1_ecmult_context_clear(secp256k1_ecmult_context_t *ctx);
static int secp256k1_ecmult_context_is_built(const secp256k1_ecmult_context_t *ctx);
static void secp256k1_ecmult_context_init(secp256k1_ecmult_context *ctx);
static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, const secp256k1_callback *cb);
static void secp256k1_ecmult_context_clone(secp256k1_ecmult_context *dst,
const secp256k1_ecmult_context *src, const secp256k1_callback *cb);
static void secp256k1_ecmult_context_clear(secp256k1_ecmult_context *ctx);
static int secp256k1_ecmult_context_is_built(const secp256k1_ecmult_context *ctx);
/** Double multiply: R = na*A + ng*G */
static void secp256k1_ecmult(const secp256k1_ecmult_context_t *ctx, secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_scalar_t *na, const secp256k1_scalar_t *ng);
static void secp256k1_ecmult(const secp256k1_ecmult_context *ctx, secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_scalar *na, const secp256k1_scalar *ng);
#endif

15
src/ecmult_const.h Normal file
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@ -0,0 +1,15 @@
/**********************************************************************
* Copyright (c) 2015 Andrew Poelstra *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_ECMULT_CONST_
#define _SECP256K1_ECMULT_CONST_
#include "scalar.h"
#include "group.h"
static void secp256k1_ecmult_const(secp256k1_gej *r, const secp256k1_ge *a, const secp256k1_scalar *q);
#endif

260
src/ecmult_const_impl.h Normal file
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@ -0,0 +1,260 @@
/**********************************************************************
* Copyright (c) 2015 Pieter Wuille, Andrew Poelstra *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_ECMULT_CONST_IMPL_
#define _SECP256K1_ECMULT_CONST_IMPL_
#include "scalar.h"
#include "group.h"
#include "ecmult_const.h"
#include "ecmult_impl.h"
#ifdef USE_ENDOMORPHISM
#define WNAF_BITS 128
#else
#define WNAF_BITS 256
#endif
#define WNAF_SIZE(w) ((WNAF_BITS + (w) - 1) / (w))
/* This is like `ECMULT_TABLE_GET_GE` but is constant time */
#define ECMULT_CONST_TABLE_GET_GE(r,pre,n,w) do { \
int m; \
int abs_n = (n) * (((n) > 0) * 2 - 1); \
int idx_n = abs_n / 2; \
secp256k1_fe neg_y; \
VERIFY_CHECK(((n) & 1) == 1); \
VERIFY_CHECK((n) >= -((1 << ((w)-1)) - 1)); \
VERIFY_CHECK((n) <= ((1 << ((w)-1)) - 1)); \
VERIFY_SETUP(secp256k1_fe_clear(&(r)->x)); \
VERIFY_SETUP(secp256k1_fe_clear(&(r)->y)); \
for (m = 0; m < ECMULT_TABLE_SIZE(w); m++) { \
/* This loop is used to avoid secret data in array indices. See
* the comment in ecmult_gen_impl.h for rationale. */ \
secp256k1_fe_cmov(&(r)->x, &(pre)[m].x, m == idx_n); \
secp256k1_fe_cmov(&(r)->y, &(pre)[m].y, m == idx_n); \
} \
(r)->infinity = 0; \
secp256k1_fe_negate(&neg_y, &(r)->y, 1); \
secp256k1_fe_cmov(&(r)->y, &neg_y, (n) != abs_n); \
} while(0)
/** Convert a number to WNAF notation. The number becomes represented by sum(2^{wi} * wnaf[i], i=0..return_val)
* with the following guarantees:
* - each wnaf[i] an odd integer between -(1 << w) and (1 << w)
* - each wnaf[i] is nonzero
* - the number of words set is returned; this is always (WNAF_BITS + w - 1) / w
*
* Adapted from `The Width-w NAF Method Provides Small Memory and Fast Elliptic Scalar
* Multiplications Secure against Side Channel Attacks`, Okeya and Tagaki. M. Joye (Ed.)
* CT-RSA 2003, LNCS 2612, pp. 328-443, 2003. Springer-Verlagy Berlin Heidelberg 2003
*
* Numbers reference steps of `Algorithm SPA-resistant Width-w NAF with Odd Scalar` on pp. 335
*/
static int secp256k1_wnaf_const(int *wnaf, secp256k1_scalar s, int w) {
int global_sign;
int skew = 0;
int word = 0;
/* 1 2 3 */
int u_last;
int u;
#ifdef USE_ENDOMORPHISM
int flip;
int bit;
secp256k1_scalar neg_s;
int not_neg_one;
/* If we are using the endomorphism, we cannot handle even numbers by negating
* them, since we are working with 128-bit numbers whose negations would be 256
* bits, eliminating the performance advantage. Instead we use a technique from
* Section 4.2 of the Okeya/Tagaki paper, which is to add either 1 (for even)
* or 2 (for odd) to the number we are encoding, then compensating after the
* multiplication. */
/* Negative 128-bit numbers will be negated, since otherwise they are 256-bit */
flip = secp256k1_scalar_is_high(&s);
/* We add 1 to even numbers, 2 to odd ones, noting that negation flips parity */
bit = flip ^ (s.d[0] & 1);
/* We check for negative one, since adding 2 to it will cause an overflow */
secp256k1_scalar_negate(&neg_s, &s);
not_neg_one = !secp256k1_scalar_is_one(&neg_s);
secp256k1_scalar_cadd_bit(&s, bit, not_neg_one);
/* If we had negative one, flip == 1, s.d[0] == 0, bit == 1, so caller expects
* that we added two to it and flipped it. In fact for -1 these operations are
* identical. We only flipped, but since skewing is required (in the sense that
* the skew must be 1 or 2, never zero) and flipping is not, we need to change
* our flags to claim that we only skewed. */
global_sign = secp256k1_scalar_cond_negate(&s, flip);
global_sign *= not_neg_one * 2 - 1;
skew = 1 << bit;
#else
/* Otherwise, we just negate to force oddness */
int is_even = secp256k1_scalar_is_even(&s);
global_sign = secp256k1_scalar_cond_negate(&s, is_even);
#endif
/* 4 */
u_last = secp256k1_scalar_shr_int(&s, w);
while (word * w < WNAF_BITS) {
int sign;
int even;
/* 4.1 4.4 */
u = secp256k1_scalar_shr_int(&s, w);
/* 4.2 */
even = ((u & 1) == 0);
sign = 2 * (u_last > 0) - 1;
u += sign * even;
u_last -= sign * even * (1 << w);
/* 4.3, adapted for global sign change */
wnaf[word++] = u_last * global_sign;
u_last = u;
}
wnaf[word] = u * global_sign;
VERIFY_CHECK(secp256k1_scalar_is_zero(&s));
VERIFY_CHECK(word == WNAF_SIZE(w));
return skew;
}
static void secp256k1_ecmult_const(secp256k1_gej *r, const secp256k1_ge *a, const secp256k1_scalar *scalar) {
secp256k1_ge pre_a[ECMULT_TABLE_SIZE(WINDOW_A)];
secp256k1_ge tmpa;
secp256k1_fe Z;
#ifdef USE_ENDOMORPHISM
secp256k1_ge pre_a_lam[ECMULT_TABLE_SIZE(WINDOW_A)];
int wnaf_1[1 + WNAF_SIZE(WINDOW_A - 1)];
int wnaf_lam[1 + WNAF_SIZE(WINDOW_A - 1)];
int skew_1;
int skew_lam;
secp256k1_scalar q_1, q_lam;
#else
int wnaf[1 + WNAF_SIZE(WINDOW_A - 1)];
#endif
int i;
secp256k1_scalar sc = *scalar;
/* build wnaf representation for q. */
#ifdef USE_ENDOMORPHISM
/* split q into q_1 and q_lam (where q = q_1 + q_lam*lambda, and q_1 and q_lam are ~128 bit) */
secp256k1_scalar_split_lambda(&q_1, &q_lam, &sc);
/* no need for zero correction when using endomorphism since even
* numbers have one added to them anyway */
skew_1 = secp256k1_wnaf_const(wnaf_1, q_1, WINDOW_A - 1);
skew_lam = secp256k1_wnaf_const(wnaf_lam, q_lam, WINDOW_A - 1);
#else
int is_zero = secp256k1_scalar_is_zero(scalar);
/* the wNAF ladder cannot handle zero, so bump this to one .. we will
* correct the result after the fact */
sc.d[0] += is_zero;
VERIFY_CHECK(!secp256k1_scalar_is_zero(&sc));
secp256k1_wnaf_const(wnaf, sc, WINDOW_A - 1);
#endif
/* Calculate odd multiples of a.
* All multiples are brought to the same Z 'denominator', which is stored
* in Z. Due to secp256k1' isomorphism we can do all operations pretending
* that the Z coordinate was 1, use affine addition formulae, and correct
* the Z coordinate of the result once at the end.
*/
secp256k1_gej_set_ge(r, a);
secp256k1_ecmult_odd_multiples_table_globalz_windowa(pre_a, &Z, r);
for (i = 0; i < ECMULT_TABLE_SIZE(WINDOW_A); i++) {
secp256k1_fe_normalize_weak(&pre_a[i].y);
}
#ifdef USE_ENDOMORPHISM
for (i = 0; i < ECMULT_TABLE_SIZE(WINDOW_A); i++) {
secp256k1_ge_mul_lambda(&pre_a_lam[i], &pre_a[i]);
}
#endif
/* first loop iteration (separated out so we can directly set r, rather
* than having it start at infinity, get doubled several times, then have
* its new value added to it) */
#ifdef USE_ENDOMORPHISM
i = wnaf_1[WNAF_SIZE(WINDOW_A - 1)];
VERIFY_CHECK(i != 0);
ECMULT_CONST_TABLE_GET_GE(&tmpa, pre_a, i, WINDOW_A);
secp256k1_gej_set_ge(r, &tmpa);
i = wnaf_lam[WNAF_SIZE(WINDOW_A - 1)];
VERIFY_CHECK(i != 0);
ECMULT_CONST_TABLE_GET_GE(&tmpa, pre_a_lam, i, WINDOW_A);
secp256k1_gej_add_ge(r, r, &tmpa);
#else
i = wnaf[WNAF_SIZE(WINDOW_A - 1)];
VERIFY_CHECK(i != 0);
ECMULT_CONST_TABLE_GET_GE(&tmpa, pre_a, i, WINDOW_A);
secp256k1_gej_set_ge(r, &tmpa);
#endif
/* remaining loop iterations */
for (i = WNAF_SIZE(WINDOW_A - 1) - 1; i >= 0; i--) {
int n;
int j;
for (j = 0; j < WINDOW_A - 1; ++j) {
secp256k1_gej_double_nonzero(r, r, NULL);
}
#ifdef USE_ENDOMORPHISM
n = wnaf_1[i];
ECMULT_CONST_TABLE_GET_GE(&tmpa, pre_a, n, WINDOW_A);
VERIFY_CHECK(n != 0);
secp256k1_gej_add_ge(r, r, &tmpa);
n = wnaf_lam[i];
ECMULT_CONST_TABLE_GET_GE(&tmpa, pre_a_lam, n, WINDOW_A);
VERIFY_CHECK(n != 0);
secp256k1_gej_add_ge(r, r, &tmpa);
#else
n = wnaf[i];
VERIFY_CHECK(n != 0);
ECMULT_CONST_TABLE_GET_GE(&tmpa, pre_a, n, WINDOW_A);
secp256k1_gej_add_ge(r, r, &tmpa);
#endif
}
secp256k1_fe_mul(&r->z, &r->z, &Z);
#ifdef USE_ENDOMORPHISM
{
/* Correct for wNAF skew */
secp256k1_ge correction = *a;
secp256k1_ge_storage correction_1_stor;
secp256k1_ge_storage correction_lam_stor;
secp256k1_ge_storage a2_stor;
secp256k1_gej tmpj;
secp256k1_gej_set_ge(&tmpj, &correction);
secp256k1_gej_double_var(&tmpj, &tmpj, NULL);
secp256k1_ge_set_gej(&correction, &tmpj);
secp256k1_ge_to_storage(&correction_1_stor, a);
secp256k1_ge_to_storage(&correction_lam_stor, a);
secp256k1_ge_to_storage(&a2_stor, &correction);
/* For odd numbers this is 2a (so replace it), for even ones a (so no-op) */
secp256k1_ge_storage_cmov(&correction_1_stor, &a2_stor, skew_1 == 2);
secp256k1_ge_storage_cmov(&correction_lam_stor, &a2_stor, skew_lam == 2);
/* Apply the correction */
secp256k1_ge_from_storage(&correction, &correction_1_stor);
secp256k1_ge_neg(&correction, &correction);
secp256k1_gej_add_ge(r, r, &correction);
secp256k1_ge_from_storage(&correction, &correction_lam_stor);
secp256k1_ge_neg(&correction, &correction);
secp256k1_ge_mul_lambda(&correction, &correction);
secp256k1_gej_add_ge(r, r, &correction);
}
#else
/* correct for zero */
r->infinity |= is_zero;
#endif
}
#endif

24
src/ecmult_gen.h
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@ -23,21 +23,21 @@ typedef struct {
* None of the resulting prec group elements have a known scalar, and neither do any of
* the intermediate sums while computing a*G.
*/
secp256k1_ge_storage_t (*prec)[64][16]; /* prec[j][i] = 16^j * i * G + U_i */
secp256k1_scalar_t blind;
secp256k1_gej_t initial;
} secp256k1_ecmult_gen_context_t;
secp256k1_ge_storage (*prec)[64][16]; /* prec[j][i] = 16^j * i * G + U_i */
secp256k1_scalar blind;
secp256k1_gej initial;
} secp256k1_ecmult_gen_context;
static void secp256k1_ecmult_gen_context_init(secp256k1_ecmult_gen_context_t* ctx);
static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context_t* ctx);
static void secp256k1_ecmult_gen_context_clone(secp256k1_ecmult_gen_context_t *dst,
const secp256k1_ecmult_gen_context_t* src);
static void secp256k1_ecmult_gen_context_clear(secp256k1_ecmult_gen_context_t* ctx);
static int secp256k1_ecmult_gen_context_is_built(const secp256k1_ecmult_gen_context_t* ctx);
static void secp256k1_ecmult_gen_context_init(secp256k1_ecmult_gen_context* ctx);
static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context* ctx, const secp256k1_callback* cb);
static void secp256k1_ecmult_gen_context_clone(secp256k1_ecmult_gen_context *dst,
const secp256k1_ecmult_gen_context* src, const secp256k1_callback* cb);
static void secp256k1_ecmult_gen_context_clear(secp256k1_ecmult_gen_context* ctx);
static int secp256k1_ecmult_gen_context_is_built(const secp256k1_ecmult_gen_context* ctx);
/** Multiply with the generator: R = a*G */
static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context_t* ctx, secp256k1_gej_t *r, const secp256k1_scalar_t *a);
static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context* ctx, secp256k1_gej *r, const secp256k1_scalar *a);
static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context_t *ctx, const unsigned char *seed32);
static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context *ctx, const unsigned char *seed32);
#endif

102
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@ -11,22 +11,26 @@
#include "group.h"
#include "ecmult_gen.h"
#include "hash_impl.h"
static void secp256k1_ecmult_gen_context_init(secp256k1_ecmult_gen_context_t *ctx) {
#ifdef USE_ECMULT_STATIC_PRECOMPUTATION
#include "ecmult_static_context.h"
#endif
static void secp256k1_ecmult_gen_context_init(secp256k1_ecmult_gen_context *ctx) {
ctx->prec = NULL;
}
static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context_t *ctx) {
secp256k1_ge_t prec[1024];
secp256k1_gej_t gj;
secp256k1_gej_t nums_gej;
static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context *ctx, const secp256k1_callback* cb) {
#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
secp256k1_ge prec[1024];
secp256k1_gej gj;
secp256k1_gej nums_gej;
int i, j;
#endif
if (ctx->prec != NULL) {
return;
}
ctx->prec = (secp256k1_ge_storage_t (*)[64][16])checked_malloc(sizeof(*ctx->prec));
#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
ctx->prec = (secp256k1_ge_storage (*)[64][16])checked_malloc(cb, sizeof(*ctx->prec));
/* get the generator */
secp256k1_gej_set_ge(&gj, &secp256k1_ge_const_g);
@ -34,77 +38,93 @@ static void secp256k1_ecmult_gen_context_build(secp256k1_ecmult_gen_context_t *c
/* Construct a group element with no known corresponding scalar (nothing up my sleeve). */
{
static const unsigned char nums_b32[33] = "The scalar for this x is unknown";
secp256k1_fe_t nums_x;
secp256k1_ge_t nums_ge;
VERIFY_CHECK(secp256k1_fe_set_b32(&nums_x, nums_b32));
VERIFY_CHECK(secp256k1_ge_set_xo_var(&nums_ge, &nums_x, 0));
secp256k1_fe nums_x;
secp256k1_ge nums_ge;
int r;
r = secp256k1_fe_set_b32(&nums_x, nums_b32);
(void)r;
VERIFY_CHECK(r);
r = secp256k1_ge_set_xo_var(&nums_ge, &nums_x, 0);
(void)r;
VERIFY_CHECK(r);
secp256k1_gej_set_ge(&nums_gej, &nums_ge);
/* Add G to make the bits in x uniformly distributed. */
secp256k1_gej_add_ge_var(&nums_gej, &nums_gej, &secp256k1_ge_const_g);
secp256k1_gej_add_ge_var(&nums_gej, &nums_gej, &secp256k1_ge_const_g, NULL);
}
/* compute prec. */
{
secp256k1_gej_t precj[1024]; /* Jacobian versions of prec. */
secp256k1_gej_t gbase;
secp256k1_gej_t numsbase;
secp256k1_gej precj[1024]; /* Jacobian versions of prec. */
secp256k1_gej gbase;
secp256k1_gej numsbase;
gbase = gj; /* 16^j * G */
numsbase = nums_gej; /* 2^j * nums. */
for (j = 0; j < 64; j++) {
/* Set precj[j*16 .. j*16+15] to (numsbase, numsbase + gbase, ..., numsbase + 15*gbase). */
precj[j*16] = numsbase;
for (i = 1; i < 16; i++) {
secp256k1_gej_add_var(&precj[j*16 + i], &precj[j*16 + i - 1], &gbase);
secp256k1_gej_add_var(&precj[j*16 + i], &precj[j*16 + i - 1], &gbase, NULL);
}
/* Multiply gbase by 16. */
for (i = 0; i < 4; i++) {
secp256k1_gej_double_var(&gbase, &gbase);
secp256k1_gej_double_var(&gbase, &gbase, NULL);
}
/* Multiply numbase by 2. */
secp256k1_gej_double_var(&numsbase, &numsbase);
secp256k1_gej_double_var(&numsbase, &numsbase, NULL);
if (j == 62) {
/* In the last iteration, numsbase is (1 - 2^j) * nums instead. */
secp256k1_gej_neg(&numsbase, &numsbase);
secp256k1_gej_add_var(&numsbase, &numsbase, &nums_gej);
secp256k1_gej_add_var(&numsbase, &numsbase, &nums_gej, NULL);
}
}
secp256k1_ge_set_all_gej_var(1024, prec, precj);
secp256k1_ge_set_all_gej_var(1024, prec, precj, cb);
}
for (j = 0; j < 64; j++) {
for (i = 0; i < 16; i++) {
secp256k1_ge_to_storage(&(*ctx->prec)[j][i], &prec[j*16 + i]);
}
}
#else
(void)cb;
ctx->prec = (secp256k1_ge_storage (*)[64][16])secp256k1_ecmult_static_context;
#endif
secp256k1_ecmult_gen_blind(ctx, NULL);
}
static int secp256k1_ecmult_gen_context_is_built(const secp256k1_ecmult_gen_context_t* ctx) {
static int secp256k1_ecmult_gen_context_is_built(const secp256k1_ecmult_gen_context* ctx) {
return ctx->prec != NULL;
}
static void secp256k1_ecmult_gen_context_clone(secp256k1_ecmult_gen_context_t *dst,
const secp256k1_ecmult_gen_context_t *src) {
static void secp256k1_ecmult_gen_context_clone(secp256k1_ecmult_gen_context *dst,
const secp256k1_ecmult_gen_context *src, const secp256k1_callback* cb) {
if (src->prec == NULL) {
dst->prec = NULL;
} else {
dst->prec = (secp256k1_ge_storage_t (*)[64][16])checked_malloc(sizeof(*dst->prec));
#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
dst->prec = (secp256k1_ge_storage (*)[64][16])checked_malloc(cb, sizeof(*dst->prec));
memcpy(dst->prec, src->prec, sizeof(*dst->prec));
#else
(void)cb;
dst->prec = src->prec;
#endif
dst->initial = src->initial;
dst->blind = src->blind;
}
}
static void secp256k1_ecmult_gen_context_clear(secp256k1_ecmult_gen_context_t *ctx) {
static void secp256k1_ecmult_gen_context_clear(secp256k1_ecmult_gen_context *ctx) {
#ifndef USE_ECMULT_STATIC_PRECOMPUTATION
free(ctx->prec);
#endif
secp256k1_scalar_clear(&ctx->blind);
secp256k1_gej_clear(&ctx->initial);
ctx->prec = NULL;
}
static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context_t *ctx, secp256k1_gej_t *r, const secp256k1_scalar_t *gn) {
secp256k1_ge_t add;
secp256k1_ge_storage_t adds;
secp256k1_scalar_t gnb;
static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context *ctx, secp256k1_gej *r, const secp256k1_scalar *gn) {
secp256k1_ge add;
secp256k1_ge_storage adds;
secp256k1_scalar gnb;
int bits;
int i, j;
memset(&adds, 0, sizeof(adds));
@ -136,14 +156,15 @@ static void secp256k1_ecmult_gen(const secp256k1_ecmult_gen_context_t *ctx, secp
}
/* Setup blinding values for secp256k1_ecmult_gen. */
static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context_t *ctx, const unsigned char *seed32) {
secp256k1_scalar_t b;
secp256k1_gej_t gb;
secp256k1_fe_t s;
static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context *ctx, const unsigned char *seed32) {
secp256k1_scalar b;
secp256k1_gej gb;
secp256k1_fe s;
unsigned char nonce32[32];
secp256k1_rfc6979_hmac_sha256_t rng;
int retry;
if (!seed32) {
unsigned char keydata[64] = {0};
if (seed32 == NULL) {
/* When seed is NULL, reset the initial point and blinding value. */
secp256k1_gej_set_ge(&ctx->initial, &secp256k1_ge_const_g);
secp256k1_gej_neg(&ctx->initial, &ctx->initial);
@ -155,13 +176,18 @@ static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context_t *ctx, cons
* and guards against weak or adversarial seeds. This is a simpler and safer interface than
* asking the caller for blinding values directly and expecting them to retry on failure.
*/
secp256k1_rfc6979_hmac_sha256_initialize(&rng, seed32 ? seed32 : nonce32, 32, nonce32, 32, NULL, 0);
memcpy(keydata, nonce32, 32);
if (seed32 != NULL) {
memcpy(keydata + 32, seed32, 32);
}
secp256k1_rfc6979_hmac_sha256_initialize(&rng, keydata, seed32 ? 64 : 32);
memset(keydata, 0, sizeof(keydata));
/* Retry for out of range results to achieve uniformity. */
do {
secp256k1_rfc6979_hmac_sha256_generate(&rng, nonce32, 32);
retry = !secp256k1_fe_set_b32(&s, nonce32);
retry |= secp256k1_fe_is_zero(&s);
} while (retry);
} while (retry); /* This branch true is cryptographically unreachable. Requires sha256_hmac output > Fp. */
/* Randomize the projection to defend against multiplier sidechannels. */
secp256k1_gej_rescale(&ctx->initial, &s);
secp256k1_fe_clear(&s);
@ -170,7 +196,7 @@ static void secp256k1_ecmult_gen_blind(secp256k1_ecmult_gen_context_t *ctx, cons
secp256k1_scalar_set_b32(&b, nonce32, &retry);
/* A blinding value of 0 works, but would undermine the projection hardening. */
retry |= secp256k1_scalar_is_zero(&b);
} while (retry);
} while (retry); /* This branch true is cryptographically unreachable. Requires sha256_hmac output > order. */
secp256k1_rfc6979_hmac_sha256_finalize(&rng);
memset(nonce32, 0, 32);
secp256k1_ecmult_gen(ctx, &gb, &b);

284
src/ecmult_impl.h
View file

@ -24,62 +24,107 @@
#define WINDOW_G 16
#endif
/** Fill a table 'pre' with precomputed odd multiples of a. W determines the size of the table.
* pre will contains the values [1*a,3*a,5*a,...,(2^(w-1)-1)*a], so it needs place for
* 2^(w-2) entries.
*
* There are two versions of this function:
* - secp256k1_ecmult_precomp_wnaf_gej, which operates on group elements in jacobian notation,
* fast to precompute, but slower to use in later additions.
* - secp256k1_ecmult_precomp_wnaf_ge, which operates on group elements in affine notations,
* (much) slower to precompute, but a bit faster to use in later additions.
* To compute a*P + b*G, we use the jacobian version for P, and the affine version for G, as
* G is constant, so it only needs to be done once in advance.
*/
static void secp256k1_ecmult_table_precomp_gej_var(secp256k1_gej_t *pre, const secp256k1_gej_t *a, int w) {
secp256k1_gej_t d;
int i;
pre[0] = *a;
secp256k1_gej_double_var(&d, &pre[0]);
for (i = 1; i < (1 << (w-2)); i++) {
secp256k1_gej_add_var(&pre[i], &d, &pre[i-1]);
}
}
static void secp256k1_ecmult_table_precomp_ge_storage_var(secp256k1_ge_storage_t *pre, const secp256k1_gej_t *a, int w) {
secp256k1_gej_t d;
int i;
const int table_size = 1 << (w-2);
secp256k1_gej_t *prej = (secp256k1_gej_t *)checked_malloc(sizeof(secp256k1_gej_t) * table_size);
secp256k1_ge_t *prea = (secp256k1_ge_t *)checked_malloc(sizeof(secp256k1_ge_t) * table_size);
prej[0] = *a;
secp256k1_gej_double_var(&d, a);
for (i = 1; i < table_size; i++) {
secp256k1_gej_add_var(&prej[i], &d, &prej[i-1]);
}
secp256k1_ge_set_all_gej_var(table_size, prea, prej);
for (i = 0; i < table_size; i++) {
secp256k1_ge_to_storage(&pre[i], &prea[i]);
}
free(prej);
free(prea);
}
/** The number of entries a table with precomputed multiples needs to have. */
#define ECMULT_TABLE_SIZE(w) (1 << ((w)-2))
/** Fill a table 'prej' with precomputed odd multiples of a. Prej will contain
* the values [1*a,3*a,...,(2*n-1)*a], so it space for n values. zr[0] will
* contain prej[0].z / a.z. The other zr[i] values = prej[i].z / prej[i-1].z.
* Prej's Z values are undefined, except for the last value.
*/
static void secp256k1_ecmult_odd_multiples_table(int n, secp256k1_gej *prej, secp256k1_fe *zr, const secp256k1_gej *a) {
secp256k1_gej d;
secp256k1_ge a_ge, d_ge;
int i;
VERIFY_CHECK(!a->infinity);
secp256k1_gej_double_var(&d, a, NULL);
/*
* Perform the additions on an isomorphism where 'd' is affine: drop the z coordinate
* of 'd', and scale the 1P starting value's x/y coordinates without changing its z.
*/
d_ge.x = d.x;
d_ge.y = d.y;
d_ge.infinity = 0;
secp256k1_ge_set_gej_zinv(&a_ge, a, &d.z);
prej[0].x = a_ge.x;
prej[0].y = a_ge.y;
prej[0].z = a->z;
prej[0].infinity = 0;
zr[0] = d.z;
for (i = 1; i < n; i++) {
secp256k1_gej_add_ge_var(&prej[i], &prej[i-1], &d_ge, &zr[i]);
}
/*
* Each point in 'prej' has a z coordinate too small by a factor of 'd.z'. Only
* the final point's z coordinate is actually used though, so just update that.
*/
secp256k1_fe_mul(&prej[n-1].z, &prej[n-1].z, &d.z);
}
/** Fill a table 'pre' with precomputed odd multiples of a.
*
* There are two versions of this function:
* - secp256k1_ecmult_odd_multiples_table_globalz_windowa which brings its
* resulting point set to a single constant Z denominator, stores the X and Y
* coordinates as ge_storage points in pre, and stores the global Z in rz.
* It only operates on tables sized for WINDOW_A wnaf multiples.
* - secp256k1_ecmult_odd_multiples_table_storage_var, which converts its
* resulting point set to actually affine points, and stores those in pre.
* It operates on tables of any size, but uses heap-allocated temporaries.
*
* To compute a*P + b*G, we compute a table for P using the first function,
* and for G using the second (which requires an inverse, but it only needs to
* happen once).
*/
static void secp256k1_ecmult_odd_multiples_table_globalz_windowa(secp256k1_ge *pre, secp256k1_fe *globalz, const secp256k1_gej *a) {
secp256k1_gej prej[ECMULT_TABLE_SIZE(WINDOW_A)];
secp256k1_fe zr[ECMULT_TABLE_SIZE(WINDOW_A)];
/* Compute the odd multiples in Jacobian form. */
secp256k1_ecmult_odd_multiples_table(ECMULT_TABLE_SIZE(WINDOW_A), prej, zr, a);
/* Bring them to the same Z denominator. */
secp256k1_ge_globalz_set_table_gej(ECMULT_TABLE_SIZE(WINDOW_A), pre, globalz, prej, zr);
}
static void secp256k1_ecmult_odd_multiples_table_storage_var(int n, secp256k1_ge_storage *pre, const secp256k1_gej *a, const secp256k1_callback *cb) {
secp256k1_gej *prej = (secp256k1_gej*)checked_malloc(cb, sizeof(secp256k1_gej) * n);
secp256k1_ge *prea = (secp256k1_ge*)checked_malloc(cb, sizeof(secp256k1_ge) * n);
secp256k1_fe *zr = (secp256k1_fe*)checked_malloc(cb, sizeof(secp256k1_fe) * n);
int i;
/* Compute the odd multiples in Jacobian form. */
secp256k1_ecmult_odd_multiples_table(n, prej, zr, a);
/* Convert them in batch to affine coordinates. */
secp256k1_ge_set_table_gej_var(n, prea, prej, zr);
/* Convert them to compact storage form. */
for (i = 0; i < n; i++) {
secp256k1_ge_to_storage(&pre[i], &prea[i]);
}
free(prea);
free(prej);
free(zr);
}
/** The following two macro retrieves a particular odd multiple from a table
* of precomputed multiples. */
#define ECMULT_TABLE_GET_GEJ(r,pre,n,w) do { \
#define ECMULT_TABLE_GET_GE(r,pre,n,w) do { \
VERIFY_CHECK(((n) & 1) == 1); \
VERIFY_CHECK((n) >= -((1 << ((w)-1)) - 1)); \
VERIFY_CHECK((n) <= ((1 << ((w)-1)) - 1)); \
if ((n) > 0) { \
*(r) = (pre)[((n)-1)/2]; \
} else { \
secp256k1_gej_neg((r), &(pre)[(-(n)-1)/2]); \
secp256k1_ge_neg((r), &(pre)[(-(n)-1)/2]); \
} \
} while(0)
#define ECMULT_TABLE_GET_GE_STORAGE(r,pre,n,w) do { \
VERIFY_CHECK(((n) & 1) == 1); \
VERIFY_CHECK((n) >= -((1 << ((w)-1)) - 1)); \
@ -92,15 +137,15 @@ static void secp256k1_ecmult_table_precomp_ge_storage_var(secp256k1_ge_storage_t
} \
} while(0)
static void secp256k1_ecmult_context_init(secp256k1_ecmult_context_t *ctx) {
static void secp256k1_ecmult_context_init(secp256k1_ecmult_context *ctx) {
ctx->pre_g = NULL;
#ifdef USE_ENDOMORPHISM
ctx->pre_g_128 = NULL;
#endif
}
static void secp256k1_ecmult_context_build(secp256k1_ecmult_context_t *ctx) {
secp256k1_gej_t gj;
static void secp256k1_ecmult_context_build(secp256k1_ecmult_context *ctx, const secp256k1_callback *cb) {
secp256k1_gej gj;
if (ctx->pre_g != NULL) {
return;
@ -109,35 +154,35 @@ static void secp256k1_ecmult_context_build(secp256k1_ecmult_context_t *ctx) {
/* get the generator */
secp256k1_gej_set_ge(&gj, &secp256k1_ge_const_g);
ctx->pre_g = (secp256k1_ge_storage_t (*)[])checked_malloc(sizeof((*ctx->pre_g)[0]) * ECMULT_TABLE_SIZE(WINDOW_G));
ctx->pre_g = (secp256k1_ge_storage (*)[])checked_malloc(cb, sizeof((*ctx->pre_g)[0]) * ECMULT_TABLE_SIZE(WINDOW_G));
/* precompute the tables with odd multiples */
secp256k1_ecmult_table_precomp_ge_storage_var(*ctx->pre_g, &gj, WINDOW_G);
secp256k1_ecmult_odd_multiples_table_storage_var(ECMULT_TABLE_SIZE(WINDOW_G), *ctx->pre_g, &gj, cb);
#ifdef USE_ENDOMORPHISM
{
secp256k1_gej_t g_128j;
secp256k1_gej g_128j;
int i;
ctx->pre_g_128 = (secp256k1_ge_storage_t (*)[])checked_malloc(sizeof((*ctx->pre_g_128)[0]) * ECMULT_TABLE_SIZE(WINDOW_G));
ctx->pre_g_128 = (secp256k1_ge_storage (*)[])checked_malloc(cb, sizeof((*ctx->pre_g_128)[0]) * ECMULT_TABLE_SIZE(WINDOW_G));
/* calculate 2^128*generator */
g_128j = gj;
for (i = 0; i < 128; i++) {
secp256k1_gej_double_var(&g_128j, &g_128j);
secp256k1_gej_double_var(&g_128j, &g_128j, NULL);
}
secp256k1_ecmult_table_precomp_ge_storage_var(*ctx->pre_g_128, &g_128j, WINDOW_G);
secp256k1_ecmult_odd_multiples_table_storage_var(ECMULT_TABLE_SIZE(WINDOW_G), *ctx->pre_g_128, &g_128j, cb);
}
#endif
}
static void secp256k1_ecmult_context_clone(secp256k1_ecmult_context_t *dst,
const secp256k1_ecmult_context_t *src) {
static void secp256k1_ecmult_context_clone(secp256k1_ecmult_context *dst,
const secp256k1_ecmult_context *src, const secp256k1_callback *cb) {
if (src->pre_g == NULL) {
dst->pre_g = NULL;
} else {
size_t size = sizeof((*dst->pre_g)[0]) * ECMULT_TABLE_SIZE(WINDOW_G);
dst->pre_g = (secp256k1_ge_storage_t (*)[])checked_malloc(size);
dst->pre_g = (secp256k1_ge_storage (*)[])checked_malloc(cb, size);
memcpy(dst->pre_g, src->pre_g, size);
}
#ifdef USE_ENDOMORPHISM
@ -145,17 +190,17 @@ static void secp256k1_ecmult_context_clone(secp256k1_ecmult_context_t *dst,
dst->pre_g_128 = NULL;
} else {
size_t size = sizeof((*dst->pre_g_128)[0]) * ECMULT_TABLE_SIZE(WINDOW_G);
dst->pre_g_128 = (secp256k1_ge_storage_t (*)[])checked_malloc(size);
dst->pre_g_128 = (secp256k1_ge_storage (*)[])checked_malloc(cb, size);
memcpy(dst->pre_g_128, src->pre_g_128, size);
}
#endif
}
static int secp256k1_ecmult_context_is_built(const secp256k1_ecmult_context_t *ctx) {
static int secp256k1_ecmult_context_is_built(const secp256k1_ecmult_context *ctx) {
return ctx->pre_g != NULL;
}
static void secp256k1_ecmult_context_clear(secp256k1_ecmult_context_t *ctx) {
static void secp256k1_ecmult_context_clear(secp256k1_ecmult_context *ctx) {
free(ctx->pre_g);
#ifdef USE_ENDOMORPHISM
free(ctx->pre_g_128);
@ -168,54 +213,68 @@ static void secp256k1_ecmult_context_clear(secp256k1_ecmult_context_t *ctx) {
* - each wnaf[i] is either 0, or an odd integer between -(1<<(w-1) - 1) and (1<<(w-1) - 1)
* - two non-zero entries in wnaf are separated by at least w-1 zeroes.
* - the number of set values in wnaf is returned. This number is at most 256, and at most one more
* - than the number of bits in the (absolute value) of the input.
* than the number of bits in the (absolute value) of the input.
*/
static int secp256k1_ecmult_wnaf(int *wnaf, const secp256k1_scalar_t *a, int w) {
secp256k1_scalar_t s = *a;
int set_bits = 0;
static int secp256k1_ecmult_wnaf(int *wnaf, int len, const secp256k1_scalar *a, int w) {
secp256k1_scalar s = *a;
int last_set_bit = -1;
int bit = 0;
int sign = 1;
int carry = 0;
VERIFY_CHECK(wnaf != NULL);
VERIFY_CHECK(0 <= len && len <= 256);
VERIFY_CHECK(a != NULL);
VERIFY_CHECK(2 <= w && w <= 31);
memset(wnaf, 0, len * sizeof(wnaf[0]));
if (secp256k1_scalar_get_bits(&s, 255, 1)) {
secp256k1_scalar_negate(&s, &s);
sign = -1;
}
while (bit < 256) {
while (bit < len) {
int now;
int word;
if (secp256k1_scalar_get_bits(&s, bit, 1) == 0) {
if (secp256k1_scalar_get_bits(&s, bit, 1) == (unsigned int)carry) {
bit++;
continue;
}
while (set_bits < bit) {
wnaf[set_bits++] = 0;
}
now = w;
if (bit + now > 256) {
now = 256 - bit;
}
word = secp256k1_scalar_get_bits_var(&s, bit, now);
if (word & (1 << (w-1))) {
secp256k1_scalar_add_bit(&s, bit + w);
wnaf[set_bits++] = sign * (word - (1 << w));
} else {
wnaf[set_bits++] = sign * word;
if (now > len - bit) {
now = len - bit;
}
word = secp256k1_scalar_get_bits_var(&s, bit, now) + carry;
carry = (word >> (w-1)) & 1;
word -= carry << w;
wnaf[bit] = sign * word;
last_set_bit = bit;
bit += now;
}
return set_bits;
#ifdef VERIFY
CHECK(carry == 0);
while (bit < 256) {
CHECK(secp256k1_scalar_get_bits(&s, bit++, 1) == 0);
}
#endif
return last_set_bit + 1;
}
static void secp256k1_ecmult(const secp256k1_ecmult_context_t *ctx, secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_scalar_t *na, const secp256k1_scalar_t *ng) {
secp256k1_gej_t tmpj;
secp256k1_gej_t pre_a[ECMULT_TABLE_SIZE(WINDOW_A)];
secp256k1_ge_t tmpa;
static void secp256k1_ecmult(const secp256k1_ecmult_context *ctx, secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_scalar *na, const secp256k1_scalar *ng) {
secp256k1_ge pre_a[ECMULT_TABLE_SIZE(WINDOW_A)];
secp256k1_ge tmpa;
secp256k1_fe Z;
#ifdef USE_ENDOMORPHISM
secp256k1_gej_t pre_a_lam[ECMULT_TABLE_SIZE(WINDOW_A)];
secp256k1_scalar_t na_1, na_lam;
secp256k1_ge pre_a_lam[ECMULT_TABLE_SIZE(WINDOW_A)];
secp256k1_scalar na_1, na_lam;
/* Splitted G factors. */
secp256k1_scalar_t ng_1, ng_128;
secp256k1_scalar ng_1, ng_128;
int wnaf_na_1[130];
int wnaf_na_lam[130];
int bits_na_1;
@ -227,7 +286,7 @@ static void secp256k1_ecmult(const secp256k1_ecmult_context_t *ctx, secp256k1_ge
#else
int wnaf_na[256];
int bits_na;
int wnaf_ng[257];
int wnaf_ng[256];
int bits_ng;
#endif
int i;
@ -235,11 +294,11 @@ static void secp256k1_ecmult(const secp256k1_ecmult_context_t *ctx, secp256k1_ge
#ifdef USE_ENDOMORPHISM
/* split na into na_1 and na_lam (where na = na_1 + na_lam*lambda, and na_1 and na_lam are ~128 bit) */
secp256k1_scalar_split_lambda_var(&na_1, &na_lam, na);
secp256k1_scalar_split_lambda(&na_1, &na_lam, na);
/* build wnaf representation for na_1 and na_lam. */
bits_na_1 = secp256k1_ecmult_wnaf(wnaf_na_1, &na_1, WINDOW_A);
bits_na_lam = secp256k1_ecmult_wnaf(wnaf_na_lam, &na_lam, WINDOW_A);
bits_na_1 = secp256k1_ecmult_wnaf(wnaf_na_1, 130, &na_1, WINDOW_A);
bits_na_lam = secp256k1_ecmult_wnaf(wnaf_na_lam, 130, &na_lam, WINDOW_A);
VERIFY_CHECK(bits_na_1 <= 130);
VERIFY_CHECK(bits_na_lam <= 130);
bits = bits_na_1;
@ -248,24 +307,33 @@ static void secp256k1_ecmult(const secp256k1_ecmult_context_t *ctx, secp256k1_ge
}
#else
/* build wnaf representation for na. */
bits_na = secp256k1_ecmult_wnaf(wnaf_na, na, WINDOW_A);
bits_na = secp256k1_ecmult_wnaf(wnaf_na, 256, na, WINDOW_A);
bits = bits_na;
#endif
/* calculate odd multiples of a */
secp256k1_ecmult_table_precomp_gej_var(pre_a, a, WINDOW_A);
/* Calculate odd multiples of a.
* All multiples are brought to the same Z 'denominator', which is stored
* in Z. Due to secp256k1' isomorphism we can do all operations pretending
* that the Z coordinate was 1, use affine addition formulae, and correct
* the Z coordinate of the result once at the end.
* The exception is the precomputed G table points, which are actually
* affine. Compared to the base used for other points, they have a Z ratio
* of 1/Z, so we can use secp256k1_gej_add_zinv_var, which uses the same
* isomorphism to efficiently add with a known Z inverse.
*/
secp256k1_ecmult_odd_multiples_table_globalz_windowa(pre_a, &Z, a);
#ifdef USE_ENDOMORPHISM
for (i = 0; i < ECMULT_TABLE_SIZE(WINDOW_A); i++) {
secp256k1_gej_mul_lambda(&pre_a_lam[i], &pre_a[i]);
secp256k1_ge_mul_lambda(&pre_a_lam[i], &pre_a[i]);
}
/* split ng into ng_1 and ng_128 (where gn = gn_1 + gn_128*2^128, and gn_1 and gn_128 are ~128 bit) */
secp256k1_scalar_split_128(&ng_1, &ng_128, ng);
/* Build wnaf representation for ng_1 and ng_128 */
bits_ng_1 = secp256k1_ecmult_wnaf(wnaf_ng_1, &ng_1, WINDOW_G);
bits_ng_128 = secp256k1_ecmult_wnaf(wnaf_ng_128, &ng_128, WINDOW_G);
bits_ng_1 = secp256k1_ecmult_wnaf(wnaf_ng_1, 129, &ng_1, WINDOW_G);
bits_ng_128 = secp256k1_ecmult_wnaf(wnaf_ng_128, 129, &ng_128, WINDOW_G);
if (bits_ng_1 > bits) {
bits = bits_ng_1;
}
@ -273,7 +341,7 @@ static void secp256k1_ecmult(const secp256k1_ecmult_context_t *ctx, secp256k1_ge
bits = bits_ng_128;
}
#else
bits_ng = secp256k1_ecmult_wnaf(wnaf_ng, ng, WINDOW_G);
bits_ng = secp256k1_ecmult_wnaf(wnaf_ng, 256, ng, WINDOW_G);
if (bits_ng > bits) {
bits = bits_ng;
}
@ -281,37 +349,41 @@ static void secp256k1_ecmult(const secp256k1_ecmult_context_t *ctx, secp256k1_ge
secp256k1_gej_set_infinity(r);
for (i = bits-1; i >= 0; i--) {
for (i = bits - 1; i >= 0; i--) {
int n;
secp256k1_gej_double_var(r, r);
secp256k1_gej_double_var(r, r, NULL);
#ifdef USE_ENDOMORPHISM
if (i < bits_na_1 && (n = wnaf_na_1[i])) {
ECMULT_TABLE_GET_GEJ(&tmpj, pre_a, n, WINDOW_A);
secp256k1_gej_add_var(r, r, &tmpj);
ECMULT_TABLE_GET_GE(&tmpa, pre_a, n, WINDOW_A);
secp256k1_gej_add_ge_var(r, r, &tmpa, NULL);
}
if (i < bits_na_lam && (n = wnaf_na_lam[i])) {
ECMULT_TABLE_GET_GEJ(&tmpj, pre_a_lam, n, WINDOW_A);
secp256k1_gej_add_var(r, r, &tmpj);
ECMULT_TABLE_GET_GE(&tmpa, pre_a_lam, n, WINDOW_A);
secp256k1_gej_add_ge_var(r, r, &tmpa, NULL);
}
if (i < bits_ng_1 && (n = wnaf_ng_1[i])) {
ECMULT_TABLE_GET_GE_STORAGE(&tmpa, *ctx->pre_g, n, WINDOW_G);
secp256k1_gej_add_ge_var(r, r, &tmpa);
secp256k1_gej_add_zinv_var(r, r, &tmpa, &Z);
}
if (i < bits_ng_128 && (n = wnaf_ng_128[i])) {
ECMULT_TABLE_GET_GE_STORAGE(&tmpa, *ctx->pre_g_128, n, WINDOW_G);
secp256k1_gej_add_ge_var(r, r, &tmpa);
secp256k1_gej_add_zinv_var(r, r, &tmpa, &Z);
}
#else
if (i < bits_na && (n = wnaf_na[i])) {
ECMULT_TABLE_GET_GEJ(&tmpj, pre_a, n, WINDOW_A);
secp256k1_gej_add_var(r, r, &tmpj);
ECMULT_TABLE_GET_GE(&tmpa, pre_a, n, WINDOW_A);
secp256k1_gej_add_ge_var(r, r, &tmpa, NULL);
}
if (i < bits_ng && (n = wnaf_ng[i])) {
ECMULT_TABLE_GET_GE_STORAGE(&tmpa, *ctx->pre_g, n, WINDOW_G);
secp256k1_gej_add_ge_var(r, r, &tmpa);
secp256k1_gej_add_zinv_var(r, r, &tmpa, &Z);
}
#endif
}
if (!r->infinity) {
secp256k1_fe_mul(&r->z, &r->z, &Z);
}
}
#endif

62
src/field.h
View file

@ -10,7 +10,7 @@
/** Field element module.
*
* Field elements can be represented in several ways, but code accessing
* it (and implementations) need to take certain properaties into account:
* it (and implementations) need to take certain properties into account:
* - Each field element can be normalized or not.
* - Each field element has a magnitude, which represents how far away
* its representation is away from normalization. Normalized elements
@ -31,89 +31,91 @@
#endif
/** Normalize a field element. */
static void secp256k1_fe_normalize(secp256k1_fe_t *r);
static void secp256k1_fe_normalize(secp256k1_fe *r);
/** Weakly normalize a field element: reduce it magnitude to 1, but don't fully normalize. */
static void secp256k1_fe_normalize_weak(secp256k1_fe_t *r);
static void secp256k1_fe_normalize_weak(secp256k1_fe *r);
/** Normalize a field element, without constant-time guarantee. */
static void secp256k1_fe_normalize_var(secp256k1_fe_t *r);
static void secp256k1_fe_normalize_var(secp256k1_fe *r);
/** Verify whether a field element represents zero i.e. would normalize to a zero value. The field
* implementation may optionally normalize the input, but this should not be relied upon. */
static int secp256k1_fe_normalizes_to_zero(secp256k1_fe_t *r);
static int secp256k1_fe_normalizes_to_zero(secp256k1_fe *r);
/** Verify whether a field element represents zero i.e. would normalize to a zero value. The field
* implementation may optionally normalize the input, but this should not be relied upon. */
static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe_t *r);
static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe *r);
/** Set a field element equal to a small integer. Resulting field element is normalized. */
static void secp256k1_fe_set_int(secp256k1_fe_t *r, int a);
static void secp256k1_fe_set_int(secp256k1_fe *r, int a);
/** Verify whether a field element is zero. Requires the input to be normalized. */
static int secp256k1_fe_is_zero(const secp256k1_fe_t *a);
static int secp256k1_fe_is_zero(const secp256k1_fe *a);
/** Check the "oddness" of a field element. Requires the input to be normalized. */
static int secp256k1_fe_is_odd(const secp256k1_fe_t *a);
static int secp256k1_fe_is_odd(const secp256k1_fe *a);
/** Compare two field elements. Requires magnitude-1 inputs. */
static int secp256k1_fe_equal_var(const secp256k1_fe_t *a, const secp256k1_fe_t *b);
static int secp256k1_fe_equal_var(const secp256k1_fe *a, const secp256k1_fe *b);
/** Compare two field elements. Requires both inputs to be normalized */
static int secp256k1_fe_cmp_var(const secp256k1_fe_t *a, const secp256k1_fe_t *b);
static int secp256k1_fe_cmp_var(const secp256k1_fe *a, const secp256k1_fe *b);
/** Set a field element equal to 32-byte big endian value. If succesful, the resulting field element is normalized. */
static int secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a);
/** Set a field element equal to 32-byte big endian value. If successful, the resulting field element is normalized. */
static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a);
/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a);
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe *a);
/** Set a field element equal to the additive inverse of another. Takes a maximum magnitude of the input
* as an argument. The magnitude of the output is one higher. */
static void secp256k1_fe_negate(secp256k1_fe_t *r, const secp256k1_fe_t *a, int m);
static void secp256k1_fe_negate(secp256k1_fe *r, const secp256k1_fe *a, int m);
/** Multiplies the passed field element with a small integer constant. Multiplies the magnitude by that
* small integer. */
static void secp256k1_fe_mul_int(secp256k1_fe_t *r, int a);
static void secp256k1_fe_mul_int(secp256k1_fe *r, int a);
/** Adds a field element to another. The result has the sum of the inputs' magnitudes as magnitude. */
static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a);
static void secp256k1_fe_add(secp256k1_fe *r, const secp256k1_fe *a);
/** Sets a field element to be the product of two others. Requires the inputs' magnitudes to be at most 8.
* The output magnitude is 1 (but not guaranteed to be normalized). */
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t * SECP256K1_RESTRICT b);
static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b);
/** Sets a field element to be the square of another. Requires the input's magnitude to be at most 8.
* The output magnitude is 1 (but not guaranteed to be normalized). */
static void secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a);
static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a);
/** Sets a field element to be the (modular) square root (if any exist) of another. Requires the
* input's magnitude to be at most 8. The output magnitude is 1 (but not guaranteed to be
* normalized). Return value indicates whether a square root was found. */
static int secp256k1_fe_sqrt_var(secp256k1_fe_t *r, const secp256k1_fe_t *a);
/** If a has a square root, it is computed in r and 1 is returned. If a does not
* have a square root, the root of its negation is computed and 0 is returned.
* The input's magnitude can be at most 8. The output magnitude is 1 (but not
* guaranteed to be normalized). The result in r will always be a square
* itself. */
static int secp256k1_fe_sqrt_var(secp256k1_fe *r, const secp256k1_fe *a);
/** Sets a field element to be the (modular) inverse of another. Requires the input's magnitude to be
* at most 8. The output magnitude is 1 (but not guaranteed to be normalized). */
static void secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a);
static void secp256k1_fe_inv(secp256k1_fe *r, const secp256k1_fe *a);
/** Potentially faster version of secp256k1_fe_inv, without constant-time guarantee. */
static void secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a);
static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *a);
/** Calculate the (modular) inverses of a batch of field elements. Requires the inputs' magnitudes to be
* at most 8. The output magnitudes are 1 (but not guaranteed to be normalized). The inputs and
* outputs must not overlap in memory. */
static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t *r, const secp256k1_fe_t *a);
static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe *r, const secp256k1_fe *a);
/** Convert a field element to the storage type. */
static void secp256k1_fe_to_storage(secp256k1_fe_storage_t *r, const secp256k1_fe_t*);
static void secp256k1_fe_to_storage(secp256k1_fe_storage *r, const secp256k1_fe *a);
/** Convert a field element back from the storage type. */
static void secp256k1_fe_from_storage(secp256k1_fe_t *r, const secp256k1_fe_storage_t*);
static void secp256k1_fe_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a);
/** If flag is true, set *r equal to *a; otherwise leave it. Constant-time. */
static void secp256k1_fe_storage_cmov(secp256k1_fe_storage_t *r, const secp256k1_fe_storage_t *a, int flag);
static void secp256k1_fe_storage_cmov(secp256k1_fe_storage *r, const secp256k1_fe_storage *a, int flag);
/** If flag is true, set *r equal to *a; otherwise leave it. Constant-time. */
static void secp256k1_fe_cmov(secp256k1_fe_t *r, const secp256k1_fe_t *a, int flag);
static void secp256k1_fe_cmov(secp256k1_fe *r, const secp256k1_fe *a, int flag);
#endif

24
src/field_10x26.h
View file

@ -16,20 +16,20 @@ typedef struct {
int magnitude;
int normalized;
#endif
} secp256k1_fe_t;
} secp256k1_fe;
/* Unpacks a constant into a overlapping multi-limbed FE element. */
#define SECP256K1_FE_CONST_INNER(d7, d6, d5, d4, d3, d2, d1, d0) { \
(d0) & 0x3FFFFFFUL, \
((d0) >> 26) | ((d1) & 0xFFFFFUL) << 6, \
((d1) >> 20) | ((d2) & 0x3FFFUL) << 12, \
((d2) >> 14) | ((d3) & 0xFFUL) << 18, \
((d3) >> 8) | ((d4) & 0x3) << 24, \
((d4) >> 2) & 0x3FFFFFFUL, \
((d4) >> 28) | ((d5) & 0x3FFFFFUL) << 4, \
((d5) >> 22) | ((d6) & 0xFFFF) << 10, \
((d6) >> 16) | ((d7) & 0x3FF) << 16, \
((d7) >> 10) \
(((uint32_t)d0) >> 26) | (((uint32_t)(d1) & 0xFFFFFUL) << 6), \
(((uint32_t)d1) >> 20) | (((uint32_t)(d2) & 0x3FFFUL) << 12), \
(((uint32_t)d2) >> 14) | (((uint32_t)(d3) & 0xFFUL) << 18), \
(((uint32_t)d3) >> 8) | (((uint32_t)(d4) & 0x3UL) << 24), \
(((uint32_t)d4) >> 2) & 0x3FFFFFFUL, \
(((uint32_t)d4) >> 28) | (((uint32_t)(d5) & 0x3FFFFFUL) << 4), \
(((uint32_t)d5) >> 22) | (((uint32_t)(d6) & 0xFFFFUL) << 10), \
(((uint32_t)d6) >> 16) | (((uint32_t)(d7) & 0x3FFUL) << 16), \
(((uint32_t)d7) >> 10) \
}
#ifdef VERIFY
@ -40,8 +40,8 @@ typedef struct {
typedef struct {
uint32_t n[8];
} secp256k1_fe_storage_t;
} secp256k1_fe_storage;
#define SECP256K1_FE_STORAGE_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {{ (d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7) }}
#define SECP256K1_FE_STORAGE_CONST_GET(d) d.n[7], d.n[6], d.n[5], d.n[4],d.n[3], d.n[2], d.n[1], d.n[0]
#endif

54
src/field_10x26_impl.h
View file

@ -14,7 +14,7 @@
#include "field.h"
#ifdef VERIFY
static void secp256k1_fe_verify(const secp256k1_fe_t *a) {
static void secp256k1_fe_verify(const secp256k1_fe *a) {
const uint32_t *d = a->n;
int m = a->normalized ? 1 : 2 * a->magnitude, r = 1;
r &= (d[0] <= 0x3FFFFFFUL * m);
@ -41,12 +41,12 @@ static void secp256k1_fe_verify(const secp256k1_fe_t *a) {
VERIFY_CHECK(r == 1);
}
#else
static void secp256k1_fe_verify(const secp256k1_fe_t *a) {
static void secp256k1_fe_verify(const secp256k1_fe *a) {
(void)a;
}
#endif
static void secp256k1_fe_normalize(secp256k1_fe_t *r) {
static void secp256k1_fe_normalize(secp256k1_fe *r) {
uint32_t t0 = r->n[0], t1 = r->n[1], t2 = r->n[2], t3 = r->n[3], t4 = r->n[4],
t5 = r->n[5], t6 = r->n[6], t7 = r->n[7], t8 = r->n[8], t9 = r->n[9];
@ -101,7 +101,7 @@ static void secp256k1_fe_normalize(secp256k1_fe_t *r) {
#endif
}
static void secp256k1_fe_normalize_weak(secp256k1_fe_t *r) {
static void secp256k1_fe_normalize_weak(secp256k1_fe *r) {
uint32_t t0 = r->n[0], t1 = r->n[1], t2 = r->n[2], t3 = r->n[3], t4 = r->n[4],
t5 = r->n[5], t6 = r->n[6], t7 = r->n[7], t8 = r->n[8], t9 = r->n[9];
@ -132,7 +132,7 @@ static void secp256k1_fe_normalize_weak(secp256k1_fe_t *r) {
#endif
}
static void secp256k1_fe_normalize_var(secp256k1_fe_t *r) {
static void secp256k1_fe_normalize_var(secp256k1_fe *r) {
uint32_t t0 = r->n[0], t1 = r->n[1], t2 = r->n[2], t3 = r->n[3], t4 = r->n[4],
t5 = r->n[5], t6 = r->n[6], t7 = r->n[7], t8 = r->n[8], t9 = r->n[9];
@ -188,7 +188,7 @@ static void secp256k1_fe_normalize_var(secp256k1_fe_t *r) {
#endif
}
static int secp256k1_fe_normalizes_to_zero(secp256k1_fe_t *r) {
static int secp256k1_fe_normalizes_to_zero(secp256k1_fe *r) {
uint32_t t0 = r->n[0], t1 = r->n[1], t2 = r->n[2], t3 = r->n[3], t4 = r->n[4],
t5 = r->n[5], t6 = r->n[6], t7 = r->n[7], t8 = r->n[8], t9 = r->n[9];
@ -217,7 +217,7 @@ static int secp256k1_fe_normalizes_to_zero(secp256k1_fe_t *r) {
return (z0 == 0) | (z1 == 0x3FFFFFFUL);
}
static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe_t *r) {
static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe *r) {
uint32_t t0, t1, t2, t3, t4, t5, t6, t7, t8, t9;
uint32_t z0, z1;
uint32_t x;
@ -252,7 +252,7 @@ static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe_t *r) {
t9 &= 0x03FFFFFUL;
t1 += (x << 6);
t1 += (t0 >> 26); t0 = z0;
t1 += (t0 >> 26);
t2 += (t1 >> 26); t1 &= 0x3FFFFFFUL; z0 |= t1; z1 &= t1 ^ 0x40UL;
t3 += (t2 >> 26); t2 &= 0x3FFFFFFUL; z0 |= t2; z1 &= t2;
t4 += (t3 >> 26); t3 &= 0x3FFFFFFUL; z0 |= t3; z1 &= t3;
@ -269,7 +269,7 @@ static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe_t *r) {
return (z0 == 0) | (z1 == 0x3FFFFFFUL);
}
SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe_t *r, int a) {
SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe *r, int a) {
r->n[0] = a;
r->n[1] = r->n[2] = r->n[3] = r->n[4] = r->n[5] = r->n[6] = r->n[7] = r->n[8] = r->n[9] = 0;
#ifdef VERIFY
@ -279,7 +279,7 @@ SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe_t *r, int a) {
#endif
}
SECP256K1_INLINE static int secp256k1_fe_is_zero(const secp256k1_fe_t *a) {
SECP256K1_INLINE static int secp256k1_fe_is_zero(const secp256k1_fe *a) {
const uint32_t *t = a->n;
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
@ -288,7 +288,7 @@ SECP256K1_INLINE static int secp256k1_fe_is_zero(const secp256k1_fe_t *a) {
return (t[0] | t[1] | t[2] | t[3] | t[4] | t[5] | t[6] | t[7] | t[8] | t[9]) == 0;
}
SECP256K1_INLINE static int secp256k1_fe_is_odd(const secp256k1_fe_t *a) {
SECP256K1_INLINE static int secp256k1_fe_is_odd(const secp256k1_fe *a) {
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
secp256k1_fe_verify(a);
@ -296,7 +296,7 @@ SECP256K1_INLINE static int secp256k1_fe_is_odd(const secp256k1_fe_t *a) {
return a->n[0] & 1;
}
SECP256K1_INLINE static void secp256k1_fe_clear(secp256k1_fe_t *a) {
SECP256K1_INLINE static void secp256k1_fe_clear(secp256k1_fe *a) {
int i;
#ifdef VERIFY
a->magnitude = 0;
@ -307,7 +307,7 @@ SECP256K1_INLINE static void secp256k1_fe_clear(secp256k1_fe_t *a) {
}
}
static int secp256k1_fe_cmp_var(const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
static int secp256k1_fe_cmp_var(const secp256k1_fe *a, const secp256k1_fe *b) {
int i;
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
@ -326,7 +326,7 @@ static int secp256k1_fe_cmp_var(const secp256k1_fe_t *a, const secp256k1_fe_t *b
return 0;
}
static int secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a) {
static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a) {
int i;
r->n[0] = r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
r->n[5] = r->n[6] = r->n[7] = r->n[8] = r->n[9] = 0;
@ -350,7 +350,7 @@ static int secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a) {
}
/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a) {
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe *a) {
int i;
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
@ -368,7 +368,7 @@ static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a) {
}
}
SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe_t *r, const secp256k1_fe_t *a, int m) {
SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe *r, const secp256k1_fe *a, int m) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= m);
secp256k1_fe_verify(a);
@ -390,7 +390,7 @@ SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe_t *r, const secp25
#endif
}
SECP256K1_INLINE static void secp256k1_fe_mul_int(secp256k1_fe_t *r, int a) {
SECP256K1_INLINE static void secp256k1_fe_mul_int(secp256k1_fe *r, int a) {
r->n[0] *= a;
r->n[1] *= a;
r->n[2] *= a;
@ -408,7 +408,7 @@ SECP256K1_INLINE static void secp256k1_fe_mul_int(secp256k1_fe_t *r, int a) {
#endif
}
SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe *r, const secp256k1_fe *a) {
#ifdef VERIFY
secp256k1_fe_verify(a);
#endif
@ -1039,7 +1039,7 @@ SECP256K1_INLINE static void secp256k1_fe_sqr_inner(uint32_t *r, const uint32_t
}
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t * SECP256K1_RESTRICT b) {
static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
VERIFY_CHECK(b->magnitude <= 8);
@ -1055,7 +1055,7 @@ static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const s
#endif
}
static void secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
secp256k1_fe_verify(a);
@ -1068,7 +1068,7 @@ static void secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
#endif
}
static SECP256K1_INLINE void secp256k1_fe_cmov(secp256k1_fe_t *r, const secp256k1_fe_t *a, int flag) {
static SECP256K1_INLINE void secp256k1_fe_cmov(secp256k1_fe *r, const secp256k1_fe *a, int flag) {
uint32_t mask0, mask1;
mask0 = flag + ~((uint32_t)0);
mask1 = ~mask0;
@ -1083,12 +1083,14 @@ static SECP256K1_INLINE void secp256k1_fe_cmov(secp256k1_fe_t *r, const secp256k
r->n[8] = (r->n[8] & mask0) | (a->n[8] & mask1);
r->n[9] = (r->n[9] & mask0) | (a->n[9] & mask1);
#ifdef VERIFY
r->magnitude = (r->magnitude & mask0) | (a->magnitude & mask1);
r->normalized = (r->normalized & mask0) | (a->normalized & mask1);
if (a->magnitude > r->magnitude) {
r->magnitude = a->magnitude;
}
r->normalized &= a->normalized;
#endif
}
static SECP256K1_INLINE void secp256k1_fe_storage_cmov(secp256k1_fe_storage_t *r, const secp256k1_fe_storage_t *a, int flag) {
static SECP256K1_INLINE void secp256k1_fe_storage_cmov(secp256k1_fe_storage *r, const secp256k1_fe_storage *a, int flag) {
uint32_t mask0, mask1;
mask0 = flag + ~((uint32_t)0);
mask1 = ~mask0;
@ -1102,7 +1104,7 @@ static SECP256K1_INLINE void secp256k1_fe_storage_cmov(secp256k1_fe_storage_t *r
r->n[7] = (r->n[7] & mask0) | (a->n[7] & mask1);
}
static void secp256k1_fe_to_storage(secp256k1_fe_storage_t *r, const secp256k1_fe_t *a) {
static void secp256k1_fe_to_storage(secp256k1_fe_storage *r, const secp256k1_fe *a) {
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
#endif
@ -1116,7 +1118,7 @@ static void secp256k1_fe_to_storage(secp256k1_fe_storage_t *r, const secp256k1_f
r->n[7] = a->n[8] >> 16 | a->n[9] << 10;
}
static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe_t *r, const secp256k1_fe_storage_t *a) {
static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a) {
r->n[0] = a->n[0] & 0x3FFFFFFUL;
r->n[1] = a->n[0] >> 26 | ((a->n[1] << 6) & 0x3FFFFFFUL);
r->n[2] = a->n[1] >> 20 | ((a->n[2] << 12) & 0x3FFFFFFUL);

22
src/field_5x52.h
View file

@ -16,15 +16,15 @@ typedef struct {
int magnitude;
int normalized;
#endif
} secp256k1_fe_t;
} secp256k1_fe;
/* Unpacks a constant into a overlapping multi-limbed FE element. */
#define SECP256K1_FE_CONST_INNER(d7, d6, d5, d4, d3, d2, d1, d0) { \
(d0) | ((uint64_t)(d1) & 0xFFFFFUL) << 32, \
((d1) >> 20) | ((uint64_t)(d2)) << 12 | ((uint64_t)(d3) & 0xFFUL) << 44, \
((d3) >> 8) | ((uint64_t)(d4) & 0xFFFFFFFUL) << 24, \
((d4) >> 28) | ((uint64_t)(d5)) << 4 | ((uint64_t)(d6) & 0xFFFFUL) << 36, \
((d6) >> 16) | ((uint64_t)(d7)) << 16 \
(d0) | (((uint64_t)(d1) & 0xFFFFFUL) << 32), \
((uint64_t)(d1) >> 20) | (((uint64_t)(d2)) << 12) | (((uint64_t)(d3) & 0xFFUL) << 44), \
((uint64_t)(d3) >> 8) | (((uint64_t)(d4) & 0xFFFFFFFUL) << 24), \
((uint64_t)(d4) >> 28) | (((uint64_t)(d5)) << 4) | (((uint64_t)(d6) & 0xFFFFUL) << 36), \
((uint64_t)(d6) >> 16) | (((uint64_t)(d7)) << 16) \
}
#ifdef VERIFY
@ -35,13 +35,13 @@ typedef struct {
typedef struct {
uint64_t n[4];
} secp256k1_fe_storage_t;
} secp256k1_fe_storage;
#define SECP256K1_FE_STORAGE_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {{ \
(d0) | ((uint64_t)(d1)) << 32, \
(d2) | ((uint64_t)(d3)) << 32, \
(d4) | ((uint64_t)(d5)) << 32, \
(d6) | ((uint64_t)(d7)) << 32 \
(d0) | (((uint64_t)(d1)) << 32), \
(d2) | (((uint64_t)(d3)) << 32), \
(d4) | (((uint64_t)(d5)) << 32), \
(d6) | (((uint64_t)(d7)) << 32) \
}}
#endif

54
src/field_5x52_impl.h
View file

@ -31,7 +31,7 @@
*/
#ifdef VERIFY
static void secp256k1_fe_verify(const secp256k1_fe_t *a) {
static void secp256k1_fe_verify(const secp256k1_fe *a) {
const uint64_t *d = a->n;
int m = a->normalized ? 1 : 2 * a->magnitude, r = 1;
/* secp256k1 'p' value defined in "Standards for Efficient Cryptography" (SEC2) 2.7.1. */
@ -51,12 +51,12 @@ static void secp256k1_fe_verify(const secp256k1_fe_t *a) {
VERIFY_CHECK(r == 1);
}
#else
static void secp256k1_fe_verify(const secp256k1_fe_t *a) {
static void secp256k1_fe_verify(const secp256k1_fe *a) {
(void)a;
}
#endif
static void secp256k1_fe_normalize(secp256k1_fe_t *r) {
static void secp256k1_fe_normalize(secp256k1_fe *r) {
uint64_t t0 = r->n[0], t1 = r->n[1], t2 = r->n[2], t3 = r->n[3], t4 = r->n[4];
/* Reduce t4 at the start so there will be at most a single carry from the first pass */
@ -99,7 +99,7 @@ static void secp256k1_fe_normalize(secp256k1_fe_t *r) {
#endif
}
static void secp256k1_fe_normalize_weak(secp256k1_fe_t *r) {
static void secp256k1_fe_normalize_weak(secp256k1_fe *r) {
uint64_t t0 = r->n[0], t1 = r->n[1], t2 = r->n[2], t3 = r->n[3], t4 = r->n[4];
/* Reduce t4 at the start so there will be at most a single carry from the first pass */
@ -123,7 +123,7 @@ static void secp256k1_fe_normalize_weak(secp256k1_fe_t *r) {
#endif
}
static void secp256k1_fe_normalize_var(secp256k1_fe_t *r) {
static void secp256k1_fe_normalize_var(secp256k1_fe *r) {
uint64_t t0 = r->n[0], t1 = r->n[1], t2 = r->n[2], t3 = r->n[3], t4 = r->n[4];
/* Reduce t4 at the start so there will be at most a single carry from the first pass */
@ -167,7 +167,7 @@ static void secp256k1_fe_normalize_var(secp256k1_fe_t *r) {
#endif
}
static int secp256k1_fe_normalizes_to_zero(secp256k1_fe_t *r) {
static int secp256k1_fe_normalizes_to_zero(secp256k1_fe *r) {
uint64_t t0 = r->n[0], t1 = r->n[1], t2 = r->n[2], t3 = r->n[3], t4 = r->n[4];
/* z0 tracks a possible raw value of 0, z1 tracks a possible raw value of P */
@ -190,7 +190,7 @@ static int secp256k1_fe_normalizes_to_zero(secp256k1_fe_t *r) {
return (z0 == 0) | (z1 == 0xFFFFFFFFFFFFFULL);
}
static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe_t *r) {
static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe *r) {
uint64_t t0, t1, t2, t3, t4;
uint64_t z0, z1;
uint64_t x;
@ -219,7 +219,7 @@ static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe_t *r) {
t4 &= 0x0FFFFFFFFFFFFULL;
t1 += (t0 >> 52); t0 = z0;
t1 += (t0 >> 52);
t2 += (t1 >> 52); t1 &= 0xFFFFFFFFFFFFFULL; z0 |= t1; z1 &= t1;
t3 += (t2 >> 52); t2 &= 0xFFFFFFFFFFFFFULL; z0 |= t2; z1 &= t2;
t4 += (t3 >> 52); t3 &= 0xFFFFFFFFFFFFFULL; z0 |= t3; z1 &= t3;
@ -231,7 +231,7 @@ static int secp256k1_fe_normalizes_to_zero_var(secp256k1_fe_t *r) {
return (z0 == 0) | (z1 == 0xFFFFFFFFFFFFFULL);
}
SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe_t *r, int a) {
SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe *r, int a) {
r->n[0] = a;
r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
#ifdef VERIFY
@ -241,7 +241,7 @@ SECP256K1_INLINE static void secp256k1_fe_set_int(secp256k1_fe_t *r, int a) {
#endif
}
SECP256K1_INLINE static int secp256k1_fe_is_zero(const secp256k1_fe_t *a) {
SECP256K1_INLINE static int secp256k1_fe_is_zero(const secp256k1_fe *a) {
const uint64_t *t = a->n;
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
@ -250,7 +250,7 @@ SECP256K1_INLINE static int secp256k1_fe_is_zero(const secp256k1_fe_t *a) {
return (t[0] | t[1] | t[2] | t[3] | t[4]) == 0;
}
SECP256K1_INLINE static int secp256k1_fe_is_odd(const secp256k1_fe_t *a) {
SECP256K1_INLINE static int secp256k1_fe_is_odd(const secp256k1_fe *a) {
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
secp256k1_fe_verify(a);
@ -258,7 +258,7 @@ SECP256K1_INLINE static int secp256k1_fe_is_odd(const secp256k1_fe_t *a) {
return a->n[0] & 1;
}
SECP256K1_INLINE static void secp256k1_fe_clear(secp256k1_fe_t *a) {
SECP256K1_INLINE static void secp256k1_fe_clear(secp256k1_fe *a) {
int i;
#ifdef VERIFY
a->magnitude = 0;
@ -269,7 +269,7 @@ SECP256K1_INLINE static void secp256k1_fe_clear(secp256k1_fe_t *a) {
}
}
static int secp256k1_fe_cmp_var(const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
static int secp256k1_fe_cmp_var(const secp256k1_fe *a, const secp256k1_fe *b) {
int i;
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
@ -288,7 +288,7 @@ static int secp256k1_fe_cmp_var(const secp256k1_fe_t *a, const secp256k1_fe_t *b
return 0;
}
static int secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a) {
static int secp256k1_fe_set_b32(secp256k1_fe *r, const unsigned char *a) {
int i;
r->n[0] = r->n[1] = r->n[2] = r->n[3] = r->n[4] = 0;
for (i=0; i<32; i++) {
@ -311,7 +311,7 @@ static int secp256k1_fe_set_b32(secp256k1_fe_t *r, const unsigned char *a) {
}
/** Convert a field element to a 32-byte big endian value. Requires the input to be normalized */
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a) {
static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe *a) {
int i;
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
@ -329,7 +329,7 @@ static void secp256k1_fe_get_b32(unsigned char *r, const secp256k1_fe_t *a) {
}
}
SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe_t *r, const secp256k1_fe_t *a, int m) {
SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe *r, const secp256k1_fe *a, int m) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= m);
secp256k1_fe_verify(a);
@ -346,7 +346,7 @@ SECP256K1_INLINE static void secp256k1_fe_negate(secp256k1_fe_t *r, const secp25
#endif
}
SECP256K1_INLINE static void secp256k1_fe_mul_int(secp256k1_fe_t *r, int a) {
SECP256K1_INLINE static void secp256k1_fe_mul_int(secp256k1_fe *r, int a) {
r->n[0] *= a;
r->n[1] *= a;
r->n[2] *= a;
@ -359,7 +359,7 @@ SECP256K1_INLINE static void secp256k1_fe_mul_int(secp256k1_fe_t *r, int a) {
#endif
}
SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe *r, const secp256k1_fe *a) {
#ifdef VERIFY
secp256k1_fe_verify(a);
#endif
@ -375,7 +375,7 @@ SECP256K1_INLINE static void secp256k1_fe_add(secp256k1_fe_t *r, const secp256k1
#endif
}
static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const secp256k1_fe_t * SECP256K1_RESTRICT b) {
static void secp256k1_fe_mul(secp256k1_fe *r, const secp256k1_fe *a, const secp256k1_fe * SECP256K1_RESTRICT b) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
VERIFY_CHECK(b->magnitude <= 8);
@ -391,7 +391,7 @@ static void secp256k1_fe_mul(secp256k1_fe_t *r, const secp256k1_fe_t *a, const s
#endif
}
static void secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
static void secp256k1_fe_sqr(secp256k1_fe *r, const secp256k1_fe *a) {
#ifdef VERIFY
VERIFY_CHECK(a->magnitude <= 8);
secp256k1_fe_verify(a);
@ -404,7 +404,7 @@ static void secp256k1_fe_sqr(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
#endif
}
static SECP256K1_INLINE void secp256k1_fe_cmov(secp256k1_fe_t *r, const secp256k1_fe_t *a, int flag) {
static SECP256K1_INLINE void secp256k1_fe_cmov(secp256k1_fe *r, const secp256k1_fe *a, int flag) {
uint64_t mask0, mask1;
mask0 = flag + ~((uint64_t)0);
mask1 = ~mask0;
@ -414,12 +414,14 @@ static SECP256K1_INLINE void secp256k1_fe_cmov(secp256k1_fe_t *r, const secp256k
r->n[3] = (r->n[3] & mask0) | (a->n[3] & mask1);
r->n[4] = (r->n[4] & mask0) | (a->n[4] & mask1);
#ifdef VERIFY
r->magnitude = (r->magnitude & mask0) | (a->magnitude & mask1);
r->normalized = (r->normalized & mask0) | (a->normalized & mask1);
if (a->magnitude > r->magnitude) {
r->magnitude = a->magnitude;
}
r->normalized &= a->normalized;
#endif
}
static SECP256K1_INLINE void secp256k1_fe_storage_cmov(secp256k1_fe_storage_t *r, const secp256k1_fe_storage_t *a, int flag) {
static SECP256K1_INLINE void secp256k1_fe_storage_cmov(secp256k1_fe_storage *r, const secp256k1_fe_storage *a, int flag) {
uint64_t mask0, mask1;
mask0 = flag + ~((uint64_t)0);
mask1 = ~mask0;
@ -429,7 +431,7 @@ static SECP256K1_INLINE void secp256k1_fe_storage_cmov(secp256k1_fe_storage_t *r
r->n[3] = (r->n[3] & mask0) | (a->n[3] & mask1);
}
static void secp256k1_fe_to_storage(secp256k1_fe_storage_t *r, const secp256k1_fe_t *a) {
static void secp256k1_fe_to_storage(secp256k1_fe_storage *r, const secp256k1_fe *a) {
#ifdef VERIFY
VERIFY_CHECK(a->normalized);
#endif
@ -439,7 +441,7 @@ static void secp256k1_fe_to_storage(secp256k1_fe_storage_t *r, const secp256k1_f
r->n[3] = a->n[3] >> 36 | a->n[4] << 16;
}
static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe_t *r, const secp256k1_fe_storage_t *a) {
static SECP256K1_INLINE void secp256k1_fe_from_storage(secp256k1_fe *r, const secp256k1_fe_storage *a) {
r->n[0] = a->n[0] & 0xFFFFFFFFFFFFFULL;
r->n[1] = a->n[0] >> 52 | ((a->n[1] << 12) & 0xFFFFFFFFFFFFFULL);
r->n[2] = a->n[1] >> 40 | ((a->n[2] << 24) & 0xFFFFFFFFFFFFFULL);

46
src/field_impl.h
View file

@ -21,15 +21,24 @@
#error "Please select field implementation"
#endif
SECP256K1_INLINE static int secp256k1_fe_equal_var(const secp256k1_fe_t *a, const secp256k1_fe_t *b) {
secp256k1_fe_t na;
SECP256K1_INLINE static int secp256k1_fe_equal_var(const secp256k1_fe *a, const secp256k1_fe *b) {
secp256k1_fe na;
secp256k1_fe_negate(&na, a, 1);
secp256k1_fe_add(&na, b);
return secp256k1_fe_normalizes_to_zero_var(&na);
}
static int secp256k1_fe_sqrt_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
secp256k1_fe_t x2, x3, x6, x9, x11, x22, x44, x88, x176, x220, x223, t1;
static int secp256k1_fe_sqrt_var(secp256k1_fe *r, const secp256k1_fe *a) {
/** Given that p is congruent to 3 mod 4, we can compute the square root of
* a mod p as the (p+1)/4'th power of a.
*
* As (p+1)/4 is an even number, it will have the same result for a and for
* (-a). Only one of these two numbers actually has a square root however,
* so we test at the end by squaring and comparing to the input.
* Also because (p+1)/4 is an even number, the computed square root is
* itself always a square (a ** ((p+1)/4) is the square of a ** ((p+1)/8)).
*/
secp256k1_fe x2, x3, x6, x9, x11, x22, x44, x88, x176, x220, x223, t1;
int j;
/** The binary representation of (p + 1)/4 has 3 blocks of 1s, with lengths in
@ -117,8 +126,8 @@ static int secp256k1_fe_sqrt_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
return secp256k1_fe_equal_var(&t1, a);
}
static void secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
secp256k1_fe_t x2, x3, x6, x9, x11, x22, x44, x88, x176, x220, x223, t1;
static void secp256k1_fe_inv(secp256k1_fe *r, const secp256k1_fe *a) {
secp256k1_fe x2, x3, x6, x9, x11, x22, x44, x88, x176, x220, x223, t1;
int j;
/** The binary representation of (p - 2) has 5 blocks of 1s, with lengths in
@ -207,11 +216,15 @@ static void secp256k1_fe_inv(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
secp256k1_fe_mul(r, a, &t1);
}
static void secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
static void secp256k1_fe_inv_var(secp256k1_fe *r, const secp256k1_fe *a) {
#if defined(USE_FIELD_INV_BUILTIN)
secp256k1_fe_inv(r, a);
#elif defined(USE_FIELD_INV_NUM)
secp256k1_num_t n, m;
secp256k1_num n, m;
static const secp256k1_fe negone = SECP256K1_FE_CONST(
0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFFUL,
0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFEUL, 0xFFFFFC2EUL
);
/* secp256k1 field prime, value p defined in "Standards for Efficient Cryptography" (SEC2) 2.7.1. */
static const unsigned char prime[32] = {
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
@ -220,21 +233,28 @@ static void secp256k1_fe_inv_var(secp256k1_fe_t *r, const secp256k1_fe_t *a) {
0xFF,0xFF,0xFF,0xFE,0xFF,0xFF,0xFC,0x2F
};
unsigned char b[32];
secp256k1_fe_t c = *a;
int res;
secp256k1_fe c = *a;
secp256k1_fe_normalize_var(&c);
secp256k1_fe_get_b32(b, &c);
secp256k1_num_set_bin(&n, b, 32);
secp256k1_num_set_bin(&m, prime, 32);
secp256k1_num_mod_inverse(&n, &n, &m);
secp256k1_num_get_bin(b, 32, &n);
VERIFY_CHECK(secp256k1_fe_set_b32(r, b));
res = secp256k1_fe_set_b32(r, b);
(void)res;
VERIFY_CHECK(res);
/* Verify the result is the (unique) valid inverse using non-GMP code. */
secp256k1_fe_mul(&c, &c, r);
secp256k1_fe_add(&c, &negone);
CHECK(secp256k1_fe_normalizes_to_zero_var(&c));
#else
#error "Please select field inverse implementation"
#endif
}
static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t *r, const secp256k1_fe_t *a) {
secp256k1_fe_t u;
static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe *r, const secp256k1_fe *a) {
secp256k1_fe u;
size_t i;
if (len < 1) {
return;
@ -252,7 +272,7 @@ static void secp256k1_fe_inv_all_var(size_t len, secp256k1_fe_t *r, const secp25
secp256k1_fe_inv_var(&u, &r[--i]);
while (i > 0) {
int j = i--;
size_t j = i--;
secp256k1_fe_mul(&r[j], &r[i], &u);
secp256k1_fe_mul(&u, &u, &a[j]);
}

74
src/gen_context.c Normal file
View file

@ -0,0 +1,74 @@
/**********************************************************************
* Copyright (c) 2013, 2014, 2015 Thomas Daede, Cory Fields *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#define USE_BASIC_CONFIG 1
#include "basic-config.h"
#include "include/secp256k1.h"
#include "field_impl.h"
#include "scalar_impl.h"
#include "group_impl.h"
#include "ecmult_gen_impl.h"
static void default_error_callback_fn(const char* str, void* data) {
(void)data;
fprintf(stderr, "[libsecp256k1] internal consistency check failed: %s\n", str);
abort();
}
static const secp256k1_callback default_error_callback = {
default_error_callback_fn,
NULL
};
int main(int argc, char **argv) {
secp256k1_ecmult_gen_context ctx;
int inner;
int outer;
FILE* fp;
(void)argc;
(void)argv;
fp = fopen("src/ecmult_static_context.h","w");
if (fp == NULL) {
fprintf(stderr, "Could not open src/ecmult_static_context.h for writing!\n");
return -1;
}
fprintf(fp, "#ifndef _SECP256K1_ECMULT_STATIC_CONTEXT_\n");
fprintf(fp, "#define _SECP256K1_ECMULT_STATIC_CONTEXT_\n");
fprintf(fp, "#include \"group.h\"\n");
fprintf(fp, "#define SC SECP256K1_GE_STORAGE_CONST\n");
fprintf(fp, "static const secp256k1_ge_storage secp256k1_ecmult_static_context[64][16] = {\n");
secp256k1_ecmult_gen_context_init(&ctx);
secp256k1_ecmult_gen_context_build(&ctx, &default_error_callback);
for(outer = 0; outer != 64; outer++) {
fprintf(fp,"{\n");
for(inner = 0; inner != 16; inner++) {
fprintf(fp," SC(%uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu, %uu)", SECP256K1_GE_STORAGE_CONST_GET((*ctx.prec)[outer][inner]));
if (inner != 15) {
fprintf(fp,",\n");
} else {
fprintf(fp,"\n");
}
}
if (outer != 63) {
fprintf(fp,"},\n");
} else {
fprintf(fp,"}\n");
}
}
fprintf(fp,"};\n");
secp256k1_ecmult_gen_context_clear(&ctx);
fprintf(fp, "#undef SC\n");
fprintf(fp, "#endif\n");
fclose(fp);
return 0;
}

106
src/group.h
View file

@ -12,110 +12,130 @@
/** A group element of the secp256k1 curve, in affine coordinates. */
typedef struct {
secp256k1_fe_t x;
secp256k1_fe_t y;
secp256k1_fe x;
secp256k1_fe y;
int infinity; /* whether this represents the point at infinity */
} secp256k1_ge_t;
} secp256k1_ge;
#define SECP256K1_GE_CONST(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) {SECP256K1_FE_CONST((a),(b),(c),(d),(e),(f),(g),(h)), SECP256K1_FE_CONST((i),(j),(k),(l),(m),(n),(o),(p)), 0}
#define SECP256K1_GE_CONST_INFINITY {SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), 1}
/** A group element of the secp256k1 curve, in jacobian coordinates. */
typedef struct {
secp256k1_fe_t x; /* actual X: x/z^2 */
secp256k1_fe_t y; /* actual Y: y/z^3 */
secp256k1_fe_t z;
secp256k1_fe x; /* actual X: x/z^2 */
secp256k1_fe y; /* actual Y: y/z^3 */
secp256k1_fe z;
int infinity; /* whether this represents the point at infinity */
} secp256k1_gej_t;
} secp256k1_gej;
#define SECP256K1_GEJ_CONST(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) {SECP256K1_FE_CONST((a),(b),(c),(d),(e),(f),(g),(h)), SECP256K1_FE_CONST((i),(j),(k),(l),(m),(n),(o),(p)), SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 1), 0}
#define SECP256K1_GEJ_CONST_INFINITY {SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 0), 1}
typedef struct {
secp256k1_fe_storage_t x;
secp256k1_fe_storage_t y;
} secp256k1_ge_storage_t;
secp256k1_fe_storage x;
secp256k1_fe_storage y;
} secp256k1_ge_storage;
#define SECP256K1_GE_STORAGE_CONST(a, b, c, d, e, f, g, h, i, j, k, l, m, n, o, p) {SECP256K1_FE_STORAGE_CONST((a),(b),(c),(d),(e),(f),(g),(h)), SECP256K1_FE_STORAGE_CONST((i),(j),(k),(l),(m),(n),(o),(p))}
/** Set a group element equal to the point at infinity */
static void secp256k1_ge_set_infinity(secp256k1_ge_t *r);
#define SECP256K1_GE_STORAGE_CONST_GET(t) SECP256K1_FE_STORAGE_CONST_GET(t.x), SECP256K1_FE_STORAGE_CONST_GET(t.y)
/** Set a group element equal to the point with given X and Y coordinates */
static void secp256k1_ge_set_xy(secp256k1_ge_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y);
static void secp256k1_ge_set_xy(secp256k1_ge *r, const secp256k1_fe *x, const secp256k1_fe *y);
/** Set a group element (affine) equal to the point with the given X coordinate
* and a Y coordinate that is a quadratic residue modulo p. The return value
* is true iff a coordinate with the given X coordinate exists.
*/
static int secp256k1_ge_set_xquad_var(secp256k1_ge *r, const secp256k1_fe *x);
/** Set a group element (affine) equal to the point with the given X coordinate, and given oddness
* for Y. Return value indicates whether the result is valid. */
static int secp256k1_ge_set_xo_var(secp256k1_ge_t *r, const secp256k1_fe_t *x, int odd);
static int secp256k1_ge_set_xo_var(secp256k1_ge *r, const secp256k1_fe *x, int odd);
/** Check whether a group element is the point at infinity. */
static int secp256k1_ge_is_infinity(const secp256k1_ge_t *a);
static int secp256k1_ge_is_infinity(const secp256k1_ge *a);
/** Check whether a group element is valid (i.e., on the curve). */
static int secp256k1_ge_is_valid_var(const secp256k1_ge_t *a);
static int secp256k1_ge_is_valid_var(const secp256k1_ge *a);
static void secp256k1_ge_neg(secp256k1_ge_t *r, const secp256k1_ge_t *a);
static void secp256k1_ge_neg(secp256k1_ge *r, const secp256k1_ge *a);
/** Set a group element equal to another which is given in jacobian coordinates */
static void secp256k1_ge_set_gej(secp256k1_ge_t *r, secp256k1_gej_t *a);
static void secp256k1_ge_set_gej(secp256k1_ge *r, secp256k1_gej *a);
/** Set a batch of group elements equal to the inputs given in jacobian coordinates */
static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge_t *r, const secp256k1_gej_t *a);
static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_callback *cb);
/** Set a batch of group elements equal to the inputs given in jacobian
* coordinates (with known z-ratios). zr must contain the known z-ratios such
* that mul(a[i].z, zr[i+1]) == a[i+1].z. zr[0] is ignored. */
static void secp256k1_ge_set_table_gej_var(size_t len, secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_fe *zr);
/** Bring a batch inputs given in jacobian coordinates (with known z-ratios) to
* the same global z "denominator". zr must contain the known z-ratios such
* that mul(a[i].z, zr[i+1]) == a[i+1].z. zr[0] is ignored. The x and y
* coordinates of the result are stored in r, the common z coordinate is
* stored in globalz. */
static void secp256k1_ge_globalz_set_table_gej(size_t len, secp256k1_ge *r, secp256k1_fe *globalz, const secp256k1_gej *a, const secp256k1_fe *zr);
/** Set a group element (jacobian) equal to the point at infinity. */
static void secp256k1_gej_set_infinity(secp256k1_gej_t *r);
/** Set a group element (jacobian) equal to the point with given X and Y coordinates. */
static void secp256k1_gej_set_xy(secp256k1_gej_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y);
static void secp256k1_gej_set_infinity(secp256k1_gej *r);
/** Set a group element (jacobian) equal to another which is given in affine coordinates. */
static void secp256k1_gej_set_ge(secp256k1_gej_t *r, const secp256k1_ge_t *a);
static void secp256k1_gej_set_ge(secp256k1_gej *r, const secp256k1_ge *a);
/** Compare the X coordinate of a group element (jacobian). */
static int secp256k1_gej_eq_x_var(const secp256k1_fe_t *x, const secp256k1_gej_t *a);
static int secp256k1_gej_eq_x_var(const secp256k1_fe *x, const secp256k1_gej *a);
/** Set r equal to the inverse of a (i.e., mirrored around the X axis) */
static void secp256k1_gej_neg(secp256k1_gej_t *r, const secp256k1_gej_t *a);
static void secp256k1_gej_neg(secp256k1_gej *r, const secp256k1_gej *a);
/** Check whether a group element is the point at infinity. */
static int secp256k1_gej_is_infinity(const secp256k1_gej_t *a);
static int secp256k1_gej_is_infinity(const secp256k1_gej *a);
/** Set r equal to the double of a. */
static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t *a);
/** Set r equal to the double of a. If rzr is not-NULL, r->z = a->z * *rzr (where infinity means an implicit z = 0).
* a may not be zero. Constant time. */
static void secp256k1_gej_double_nonzero(secp256k1_gej *r, const secp256k1_gej *a, secp256k1_fe *rzr);
/** Set r equal to the sum of a and b. */
static void secp256k1_gej_add_var(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_gej_t *b);
/** Set r equal to the double of a. If rzr is not-NULL, r->z = a->z * *rzr (where infinity means an implicit z = 0). */
static void secp256k1_gej_double_var(secp256k1_gej *r, const secp256k1_gej *a, secp256k1_fe *rzr);
/** Set r equal to the sum of a and b. If rzr is non-NULL, r->z = a->z * *rzr (a cannot be infinity in that case). */
static void secp256k1_gej_add_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_gej *b, secp256k1_fe *rzr);
/** Set r equal to the sum of a and b (with b given in affine coordinates, and not infinity). */
static void secp256k1_gej_add_ge(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_ge_t *b);
static void secp256k1_gej_add_ge(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b);
/** Set r equal to the sum of a and b (with b given in affine coordinates). This is more efficient
than secp256k1_gej_add_var. It is identical to secp256k1_gej_add_ge but without constant-time
guarantee, and b is allowed to be infinity. */
static void secp256k1_gej_add_ge_var(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_ge_t *b);
guarantee, and b is allowed to be infinity. If rzr is non-NULL, r->z = a->z * *rzr (a cannot be infinity in that case). */
static void secp256k1_gej_add_ge_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b, secp256k1_fe *rzr);
/** Set r equal to the sum of a and b (with the inverse of b's Z coordinate passed as bzinv). */
static void secp256k1_gej_add_zinv_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b, const secp256k1_fe *bzinv);
#ifdef USE_ENDOMORPHISM
/** Set r to be equal to lambda times a, where lambda is chosen in a way such that this is very fast. */
static void secp256k1_gej_mul_lambda(secp256k1_gej_t *r, const secp256k1_gej_t *a);
static void secp256k1_ge_mul_lambda(secp256k1_ge *r, const secp256k1_ge *a);
#endif
/** Clear a secp256k1_gej_t to prevent leaking sensitive information. */
static void secp256k1_gej_clear(secp256k1_gej_t *r);
/** Clear a secp256k1_gej to prevent leaking sensitive information. */
static void secp256k1_gej_clear(secp256k1_gej *r);
/** Clear a secp256k1_ge_t to prevent leaking sensitive information. */
static void secp256k1_ge_clear(secp256k1_ge_t *r);
/** Clear a secp256k1_ge to prevent leaking sensitive information. */
static void secp256k1_ge_clear(secp256k1_ge *r);
/** Convert a group element to the storage type. */
static void secp256k1_ge_to_storage(secp256k1_ge_storage_t *r, const secp256k1_ge_t*);
static void secp256k1_ge_to_storage(secp256k1_ge_storage *r, const secp256k1_ge *a);
/** Convert a group element back from the storage type. */
static void secp256k1_ge_from_storage(secp256k1_ge_t *r, const secp256k1_ge_storage_t*);
static void secp256k1_ge_from_storage(secp256k1_ge *r, const secp256k1_ge_storage *a);
/** If flag is true, set *r equal to *a; otherwise leave it. Constant-time. */
static void secp256k1_ge_storage_cmov(secp256k1_ge_storage_t *r, const secp256k1_ge_storage_t *a, int flag);
static void secp256k1_ge_storage_cmov(secp256k1_ge_storage *r, const secp256k1_ge_storage *a, int flag);
/** Rescale a jacobian point by b which must be non-zero. Constant-time. */
static void secp256k1_gej_rescale(secp256k1_gej_t *r, const secp256k1_fe_t *b);
static void secp256k1_gej_rescale(secp256k1_gej *r, const secp256k1_fe *b);
#endif

375
src/group_impl.h
View file

@ -16,35 +16,41 @@
/** Generator for secp256k1, value 'g' defined in
* "Standards for Efficient Cryptography" (SEC2) 2.7.1.
*/
static const secp256k1_ge_t secp256k1_ge_const_g = SECP256K1_GE_CONST(
static const secp256k1_ge secp256k1_ge_const_g = SECP256K1_GE_CONST(
0x79BE667EUL, 0xF9DCBBACUL, 0x55A06295UL, 0xCE870B07UL,
0x029BFCDBUL, 0x2DCE28D9UL, 0x59F2815BUL, 0x16F81798UL,
0x483ADA77UL, 0x26A3C465UL, 0x5DA4FBFCUL, 0x0E1108A8UL,
0xFD17B448UL, 0xA6855419UL, 0x9C47D08FUL, 0xFB10D4B8UL
);
static void secp256k1_ge_set_infinity(secp256k1_ge_t *r) {
r->infinity = 1;
static void secp256k1_ge_set_gej_zinv(secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_fe *zi) {
secp256k1_fe zi2;
secp256k1_fe zi3;
secp256k1_fe_sqr(&zi2, zi);
secp256k1_fe_mul(&zi3, &zi2, zi);
secp256k1_fe_mul(&r->x, &a->x, &zi2);
secp256k1_fe_mul(&r->y, &a->y, &zi3);
r->infinity = a->infinity;
}
static void secp256k1_ge_set_xy(secp256k1_ge_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y) {
static void secp256k1_ge_set_xy(secp256k1_ge *r, const secp256k1_fe *x, const secp256k1_fe *y) {
r->infinity = 0;
r->x = *x;
r->y = *y;
}
static int secp256k1_ge_is_infinity(const secp256k1_ge_t *a) {
static int secp256k1_ge_is_infinity(const secp256k1_ge *a) {
return a->infinity;
}
static void secp256k1_ge_neg(secp256k1_ge_t *r, const secp256k1_ge_t *a) {
static void secp256k1_ge_neg(secp256k1_ge *r, const secp256k1_ge *a) {
*r = *a;
secp256k1_fe_normalize_weak(&r->y);
secp256k1_fe_negate(&r->y, &r->y, 1);
}
static void secp256k1_ge_set_gej(secp256k1_ge_t *r, secp256k1_gej_t *a) {
secp256k1_fe_t z2, z3;
static void secp256k1_ge_set_gej(secp256k1_ge *r, secp256k1_gej *a) {
secp256k1_fe z2, z3;
r->infinity = a->infinity;
secp256k1_fe_inv(&a->z, &a->z);
secp256k1_fe_sqr(&z2, &a->z);
@ -56,8 +62,8 @@ static void secp256k1_ge_set_gej(secp256k1_ge_t *r, secp256k1_gej_t *a) {
r->y = a->y;
}
static void secp256k1_ge_set_gej_var(secp256k1_ge_t *r, secp256k1_gej_t *a) {
secp256k1_fe_t z2, z3;
static void secp256k1_ge_set_gej_var(secp256k1_ge *r, secp256k1_gej *a) {
secp256k1_fe z2, z3;
r->infinity = a->infinity;
if (a->infinity) {
return;
@ -72,19 +78,19 @@ static void secp256k1_ge_set_gej_var(secp256k1_ge_t *r, secp256k1_gej_t *a) {
r->y = a->y;
}
static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge_t *r, const secp256k1_gej_t *a) {
secp256k1_fe_t *az;
secp256k1_fe_t *azi;
static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_callback *cb) {
secp256k1_fe *az;
secp256k1_fe *azi;
size_t i;
size_t count = 0;
az = (secp256k1_fe_t *)checked_malloc(sizeof(secp256k1_fe_t) * len);
az = (secp256k1_fe *)checked_malloc(cb, sizeof(secp256k1_fe) * len);
for (i = 0; i < len; i++) {
if (!a[i].infinity) {
az[count++] = a[i].z;
}
}
azi = (secp256k1_fe_t *)checked_malloc(sizeof(secp256k1_fe_t) * count);
azi = (secp256k1_fe *)checked_malloc(cb, sizeof(secp256k1_fe) * count);
secp256k1_fe_inv_all_var(count, azi, az);
free(az);
@ -92,53 +98,86 @@ static void secp256k1_ge_set_all_gej_var(size_t len, secp256k1_ge_t *r, const se
for (i = 0; i < len; i++) {
r[i].infinity = a[i].infinity;
if (!a[i].infinity) {
secp256k1_fe_t zi2, zi3;
secp256k1_fe_t *zi = &azi[count++];
secp256k1_fe_sqr(&zi2, zi);
secp256k1_fe_mul(&zi3, &zi2, zi);
secp256k1_fe_mul(&r[i].x, &a[i].x, &zi2);
secp256k1_fe_mul(&r[i].y, &a[i].y, &zi3);
secp256k1_ge_set_gej_zinv(&r[i], &a[i], &azi[count++]);
}
}
free(azi);
}
static void secp256k1_gej_set_infinity(secp256k1_gej_t *r) {
static void secp256k1_ge_set_table_gej_var(size_t len, secp256k1_ge *r, const secp256k1_gej *a, const secp256k1_fe *zr) {
size_t i = len - 1;
secp256k1_fe zi;
if (len > 0) {
/* Compute the inverse of the last z coordinate, and use it to compute the last affine output. */
secp256k1_fe_inv(&zi, &a[i].z);
secp256k1_ge_set_gej_zinv(&r[i], &a[i], &zi);
/* Work out way backwards, using the z-ratios to scale the x/y values. */
while (i > 0) {
secp256k1_fe_mul(&zi, &zi, &zr[i]);
i--;
secp256k1_ge_set_gej_zinv(&r[i], &a[i], &zi);
}
}
}
static void secp256k1_ge_globalz_set_table_gej(size_t len, secp256k1_ge *r, secp256k1_fe *globalz, const secp256k1_gej *a, const secp256k1_fe *zr) {
size_t i = len - 1;
secp256k1_fe zs;
if (len > 0) {
/* The z of the final point gives us the "global Z" for the table. */
r[i].x = a[i].x;
r[i].y = a[i].y;
*globalz = a[i].z;
r[i].infinity = 0;
zs = zr[i];
/* Work our way backwards, using the z-ratios to scale the x/y values. */
while (i > 0) {
if (i != len - 1) {
secp256k1_fe_mul(&zs, &zs, &zr[i]);
}
i--;
secp256k1_ge_set_gej_zinv(&r[i], &a[i], &zs);
}
}
}
static void secp256k1_gej_set_infinity(secp256k1_gej *r) {
r->infinity = 1;
secp256k1_fe_set_int(&r->x, 0);
secp256k1_fe_set_int(&r->y, 0);
secp256k1_fe_set_int(&r->z, 0);
}
static void secp256k1_gej_set_xy(secp256k1_gej_t *r, const secp256k1_fe_t *x, const secp256k1_fe_t *y) {
r->infinity = 0;
r->x = *x;
r->y = *y;
secp256k1_fe_set_int(&r->z, 1);
}
static void secp256k1_gej_clear(secp256k1_gej_t *r) {
static void secp256k1_gej_clear(secp256k1_gej *r) {
r->infinity = 0;
secp256k1_fe_clear(&r->x);
secp256k1_fe_clear(&r->y);
secp256k1_fe_clear(&r->z);
}
static void secp256k1_ge_clear(secp256k1_ge_t *r) {
static void secp256k1_ge_clear(secp256k1_ge *r) {
r->infinity = 0;
secp256k1_fe_clear(&r->x);
secp256k1_fe_clear(&r->y);
}
static int secp256k1_ge_set_xo_var(secp256k1_ge_t *r, const secp256k1_fe_t *x, int odd) {
secp256k1_fe_t x2, x3, c;
static int secp256k1_ge_set_xquad_var(secp256k1_ge *r, const secp256k1_fe *x) {
secp256k1_fe x2, x3, c;
r->x = *x;
secp256k1_fe_sqr(&x2, x);
secp256k1_fe_mul(&x3, x, &x2);
r->infinity = 0;
secp256k1_fe_set_int(&c, 7);
secp256k1_fe_add(&c, &x3);
if (!secp256k1_fe_sqrt_var(&r->y, &c)) {
return secp256k1_fe_sqrt_var(&r->y, &c);
}
static int secp256k1_ge_set_xo_var(secp256k1_ge *r, const secp256k1_fe *x, int odd) {
if (!secp256k1_ge_set_xquad_var(r, x)) {
return 0;
}
secp256k1_fe_normalize_var(&r->y);
@ -146,24 +185,25 @@ static int secp256k1_ge_set_xo_var(secp256k1_ge_t *r, const secp256k1_fe_t *x, i
secp256k1_fe_negate(&r->y, &r->y, 1);
}
return 1;
}
static void secp256k1_gej_set_ge(secp256k1_gej_t *r, const secp256k1_ge_t *a) {
static void secp256k1_gej_set_ge(secp256k1_gej *r, const secp256k1_ge *a) {
r->infinity = a->infinity;
r->x = a->x;
r->y = a->y;
secp256k1_fe_set_int(&r->z, 1);
}
static int secp256k1_gej_eq_x_var(const secp256k1_fe_t *x, const secp256k1_gej_t *a) {
secp256k1_fe_t r, r2;
static int secp256k1_gej_eq_x_var(const secp256k1_fe *x, const secp256k1_gej *a) {
secp256k1_fe r, r2;
VERIFY_CHECK(!a->infinity);
secp256k1_fe_sqr(&r, &a->z); secp256k1_fe_mul(&r, &r, x);
r2 = a->x; secp256k1_fe_normalize_weak(&r2);
return secp256k1_fe_equal_var(&r, &r2);
}
static void secp256k1_gej_neg(secp256k1_gej_t *r, const secp256k1_gej_t *a) {
static void secp256k1_gej_neg(secp256k1_gej *r, const secp256k1_gej *a) {
r->infinity = a->infinity;
r->x = a->x;
r->y = a->y;
@ -172,12 +212,12 @@ static void secp256k1_gej_neg(secp256k1_gej_t *r, const secp256k1_gej_t *a) {
secp256k1_fe_negate(&r->y, &r->y, 1);
}
static int secp256k1_gej_is_infinity(const secp256k1_gej_t *a) {
static int secp256k1_gej_is_infinity(const secp256k1_gej *a) {
return a->infinity;
}
static int secp256k1_gej_is_valid_var(const secp256k1_gej_t *a) {
secp256k1_fe_t y2, x3, z2, z6;
static int secp256k1_gej_is_valid_var(const secp256k1_gej *a) {
secp256k1_fe y2, x3, z2, z6;
if (a->infinity) {
return 0;
}
@ -196,8 +236,8 @@ static int secp256k1_gej_is_valid_var(const secp256k1_gej_t *a) {
return secp256k1_fe_equal_var(&y2, &x3);
}
static int secp256k1_ge_is_valid_var(const secp256k1_ge_t *a) {
secp256k1_fe_t y2, x3, c;
static int secp256k1_ge_is_valid_var(const secp256k1_ge *a) {
secp256k1_fe y2, x3, c;
if (a->infinity) {
return 0;
}
@ -210,18 +250,27 @@ static int secp256k1_ge_is_valid_var(const secp256k1_ge_t *a) {
return secp256k1_fe_equal_var(&y2, &x3);
}
static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t *a) {
static void secp256k1_gej_double_var(secp256k1_gej *r, const secp256k1_gej *a, secp256k1_fe *rzr) {
/* Operations: 3 mul, 4 sqr, 0 normalize, 12 mul_int/add/negate */
secp256k1_fe_t t1,t2,t3,t4;
secp256k1_fe t1,t2,t3,t4;
/** For secp256k1, 2Q is infinity if and only if Q is infinity. This is because if 2Q = infinity,
* Q must equal -Q, or that Q.y == -(Q.y), or Q.y is 0. For a point on y^2 = x^3 + 7 to have
* y=0, x^3 must be -7 mod p. However, -7 has no cube root mod p.
*/
r->infinity = a->infinity;
if (r->infinity) {
if (rzr != NULL) {
secp256k1_fe_set_int(rzr, 1);
}
return;
}
if (rzr != NULL) {
*rzr = a->y;
secp256k1_fe_normalize_weak(rzr);
secp256k1_fe_mul_int(rzr, 2);
}
secp256k1_fe_mul(&r->z, &a->z, &a->y);
secp256k1_fe_mul_int(&r->z, 2); /* Z' = 2*Y*Z (2) */
secp256k1_fe_sqr(&t1, &a->x);
@ -244,17 +293,29 @@ static void secp256k1_gej_double_var(secp256k1_gej_t *r, const secp256k1_gej_t *
secp256k1_fe_add(&r->y, &t2); /* Y' = 36*X^3*Y^2 - 27*X^6 - 8*Y^4 (4) */
}
static void secp256k1_gej_add_var(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_gej_t *b) {
static SECP256K1_INLINE void secp256k1_gej_double_nonzero(secp256k1_gej *r, const secp256k1_gej *a, secp256k1_fe *rzr) {
VERIFY_CHECK(!secp256k1_gej_is_infinity(a));
secp256k1_gej_double_var(r, a, rzr);
}
static void secp256k1_gej_add_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_gej *b, secp256k1_fe *rzr) {
/* Operations: 12 mul, 4 sqr, 2 normalize, 12 mul_int/add/negate */
secp256k1_fe_t z22, z12, u1, u2, s1, s2, h, i, i2, h2, h3, t;
secp256k1_fe z22, z12, u1, u2, s1, s2, h, i, i2, h2, h3, t;
if (a->infinity) {
VERIFY_CHECK(rzr == NULL);
*r = *b;
return;
}
if (b->infinity) {
if (rzr != NULL) {
secp256k1_fe_set_int(rzr, 1);
}
*r = *a;
return;
}
r->infinity = 0;
secp256k1_fe_sqr(&z22, &b->z);
secp256k1_fe_sqr(&z12, &a->z);
@ -266,8 +327,11 @@ static void secp256k1_gej_add_var(secp256k1_gej_t *r, const secp256k1_gej_t *a,
secp256k1_fe_negate(&i, &s1, 1); secp256k1_fe_add(&i, &s2);
if (secp256k1_fe_normalizes_to_zero_var(&h)) {
if (secp256k1_fe_normalizes_to_zero_var(&i)) {
secp256k1_gej_double_var(r, a);
secp256k1_gej_double_var(r, a, rzr);
} else {
if (rzr != NULL) {
secp256k1_fe_set_int(rzr, 0);
}
r->infinity = 1;
}
return;
@ -275,7 +339,11 @@ static void secp256k1_gej_add_var(secp256k1_gej_t *r, const secp256k1_gej_t *a,
secp256k1_fe_sqr(&i2, &i);
secp256k1_fe_sqr(&h2, &h);
secp256k1_fe_mul(&h3, &h, &h2);
secp256k1_fe_mul(&r->z, &a->z, &b->z); secp256k1_fe_mul(&r->z, &r->z, &h);
secp256k1_fe_mul(&h, &h, &b->z);
if (rzr != NULL) {
*rzr = h;
}
secp256k1_fe_mul(&r->z, &a->z, &h);
secp256k1_fe_mul(&t, &u1, &h2);
r->x = t; secp256k1_fe_mul_int(&r->x, 2); secp256k1_fe_add(&r->x, &h3); secp256k1_fe_negate(&r->x, &r->x, 3); secp256k1_fe_add(&r->x, &i2);
secp256k1_fe_negate(&r->y, &r->x, 5); secp256k1_fe_add(&r->y, &t); secp256k1_fe_mul(&r->y, &r->y, &i);
@ -283,21 +351,23 @@ static void secp256k1_gej_add_var(secp256k1_gej_t *r, const secp256k1_gej_t *a,
secp256k1_fe_add(&r->y, &h3);
}
static void secp256k1_gej_add_ge_var(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_ge_t *b) {
static void secp256k1_gej_add_ge_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b, secp256k1_fe *rzr) {
/* 8 mul, 3 sqr, 4 normalize, 12 mul_int/add/negate */
secp256k1_fe_t z12, u1, u2, s1, s2, h, i, i2, h2, h3, t;
secp256k1_fe z12, u1, u2, s1, s2, h, i, i2, h2, h3, t;
if (a->infinity) {
r->infinity = b->infinity;
r->x = b->x;
r->y = b->y;
secp256k1_fe_set_int(&r->z, 1);
VERIFY_CHECK(rzr == NULL);
secp256k1_gej_set_ge(r, b);
return;
}
if (b->infinity) {
if (rzr != NULL) {
secp256k1_fe_set_int(rzr, 1);
}
*r = *a;
return;
}
r->infinity = 0;
secp256k1_fe_sqr(&z12, &a->z);
u1 = a->x; secp256k1_fe_normalize_weak(&u1);
secp256k1_fe_mul(&u2, &b->x, &z12);
@ -307,7 +377,69 @@ static void secp256k1_gej_add_ge_var(secp256k1_gej_t *r, const secp256k1_gej_t *
secp256k1_fe_negate(&i, &s1, 1); secp256k1_fe_add(&i, &s2);
if (secp256k1_fe_normalizes_to_zero_var(&h)) {
if (secp256k1_fe_normalizes_to_zero_var(&i)) {
secp256k1_gej_double_var(r, a);
secp256k1_gej_double_var(r, a, rzr);
} else {
if (rzr != NULL) {
secp256k1_fe_set_int(rzr, 0);
}
r->infinity = 1;
}
return;
}
secp256k1_fe_sqr(&i2, &i);
secp256k1_fe_sqr(&h2, &h);
secp256k1_fe_mul(&h3, &h, &h2);
if (rzr != NULL) {
*rzr = h;
}
secp256k1_fe_mul(&r->z, &a->z, &h);
secp256k1_fe_mul(&t, &u1, &h2);
r->x = t; secp256k1_fe_mul_int(&r->x, 2); secp256k1_fe_add(&r->x, &h3); secp256k1_fe_negate(&r->x, &r->x, 3); secp256k1_fe_add(&r->x, &i2);
secp256k1_fe_negate(&r->y, &r->x, 5); secp256k1_fe_add(&r->y, &t); secp256k1_fe_mul(&r->y, &r->y, &i);
secp256k1_fe_mul(&h3, &h3, &s1); secp256k1_fe_negate(&h3, &h3, 1);
secp256k1_fe_add(&r->y, &h3);
}
static void secp256k1_gej_add_zinv_var(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b, const secp256k1_fe *bzinv) {
/* 9 mul, 3 sqr, 4 normalize, 12 mul_int/add/negate */
secp256k1_fe az, z12, u1, u2, s1, s2, h, i, i2, h2, h3, t;
if (b->infinity) {
*r = *a;
return;
}
if (a->infinity) {
secp256k1_fe bzinv2, bzinv3;
r->infinity = b->infinity;
secp256k1_fe_sqr(&bzinv2, bzinv);
secp256k1_fe_mul(&bzinv3, &bzinv2, bzinv);
secp256k1_fe_mul(&r->x, &b->x, &bzinv2);
secp256k1_fe_mul(&r->y, &b->y, &bzinv3);
secp256k1_fe_set_int(&r->z, 1);
return;
}
r->infinity = 0;
/** We need to calculate (rx,ry,rz) = (ax,ay,az) + (bx,by,1/bzinv). Due to
* secp256k1's isomorphism we can multiply the Z coordinates on both sides
* by bzinv, and get: (rx,ry,rz*bzinv) = (ax,ay,az*bzinv) + (bx,by,1).
* This means that (rx,ry,rz) can be calculated as
* (ax,ay,az*bzinv) + (bx,by,1), when not applying the bzinv factor to rz.
* The variable az below holds the modified Z coordinate for a, which is used
* for the computation of rx and ry, but not for rz.
*/
secp256k1_fe_mul(&az, &a->z, bzinv);
secp256k1_fe_sqr(&z12, &az);
u1 = a->x; secp256k1_fe_normalize_weak(&u1);
secp256k1_fe_mul(&u2, &b->x, &z12);
s1 = a->y; secp256k1_fe_normalize_weak(&s1);
secp256k1_fe_mul(&s2, &b->y, &z12); secp256k1_fe_mul(&s2, &s2, &az);
secp256k1_fe_negate(&h, &u1, 1); secp256k1_fe_add(&h, &u2);
secp256k1_fe_negate(&i, &s1, 1); secp256k1_fe_add(&i, &s2);
if (secp256k1_fe_normalizes_to_zero_var(&h)) {
if (secp256k1_fe_normalizes_to_zero_var(&i)) {
secp256k1_gej_double_var(r, a, NULL);
} else {
r->infinity = 1;
}
@ -324,11 +456,13 @@ static void secp256k1_gej_add_ge_var(secp256k1_gej_t *r, const secp256k1_gej_t *
secp256k1_fe_add(&r->y, &h3);
}
static void secp256k1_gej_add_ge(secp256k1_gej_t *r, const secp256k1_gej_t *a, const secp256k1_ge_t *b) {
/* Operations: 7 mul, 5 sqr, 5 normalize, 17 mul_int/add/negate/cmov */
static const secp256k1_fe_t fe_1 = SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 1);
secp256k1_fe_t zz, u1, u2, s1, s2, z, t, m, n, q, rr;
int infinity;
static void secp256k1_gej_add_ge(secp256k1_gej *r, const secp256k1_gej *a, const secp256k1_ge *b) {
/* Operations: 7 mul, 5 sqr, 4 normalize, 21 mul_int/add/negate/cmov */
static const secp256k1_fe fe_1 = SECP256K1_FE_CONST(0, 0, 0, 0, 0, 0, 0, 1);
secp256k1_fe zz, u1, u2, s1, s2, t, tt, m, n, q, rr;
secp256k1_fe m_alt, rr_alt;
int infinity, degenerate;
VERIFY_CHECK(!b->infinity);
VERIFY_CHECK(a->infinity == 0 || a->infinity == 1);
@ -352,53 +486,102 @@ static void secp256k1_gej_add_ge(secp256k1_gej_t *r, const secp256k1_gej_t *a, c
* Y3 = 4*(R*(3*Q-2*R^2)-M^4)
* Z3 = 2*M*Z
* (Note that the paper uses xi = Xi / Zi and yi = Yi / Zi instead.)
*
* This formula has the benefit of being the same for both addition
* of distinct points and doubling. However, it breaks down in the
* case that either point is infinity, or that y1 = -y2. We handle
* these cases in the following ways:
*
* - If b is infinity we simply bail by means of a VERIFY_CHECK.
*
* - If a is infinity, we detect this, and at the end of the
* computation replace the result (which will be meaningless,
* but we compute to be constant-time) with b.x : b.y : 1.
*
* - If a = -b, we have y1 = -y2, which is a degenerate case.
* But here the answer is infinity, so we simply set the
* infinity flag of the result, overriding the computed values
* without even needing to cmov.
*
* - If y1 = -y2 but x1 != x2, which does occur thanks to certain
* properties of our curve (specifically, 1 has nontrivial cube
* roots in our field, and the curve equation has no x coefficient)
* then the answer is not infinity but also not given by the above
* equation. In this case, we cmov in place an alternate expression
* for lambda. Specifically (y1 - y2)/(x1 - x2). Where both these
* expressions for lambda are defined, they are equal, and can be
* obtained from each other by multiplication by (y1 + y2)/(y1 + y2)
* then substitution of x^3 + 7 for y^2 (using the curve equation).
* For all pairs of nonzero points (a, b) at least one is defined,
* so this covers everything.
*/
secp256k1_fe_sqr(&zz, &a->z); /* z = Z1^2 */
u1 = a->x; secp256k1_fe_normalize_weak(&u1); /* u1 = U1 = X1*Z2^2 (1) */
secp256k1_fe_mul(&u2, &b->x, &zz); /* u2 = U2 = X2*Z1^2 (1) */
s1 = a->y; secp256k1_fe_normalize_weak(&s1); /* s1 = S1 = Y1*Z2^3 (1) */
secp256k1_fe_mul(&s2, &b->y, &zz); /* s2 = Y2*Z2^2 (1) */
secp256k1_fe_mul(&s2, &b->y, &zz); /* s2 = Y2*Z1^2 (1) */
secp256k1_fe_mul(&s2, &s2, &a->z); /* s2 = S2 = Y2*Z1^3 (1) */
z = a->z; /* z = Z = Z1*Z2 (8) */
t = u1; secp256k1_fe_add(&t, &u2); /* t = T = U1+U2 (2) */
m = s1; secp256k1_fe_add(&m, &s2); /* m = M = S1+S2 (2) */
secp256k1_fe_sqr(&n, &m); /* n = M^2 (1) */
secp256k1_fe_mul(&q, &n, &t); /* q = Q = T*M^2 (1) */
secp256k1_fe_sqr(&n, &n); /* n = M^4 (1) */
secp256k1_fe_sqr(&rr, &t); /* rr = T^2 (1) */
secp256k1_fe_mul(&t, &u1, &u2); secp256k1_fe_negate(&t, &t, 1); /* t = -U1*U2 (2) */
secp256k1_fe_add(&rr, &t); /* rr = R = T^2-U1*U2 (3) */
secp256k1_fe_sqr(&t, &rr); /* t = R^2 (1) */
secp256k1_fe_mul(&r->z, &m, &z); /* r->z = M*Z (1) */
infinity = secp256k1_fe_normalizes_to_zero(&r->z) * (1 - a->infinity);
secp256k1_fe_mul_int(&r->z, 2 * (1 - a->infinity)); /* r->z = Z3 = 2*M*Z (2) */
r->x = t; /* r->x = R^2 (1) */
secp256k1_fe_negate(&q, &q, 1); /* q = -Q (2) */
secp256k1_fe_add(&r->x, &q); /* r->x = R^2-Q (3) */
secp256k1_fe_normalize(&r->x);
secp256k1_fe_mul_int(&q, 3); /* q = -3*Q (6) */
secp256k1_fe_mul_int(&t, 2); /* t = 2*R^2 (2) */
secp256k1_fe_add(&t, &q); /* t = 2*R^2-3*Q (8) */
secp256k1_fe_mul(&t, &t, &rr); /* t = R*(2*R^2-3*Q) (1) */
secp256k1_fe_add(&t, &n); /* t = R*(2*R^2-3*Q)+M^4 (2) */
secp256k1_fe_negate(&r->y, &t, 2); /* r->y = R*(3*Q-2*R^2)-M^4 (3) */
secp256k1_fe_normalize_weak(&r->y);
secp256k1_fe_mul_int(&r->x, 4 * (1 - a->infinity)); /* r->x = X3 = 4*(R^2-Q) */
secp256k1_fe_mul_int(&r->y, 4 * (1 - a->infinity)); /* r->y = Y3 = 4*R*(3*Q-2*R^2)-4*M^4 (4) */
secp256k1_fe_negate(&m_alt, &u2, 1); /* Malt = -X2*Z1^2 */
secp256k1_fe_mul(&tt, &u1, &m_alt); /* tt = -U1*U2 (2) */
secp256k1_fe_add(&rr, &tt); /* rr = R = T^2-U1*U2 (3) */
/** If lambda = R/M = 0/0 we have a problem (except in the "trivial"
* case that Z = z1z2 = 0, and this is special-cased later on). */
degenerate = secp256k1_fe_normalizes_to_zero(&m) &
secp256k1_fe_normalizes_to_zero(&rr);
/* This only occurs when y1 == -y2 and x1^3 == x2^3, but x1 != x2.
* This means either x1 == beta*x2 or beta*x1 == x2, where beta is
* a nontrivial cube root of one. In either case, an alternate
* non-indeterminate expression for lambda is (y1 - y2)/(x1 - x2),
* so we set R/M equal to this. */
rr_alt = s1;
secp256k1_fe_mul_int(&rr_alt, 2); /* rr = Y1*Z2^3 - Y2*Z1^3 (2) */
secp256k1_fe_add(&m_alt, &u1); /* Malt = X1*Z2^2 - X2*Z1^2 */
/** In case a->infinity == 1, the above code results in r->x, r->y, and r->z all equal to 0.
* Replace r with b->x, b->y, 1 in that case.
*/
secp256k1_fe_cmov(&rr_alt, &rr, !degenerate);
secp256k1_fe_cmov(&m_alt, &m, !degenerate);
/* Now Ralt / Malt = lambda and is guaranteed not to be 0/0.
* From here on out Ralt and Malt represent the numerator
* and denominator of lambda; R and M represent the explicit
* expressions x1^2 + x2^2 + x1x2 and y1 + y2. */
secp256k1_fe_sqr(&n, &m_alt); /* n = Malt^2 (1) */
secp256k1_fe_mul(&q, &n, &t); /* q = Q = T*Malt^2 (1) */
/* These two lines use the observation that either M == Malt or M == 0,
* so M^3 * Malt is either Malt^4 (which is computed by squaring), or
* zero (which is "computed" by cmov). So the cost is one squaring
* versus two multiplications. */
secp256k1_fe_sqr(&n, &n);
secp256k1_fe_cmov(&n, &m, degenerate); /* n = M^3 * Malt (2) */
secp256k1_fe_sqr(&t, &rr_alt); /* t = Ralt^2 (1) */
secp256k1_fe_mul(&r->z, &a->z, &m_alt); /* r->z = Malt*Z (1) */
infinity = secp256k1_fe_normalizes_to_zero(&r->z) * (1 - a->infinity);
secp256k1_fe_mul_int(&r->z, 2); /* r->z = Z3 = 2*Malt*Z (2) */
secp256k1_fe_negate(&q, &q, 1); /* q = -Q (2) */
secp256k1_fe_add(&t, &q); /* t = Ralt^2-Q (3) */
secp256k1_fe_normalize_weak(&t);
r->x = t; /* r->x = Ralt^2-Q (1) */
secp256k1_fe_mul_int(&t, 2); /* t = 2*x3 (2) */
secp256k1_fe_add(&t, &q); /* t = 2*x3 - Q: (4) */
secp256k1_fe_mul(&t, &t, &rr_alt); /* t = Ralt*(2*x3 - Q) (1) */
secp256k1_fe_add(&t, &n); /* t = Ralt*(2*x3 - Q) + M^3*Malt (3) */
secp256k1_fe_negate(&r->y, &t, 3); /* r->y = Ralt*(Q - 2x3) - M^3*Malt (4) */
secp256k1_fe_normalize_weak(&r->y);
secp256k1_fe_mul_int(&r->x, 4); /* r->x = X3 = 4*(Ralt^2-Q) */
secp256k1_fe_mul_int(&r->y, 4); /* r->y = Y3 = 4*Ralt*(Q - 2x3) - 4*M^3*Malt (4) */
/** In case a->infinity == 1, replace r with (b->x, b->y, 1). */
secp256k1_fe_cmov(&r->x, &b->x, a->infinity);
secp256k1_fe_cmov(&r->y, &b->y, a->infinity);
secp256k1_fe_cmov(&r->z, &fe_1, a->infinity);
r->infinity = infinity;
}
static void secp256k1_gej_rescale(secp256k1_gej_t *r, const secp256k1_fe_t *s) {
static void secp256k1_gej_rescale(secp256k1_gej *r, const secp256k1_fe *s) {
/* Operations: 4 mul, 1 sqr */
secp256k1_fe_t zz;
secp256k1_fe zz;
VERIFY_CHECK(!secp256k1_fe_is_zero(s));
secp256k1_fe_sqr(&zz, s);
secp256k1_fe_mul(&r->x, &r->x, &zz); /* r->x *= s^2 */
@ -407,8 +590,8 @@ static void secp256k1_gej_rescale(secp256k1_gej_t *r, const secp256k1_fe_t *s) {
secp256k1_fe_mul(&r->z, &r->z, s); /* r->z *= s */
}
static void secp256k1_ge_to_storage(secp256k1_ge_storage_t *r, const secp256k1_ge_t *a) {
secp256k1_fe_t x, y;
static void secp256k1_ge_to_storage(secp256k1_ge_storage *r, const secp256k1_ge *a) {
secp256k1_fe x, y;
VERIFY_CHECK(!a->infinity);
x = a->x;
secp256k1_fe_normalize(&x);
@ -418,20 +601,20 @@ static void secp256k1_ge_to_storage(secp256k1_ge_storage_t *r, const secp256k1_g
secp256k1_fe_to_storage(&r->y, &y);
}
static void secp256k1_ge_from_storage(secp256k1_ge_t *r, const secp256k1_ge_storage_t *a) {
static void secp256k1_ge_from_storage(secp256k1_ge *r, const secp256k1_ge_storage *a) {
secp256k1_fe_from_storage(&r->x, &a->x);
secp256k1_fe_from_storage(&r->y, &a->y);
r->infinity = 0;
}
static SECP256K1_INLINE void secp256k1_ge_storage_cmov(secp256k1_ge_storage_t *r, const secp256k1_ge_storage_t *a, int flag) {
static SECP256K1_INLINE void secp256k1_ge_storage_cmov(secp256k1_ge_storage *r, const secp256k1_ge_storage *a, int flag) {
secp256k1_fe_storage_cmov(&r->x, &a->x, flag);
secp256k1_fe_storage_cmov(&r->y, &a->y, flag);
}
#ifdef USE_ENDOMORPHISM
static void secp256k1_gej_mul_lambda(secp256k1_gej_t *r, const secp256k1_gej_t *a) {
static const secp256k1_fe_t beta = SECP256K1_FE_CONST(
static void secp256k1_ge_mul_lambda(secp256k1_ge *r, const secp256k1_ge *a) {
static const secp256k1_fe beta = SECP256K1_FE_CONST(
0x7ae96a2bul, 0x657c0710ul, 0x6e64479eul, 0xac3434e9ul,
0x9cf04975ul, 0x12f58995ul, 0xc1396c28ul, 0x719501eeul
);

2
src/hash.h
View file

@ -34,7 +34,7 @@ typedef struct {
int retry;
} secp256k1_rfc6979_hmac_sha256_t;
static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha256_t *rng, const unsigned char *key, size_t keylen, const unsigned char *msg, size_t msglen, const unsigned char *rnd, size_t rndlen);
static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha256_t *rng, const unsigned char *key, size_t keylen);
static void secp256k1_rfc6979_hmac_sha256_generate(secp256k1_rfc6979_hmac_sha256_t *rng, unsigned char *out, size_t outlen);
static void secp256k1_rfc6979_hmac_sha256_finalize(secp256k1_rfc6979_hmac_sha256_t *rng);

12
src/hash_impl.h
View file

@ -202,7 +202,7 @@ static void secp256k1_hmac_sha256_finalize(secp256k1_hmac_sha256_t *hash, unsign
}
static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha256_t *rng, const unsigned char *key, size_t keylen, const unsigned char *msg, size_t msglen, const unsigned char *rnd, size_t rndlen) {
static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha256_t *rng, const unsigned char *key, size_t keylen) {
secp256k1_hmac_sha256_t hmac;
static const unsigned char zero[1] = {0x00};
static const unsigned char one[1] = {0x01};
@ -215,11 +215,6 @@ static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha2
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_write(&hmac, zero, 1);
secp256k1_hmac_sha256_write(&hmac, key, keylen);
secp256k1_hmac_sha256_write(&hmac, msg, msglen);
if (rnd && rndlen) {
/* RFC6979 3.6 "Additional data". */
secp256k1_hmac_sha256_write(&hmac, rnd, rndlen);
}
secp256k1_hmac_sha256_finalize(&hmac, rng->k);
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
@ -230,11 +225,6 @@ static void secp256k1_rfc6979_hmac_sha256_initialize(secp256k1_rfc6979_hmac_sha2
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);
secp256k1_hmac_sha256_write(&hmac, one, 1);
secp256k1_hmac_sha256_write(&hmac, key, keylen);
secp256k1_hmac_sha256_write(&hmac, msg, msglen);
if (rnd && rndlen) {
/* RFC6979 3.6 "Additional data". */
secp256k1_hmac_sha256_write(&hmac, rnd, rndlen);
}
secp256k1_hmac_sha256_finalize(&hmac, rng->k);
secp256k1_hmac_sha256_initialize(&hmac, rng->k, 32);
secp256k1_hmac_sha256_write(&hmac, rng->v, 32);

8
src/modules/ecdh/Makefile.am.include Normal file
View file

@ -0,0 +1,8 @@
include_HEADERS += include/secp256k1_ecdh.h
noinst_HEADERS += src/modules/ecdh/main_impl.h
noinst_HEADERS += src/modules/ecdh/tests_impl.h
if USE_BENCHMARK
noinst_PROGRAMS += bench_ecdh
bench_ecdh_SOURCES = src/bench_ecdh.c
bench_ecdh_LDADD = libsecp256k1.la $(SECP_LIBS)
endif

54
src/modules/ecdh/main_impl.h Normal file
View file

@ -0,0 +1,54 @@
/**********************************************************************
* Copyright (c) 2015 Andrew Poelstra *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_MODULE_ECDH_MAIN_
#define _SECP256K1_MODULE_ECDH_MAIN_
#include "include/secp256k1_ecdh.h"
#include "ecmult_const_impl.h"
int secp256k1_ecdh(const secp256k1_context* ctx, unsigned char *result, const secp256k1_pubkey *point, const unsigned char *scalar) {
int ret = 0;
int overflow = 0;
secp256k1_gej res;
secp256k1_ge pt;
secp256k1_scalar s;
ARG_CHECK(result != NULL);
ARG_CHECK(point != NULL);
ARG_CHECK(scalar != NULL);
(void)ctx;
secp256k1_pubkey_load(ctx, &pt, point);
secp256k1_scalar_set_b32(&s, scalar, &overflow);
if (overflow || secp256k1_scalar_is_zero(&s)) {
ret = 0;
} else {
unsigned char x[32];
unsigned char y[1];
secp256k1_sha256_t sha;
secp256k1_ecmult_const(&res, &pt, &s);
secp256k1_ge_set_gej(&pt, &res);
/* Compute a hash of the point in compressed form
* Note we cannot use secp256k1_eckey_pubkey_serialize here since it does not
* expect its output to be secret and has a timing sidechannel. */
secp256k1_fe_normalize(&pt.x);
secp256k1_fe_normalize(&pt.y);
secp256k1_fe_get_b32(x, &pt.x);
y[0] = 0x02 | secp256k1_fe_is_odd(&pt.y);
secp256k1_sha256_initialize(&sha);
secp256k1_sha256_write(&sha, y, sizeof(y));
secp256k1_sha256_write(&sha, x, sizeof(x));
secp256k1_sha256_finalize(&sha, result);
ret = 1;
}
secp256k1_scalar_clear(&s);
return ret;
}
#endif

75
src/modules/ecdh/tests_impl.h Normal file
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@ -0,0 +1,75 @@
/**********************************************************************
* Copyright (c) 2015 Andrew Poelstra *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_MODULE_ECDH_TESTS_
#define _SECP256K1_MODULE_ECDH_TESTS_
void test_ecdh_generator_basepoint(void) {
unsigned char s_one[32] = { 0 };
secp256k1_pubkey point[2];
int i;
s_one[31] = 1;
/* Check against pubkey creation when the basepoint is the generator */
for (i = 0; i < 100; ++i) {
secp256k1_sha256_t sha;
unsigned char s_b32[32];
unsigned char output_ecdh[32];
unsigned char output_ser[32];
unsigned char point_ser[33];
size_t point_ser_len = sizeof(point_ser);
secp256k1_scalar s;
random_scalar_order(&s);
secp256k1_scalar_get_b32(s_b32, &s);
/* compute using ECDH function */
CHECK(secp256k1_ec_pubkey_create(ctx, &point[0], s_one) == 1);
CHECK(secp256k1_ecdh(ctx, output_ecdh, &point[0], s_b32) == 1);
/* compute "explicitly" */
CHECK(secp256k1_ec_pubkey_create(ctx, &point[1], s_b32) == 1);
CHECK(secp256k1_ec_pubkey_serialize(ctx, point_ser, &point_ser_len, &point[1], SECP256K1_EC_COMPRESSED) == 1);
CHECK(point_ser_len == sizeof(point_ser));
secp256k1_sha256_initialize(&sha);
secp256k1_sha256_write(&sha, point_ser, point_ser_len);
secp256k1_sha256_finalize(&sha, output_ser);
/* compare */
CHECK(memcmp(output_ecdh, output_ser, sizeof(output_ser)) == 0);
}
}
void test_bad_scalar(void) {
unsigned char s_zero[32] = { 0 };
unsigned char s_overflow[32] = {
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff,
0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xfe,
0xba, 0xae, 0xdc, 0xe6, 0xaf, 0x48, 0xa0, 0x3b,
0xbf, 0xd2, 0x5e, 0x8c, 0xd0, 0x36, 0x41, 0x41
};
unsigned char s_rand[32] = { 0 };
unsigned char output[32];
secp256k1_scalar rand;
secp256k1_pubkey point;
/* Create random point */
random_scalar_order(&rand);
secp256k1_scalar_get_b32(s_rand, &rand);
CHECK(secp256k1_ec_pubkey_create(ctx, &point, s_rand) == 1);
/* Try to multiply it by bad values */
CHECK(secp256k1_ecdh(ctx, output, &point, s_zero) == 0);
CHECK(secp256k1_ecdh(ctx, output, &point, s_overflow) == 0);
/* ...and a good one */
s_overflow[31] -= 1;
CHECK(secp256k1_ecdh(ctx, output, &point, s_overflow) == 1);
}
void run_ecdh_tests(void) {
test_ecdh_generator_basepoint();
test_bad_scalar();
}
#endif

8
src/modules/recovery/Makefile.am.include Normal file
View file

@ -0,0 +1,8 @@
include_HEADERS += include/secp256k1_recovery.h
noinst_HEADERS += src/modules/recovery/main_impl.h
noinst_HEADERS += src/modules/recovery/tests_impl.h
if USE_BENCHMARK
noinst_PROGRAMS += bench_recover
bench_recover_SOURCES = src/bench_recover.c
bench_recover_LDADD = libsecp256k1.la $(SECP_LIBS)
endif

193
src/modules/recovery/main_impl.h Normal file
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@ -0,0 +1,193 @@
/**********************************************************************
* Copyright (c) 2013-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_MODULE_RECOVERY_MAIN_
#define _SECP256K1_MODULE_RECOVERY_MAIN_
#include "include/secp256k1_recovery.h"
static void secp256k1_ecdsa_recoverable_signature_load(const secp256k1_context* ctx, secp256k1_scalar* r, secp256k1_scalar* s, int* recid, const secp256k1_ecdsa_recoverable_signature* sig) {
(void)ctx;
if (sizeof(secp256k1_scalar) == 32) {
/* When the secp256k1_scalar type is exactly 32 byte, use its
* representation inside secp256k1_ecdsa_signature, as conversion is very fast.
* Note that secp256k1_ecdsa_signature_save must use the same representation. */
memcpy(r, &sig->data[0], 32);
memcpy(s, &sig->data[32], 32);
} else {
secp256k1_scalar_set_b32(r, &sig->data[0], NULL);
secp256k1_scalar_set_b32(s, &sig->data[32], NULL);
}
*recid = sig->data[64];
}
static void secp256k1_ecdsa_recoverable_signature_save(secp256k1_ecdsa_recoverable_signature* sig, const secp256k1_scalar* r, const secp256k1_scalar* s, int recid) {
if (sizeof(secp256k1_scalar) == 32) {
memcpy(&sig->data[0], r, 32);
memcpy(&sig->data[32], s, 32);
} else {
secp256k1_scalar_get_b32(&sig->data[0], r);
secp256k1_scalar_get_b32(&sig->data[32], s);
}
sig->data[64] = recid;
}
int secp256k1_ecdsa_recoverable_signature_parse_compact(const secp256k1_context* ctx, secp256k1_ecdsa_recoverable_signature* sig, const unsigned char *input64, int recid) {
secp256k1_scalar r, s;
int ret = 1;
int overflow = 0;
(void)ctx;
ARG_CHECK(sig != NULL);
ARG_CHECK(input64 != NULL);
ARG_CHECK(recid >= 0 && recid <= 3);
secp256k1_scalar_set_b32(&r, &input64[0], &overflow);
ret &= !overflow;
secp256k1_scalar_set_b32(&s, &input64[32], &overflow);
ret &= !overflow;
if (ret) {
secp256k1_ecdsa_recoverable_signature_save(sig, &r, &s, recid);
} else {
memset(sig, 0, sizeof(*sig));
}
return ret;
}
int secp256k1_ecdsa_recoverable_signature_serialize_compact(const secp256k1_context* ctx, unsigned char *output64, int *recid, const secp256k1_ecdsa_recoverable_signature* sig) {
secp256k1_scalar r, s;
(void)ctx;
ARG_CHECK(output64 != NULL);
ARG_CHECK(sig != NULL);
ARG_CHECK(recid != NULL);
secp256k1_ecdsa_recoverable_signature_load(ctx, &r, &s, recid, sig);
secp256k1_scalar_get_b32(&output64[0], &r);
secp256k1_scalar_get_b32(&output64[32], &s);
return 1;
}
int secp256k1_ecdsa_recoverable_signature_convert(const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const secp256k1_ecdsa_recoverable_signature* sigin) {
secp256k1_scalar r, s;
int recid;
(void)ctx;
ARG_CHECK(sig != NULL);
ARG_CHECK(sigin != NULL);
secp256k1_ecdsa_recoverable_signature_load(ctx, &r, &s, &recid, sigin);
secp256k1_ecdsa_signature_save(sig, &r, &s);
return 1;
}
static int secp256k1_ecdsa_sig_recover(const secp256k1_ecmult_context *ctx, const secp256k1_scalar *sigr, const secp256k1_scalar* sigs, secp256k1_ge *pubkey, const secp256k1_scalar *message, int recid) {
unsigned char brx[32];
secp256k1_fe fx;
secp256k1_ge x;
secp256k1_gej xj;
secp256k1_scalar rn, u1, u2;
secp256k1_gej qj;
int r;
if (secp256k1_scalar_is_zero(sigr) || secp256k1_scalar_is_zero(sigs)) {
return 0;
}
secp256k1_scalar_get_b32(brx, sigr);
r = secp256k1_fe_set_b32(&fx, brx);
(void)r;
VERIFY_CHECK(r); /* brx comes from a scalar, so is less than the order; certainly less than p */
if (recid & 2) {
if (secp256k1_fe_cmp_var(&fx, &secp256k1_ecdsa_const_p_minus_order) >= 0) {
return 0;
}
secp256k1_fe_add(&fx, &secp256k1_ecdsa_const_order_as_fe);
}
if (!secp256k1_ge_set_xo_var(&x, &fx, recid & 1)) {
return 0;
}
secp256k1_gej_set_ge(&xj, &x);
secp256k1_scalar_inverse_var(&rn, sigr);
secp256k1_scalar_mul(&u1, &rn, message);
secp256k1_scalar_negate(&u1, &u1);
secp256k1_scalar_mul(&u2, &rn, sigs);
secp256k1_ecmult(ctx, &qj, &xj, &u2, &u1);
secp256k1_ge_set_gej_var(pubkey, &qj);
return !secp256k1_gej_is_infinity(&qj);
}
int secp256k1_ecdsa_sign_recoverable(const secp256k1_context* ctx, secp256k1_ecdsa_recoverable_signature *signature, const unsigned char *msg32, const unsigned char *seckey, secp256k1_nonce_function noncefp, const void* noncedata) {
secp256k1_scalar r, s;
secp256k1_scalar sec, non, msg;
int recid;
int ret = 0;
int overflow = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(signature != NULL);
ARG_CHECK(seckey != NULL);
if (noncefp == NULL) {
noncefp = secp256k1_nonce_function_default;
}
secp256k1_scalar_set_b32(&sec, seckey, &overflow);
/* Fail if the secret key is invalid. */
if (!overflow && !secp256k1_scalar_is_zero(&sec)) {
unsigned int count = 0;
secp256k1_scalar_set_b32(&msg, msg32, NULL);
while (1) {
unsigned char nonce32[32];
ret = noncefp(nonce32, msg32, seckey, NULL, (void*)noncedata, count);
if (!ret) {
break;
}
secp256k1_scalar_set_b32(&non, nonce32, &overflow);
memset(nonce32, 0, 32);
if (!secp256k1_scalar_is_zero(&non) && !overflow) {
if (secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, &r, &s, &sec, &msg, &non, &recid)) {
break;
}
}
count++;
}
secp256k1_scalar_clear(&msg);
secp256k1_scalar_clear(&non);
secp256k1_scalar_clear(&sec);
}
if (ret) {
secp256k1_ecdsa_recoverable_signature_save(signature, &r, &s, recid);
} else {
memset(signature, 0, sizeof(*signature));
}
return ret;
}
int secp256k1_ecdsa_recover(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const secp256k1_ecdsa_recoverable_signature *signature, const unsigned char *msg32) {
secp256k1_ge q;
secp256k1_scalar r, s;
secp256k1_scalar m;
int recid;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(signature != NULL);
ARG_CHECK(pubkey != NULL);
secp256k1_ecdsa_recoverable_signature_load(ctx, &r, &s, &recid, signature);
ARG_CHECK(recid >= 0 && recid < 4);
secp256k1_scalar_set_b32(&m, msg32, NULL);
if (secp256k1_ecdsa_sig_recover(&ctx->ecmult_ctx, &r, &s, &q, &m, recid)) {
secp256k1_pubkey_save(pubkey, &q);
return 1;
} else {
memset(pubkey, 0, sizeof(*pubkey));
return 0;
}
}
#endif

250
src/modules/recovery/tests_impl.h Normal file
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@ -0,0 +1,250 @@
/**********************************************************************
* Copyright (c) 2013-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef _SECP256K1_MODULE_RECOVERY_TESTS_
#define _SECP256K1_MODULE_RECOVERY_TESTS_
void test_ecdsa_recovery_end_to_end(void) {
unsigned char extra[32] = {0x00};
unsigned char privkey[32];
unsigned char message[32];
secp256k1_ecdsa_signature signature[5];
secp256k1_ecdsa_recoverable_signature rsignature[5];
unsigned char sig[74];
secp256k1_pubkey pubkey;
secp256k1_pubkey recpubkey;
int recid = 0;
/* Generate a random key and message. */
{
secp256k1_scalar msg, key;
random_scalar_order_test(&msg);
random_scalar_order_test(&key);
secp256k1_scalar_get_b32(privkey, &key);
secp256k1_scalar_get_b32(message, &msg);
}
/* Construct and verify corresponding public key. */
CHECK(secp256k1_ec_seckey_verify(ctx, privkey) == 1);
CHECK(secp256k1_ec_pubkey_create(ctx, &pubkey, privkey) == 1);
/* Serialize/parse compact and verify/recover. */
extra[0] = 0;
CHECK(secp256k1_ecdsa_sign_recoverable(ctx, &rsignature[0], message, privkey, NULL, NULL) == 1);
CHECK(secp256k1_ecdsa_sign(ctx, &signature[0], message, privkey, NULL, NULL) == 1);
CHECK(secp256k1_ecdsa_sign_recoverable(ctx, &rsignature[4], message, privkey, NULL, NULL) == 1);
CHECK(secp256k1_ecdsa_sign_recoverable(ctx, &rsignature[1], message, privkey, NULL, extra) == 1);
extra[31] = 1;
CHECK(secp256k1_ecdsa_sign_recoverable(ctx, &rsignature[2], message, privkey, NULL, extra) == 1);
extra[31] = 0;
extra[0] = 1;
CHECK(secp256k1_ecdsa_sign_recoverable(ctx, &rsignature[3], message, privkey, NULL, extra) == 1);
CHECK(secp256k1_ecdsa_recoverable_signature_serialize_compact(ctx, sig, &recid, &rsignature[4]) == 1);
CHECK(secp256k1_ecdsa_recoverable_signature_convert(ctx, &signature[4], &rsignature[4]) == 1);
CHECK(memcmp(&signature[4], &signature[0], 64) == 0);
CHECK(secp256k1_ecdsa_verify(ctx, &signature[4], message, &pubkey) == 1);
memset(&rsignature[4], 0, sizeof(rsignature[4]));
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsignature[4], sig, recid) == 1);
CHECK(secp256k1_ecdsa_recoverable_signature_convert(ctx, &signature[4], &rsignature[4]) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &signature[4], message, &pubkey) == 1);
/* Parse compact (with recovery id) and recover. */
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsignature[4], sig, recid) == 1);
CHECK(secp256k1_ecdsa_recover(ctx, &recpubkey, &rsignature[4], message) == 1);
CHECK(memcmp(&pubkey, &recpubkey, sizeof(pubkey)) == 0);
/* Serialize/destroy/parse signature and verify again. */
CHECK(secp256k1_ecdsa_recoverable_signature_serialize_compact(ctx, sig, &recid, &rsignature[4]) == 1);
sig[secp256k1_rand_bits(6)] += 1 + secp256k1_rand_int(255);
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsignature[4], sig, recid) == 1);
CHECK(secp256k1_ecdsa_recoverable_signature_convert(ctx, &signature[4], &rsignature[4]) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &signature[4], message, &pubkey) == 0);
/* Recover again */
CHECK(secp256k1_ecdsa_recover(ctx, &recpubkey, &rsignature[4], message) == 0 ||
memcmp(&pubkey, &recpubkey, sizeof(pubkey)) != 0);
}
/* Tests several edge cases. */
void test_ecdsa_recovery_edge_cases(void) {
const unsigned char msg32[32] = {
'T', 'h', 'i', 's', ' ', 'i', 's', ' ',
'a', ' ', 'v', 'e', 'r', 'y', ' ', 's',
'e', 'c', 'r', 'e', 't', ' ', 'm', 'e',
's', 's', 'a', 'g', 'e', '.', '.', '.'
};
const unsigned char sig64[64] = {
/* Generated by signing the above message with nonce 'This is the nonce we will use...'
* and secret key 0 (which is not valid), resulting in recid 0. */
0x67, 0xCB, 0x28, 0x5F, 0x9C, 0xD1, 0x94, 0xE8,
0x40, 0xD6, 0x29, 0x39, 0x7A, 0xF5, 0x56, 0x96,
0x62, 0xFD, 0xE4, 0x46, 0x49, 0x99, 0x59, 0x63,
0x17, 0x9A, 0x7D, 0xD1, 0x7B, 0xD2, 0x35, 0x32,
0x4B, 0x1B, 0x7D, 0xF3, 0x4C, 0xE1, 0xF6, 0x8E,
0x69, 0x4F, 0xF6, 0xF1, 0x1A, 0xC7, 0x51, 0xDD,
0x7D, 0xD7, 0x3E, 0x38, 0x7E, 0xE4, 0xFC, 0x86,
0x6E, 0x1B, 0xE8, 0xEC, 0xC7, 0xDD, 0x95, 0x57
};
secp256k1_pubkey pubkey;
/* signature (r,s) = (4,4), which can be recovered with all 4 recids. */
const unsigned char sigb64[64] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
};
secp256k1_pubkey pubkeyb;
secp256k1_ecdsa_recoverable_signature rsig;
secp256k1_ecdsa_signature sig;
int recid;
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sig64, 0));
CHECK(!secp256k1_ecdsa_recover(ctx, &pubkey, &rsig, msg32));
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sig64, 1));
CHECK(secp256k1_ecdsa_recover(ctx, &pubkey, &rsig, msg32));
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sig64, 2));
CHECK(!secp256k1_ecdsa_recover(ctx, &pubkey, &rsig, msg32));
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sig64, 3));
CHECK(!secp256k1_ecdsa_recover(ctx, &pubkey, &rsig, msg32));
for (recid = 0; recid < 4; recid++) {
int i;
int recid2;
/* (4,4) encoded in DER. */
unsigned char sigbder[8] = {0x30, 0x06, 0x02, 0x01, 0x04, 0x02, 0x01, 0x04};
unsigned char sigcder_zr[7] = {0x30, 0x05, 0x02, 0x00, 0x02, 0x01, 0x01};
unsigned char sigcder_zs[7] = {0x30, 0x05, 0x02, 0x01, 0x01, 0x02, 0x00};
unsigned char sigbderalt1[39] = {
0x30, 0x25, 0x02, 0x20, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x04, 0x02, 0x01, 0x04,
};
unsigned char sigbderalt2[39] = {
0x30, 0x25, 0x02, 0x01, 0x04, 0x02, 0x20, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
};
unsigned char sigbderalt3[40] = {
0x30, 0x26, 0x02, 0x21, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x04, 0x02, 0x01, 0x04,
};
unsigned char sigbderalt4[40] = {
0x30, 0x26, 0x02, 0x01, 0x04, 0x02, 0x21, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x04,
};
/* (order + r,4) encoded in DER. */
unsigned char sigbderlong[40] = {
0x30, 0x26, 0x02, 0x21, 0x00, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF,
0xFF, 0xFF, 0xFF, 0xFF, 0xFE, 0xBA, 0xAE, 0xDC,
0xE6, 0xAF, 0x48, 0xA0, 0x3B, 0xBF, 0xD2, 0x5E,
0x8C, 0xD0, 0x36, 0x41, 0x45, 0x02, 0x01, 0x04
};
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sigb64, recid) == 1);
CHECK(secp256k1_ecdsa_recover(ctx, &pubkeyb, &rsig, msg32) == 1);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbder, sizeof(sigbder)) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyb) == 1);
for (recid2 = 0; recid2 < 4; recid2++) {
secp256k1_pubkey pubkey2b;
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sigb64, recid2) == 1);
CHECK(secp256k1_ecdsa_recover(ctx, &pubkey2b, &rsig, msg32) == 1);
/* Verifying with (order + r,4) should always fail. */
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbderlong, sizeof(sigbderlong)) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyb) == 0);
}
/* DER parsing tests. */
/* Zero length r/s. */
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigcder_zr, sizeof(sigcder_zr)) == 0);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigcder_zs, sizeof(sigcder_zs)) == 0);
/* Leading zeros. */
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbderalt1, sizeof(sigbderalt1)) == 0);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbderalt2, sizeof(sigbderalt2)) == 0);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbderalt3, sizeof(sigbderalt3)) == 0);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbderalt4, sizeof(sigbderalt4)) == 0);
sigbderalt3[4] = 1;
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbderalt3, sizeof(sigbderalt3)) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyb) == 0);
sigbderalt4[7] = 1;
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbderalt4, sizeof(sigbderalt4)) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyb) == 0);
/* Damage signature. */
sigbder[7]++;
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbder, sizeof(sigbder)) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyb) == 0);
sigbder[7]--;
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbder, 6) == 0);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbder, sizeof(sigbder) - 1) == 0);
for(i = 0; i < 8; i++) {
int c;
unsigned char orig = sigbder[i];
/*Try every single-byte change.*/
for (c = 0; c < 256; c++) {
if (c == orig ) {
continue;
}
sigbder[i] = c;
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigbder, sizeof(sigbder)) == 0 || secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyb) == 0);
}
sigbder[i] = orig;
}
}
/* Test r/s equal to zero */
{
/* (1,1) encoded in DER. */
unsigned char sigcder[8] = {0x30, 0x06, 0x02, 0x01, 0x01, 0x02, 0x01, 0x01};
unsigned char sigc64[64] = {
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x01,
};
secp256k1_pubkey pubkeyc;
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sigc64, 0) == 1);
CHECK(secp256k1_ecdsa_recover(ctx, &pubkeyc, &rsig, msg32) == 1);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigcder, sizeof(sigcder)) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyc) == 1);
sigcder[4] = 0;
sigc64[31] = 0;
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sigc64, 0) == 1);
CHECK(secp256k1_ecdsa_recover(ctx, &pubkeyb, &rsig, msg32) == 0);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigcder, sizeof(sigcder)) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyc) == 0);
sigcder[4] = 1;
sigcder[7] = 0;
sigc64[31] = 1;
sigc64[63] = 0;
CHECK(secp256k1_ecdsa_recoverable_signature_parse_compact(ctx, &rsig, sigc64, 0) == 1);
CHECK(secp256k1_ecdsa_recover(ctx, &pubkeyb, &rsig, msg32) == 0);
CHECK(secp256k1_ecdsa_signature_parse_der(ctx, &sig, sigcder, sizeof(sigcder)) == 1);
CHECK(secp256k1_ecdsa_verify(ctx, &sig, msg32, &pubkeyc) == 0);
}
}
void run_recovery_tests(void) {
int i;
for (i = 0; i < 64*count; i++) {
test_ecdsa_recovery_end_to_end();
}
test_ecdsa_recovery_edge_cases();
}
#endif

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include_HEADERS += include/secp256k1_schnorr.h
noinst_HEADERS += src/modules/schnorr/main_impl.h
noinst_HEADERS += src/modules/schnorr/schnorr.h
noinst_HEADERS += src/modules/schnorr/schnorr_impl.h
noinst_HEADERS += src/modules/schnorr/tests_impl.h
if USE_BENCHMARK
noinst_PROGRAMS += bench_schnorr_verify
bench_schnorr_verify_SOURCES = src/bench_schnorr_verify.c
bench_schnorr_verify_LDADD = libsecp256k1.la $(SECP_LIBS)
endif

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/**********************************************************************
* Copyright (c) 2014-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef SECP256K1_MODULE_SCHNORR_MAIN
#define SECP256K1_MODULE_SCHNORR_MAIN
#include "include/secp256k1_schnorr.h"
#include "modules/schnorr/schnorr_impl.h"
static void secp256k1_schnorr_msghash_sha256(unsigned char *h32, const unsigned char *r32, const unsigned char *msg32) {
secp256k1_sha256_t sha;
secp256k1_sha256_initialize(&sha);
secp256k1_sha256_write(&sha, r32, 32);
secp256k1_sha256_write(&sha, msg32, 32);
secp256k1_sha256_finalize(&sha, h32);
}
static const unsigned char secp256k1_schnorr_algo16[17] = "Schnorr+SHA256 ";
int secp256k1_schnorr_sign(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const unsigned char *seckey, secp256k1_nonce_function noncefp, const void* noncedata) {
secp256k1_scalar sec, non;
int ret = 0;
int overflow = 0;
unsigned int count = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(sig64 != NULL);
ARG_CHECK(seckey != NULL);
if (noncefp == NULL) {
noncefp = secp256k1_nonce_function_default;
}
secp256k1_scalar_set_b32(&sec, seckey, NULL);
while (1) {
unsigned char nonce32[32];
ret = noncefp(nonce32, msg32, seckey, secp256k1_schnorr_algo16, (void*)noncedata, count);
if (!ret) {
break;
}
secp256k1_scalar_set_b32(&non, nonce32, &overflow);
memset(nonce32, 0, 32);
if (!secp256k1_scalar_is_zero(&non) && !overflow) {
if (secp256k1_schnorr_sig_sign(&ctx->ecmult_gen_ctx, sig64, &sec, &non, NULL, secp256k1_schnorr_msghash_sha256, msg32)) {
break;
}
}
count++;
}
if (!ret) {
memset(sig64, 0, 64);
}
secp256k1_scalar_clear(&non);
secp256k1_scalar_clear(&sec);
return ret;
}
int secp256k1_schnorr_verify(const secp256k1_context* ctx, const unsigned char *sig64, const unsigned char *msg32, const secp256k1_pubkey *pubkey) {
secp256k1_ge q;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(sig64 != NULL);
ARG_CHECK(pubkey != NULL);
secp256k1_pubkey_load(ctx, &q, pubkey);
return secp256k1_schnorr_sig_verify(&ctx->ecmult_ctx, sig64, &q, secp256k1_schnorr_msghash_sha256, msg32);
}
int secp256k1_schnorr_recover(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *sig64, const unsigned char *msg32) {
secp256k1_ge q;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(sig64 != NULL);
ARG_CHECK(pubkey != NULL);
if (secp256k1_schnorr_sig_recover(&ctx->ecmult_ctx, sig64, &q, secp256k1_schnorr_msghash_sha256, msg32)) {
secp256k1_pubkey_save(pubkey, &q);
return 1;
} else {
memset(pubkey, 0, sizeof(*pubkey));
return 0;
}
}
int secp256k1_schnorr_generate_nonce_pair(const secp256k1_context* ctx, secp256k1_pubkey *pubnonce, unsigned char *privnonce32, const unsigned char *sec32, const unsigned char *msg32, secp256k1_nonce_function noncefp, const void* noncedata) {
int count = 0;
int ret = 1;
secp256k1_gej Qj;
secp256k1_ge Q;
secp256k1_scalar sec;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(sec32 != NULL);
ARG_CHECK(pubnonce != NULL);
ARG_CHECK(privnonce32 != NULL);
if (noncefp == NULL) {
noncefp = secp256k1_nonce_function_default;
}
do {
int overflow;
ret = noncefp(privnonce32, sec32, msg32, secp256k1_schnorr_algo16, (void*)noncedata, count++);
if (!ret) {
break;
}
secp256k1_scalar_set_b32(&sec, privnonce32, &overflow);
if (overflow || secp256k1_scalar_is_zero(&sec)) {
continue;
}
secp256k1_ecmult_gen(&ctx->ecmult_gen_ctx, &Qj, &sec);
secp256k1_ge_set_gej(&Q, &Qj);
secp256k1_pubkey_save(pubnonce, &Q);
break;
} while(1);
secp256k1_scalar_clear(&sec);
if (!ret) {
memset(pubnonce, 0, sizeof(*pubnonce));
}
return ret;
}
int secp256k1_schnorr_partial_sign(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char *msg32, const unsigned char *sec32, const secp256k1_pubkey *pubnonce_others, const unsigned char *secnonce32) {
int overflow = 0;
secp256k1_scalar sec, non;
secp256k1_ge pubnon;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(sig64 != NULL);
ARG_CHECK(sec32 != NULL);
ARG_CHECK(secnonce32 != NULL);
ARG_CHECK(pubnonce_others != NULL);
secp256k1_scalar_set_b32(&sec, sec32, &overflow);
if (overflow || secp256k1_scalar_is_zero(&sec)) {
return -1;
}
secp256k1_scalar_set_b32(&non, secnonce32, &overflow);
if (overflow || secp256k1_scalar_is_zero(&non)) {
return -1;
}
secp256k1_pubkey_load(ctx, &pubnon, pubnonce_others);
return secp256k1_schnorr_sig_sign(&ctx->ecmult_gen_ctx, sig64, &sec, &non, &pubnon, secp256k1_schnorr_msghash_sha256, msg32);
}
int secp256k1_schnorr_partial_combine(const secp256k1_context* ctx, unsigned char *sig64, const unsigned char * const *sig64sin, size_t n) {
ARG_CHECK(sig64 != NULL);
ARG_CHECK(n >= 1);
ARG_CHECK(sig64sin != NULL);
return secp256k1_schnorr_sig_combine(sig64, n, sig64sin);
}
#endif

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/***********************************************************************
* Copyright (c) 2014-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php. *
***********************************************************************/
#ifndef _SECP256K1_MODULE_SCHNORR_H_
#define _SECP256K1_MODULE_SCHNORR_H_
#include "scalar.h"
#include "group.h"
typedef void (*secp256k1_schnorr_msghash)(unsigned char *h32, const unsigned char *r32, const unsigned char *msg32);
static int secp256k1_schnorr_sig_sign(const secp256k1_ecmult_gen_context* ctx, unsigned char *sig64, const secp256k1_scalar *key, const secp256k1_scalar *nonce, const secp256k1_ge *pubnonce, secp256k1_schnorr_msghash hash, const unsigned char *msg32);
static int secp256k1_schnorr_sig_verify(const secp256k1_ecmult_context* ctx, const unsigned char *sig64, const secp256k1_ge *pubkey, secp256k1_schnorr_msghash hash, const unsigned char *msg32);
static int secp256k1_schnorr_sig_recover(const secp256k1_ecmult_context* ctx, const unsigned char *sig64, secp256k1_ge *pubkey, secp256k1_schnorr_msghash hash, const unsigned char *msg32);
static int secp256k1_schnorr_sig_combine(unsigned char *sig64, size_t n, const unsigned char * const *sig64ins);
#endif

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/***********************************************************************
* Copyright (c) 2014-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php. *
***********************************************************************/
#ifndef _SECP256K1_SCHNORR_IMPL_H_
#define _SECP256K1_SCHNORR_IMPL_H_
#include <string.h>
#include "schnorr.h"
#include "num.h"
#include "field.h"
#include "group.h"
#include "ecmult.h"
#include "ecmult_gen.h"
/**
* Custom Schnorr-based signature scheme. They support multiparty signing, public key
* recovery and batch validation.
*
* Rationale for verifying R's y coordinate:
* In order to support batch validation and public key recovery, the full R point must
* be known to verifiers, rather than just its x coordinate. In order to not risk
* being more strict in batch validation than normal validation, validators must be
* required to reject signatures with incorrect y coordinate. This is only possible
* by including a (relatively slow) field inverse, or a field square root. However,
* batch validation offers potentially much higher benefits than this cost.
*
* Rationale for having an implicit y coordinate oddness:
* If we commit to having the full R point known to verifiers, there are two mechanism.
* Either include its oddness in the signature, or give it an implicit fixed value.
* As the R y coordinate can be flipped by a simple negation of the nonce, we choose the
* latter, as it comes with nearly zero impact on signing or validation performance, and
* saves a byte in the signature.
*
* Signing:
* Inputs: 32-byte message m, 32-byte scalar key x (!=0), 32-byte scalar nonce k (!=0)
*
* Compute point R = k * G. Reject nonce if R's y coordinate is odd (or negate nonce).
* Compute 32-byte r, the serialization of R's x coordinate.
* Compute scalar h = Hash(r || m). Reject nonce if h == 0 or h >= order.
* Compute scalar s = k - h * x.
* The signature is (r, s).
*
*
* Verification:
* Inputs: 32-byte message m, public key point Q, signature: (32-byte r, scalar s)
*
* Signature is invalid if s >= order.
* Signature is invalid if r >= p.
* Compute scalar h = Hash(r || m). Signature is invalid if h == 0 or h >= order.
* Option 1 (faster for single verification):
* Compute point R = h * Q + s * G. Signature is invalid if R is infinity or R's y coordinate is odd.
* Signature is valid if the serialization of R's x coordinate equals r.
* Option 2 (allows batch validation and pubkey recovery):
* Decompress x coordinate r into point R, with odd y coordinate. Fail if R is not on the curve.
* Signature is valid if R + h * Q + s * G == 0.
*/
static int secp256k1_schnorr_sig_sign(const secp256k1_ecmult_gen_context* ctx, unsigned char *sig64, const secp256k1_scalar *key, const secp256k1_scalar *nonce, const secp256k1_ge *pubnonce, secp256k1_schnorr_msghash hash, const unsigned char *msg32) {
secp256k1_gej Rj;
secp256k1_ge Ra;
unsigned char h32[32];
secp256k1_scalar h, s;
int overflow;
secp256k1_scalar n;
if (secp256k1_scalar_is_zero(key) || secp256k1_scalar_is_zero(nonce)) {
return 0;
}
n = *nonce;
secp256k1_ecmult_gen(ctx, &Rj, &n);
if (pubnonce != NULL) {
secp256k1_gej_add_ge(&Rj, &Rj, pubnonce);
}
secp256k1_ge_set_gej(&Ra, &Rj);
secp256k1_fe_normalize(&Ra.y);
if (secp256k1_fe_is_odd(&Ra.y)) {
/* R's y coordinate is odd, which is not allowed (see rationale above).
Force it to be even by negating the nonce. Note that this even works
for multiparty signing, as the R point is known to all participants,
which can all decide to flip the sign in unison, resulting in the
overall R point to be negated too. */
secp256k1_scalar_negate(&n, &n);
}
secp256k1_fe_normalize(&Ra.x);
secp256k1_fe_get_b32(sig64, &Ra.x);
hash(h32, sig64, msg32);
overflow = 0;
secp256k1_scalar_set_b32(&h, h32, &overflow);
if (overflow || secp256k1_scalar_is_zero(&h)) {
secp256k1_scalar_clear(&n);
return 0;
}
secp256k1_scalar_mul(&s, &h, key);
secp256k1_scalar_negate(&s, &s);
secp256k1_scalar_add(&s, &s, &n);
secp256k1_scalar_clear(&n);
secp256k1_scalar_get_b32(sig64 + 32, &s);
return 1;
}
static int secp256k1_schnorr_sig_verify(const secp256k1_ecmult_context* ctx, const unsigned char *sig64, const secp256k1_ge *pubkey, secp256k1_schnorr_msghash hash, const unsigned char *msg32) {
secp256k1_gej Qj, Rj;
secp256k1_ge Ra;
secp256k1_fe Rx;
secp256k1_scalar h, s;
unsigned char hh[32];
int overflow;
if (secp256k1_ge_is_infinity(pubkey)) {
return 0;
}
hash(hh, sig64, msg32);
overflow = 0;
secp256k1_scalar_set_b32(&h, hh, &overflow);
if (overflow || secp256k1_scalar_is_zero(&h)) {
return 0;
}
overflow = 0;
secp256k1_scalar_set_b32(&s, sig64 + 32, &overflow);
if (overflow) {
return 0;
}
if (!secp256k1_fe_set_b32(&Rx, sig64)) {
return 0;
}
secp256k1_gej_set_ge(&Qj, pubkey);
secp256k1_ecmult(ctx, &Rj, &Qj, &h, &s);
if (secp256k1_gej_is_infinity(&Rj)) {
return 0;
}
secp256k1_ge_set_gej_var(&Ra, &Rj);
secp256k1_fe_normalize_var(&Ra.y);
if (secp256k1_fe_is_odd(&Ra.y)) {
return 0;
}
return secp256k1_fe_equal_var(&Rx, &Ra.x);
}
static int secp256k1_schnorr_sig_recover(const secp256k1_ecmult_context* ctx, const unsigned char *sig64, secp256k1_ge *pubkey, secp256k1_schnorr_msghash hash, const unsigned char *msg32) {
secp256k1_gej Qj, Rj;
secp256k1_ge Ra;
secp256k1_fe Rx;
secp256k1_scalar h, s;
unsigned char hh[32];
int overflow;
hash(hh, sig64, msg32);
overflow = 0;
secp256k1_scalar_set_b32(&h, hh, &overflow);
if (overflow || secp256k1_scalar_is_zero(&h)) {
return 0;
}
overflow = 0;
secp256k1_scalar_set_b32(&s, sig64 + 32, &overflow);
if (overflow) {
return 0;
}
if (!secp256k1_fe_set_b32(&Rx, sig64)) {
return 0;
}
if (!secp256k1_ge_set_xo_var(&Ra, &Rx, 0)) {
return 0;
}
secp256k1_gej_set_ge(&Rj, &Ra);
secp256k1_scalar_inverse_var(&h, &h);
secp256k1_scalar_negate(&s, &s);
secp256k1_scalar_mul(&s, &s, &h);
secp256k1_ecmult(ctx, &Qj, &Rj, &h, &s);
if (secp256k1_gej_is_infinity(&Qj)) {
return 0;
}
secp256k1_ge_set_gej(pubkey, &Qj);
return 1;
}
static int secp256k1_schnorr_sig_combine(unsigned char *sig64, size_t n, const unsigned char * const *sig64ins) {
secp256k1_scalar s = SECP256K1_SCALAR_CONST(0, 0, 0, 0, 0, 0, 0, 0);
size_t i;
for (i = 0; i < n; i++) {
secp256k1_scalar si;
int overflow;
secp256k1_scalar_set_b32(&si, sig64ins[i] + 32, &overflow);
if (overflow) {
return -1;
}
if (i) {
if (memcmp(sig64ins[i - 1], sig64ins[i], 32) != 0) {
return -1;
}
}
secp256k1_scalar_add(&s, &s, &si);
}
if (secp256k1_scalar_is_zero(&s)) {
return 0;
}
memcpy(sig64, sig64ins[0], 32);
secp256k1_scalar_get_b32(sig64 + 32, &s);
secp256k1_scalar_clear(&s);
return 1;
}
#endif

175
src/modules/schnorr/tests_impl.h Normal file
View file

@ -0,0 +1,175 @@
/**********************************************************************
* Copyright (c) 2014-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
#ifndef SECP256K1_MODULE_SCHNORR_TESTS
#define SECP256K1_MODULE_SCHNORR_TESTS
#include "include/secp256k1_schnorr.h"
void test_schnorr_end_to_end(void) {
unsigned char privkey[32];
unsigned char message[32];
unsigned char schnorr_signature[64];
secp256k1_pubkey pubkey, recpubkey;
/* Generate a random key and message. */
{
secp256k1_scalar key;
random_scalar_order_test(&key);
secp256k1_scalar_get_b32(privkey, &key);
secp256k1_rand256_test(message);
}
/* Construct and verify corresponding public key. */
CHECK(secp256k1_ec_seckey_verify(ctx, privkey) == 1);
CHECK(secp256k1_ec_pubkey_create(ctx, &pubkey, privkey) == 1);
/* Schnorr sign. */
CHECK(secp256k1_schnorr_sign(ctx, schnorr_signature, message, privkey, NULL, NULL) == 1);
CHECK(secp256k1_schnorr_verify(ctx, schnorr_signature, message, &pubkey) == 1);
CHECK(secp256k1_schnorr_recover(ctx, &recpubkey, schnorr_signature, message) == 1);
CHECK(memcmp(&pubkey, &recpubkey, sizeof(pubkey)) == 0);
/* Destroy signature and verify again. */
schnorr_signature[secp256k1_rand_bits(6)] += 1 + secp256k1_rand_int(255);
CHECK(secp256k1_schnorr_verify(ctx, schnorr_signature, message, &pubkey) == 0);
CHECK(secp256k1_schnorr_recover(ctx, &recpubkey, schnorr_signature, message) != 1 ||
memcmp(&pubkey, &recpubkey, sizeof(pubkey)) != 0);
}
/** Horribly broken hash function. Do not use for anything but tests. */
void test_schnorr_hash(unsigned char *h32, const unsigned char *r32, const unsigned char *msg32) {
int i;
for (i = 0; i < 32; i++) {
h32[i] = r32[i] ^ msg32[i];
}
}
void test_schnorr_sign_verify(void) {
unsigned char msg32[32];
unsigned char sig64[3][64];
secp256k1_gej pubkeyj[3];
secp256k1_ge pubkey[3];
secp256k1_scalar nonce[3], key[3];
int i = 0;
int k;
secp256k1_rand256_test(msg32);
for (k = 0; k < 3; k++) {
random_scalar_order_test(&key[k]);
do {
random_scalar_order_test(&nonce[k]);
if (secp256k1_schnorr_sig_sign(&ctx->ecmult_gen_ctx, sig64[k], &key[k], &nonce[k], NULL, &test_schnorr_hash, msg32)) {
break;
}
} while(1);
secp256k1_ecmult_gen(&ctx->ecmult_gen_ctx, &pubkeyj[k], &key[k]);
secp256k1_ge_set_gej_var(&pubkey[k], &pubkeyj[k]);
CHECK(secp256k1_schnorr_sig_verify(&ctx->ecmult_ctx, sig64[k], &pubkey[k], &test_schnorr_hash, msg32));
for (i = 0; i < 4; i++) {
int pos = secp256k1_rand_bits(6);
int mod = 1 + secp256k1_rand_int(255);
sig64[k][pos] ^= mod;
CHECK(secp256k1_schnorr_sig_verify(&ctx->ecmult_ctx, sig64[k], &pubkey[k], &test_schnorr_hash, msg32) == 0);
sig64[k][pos] ^= mod;
}
}
}
void test_schnorr_threshold(void) {
unsigned char msg[32];
unsigned char sec[5][32];
secp256k1_pubkey pub[5];
unsigned char nonce[5][32];
secp256k1_pubkey pubnonce[5];
unsigned char sig[5][64];
const unsigned char* sigs[5];
unsigned char allsig[64];
const secp256k1_pubkey* pubs[5];
secp256k1_pubkey allpub;
int n, i;
int damage;
int ret = 0;
damage = secp256k1_rand_bits(1) ? (1 + secp256k1_rand_int(4)) : 0;
secp256k1_rand256_test(msg);
n = 2 + secp256k1_rand_int(4);
for (i = 0; i < n; i++) {
do {
secp256k1_rand256_test(sec[i]);
} while (!secp256k1_ec_seckey_verify(ctx, sec[i]));
CHECK(secp256k1_ec_pubkey_create(ctx, &pub[i], sec[i]));
CHECK(secp256k1_schnorr_generate_nonce_pair(ctx, &pubnonce[i], nonce[i], msg, sec[i], NULL, NULL));
pubs[i] = &pub[i];
}
if (damage == 1) {
nonce[secp256k1_rand_int(n)][secp256k1_rand_int(32)] ^= 1 + secp256k1_rand_int(255);
} else if (damage == 2) {
sec[secp256k1_rand_int(n)][secp256k1_rand_int(32)] ^= 1 + secp256k1_rand_int(255);
}
for (i = 0; i < n; i++) {
secp256k1_pubkey allpubnonce;
const secp256k1_pubkey *pubnonces[4];
int j;
for (j = 0; j < i; j++) {
pubnonces[j] = &pubnonce[j];
}
for (j = i + 1; j < n; j++) {
pubnonces[j - 1] = &pubnonce[j];
}
CHECK(secp256k1_ec_pubkey_combine(ctx, &allpubnonce, pubnonces, n - 1));
ret |= (secp256k1_schnorr_partial_sign(ctx, sig[i], msg, sec[i], &allpubnonce, nonce[i]) != 1) * 1;
sigs[i] = sig[i];
}
if (damage == 3) {
sig[secp256k1_rand_int(n)][secp256k1_rand_bits(6)] ^= 1 + secp256k1_rand_int(255);
}
ret |= (secp256k1_ec_pubkey_combine(ctx, &allpub, pubs, n) != 1) * 2;
if ((ret & 1) == 0) {
ret |= (secp256k1_schnorr_partial_combine(ctx, allsig, sigs, n) != 1) * 4;
}
if (damage == 4) {
allsig[secp256k1_rand_int(32)] ^= 1 + secp256k1_rand_int(255);
}
if ((ret & 7) == 0) {
ret |= (secp256k1_schnorr_verify(ctx, allsig, msg, &allpub) != 1) * 8;
}
CHECK((ret == 0) == (damage == 0));
}
void test_schnorr_recovery(void) {
unsigned char msg32[32];
unsigned char sig64[64];
secp256k1_ge Q;
secp256k1_rand256_test(msg32);
secp256k1_rand256_test(sig64);
secp256k1_rand256_test(sig64 + 32);
if (secp256k1_schnorr_sig_recover(&ctx->ecmult_ctx, sig64, &Q, &test_schnorr_hash, msg32) == 1) {
CHECK(secp256k1_schnorr_sig_verify(&ctx->ecmult_ctx, sig64, &Q, &test_schnorr_hash, msg32) == 1);
}
}
void run_schnorr_tests(void) {
int i;
for (i = 0; i < 32*count; i++) {
test_schnorr_end_to_end();
}
for (i = 0; i < 32 * count; i++) {
test_schnorr_sign_verify();
}
for (i = 0; i < 16 * count; i++) {
test_schnorr_recovery();
}
for (i = 0; i < 10 * count; i++) {
test_schnorr_threshold();
}
}
#endif

28
src/num.h
View file

@ -20,48 +20,48 @@
#endif
/** Copy a number. */
static void secp256k1_num_copy(secp256k1_num_t *r, const secp256k1_num_t *a);
static void secp256k1_num_copy(secp256k1_num *r, const secp256k1_num *a);
/** Convert a number's absolute value to a binary big-endian string.
* There must be enough place. */
static void secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num_t *a);
static void secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num *a);
/** Set a number to the value of a binary big-endian string. */
static void secp256k1_num_set_bin(secp256k1_num_t *r, const unsigned char *a, unsigned int alen);
static void secp256k1_num_set_bin(secp256k1_num *r, const unsigned char *a, unsigned int alen);
/** Compute a modular inverse. The input must be less than the modulus. */
static void secp256k1_num_mod_inverse(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *m);
static void secp256k1_num_mod_inverse(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *m);
/** Compare the absolute value of two numbers. */
static int secp256k1_num_cmp(const secp256k1_num_t *a, const secp256k1_num_t *b);
static int secp256k1_num_cmp(const secp256k1_num *a, const secp256k1_num *b);
/** Test whether two number are equal (including sign). */
static int secp256k1_num_eq(const secp256k1_num_t *a, const secp256k1_num_t *b);
static int secp256k1_num_eq(const secp256k1_num *a, const secp256k1_num *b);
/** Add two (signed) numbers. */
static void secp256k1_num_add(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b);
static void secp256k1_num_add(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b);
/** Subtract two (signed) numbers. */
static void secp256k1_num_sub(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b);
static void secp256k1_num_sub(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b);
/** Multiply two (signed) numbers. */
static void secp256k1_num_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b);
static void secp256k1_num_mul(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b);
/** Replace a number by its remainder modulo m. M's sign is ignored. The result is a number between 0 and m-1,
even if r was negative. */
static void secp256k1_num_mod(secp256k1_num_t *r, const secp256k1_num_t *m);
static void secp256k1_num_mod(secp256k1_num *r, const secp256k1_num *m);
/** Right-shift the passed number by bits bits. */
static void secp256k1_num_shift(secp256k1_num_t *r, int bits);
static void secp256k1_num_shift(secp256k1_num *r, int bits);
/** Check whether a number is zero. */
static int secp256k1_num_is_zero(const secp256k1_num_t *a);
static int secp256k1_num_is_zero(const secp256k1_num *a);
/** Check whether a number is strictly negative. */
static int secp256k1_num_is_neg(const secp256k1_num_t *a);
static int secp256k1_num_is_neg(const secp256k1_num *a);
/** Change a number's sign. */
static void secp256k1_num_negate(secp256k1_num_t *r);
static void secp256k1_num_negate(secp256k1_num *r);
#endif

2
src/num_gmp.h
View file

@ -15,6 +15,6 @@ typedef struct {
mp_limb_t data[2*NUM_LIMBS];
int neg;
int limbs;
} secp256k1_num_t;
} secp256k1_num;
#endif

40
src/num_gmp_impl.h
View file

@ -15,18 +15,18 @@
#include "num.h"
#ifdef VERIFY
static void secp256k1_num_sanity(const secp256k1_num_t *a) {
static void secp256k1_num_sanity(const secp256k1_num *a) {
VERIFY_CHECK(a->limbs == 1 || (a->limbs > 1 && a->data[a->limbs-1] != 0));
}
#else
#define secp256k1_num_sanity(a) do { } while(0)
#endif
static void secp256k1_num_copy(secp256k1_num_t *r, const secp256k1_num_t *a) {
static void secp256k1_num_copy(secp256k1_num *r, const secp256k1_num *a) {
*r = *a;
}
static void secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num_t *a) {
static void secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const secp256k1_num *a) {
unsigned char tmp[65];
int len = 0;
int shift = 0;
@ -42,7 +42,7 @@ static void secp256k1_num_get_bin(unsigned char *r, unsigned int rlen, const sec
memset(tmp, 0, sizeof(tmp));
}
static void secp256k1_num_set_bin(secp256k1_num_t *r, const unsigned char *a, unsigned int alen) {
static void secp256k1_num_set_bin(secp256k1_num *r, const unsigned char *a, unsigned int alen) {
int len;
VERIFY_CHECK(alen > 0);
VERIFY_CHECK(alen <= 64);
@ -59,7 +59,7 @@ static void secp256k1_num_set_bin(secp256k1_num_t *r, const unsigned char *a, un
}
}
static void secp256k1_num_add_abs(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
static void secp256k1_num_add_abs(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b) {
mp_limb_t c = mpn_add(r->data, a->data, a->limbs, b->data, b->limbs);
r->limbs = a->limbs;
if (c != 0) {
@ -68,8 +68,9 @@ static void secp256k1_num_add_abs(secp256k1_num_t *r, const secp256k1_num_t *a,
}
}
static void secp256k1_num_sub_abs(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
static void secp256k1_num_sub_abs(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b) {
mp_limb_t c = mpn_sub(r->data, a->data, a->limbs, b->data, b->limbs);
(void)c;
VERIFY_CHECK(c == 0);
r->limbs = a->limbs;
while (r->limbs > 1 && r->data[r->limbs-1]==0) {
@ -77,7 +78,7 @@ static void secp256k1_num_sub_abs(secp256k1_num_t *r, const secp256k1_num_t *a,
}
}
static void secp256k1_num_mod(secp256k1_num_t *r, const secp256k1_num_t *m) {
static void secp256k1_num_mod(secp256k1_num *r, const secp256k1_num *m) {
secp256k1_num_sanity(r);
secp256k1_num_sanity(m);
@ -97,7 +98,7 @@ static void secp256k1_num_mod(secp256k1_num_t *r, const secp256k1_num_t *m) {
}
}
static void secp256k1_num_mod_inverse(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *m) {
static void secp256k1_num_mod_inverse(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *m) {
int i;
mp_limb_t g[NUM_LIMBS+1];
mp_limb_t u[NUM_LIMBS+1];
@ -125,6 +126,7 @@ static void secp256k1_num_mod_inverse(secp256k1_num_t *r, const secp256k1_num_t
}
sn = NUM_LIMBS+1;
gn = mpn_gcdext(g, r->data, &sn, u, m->limbs, v, m->limbs);
(void)gn;
VERIFY_CHECK(gn == 1);
VERIFY_CHECK(g[0] == 1);
r->neg = a->neg ^ m->neg;
@ -142,15 +144,15 @@ static void secp256k1_num_mod_inverse(secp256k1_num_t *r, const secp256k1_num_t
memset(v, 0, sizeof(v));
}
static int secp256k1_num_is_zero(const secp256k1_num_t *a) {
static int secp256k1_num_is_zero(const secp256k1_num *a) {
return (a->limbs == 1 && a->data[0] == 0);
}
static int secp256k1_num_is_neg(const secp256k1_num_t *a) {
static int secp256k1_num_is_neg(const secp256k1_num *a) {
return (a->limbs > 1 || a->data[0] != 0) && a->neg;
}
static int secp256k1_num_cmp(const secp256k1_num_t *a, const secp256k1_num_t *b) {
static int secp256k1_num_cmp(const secp256k1_num *a, const secp256k1_num *b) {
if (a->limbs > b->limbs) {
return 1;
}
@ -160,7 +162,7 @@ static int secp256k1_num_cmp(const secp256k1_num_t *a, const secp256k1_num_t *b)
return mpn_cmp(a->data, b->data, a->limbs);
}
static int secp256k1_num_eq(const secp256k1_num_t *a, const secp256k1_num_t *b) {
static int secp256k1_num_eq(const secp256k1_num *a, const secp256k1_num *b) {
if (a->limbs > b->limbs) {
return 0;
}
@ -173,7 +175,7 @@ static int secp256k1_num_eq(const secp256k1_num_t *a, const secp256k1_num_t *b)
return mpn_cmp(a->data, b->data, a->limbs) == 0;
}
static void secp256k1_num_subadd(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b, int bneg) {
static void secp256k1_num_subadd(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b, int bneg) {
if (!(b->neg ^ bneg ^ a->neg)) { /* a and b have the same sign */
r->neg = a->neg;
if (a->limbs >= b->limbs) {
@ -192,19 +194,19 @@ static void secp256k1_num_subadd(secp256k1_num_t *r, const secp256k1_num_t *a, c
}
}
static void secp256k1_num_add(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
static void secp256k1_num_add(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b) {
secp256k1_num_sanity(a);
secp256k1_num_sanity(b);
secp256k1_num_subadd(r, a, b, 0);
}
static void secp256k1_num_sub(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
static void secp256k1_num_sub(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b) {
secp256k1_num_sanity(a);
secp256k1_num_sanity(b);
secp256k1_num_subadd(r, a, b, 1);
}
static void secp256k1_num_mul(secp256k1_num_t *r, const secp256k1_num_t *a, const secp256k1_num_t *b) {
static void secp256k1_num_mul(secp256k1_num *r, const secp256k1_num *a, const secp256k1_num *b) {
mp_limb_t tmp[2*NUM_LIMBS+1];
secp256k1_num_sanity(a);
secp256k1_num_sanity(b);
@ -231,13 +233,13 @@ static void secp256k1_num_mul(secp256k1_num_t *r, const secp256k1_num_t *a, cons
memset(tmp, 0, sizeof(tmp));
}
static void secp256k1_num_shift(secp256k1_num_t *r, int bits) {
int i;
static void secp256k1_num_shift(secp256k1_num *r, int bits) {
if (bits % GMP_NUMB_BITS) {
/* Shift within limbs. */
mpn_rshift(r->data, r->data, r->limbs, bits % GMP_NUMB_BITS);
}
if (bits >= GMP_NUMB_BITS) {
int i;
/* Shift full limbs. */
for (i = 0; i < r->limbs; i++) {
int index = i + (bits / GMP_NUMB_BITS);
@ -253,7 +255,7 @@ static void secp256k1_num_shift(secp256k1_num_t *r, int bits) {
}
}
static void secp256k1_num_negate(secp256k1_num_t *r) {
static void secp256k1_num_negate(secp256k1_num *r) {
r->neg ^= 1;
}

57
src/scalar.h
View file

@ -22,72 +22,83 @@
#endif
/** Clear a scalar to prevent the leak of sensitive data. */
static void secp256k1_scalar_clear(secp256k1_scalar_t *r);
static void secp256k1_scalar_clear(secp256k1_scalar *r);
/** Access bits from a scalar. All requested bits must belong to the same 32-bit limb. */
static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar_t *a, unsigned int offset, unsigned int count);
static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar *a, unsigned int offset, unsigned int count);
/** Access bits from a scalar. Not constant time. */
static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar_t *a, unsigned int offset, unsigned int count);
static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar *a, unsigned int offset, unsigned int count);
/** Set a scalar from a big endian byte array. */
static void secp256k1_scalar_set_b32(secp256k1_scalar_t *r, const unsigned char *bin, int *overflow);
static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *bin, int *overflow);
/** Set a scalar to an unsigned integer. */
static void secp256k1_scalar_set_int(secp256k1_scalar_t *r, unsigned int v);
static void secp256k1_scalar_set_int(secp256k1_scalar *r, unsigned int v);
/** Convert a scalar to a byte array. */
static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar_t* a);
static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar* a);
/** Add two scalars together (modulo the group order). Returns whether it overflowed. */
static int secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b);
static int secp256k1_scalar_add(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b);
/** Add a power of two to a scalar. The result is not allowed to overflow. */
static void secp256k1_scalar_add_bit(secp256k1_scalar_t *r, unsigned int bit);
/** Conditionally add a power of two to a scalar. The result is not allowed to overflow. */
static void secp256k1_scalar_cadd_bit(secp256k1_scalar *r, unsigned int bit, int flag);
/** Multiply two scalars (modulo the group order). */
static void secp256k1_scalar_mul(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b);
static void secp256k1_scalar_mul(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b);
/** Shift a scalar right by some amount strictly between 0 and 16, returning
* the low bits that were shifted off */
static int secp256k1_scalar_shr_int(secp256k1_scalar *r, int n);
/** Compute the square of a scalar (modulo the group order). */
static void secp256k1_scalar_sqr(secp256k1_scalar_t *r, const secp256k1_scalar_t *a);
static void secp256k1_scalar_sqr(secp256k1_scalar *r, const secp256k1_scalar *a);
/** Compute the inverse of a scalar (modulo the group order). */
static void secp256k1_scalar_inverse(secp256k1_scalar_t *r, const secp256k1_scalar_t *a);
static void secp256k1_scalar_inverse(secp256k1_scalar *r, const secp256k1_scalar *a);
/** Compute the inverse of a scalar (modulo the group order), without constant-time guarantee. */
static void secp256k1_scalar_inverse_var(secp256k1_scalar_t *r, const secp256k1_scalar_t *a);
static void secp256k1_scalar_inverse_var(secp256k1_scalar *r, const secp256k1_scalar *a);
/** Compute the complement of a scalar (modulo the group order). */
static void secp256k1_scalar_negate(secp256k1_scalar_t *r, const secp256k1_scalar_t *a);
static void secp256k1_scalar_negate(secp256k1_scalar *r, const secp256k1_scalar *a);
/** Check whether a scalar equals zero. */
static int secp256k1_scalar_is_zero(const secp256k1_scalar_t *a);
static int secp256k1_scalar_is_zero(const secp256k1_scalar *a);
/** Check whether a scalar equals one. */
static int secp256k1_scalar_is_one(const secp256k1_scalar_t *a);
static int secp256k1_scalar_is_one(const secp256k1_scalar *a);
/** Check whether a scalar, considered as an nonnegative integer, is even. */
static int secp256k1_scalar_is_even(const secp256k1_scalar *a);
/** Check whether a scalar is higher than the group order divided by 2. */
static int secp256k1_scalar_is_high(const secp256k1_scalar_t *a);
static int secp256k1_scalar_is_high(const secp256k1_scalar *a);
/** Conditionally negate a number, in constant time.
* Returns -1 if the number was negated, 1 otherwise */
static int secp256k1_scalar_cond_negate(secp256k1_scalar *a, int flag);
#ifndef USE_NUM_NONE
/** Convert a scalar to a number. */
static void secp256k1_scalar_get_num(secp256k1_num_t *r, const secp256k1_scalar_t *a);
static void secp256k1_scalar_get_num(secp256k1_num *r, const secp256k1_scalar *a);
/** Get the order of the group as a number. */
static void secp256k1_scalar_order_get_num(secp256k1_num_t *r);
static void secp256k1_scalar_order_get_num(secp256k1_num *r);
#endif
/** Compare two scalars. */
static int secp256k1_scalar_eq(const secp256k1_scalar_t *a, const secp256k1_scalar_t *b);
static int secp256k1_scalar_eq(const secp256k1_scalar *a, const secp256k1_scalar *b);
#ifdef USE_ENDOMORPHISM
/** Find r1 and r2 such that r1+r2*2^128 = a. */
static void secp256k1_scalar_split_128(secp256k1_scalar_t *r1, secp256k1_scalar_t *r2, const secp256k1_scalar_t *a);
static void secp256k1_scalar_split_128(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *a);
/** Find r1 and r2 such that r1+r2*lambda = a, and r1 and r2 are maximum 128 bits long (see secp256k1_gej_mul_lambda). */
static void secp256k1_scalar_split_lambda_var(secp256k1_scalar_t *r1, secp256k1_scalar_t *r2, const secp256k1_scalar_t *a);
static void secp256k1_scalar_split_lambda(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *a);
#endif
/** Multiply a and b (without taking the modulus!), divide by 2**shift, and round to the nearest integer. Shift must be at least 256. */
static void secp256k1_scalar_mul_shift_var(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b, unsigned int shift);
static void secp256k1_scalar_mul_shift_var(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b, unsigned int shift);
#endif

2
src/scalar_4x64.h
View file

@ -12,7 +12,7 @@
/** A scalar modulo the group order of the secp256k1 curve. */
typedef struct {
uint64_t d[4];
} secp256k1_scalar_t;
} secp256k1_scalar;
#define SECP256K1_SCALAR_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {{((uint64_t)(d1)) << 32 | (d0), ((uint64_t)(d3)) << 32 | (d2), ((uint64_t)(d5)) << 32 | (d4), ((uint64_t)(d7)) << 32 | (d6)}}

81
src/scalar_4x64_impl.h
View file

@ -24,26 +24,26 @@
#define SECP256K1_N_H_2 ((uint64_t)0xFFFFFFFFFFFFFFFFULL)
#define SECP256K1_N_H_3 ((uint64_t)0x7FFFFFFFFFFFFFFFULL)
SECP256K1_INLINE static void secp256k1_scalar_clear(secp256k1_scalar_t *r) {
SECP256K1_INLINE static void secp256k1_scalar_clear(secp256k1_scalar *r) {
r->d[0] = 0;
r->d[1] = 0;
r->d[2] = 0;
r->d[3] = 0;
}
SECP256K1_INLINE static void secp256k1_scalar_set_int(secp256k1_scalar_t *r, unsigned int v) {
SECP256K1_INLINE static void secp256k1_scalar_set_int(secp256k1_scalar *r, unsigned int v) {
r->d[0] = v;
r->d[1] = 0;
r->d[2] = 0;
r->d[3] = 0;
}
SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar_t *a, unsigned int offset, unsigned int count) {
SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar *a, unsigned int offset, unsigned int count) {
VERIFY_CHECK((offset + count - 1) >> 6 == offset >> 6);
return (a->d[offset >> 6] >> (offset & 0x3F)) & ((((uint64_t)1) << count) - 1);
}
SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar_t *a, unsigned int offset, unsigned int count) {
SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar *a, unsigned int offset, unsigned int count) {
VERIFY_CHECK(count < 32);
VERIFY_CHECK(offset + count <= 256);
if ((offset + count - 1) >> 6 == offset >> 6) {
@ -54,7 +54,7 @@ SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits_var(const secp256
}
}
SECP256K1_INLINE static int secp256k1_scalar_check_overflow(const secp256k1_scalar_t *a) {
SECP256K1_INLINE static int secp256k1_scalar_check_overflow(const secp256k1_scalar *a) {
int yes = 0;
int no = 0;
no |= (a->d[3] < SECP256K1_N_3); /* No need for a > check. */
@ -66,7 +66,7 @@ SECP256K1_INLINE static int secp256k1_scalar_check_overflow(const secp256k1_scal
return yes;
}
SECP256K1_INLINE static int secp256k1_scalar_reduce(secp256k1_scalar_t *r, unsigned int overflow) {
SECP256K1_INLINE static int secp256k1_scalar_reduce(secp256k1_scalar *r, unsigned int overflow) {
uint128_t t;
VERIFY_CHECK(overflow <= 1);
t = (uint128_t)r->d[0] + overflow * SECP256K1_N_C_0;
@ -80,7 +80,7 @@ SECP256K1_INLINE static int secp256k1_scalar_reduce(secp256k1_scalar_t *r, unsig
return overflow;
}
static int secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b) {
static int secp256k1_scalar_add(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b) {
int overflow;
uint128_t t = (uint128_t)a->d[0] + b->d[0];
r->d[0] = t & 0xFFFFFFFFFFFFFFFFULL; t >>= 64;
@ -96,9 +96,10 @@ static int secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t
return overflow;
}
static void secp256k1_scalar_add_bit(secp256k1_scalar_t *r, unsigned int bit) {
static void secp256k1_scalar_cadd_bit(secp256k1_scalar *r, unsigned int bit, int flag) {
uint128_t t;
VERIFY_CHECK(bit < 256);
bit += ((uint32_t) flag - 1) & 0x100; /* forcing (bit >> 6) > 3 makes this a noop */
t = (uint128_t)r->d[0] + (((uint64_t)((bit >> 6) == 0)) << (bit & 0x3F));
r->d[0] = t & 0xFFFFFFFFFFFFFFFFULL; t >>= 64;
t += (uint128_t)r->d[1] + (((uint64_t)((bit >> 6) == 1)) << (bit & 0x3F));
@ -113,7 +114,7 @@ static void secp256k1_scalar_add_bit(secp256k1_scalar_t *r, unsigned int bit) {
#endif
}
static void secp256k1_scalar_set_b32(secp256k1_scalar_t *r, const unsigned char *b32, int *overflow) {
static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *b32, int *overflow) {
int over;
r->d[0] = (uint64_t)b32[31] | (uint64_t)b32[30] << 8 | (uint64_t)b32[29] << 16 | (uint64_t)b32[28] << 24 | (uint64_t)b32[27] << 32 | (uint64_t)b32[26] << 40 | (uint64_t)b32[25] << 48 | (uint64_t)b32[24] << 56;
r->d[1] = (uint64_t)b32[23] | (uint64_t)b32[22] << 8 | (uint64_t)b32[21] << 16 | (uint64_t)b32[20] << 24 | (uint64_t)b32[19] << 32 | (uint64_t)b32[18] << 40 | (uint64_t)b32[17] << 48 | (uint64_t)b32[16] << 56;
@ -125,18 +126,18 @@ static void secp256k1_scalar_set_b32(secp256k1_scalar_t *r, const unsigned char
}
}
static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar_t* a) {
static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar* a) {
bin[0] = a->d[3] >> 56; bin[1] = a->d[3] >> 48; bin[2] = a->d[3] >> 40; bin[3] = a->d[3] >> 32; bin[4] = a->d[3] >> 24; bin[5] = a->d[3] >> 16; bin[6] = a->d[3] >> 8; bin[7] = a->d[3];
bin[8] = a->d[2] >> 56; bin[9] = a->d[2] >> 48; bin[10] = a->d[2] >> 40; bin[11] = a->d[2] >> 32; bin[12] = a->d[2] >> 24; bin[13] = a->d[2] >> 16; bin[14] = a->d[2] >> 8; bin[15] = a->d[2];
bin[16] = a->d[1] >> 56; bin[17] = a->d[1] >> 48; bin[18] = a->d[1] >> 40; bin[19] = a->d[1] >> 32; bin[20] = a->d[1] >> 24; bin[21] = a->d[1] >> 16; bin[22] = a->d[1] >> 8; bin[23] = a->d[1];
bin[24] = a->d[0] >> 56; bin[25] = a->d[0] >> 48; bin[26] = a->d[0] >> 40; bin[27] = a->d[0] >> 32; bin[28] = a->d[0] >> 24; bin[29] = a->d[0] >> 16; bin[30] = a->d[0] >> 8; bin[31] = a->d[0];
}
SECP256K1_INLINE static int secp256k1_scalar_is_zero(const secp256k1_scalar_t *a) {
SECP256K1_INLINE static int secp256k1_scalar_is_zero(const secp256k1_scalar *a) {
return (a->d[0] | a->d[1] | a->d[2] | a->d[3]) == 0;
}
static void secp256k1_scalar_negate(secp256k1_scalar_t *r, const secp256k1_scalar_t *a) {
static void secp256k1_scalar_negate(secp256k1_scalar *r, const secp256k1_scalar *a) {
uint64_t nonzero = 0xFFFFFFFFFFFFFFFFULL * (secp256k1_scalar_is_zero(a) == 0);
uint128_t t = (uint128_t)(~a->d[0]) + SECP256K1_N_0 + 1;
r->d[0] = t & nonzero; t >>= 64;
@ -148,11 +149,11 @@ static void secp256k1_scalar_negate(secp256k1_scalar_t *r, const secp256k1_scala
r->d[3] = t & nonzero;
}
SECP256K1_INLINE static int secp256k1_scalar_is_one(const secp256k1_scalar_t *a) {
SECP256K1_INLINE static int secp256k1_scalar_is_one(const secp256k1_scalar *a) {
return ((a->d[0] ^ 1) | a->d[1] | a->d[2] | a->d[3]) == 0;
}
static int secp256k1_scalar_is_high(const secp256k1_scalar_t *a) {
static int secp256k1_scalar_is_high(const secp256k1_scalar *a) {
int yes = 0;
int no = 0;
no |= (a->d[3] < SECP256K1_N_H_3);
@ -164,6 +165,22 @@ static int secp256k1_scalar_is_high(const secp256k1_scalar_t *a) {
return yes;
}
static int secp256k1_scalar_cond_negate(secp256k1_scalar *r, int flag) {
/* If we are flag = 0, mask = 00...00 and this is a no-op;
* if we are flag = 1, mask = 11...11 and this is identical to secp256k1_scalar_negate */
uint64_t mask = !flag - 1;
uint64_t nonzero = (secp256k1_scalar_is_zero(r) != 0) - 1;
uint128_t t = (uint128_t)(r->d[0] ^ mask) + ((SECP256K1_N_0 + 1) & mask);
r->d[0] = t & nonzero; t >>= 64;
t += (uint128_t)(r->d[1] ^ mask) + (SECP256K1_N_1 & mask);
r->d[1] = t & nonzero; t >>= 64;
t += (uint128_t)(r->d[2] ^ mask) + (SECP256K1_N_2 & mask);
r->d[2] = t & nonzero; t >>= 64;
t += (uint128_t)(r->d[3] ^ mask) + (SECP256K1_N_3 & mask);
r->d[3] = t & nonzero;
return 2 * (mask == 0) - 1;
}
/* Inspired by the macros in OpenSSL's crypto/bn/asm/x86_64-gcc.c. */
/** Add a*b to the number defined by (c0,c1,c2). c2 must never overflow. */
@ -250,7 +267,7 @@ static int secp256k1_scalar_is_high(const secp256k1_scalar_t *a) {
VERIFY_CHECK(c2 == 0); \
}
static void secp256k1_scalar_reduce_512(secp256k1_scalar_t *r, const uint64_t *l) {
static void secp256k1_scalar_reduce_512(secp256k1_scalar *r, const uint64_t *l) {
#ifdef USE_ASM_X86_64
/* Reduce 512 bits into 385. */
uint64_t m0, m1, m2, m3, m4, m5, m6;
@ -559,7 +576,7 @@ static void secp256k1_scalar_reduce_512(secp256k1_scalar_t *r, const uint64_t *l
secp256k1_scalar_reduce(r, c + secp256k1_scalar_check_overflow(r));
}
static void secp256k1_scalar_mul_512(uint64_t l[8], const secp256k1_scalar_t *a, const secp256k1_scalar_t *b) {
static void secp256k1_scalar_mul_512(uint64_t l[8], const secp256k1_scalar *a, const secp256k1_scalar *b) {
#ifdef USE_ASM_X86_64
const uint64_t *pb = b->d;
__asm__ __volatile__(
@ -721,12 +738,12 @@ static void secp256k1_scalar_mul_512(uint64_t l[8], const secp256k1_scalar_t *a,
extract(l[5]);
muladd_fast(a->d[3], b->d[3]);
extract_fast(l[6]);
VERIFY_CHECK(c1 <= 0);
VERIFY_CHECK(c1 == 0);
l[7] = c0;
#endif
}
static void secp256k1_scalar_sqr_512(uint64_t l[8], const secp256k1_scalar_t *a) {
static void secp256k1_scalar_sqr_512(uint64_t l[8], const secp256k1_scalar *a) {
#ifdef USE_ASM_X86_64
__asm__ __volatile__(
/* Preload */
@ -871,19 +888,32 @@ static void secp256k1_scalar_sqr_512(uint64_t l[8], const secp256k1_scalar_t *a)
#undef extract
#undef extract_fast
static void secp256k1_scalar_mul(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b) {
static void secp256k1_scalar_mul(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b) {
uint64_t l[8];
secp256k1_scalar_mul_512(l, a, b);
secp256k1_scalar_reduce_512(r, l);
}
static void secp256k1_scalar_sqr(secp256k1_scalar_t *r, const secp256k1_scalar_t *a) {
static int secp256k1_scalar_shr_int(secp256k1_scalar *r, int n) {
int ret;
VERIFY_CHECK(n > 0);
VERIFY_CHECK(n < 16);
ret = r->d[0] & ((1 << n) - 1);
r->d[0] = (r->d[0] >> n) + (r->d[1] << (64 - n));
r->d[1] = (r->d[1] >> n) + (r->d[2] << (64 - n));
r->d[2] = (r->d[2] >> n) + (r->d[3] << (64 - n));
r->d[3] = (r->d[3] >> n);
return ret;
}
static void secp256k1_scalar_sqr(secp256k1_scalar *r, const secp256k1_scalar *a) {
uint64_t l[8];
secp256k1_scalar_sqr_512(l, a);
secp256k1_scalar_reduce_512(r, l);
}
static void secp256k1_scalar_split_128(secp256k1_scalar_t *r1, secp256k1_scalar_t *r2, const secp256k1_scalar_t *a) {
#ifdef USE_ENDOMORPHISM
static void secp256k1_scalar_split_128(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *a) {
r1->d[0] = a->d[0];
r1->d[1] = a->d[1];
r1->d[2] = 0;
@ -893,12 +923,13 @@ static void secp256k1_scalar_split_128(secp256k1_scalar_t *r1, secp256k1_scalar_
r2->d[2] = 0;
r2->d[3] = 0;
}
#endif
SECP256K1_INLINE static int secp256k1_scalar_eq(const secp256k1_scalar_t *a, const secp256k1_scalar_t *b) {
SECP256K1_INLINE static int secp256k1_scalar_eq(const secp256k1_scalar *a, const secp256k1_scalar *b) {
return ((a->d[0] ^ b->d[0]) | (a->d[1] ^ b->d[1]) | (a->d[2] ^ b->d[2]) | (a->d[3] ^ b->d[3])) == 0;
}
SECP256K1_INLINE static void secp256k1_scalar_mul_shift_var(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b, unsigned int shift) {
SECP256K1_INLINE static void secp256k1_scalar_mul_shift_var(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b, unsigned int shift) {
uint64_t l[8];
unsigned int shiftlimbs;
unsigned int shiftlow;
@ -912,9 +943,7 @@ SECP256K1_INLINE static void secp256k1_scalar_mul_shift_var(secp256k1_scalar_t *
r->d[1] = shift < 448 ? (l[1 + shiftlimbs] >> shiftlow | (shift < 384 && shiftlow ? (l[2 + shiftlimbs] << shifthigh) : 0)) : 0;
r->d[2] = shift < 384 ? (l[2 + shiftlimbs] >> shiftlow | (shift < 320 && shiftlow ? (l[3 + shiftlimbs] << shifthigh) : 0)) : 0;
r->d[3] = shift < 320 ? (l[3 + shiftlimbs] >> shiftlow) : 0;
if ((l[(shift - 1) >> 6] >> ((shift - 1) & 0x3f)) & 1) {
secp256k1_scalar_add_bit(r, 0);
}
secp256k1_scalar_cadd_bit(r, 0, (l[(shift - 1) >> 6] >> ((shift - 1) & 0x3f)) & 1);
}
#endif

2
src/scalar_8x32.h
View file

@ -12,7 +12,7 @@
/** A scalar modulo the group order of the secp256k1 curve. */
typedef struct {
uint32_t d[8];
} secp256k1_scalar_t;
} secp256k1_scalar;
#define SECP256K1_SCALAR_CONST(d7, d6, d5, d4, d3, d2, d1, d0) {{(d0), (d1), (d2), (d3), (d4), (d5), (d6), (d7)}}

90
src/scalar_8x32_impl.h
View file

@ -34,7 +34,7 @@
#define SECP256K1_N_H_6 ((uint32_t)0xFFFFFFFFUL)
#define SECP256K1_N_H_7 ((uint32_t)0x7FFFFFFFUL)
SECP256K1_INLINE static void secp256k1_scalar_clear(secp256k1_scalar_t *r) {
SECP256K1_INLINE static void secp256k1_scalar_clear(secp256k1_scalar *r) {
r->d[0] = 0;
r->d[1] = 0;
r->d[2] = 0;
@ -45,7 +45,7 @@ SECP256K1_INLINE static void secp256k1_scalar_clear(secp256k1_scalar_t *r) {
r->d[7] = 0;
}
SECP256K1_INLINE static void secp256k1_scalar_set_int(secp256k1_scalar_t *r, unsigned int v) {
SECP256K1_INLINE static void secp256k1_scalar_set_int(secp256k1_scalar *r, unsigned int v) {
r->d[0] = v;
r->d[1] = 0;
r->d[2] = 0;
@ -56,12 +56,12 @@ SECP256K1_INLINE static void secp256k1_scalar_set_int(secp256k1_scalar_t *r, uns
r->d[7] = 0;
}
SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar_t *a, unsigned int offset, unsigned int count) {
SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits(const secp256k1_scalar *a, unsigned int offset, unsigned int count) {
VERIFY_CHECK((offset + count - 1) >> 5 == offset >> 5);
return (a->d[offset >> 5] >> (offset & 0x1F)) & ((1 << count) - 1);
}
SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar_t *a, unsigned int offset, unsigned int count) {
SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits_var(const secp256k1_scalar *a, unsigned int offset, unsigned int count) {
VERIFY_CHECK(count < 32);
VERIFY_CHECK(offset + count <= 256);
if ((offset + count - 1) >> 5 == offset >> 5) {
@ -72,7 +72,7 @@ SECP256K1_INLINE static unsigned int secp256k1_scalar_get_bits_var(const secp256
}
}
SECP256K1_INLINE static int secp256k1_scalar_check_overflow(const secp256k1_scalar_t *a) {
SECP256K1_INLINE static int secp256k1_scalar_check_overflow(const secp256k1_scalar *a) {
int yes = 0;
int no = 0;
no |= (a->d[7] < SECP256K1_N_7); /* No need for a > check. */
@ -90,7 +90,7 @@ SECP256K1_INLINE static int secp256k1_scalar_check_overflow(const secp256k1_scal
return yes;
}
SECP256K1_INLINE static int secp256k1_scalar_reduce(secp256k1_scalar_t *r, uint32_t overflow) {
SECP256K1_INLINE static int secp256k1_scalar_reduce(secp256k1_scalar *r, uint32_t overflow) {
uint64_t t;
VERIFY_CHECK(overflow <= 1);
t = (uint64_t)r->d[0] + overflow * SECP256K1_N_C_0;
@ -112,7 +112,7 @@ SECP256K1_INLINE static int secp256k1_scalar_reduce(secp256k1_scalar_t *r, uint3
return overflow;
}
static int secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b) {
static int secp256k1_scalar_add(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b) {
int overflow;
uint64_t t = (uint64_t)a->d[0] + b->d[0];
r->d[0] = t & 0xFFFFFFFFULL; t >>= 32;
@ -136,9 +136,10 @@ static int secp256k1_scalar_add(secp256k1_scalar_t *r, const secp256k1_scalar_t
return overflow;
}
static void secp256k1_scalar_add_bit(secp256k1_scalar_t *r, unsigned int bit) {
static void secp256k1_scalar_cadd_bit(secp256k1_scalar *r, unsigned int bit, int flag) {
uint64_t t;
VERIFY_CHECK(bit < 256);
bit += ((uint32_t) flag - 1) & 0x100; /* forcing (bit >> 5) > 7 makes this a noop */
t = (uint64_t)r->d[0] + (((uint32_t)((bit >> 5) == 0)) << (bit & 0x1F));
r->d[0] = t & 0xFFFFFFFFULL; t >>= 32;
t += (uint64_t)r->d[1] + (((uint32_t)((bit >> 5) == 1)) << (bit & 0x1F));
@ -161,7 +162,7 @@ static void secp256k1_scalar_add_bit(secp256k1_scalar_t *r, unsigned int bit) {
#endif
}
static void secp256k1_scalar_set_b32(secp256k1_scalar_t *r, const unsigned char *b32, int *overflow) {
static void secp256k1_scalar_set_b32(secp256k1_scalar *r, const unsigned char *b32, int *overflow) {
int over;
r->d[0] = (uint32_t)b32[31] | (uint32_t)b32[30] << 8 | (uint32_t)b32[29] << 16 | (uint32_t)b32[28] << 24;
r->d[1] = (uint32_t)b32[27] | (uint32_t)b32[26] << 8 | (uint32_t)b32[25] << 16 | (uint32_t)b32[24] << 24;
@ -177,7 +178,7 @@ static void secp256k1_scalar_set_b32(secp256k1_scalar_t *r, const unsigned char
}
}
static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar_t* a) {
static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar* a) {
bin[0] = a->d[7] >> 24; bin[1] = a->d[7] >> 16; bin[2] = a->d[7] >> 8; bin[3] = a->d[7];
bin[4] = a->d[6] >> 24; bin[5] = a->d[6] >> 16; bin[6] = a->d[6] >> 8; bin[7] = a->d[6];
bin[8] = a->d[5] >> 24; bin[9] = a->d[5] >> 16; bin[10] = a->d[5] >> 8; bin[11] = a->d[5];
@ -188,11 +189,11 @@ static void secp256k1_scalar_get_b32(unsigned char *bin, const secp256k1_scalar_
bin[28] = a->d[0] >> 24; bin[29] = a->d[0] >> 16; bin[30] = a->d[0] >> 8; bin[31] = a->d[0];
}
SECP256K1_INLINE static int secp256k1_scalar_is_zero(const secp256k1_scalar_t *a) {
SECP256K1_INLINE static int secp256k1_scalar_is_zero(const secp256k1_scalar *a) {
return (a->d[0] | a->d[1] | a->d[2] | a->d[3] | a->d[4] | a->d[5] | a->d[6] | a->d[7]) == 0;
}
static void secp256k1_scalar_negate(secp256k1_scalar_t *r, const secp256k1_scalar_t *a) {
static void secp256k1_scalar_negate(secp256k1_scalar *r, const secp256k1_scalar *a) {
uint32_t nonzero = 0xFFFFFFFFUL * (secp256k1_scalar_is_zero(a) == 0);
uint64_t t = (uint64_t)(~a->d[0]) + SECP256K1_N_0 + 1;
r->d[0] = t & nonzero; t >>= 32;
@ -212,11 +213,11 @@ static void secp256k1_scalar_negate(secp256k1_scalar_t *r, const secp256k1_scala
r->d[7] = t & nonzero;
}
SECP256K1_INLINE static int secp256k1_scalar_is_one(const secp256k1_scalar_t *a) {
SECP256K1_INLINE static int secp256k1_scalar_is_one(const secp256k1_scalar *a) {
return ((a->d[0] ^ 1) | a->d[1] | a->d[2] | a->d[3] | a->d[4] | a->d[5] | a->d[6] | a->d[7]) == 0;
}
static int secp256k1_scalar_is_high(const secp256k1_scalar_t *a) {
static int secp256k1_scalar_is_high(const secp256k1_scalar *a) {
int yes = 0;
int no = 0;
no |= (a->d[7] < SECP256K1_N_H_7);
@ -234,6 +235,31 @@ static int secp256k1_scalar_is_high(const secp256k1_scalar_t *a) {
return yes;
}
static int secp256k1_scalar_cond_negate(secp256k1_scalar *r, int flag) {
/* If we are flag = 0, mask = 00...00 and this is a no-op;
* if we are flag = 1, mask = 11...11 and this is identical to secp256k1_scalar_negate */
uint32_t mask = !flag - 1;
uint32_t nonzero = 0xFFFFFFFFUL * (secp256k1_scalar_is_zero(r) == 0);
uint64_t t = (uint64_t)(r->d[0] ^ mask) + ((SECP256K1_N_0 + 1) & mask);
r->d[0] = t & nonzero; t >>= 32;
t += (uint64_t)(r->d[1] ^ mask) + (SECP256K1_N_1 & mask);
r->d[1] = t & nonzero; t >>= 32;
t += (uint64_t)(r->d[2] ^ mask) + (SECP256K1_N_2 & mask);
r->d[2] = t & nonzero; t >>= 32;
t += (uint64_t)(r->d[3] ^ mask) + (SECP256K1_N_3 & mask);
r->d[3] = t & nonzero; t >>= 32;
t += (uint64_t)(r->d[4] ^ mask) + (SECP256K1_N_4 & mask);
r->d[4] = t & nonzero; t >>= 32;
t += (uint64_t)(r->d[5] ^ mask) + (SECP256K1_N_5 & mask);
r->d[5] = t & nonzero; t >>= 32;
t += (uint64_t)(r->d[6] ^ mask) + (SECP256K1_N_6 & mask);
r->d[6] = t & nonzero; t >>= 32;
t += (uint64_t)(r->d[7] ^ mask) + (SECP256K1_N_7 & mask);
r->d[7] = t & nonzero;
return 2 * (mask == 0) - 1;
}
/* Inspired by the macros in OpenSSL's crypto/bn/asm/x86_64-gcc.c. */
/** Add a*b to the number defined by (c0,c1,c2). c2 must never overflow. */
@ -320,7 +346,7 @@ static int secp256k1_scalar_is_high(const secp256k1_scalar_t *a) {
VERIFY_CHECK(c2 == 0); \
}
static void secp256k1_scalar_reduce_512(secp256k1_scalar_t *r, const uint32_t *l) {
static void secp256k1_scalar_reduce_512(secp256k1_scalar *r, const uint32_t *l) {
uint64_t c;
uint32_t n0 = l[8], n1 = l[9], n2 = l[10], n3 = l[11], n4 = l[12], n5 = l[13], n6 = l[14], n7 = l[15];
uint32_t m0, m1, m2, m3, m4, m5, m6, m7, m8, m9, m10, m11, m12;
@ -462,7 +488,7 @@ static void secp256k1_scalar_reduce_512(secp256k1_scalar_t *r, const uint32_t *l
secp256k1_scalar_reduce(r, c + secp256k1_scalar_check_overflow(r));
}
static void secp256k1_scalar_mul_512(uint32_t *l, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b) {
static void secp256k1_scalar_mul_512(uint32_t *l, const secp256k1_scalar *a, const secp256k1_scalar *b) {
/* 96 bit accumulator. */
uint32_t c0 = 0, c1 = 0, c2 = 0;
@ -550,7 +576,7 @@ static void secp256k1_scalar_mul_512(uint32_t *l, const secp256k1_scalar_t *a, c
l[15] = c0;
}
static void secp256k1_scalar_sqr_512(uint32_t *l, const secp256k1_scalar_t *a) {
static void secp256k1_scalar_sqr_512(uint32_t *l, const secp256k1_scalar *a) {
/* 96 bit accumulator. */
uint32_t c0 = 0, c1 = 0, c2 = 0;
@ -618,20 +644,36 @@ static void secp256k1_scalar_sqr_512(uint32_t *l, const secp256k1_scalar_t *a) {
#undef extract
#undef extract_fast
static void secp256k1_scalar_mul(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b) {
static void secp256k1_scalar_mul(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b) {
uint32_t l[16];
secp256k1_scalar_mul_512(l, a, b);
secp256k1_scalar_reduce_512(r, l);
}
static void secp256k1_scalar_sqr(secp256k1_scalar_t *r, const secp256k1_scalar_t *a) {
static int secp256k1_scalar_shr_int(secp256k1_scalar *r, int n) {
int ret;
VERIFY_CHECK(n > 0);
VERIFY_CHECK(n < 16);
ret = r->d[0] & ((1 << n) - 1);
r->d[0] = (r->d[0] >> n) + (r->d[1] << (32 - n));
r->d[1] = (r->d[1] >> n) + (r->d[2] << (32 - n));
r->d[2] = (r->d[2] >> n) + (r->d[3] << (32 - n));
r->d[3] = (r->d[3] >> n) + (r->d[4] << (32 - n));
r->d[4] = (r->d[4] >> n) + (r->d[5] << (32 - n));
r->d[5] = (r->d[5] >> n) + (r->d[6] << (32 - n));
r->d[6] = (r->d[6] >> n) + (r->d[7] << (32 - n));
r->d[7] = (r->d[7] >> n);
return ret;
}
static void secp256k1_scalar_sqr(secp256k1_scalar *r, const secp256k1_scalar *a) {
uint32_t l[16];
secp256k1_scalar_sqr_512(l, a);
secp256k1_scalar_reduce_512(r, l);
}
#ifdef USE_ENDOMORPHISM
static void secp256k1_scalar_split_128(secp256k1_scalar_t *r1, secp256k1_scalar_t *r2, const secp256k1_scalar_t *a) {
static void secp256k1_scalar_split_128(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *a) {
r1->d[0] = a->d[0];
r1->d[1] = a->d[1];
r1->d[2] = a->d[2];
@ -651,11 +693,11 @@ static void secp256k1_scalar_split_128(secp256k1_scalar_t *r1, secp256k1_scalar_
}
#endif
SECP256K1_INLINE static int secp256k1_scalar_eq(const secp256k1_scalar_t *a, const secp256k1_scalar_t *b) {
SECP256K1_INLINE static int secp256k1_scalar_eq(const secp256k1_scalar *a, const secp256k1_scalar *b) {
return ((a->d[0] ^ b->d[0]) | (a->d[1] ^ b->d[1]) | (a->d[2] ^ b->d[2]) | (a->d[3] ^ b->d[3]) | (a->d[4] ^ b->d[4]) | (a->d[5] ^ b->d[5]) | (a->d[6] ^ b->d[6]) | (a->d[7] ^ b->d[7])) == 0;
}
SECP256K1_INLINE static void secp256k1_scalar_mul_shift_var(secp256k1_scalar_t *r, const secp256k1_scalar_t *a, const secp256k1_scalar_t *b, unsigned int shift) {
SECP256K1_INLINE static void secp256k1_scalar_mul_shift_var(secp256k1_scalar *r, const secp256k1_scalar *a, const secp256k1_scalar *b, unsigned int shift) {
uint32_t l[16];
unsigned int shiftlimbs;
unsigned int shiftlow;
@ -673,9 +715,7 @@ SECP256K1_INLINE static void secp256k1_scalar_mul_shift_var(secp256k1_scalar_t *
r->d[5] = shift < 352 ? (l[5 + shiftlimbs] >> shiftlow | (shift < 320 && shiftlow ? (l[6 + shiftlimbs] << shifthigh) : 0)) : 0;
r->d[6] = shift < 320 ? (l[6 + shiftlimbs] >> shiftlow | (shift < 288 && shiftlow ? (l[7 + shiftlimbs] << shifthigh) : 0)) : 0;
r->d[7] = shift < 288 ? (l[7 + shiftlimbs] >> shiftlow) : 0;
if ((l[(shift - 1) >> 5] >> ((shift - 1) & 0x1f)) & 1) {
secp256k1_scalar_add_bit(r, 0);
}
secp256k1_scalar_cadd_bit(r, 0, (l[(shift - 1) >> 5] >> ((shift - 1) & 0x1f)) & 1);
}
#endif

40
src/scalar_impl.h
View file

@ -25,14 +25,14 @@
#endif
#ifndef USE_NUM_NONE
static void secp256k1_scalar_get_num(secp256k1_num_t *r, const secp256k1_scalar_t *a) {
static void secp256k1_scalar_get_num(secp256k1_num *r, const secp256k1_scalar *a) {
unsigned char c[32];
secp256k1_scalar_get_b32(c, a);
secp256k1_num_set_bin(r, c, 32);
}
/** secp256k1 curve order, see secp256k1_ecdsa_const_order_as_fe in ecdsa_impl.h */
static void secp256k1_scalar_order_get_num(secp256k1_num_t *r) {
static void secp256k1_scalar_order_get_num(secp256k1_num *r) {
static const unsigned char order[32] = {
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,
0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFF,0xFE,
@ -43,11 +43,11 @@ static void secp256k1_scalar_order_get_num(secp256k1_num_t *r) {
}
#endif
static void secp256k1_scalar_inverse(secp256k1_scalar_t *r, const secp256k1_scalar_t *x) {
secp256k1_scalar_t *t;
static void secp256k1_scalar_inverse(secp256k1_scalar *r, const secp256k1_scalar *x) {
secp256k1_scalar *t;
int i;
/* First compute x ^ (2^N - 1) for some values of N. */
secp256k1_scalar_t x2, x3, x4, x6, x7, x8, x15, x30, x60, x120, x127;
secp256k1_scalar x2, x3, x4, x6, x7, x8, x15, x30, x60, x120, x127;
secp256k1_scalar_sqr(&x2, x);
secp256k1_scalar_mul(&x2, &x2, x);
@ -234,18 +234,27 @@ static void secp256k1_scalar_inverse(secp256k1_scalar_t *r, const secp256k1_scal
secp256k1_scalar_mul(r, t, &x6); /* 111111 */
}
static void secp256k1_scalar_inverse_var(secp256k1_scalar_t *r, const secp256k1_scalar_t *x) {
SECP256K1_INLINE static int secp256k1_scalar_is_even(const secp256k1_scalar *a) {
/* d[0] is present and is the lowest word for all representations */
return !(a->d[0] & 1);
}
static void secp256k1_scalar_inverse_var(secp256k1_scalar *r, const secp256k1_scalar *x) {
#if defined(USE_SCALAR_INV_BUILTIN)
secp256k1_scalar_inverse(r, x);
#elif defined(USE_SCALAR_INV_NUM)
unsigned char b[32];
secp256k1_num_t n, m;
secp256k1_scalar_get_b32(b, x);
secp256k1_num n, m;
secp256k1_scalar t = *x;
secp256k1_scalar_get_b32(b, &t);
secp256k1_num_set_bin(&n, b, 32);
secp256k1_scalar_order_get_num(&m);
secp256k1_num_mod_inverse(&n, &n, &m);
secp256k1_num_get_bin(b, 32, &n);
secp256k1_scalar_set_b32(r, b, NULL);
/* Verify that the inverse was computed correctly, without GMP code. */
secp256k1_scalar_mul(&t, &t, r);
CHECK(secp256k1_scalar_is_one(&t));
#else
#error "Please select scalar inverse implementation"
#endif
@ -290,30 +299,31 @@ static void secp256k1_scalar_inverse_var(secp256k1_scalar_t *r, const secp256k1_
* The function below splits a in r1 and r2, such that r1 + lambda * r2 == a (mod order).
*/
static void secp256k1_scalar_split_lambda_var(secp256k1_scalar_t *r1, secp256k1_scalar_t *r2, const secp256k1_scalar_t *a) {
secp256k1_scalar_t c1, c2;
static const secp256k1_scalar_t minus_lambda = SECP256K1_SCALAR_CONST(
static void secp256k1_scalar_split_lambda(secp256k1_scalar *r1, secp256k1_scalar *r2, const secp256k1_scalar *a) {
secp256k1_scalar c1, c2;
static const secp256k1_scalar minus_lambda = SECP256K1_SCALAR_CONST(
0xAC9C52B3UL, 0x3FA3CF1FUL, 0x5AD9E3FDUL, 0x77ED9BA4UL,
0xA880B9FCUL, 0x8EC739C2UL, 0xE0CFC810UL, 0xB51283CFUL
);
static const secp256k1_scalar_t minus_b1 = SECP256K1_SCALAR_CONST(
static const secp256k1_scalar minus_b1 = SECP256K1_SCALAR_CONST(
0x00000000UL, 0x00000000UL, 0x00000000UL, 0x00000000UL,
0xE4437ED6UL, 0x010E8828UL, 0x6F547FA9UL, 0x0ABFE4C3UL
);
static const secp256k1_scalar_t minus_b2 = SECP256K1_SCALAR_CONST(
static const secp256k1_scalar minus_b2 = SECP256K1_SCALAR_CONST(
0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFFUL, 0xFFFFFFFEUL,
0x8A280AC5UL, 0x0774346DUL, 0xD765CDA8UL, 0x3DB1562CUL
);
static const secp256k1_scalar_t g1 = SECP256K1_SCALAR_CONST(
static const secp256k1_scalar g1 = SECP256K1_SCALAR_CONST(
0x00000000UL, 0x00000000UL, 0x00000000UL, 0x00003086UL,
0xD221A7D4UL, 0x6BCDE86CUL, 0x90E49284UL, 0xEB153DABUL
);
static const secp256k1_scalar_t g2 = SECP256K1_SCALAR_CONST(
static const secp256k1_scalar g2 = SECP256K1_SCALAR_CONST(
0x00000000UL, 0x00000000UL, 0x00000000UL, 0x0000E443UL,
0x7ED6010EUL, 0x88286F54UL, 0x7FA90ABFUL, 0xE4C42212UL
);
VERIFY_CHECK(r1 != a);
VERIFY_CHECK(r2 != a);
/* these _var calls are constant time since the shift amount is constant */
secp256k1_scalar_mul_shift_var(&c1, a, &g1, 272);
secp256k1_scalar_mul_shift_var(&c2, a, &g2, 272);
secp256k1_scalar_mul(&c1, &c1, &minus_b1);

677
src/secp256k1.c
View file

@ -14,81 +14,328 @@
#include "scalar_impl.h"
#include "group_impl.h"
#include "ecmult_impl.h"
#include "ecmult_const_impl.h"
#include "ecmult_gen_impl.h"
#include "ecdsa_impl.h"
#include "eckey_impl.h"
#include "hash_impl.h"
struct secp256k1_context_struct {
secp256k1_ecmult_context_t ecmult_ctx;
secp256k1_ecmult_gen_context_t ecmult_gen_ctx;
#define ARG_CHECK(cond) do { \
if (EXPECT(!(cond), 0)) { \
secp256k1_callback_call(&ctx->illegal_callback, #cond); \
return 0; \
} \
} while(0)
static void default_illegal_callback_fn(const char* str, void* data) {
(void)data;
fprintf(stderr, "[libsecp256k1] illegal argument: %s\n", str);
abort();
}
static const secp256k1_callback default_illegal_callback = {
default_illegal_callback_fn,
NULL
};
secp256k1_context_t* secp256k1_context_create(int flags) {
secp256k1_context_t* ret = (secp256k1_context_t*)checked_malloc(sizeof(secp256k1_context_t));
static void default_error_callback_fn(const char* str, void* data) {
(void)data;
fprintf(stderr, "[libsecp256k1] internal consistency check failed: %s\n", str);
abort();
}
static const secp256k1_callback default_error_callback = {
default_error_callback_fn,
NULL
};
struct secp256k1_context_struct {
secp256k1_ecmult_context ecmult_ctx;
secp256k1_ecmult_gen_context ecmult_gen_ctx;
secp256k1_callback illegal_callback;
secp256k1_callback error_callback;
};
secp256k1_context* secp256k1_context_create(unsigned int flags) {
secp256k1_context* ret = (secp256k1_context*)checked_malloc(&default_error_callback, sizeof(secp256k1_context));
ret->illegal_callback = default_illegal_callback;
ret->error_callback = default_error_callback;
if (EXPECT((flags & SECP256K1_FLAGS_TYPE_MASK) != SECP256K1_FLAGS_TYPE_CONTEXT, 0)) {
secp256k1_callback_call(&ret->illegal_callback,
"Invalid flags");
free(ret);
return NULL;
}
secp256k1_ecmult_context_init(&ret->ecmult_ctx);
secp256k1_ecmult_gen_context_init(&ret->ecmult_gen_ctx);
if (flags & SECP256K1_CONTEXT_SIGN) {
secp256k1_ecmult_gen_context_build(&ret->ecmult_gen_ctx);
if (flags & SECP256K1_FLAGS_BIT_CONTEXT_SIGN) {
secp256k1_ecmult_gen_context_build(&ret->ecmult_gen_ctx, &ret->error_callback);
}
if (flags & SECP256K1_CONTEXT_VERIFY) {
secp256k1_ecmult_context_build(&ret->ecmult_ctx);
if (flags & SECP256K1_FLAGS_BIT_CONTEXT_VERIFY) {
secp256k1_ecmult_context_build(&ret->ecmult_ctx, &ret->error_callback);
}
return ret;
}
secp256k1_context_t* secp256k1_context_clone(const secp256k1_context_t* ctx) {
secp256k1_context_t* ret = (secp256k1_context_t*)checked_malloc(sizeof(secp256k1_context_t));
secp256k1_ecmult_context_clone(&ret->ecmult_ctx, &ctx->ecmult_ctx);
secp256k1_ecmult_gen_context_clone(&ret->ecmult_gen_ctx, &ctx->ecmult_gen_ctx);
secp256k1_context* secp256k1_context_clone(const secp256k1_context* ctx) {
secp256k1_context* ret = (secp256k1_context*)checked_malloc(&ctx->error_callback, sizeof(secp256k1_context));
ret->illegal_callback = ctx->illegal_callback;
ret->error_callback = ctx->error_callback;
secp256k1_ecmult_context_clone(&ret->ecmult_ctx, &ctx->ecmult_ctx, &ctx->error_callback);
secp256k1_ecmult_gen_context_clone(&ret->ecmult_gen_ctx, &ctx->ecmult_gen_ctx, &ctx->error_callback);
return ret;
}
void secp256k1_context_destroy(secp256k1_context_t* ctx) {
secp256k1_ecmult_context_clear(&ctx->ecmult_ctx);
secp256k1_ecmult_gen_context_clear(&ctx->ecmult_gen_ctx);
void secp256k1_context_destroy(secp256k1_context* ctx) {
if (ctx != NULL) {
secp256k1_ecmult_context_clear(&ctx->ecmult_ctx);
secp256k1_ecmult_gen_context_clear(&ctx->ecmult_gen_ctx);
free(ctx);
free(ctx);
}
}
int secp256k1_ecdsa_verify(const secp256k1_context_t* ctx, const unsigned char *msg32, const unsigned char *sig, int siglen, const unsigned char *pubkey, int pubkeylen) {
secp256k1_ge_t q;
secp256k1_ecdsa_sig_t s;
secp256k1_scalar_t m;
int ret = -3;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
DEBUG_CHECK(msg32 != NULL);
DEBUG_CHECK(sig != NULL);
DEBUG_CHECK(pubkey != NULL);
void secp256k1_context_set_illegal_callback(secp256k1_context* ctx, void (*fun)(const char* message, void* data), const void* data) {
if (fun == NULL) {
fun = default_illegal_callback_fn;
}
ctx->illegal_callback.fn = fun;
ctx->illegal_callback.data = data;
}
void secp256k1_context_set_error_callback(secp256k1_context* ctx, void (*fun)(const char* message, void* data), const void* data) {
if (fun == NULL) {
fun = default_error_callback_fn;
}
ctx->error_callback.fn = fun;
ctx->error_callback.data = data;
}
static int secp256k1_pubkey_load(const secp256k1_context* ctx, secp256k1_ge* ge, const secp256k1_pubkey* pubkey) {
if (sizeof(secp256k1_ge_storage) == 64) {
/* When the secp256k1_ge_storage type is exactly 64 byte, use its
* representation inside secp256k1_pubkey, as conversion is very fast.
* Note that secp256k1_pubkey_save must use the same representation. */
secp256k1_ge_storage s;
memcpy(&s, &pubkey->data[0], 64);
secp256k1_ge_from_storage(ge, &s);
} else {
/* Otherwise, fall back to 32-byte big endian for X and Y. */
secp256k1_fe x, y;
secp256k1_fe_set_b32(&x, pubkey->data);
secp256k1_fe_set_b32(&y, pubkey->data + 32);
secp256k1_ge_set_xy(ge, &x, &y);
}
ARG_CHECK(!secp256k1_fe_is_zero(&ge->x));
return 1;
}
static void secp256k1_pubkey_save(secp256k1_pubkey* pubkey, secp256k1_ge* ge) {
if (sizeof(secp256k1_ge_storage) == 64) {
secp256k1_ge_storage s;
secp256k1_ge_to_storage(&s, ge);
memcpy(&pubkey->data[0], &s, 64);
} else {
VERIFY_CHECK(!secp256k1_ge_is_infinity(ge));
secp256k1_fe_normalize_var(&ge->x);
secp256k1_fe_normalize_var(&ge->y);
secp256k1_fe_get_b32(pubkey->data, &ge->x);
secp256k1_fe_get_b32(pubkey->data + 32, &ge->y);
}
}
int secp256k1_ec_pubkey_parse(const secp256k1_context* ctx, secp256k1_pubkey* pubkey, const unsigned char *input, size_t inputlen) {
secp256k1_ge Q;
(void)ctx;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(pubkey != NULL);
memset(pubkey, 0, sizeof(*pubkey));
ARG_CHECK(input != NULL);
if (!secp256k1_eckey_pubkey_parse(&Q, input, inputlen)) {
return 0;
}
secp256k1_pubkey_save(pubkey, &Q);
secp256k1_ge_clear(&Q);
return 1;
}
int secp256k1_ec_pubkey_serialize(const secp256k1_context* ctx, unsigned char *output, size_t *outputlen, const secp256k1_pubkey* pubkey, unsigned int flags) {
secp256k1_ge Q;
size_t len;
int ret = 0;
(void)ctx;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(outputlen != NULL);
ARG_CHECK(*outputlen >= ((flags & SECP256K1_FLAGS_BIT_COMPRESSION) ? 33 : 65));
len = *outputlen;
*outputlen = 0;
ARG_CHECK(output != NULL);
memset(output, 0, len);
ARG_CHECK(pubkey != NULL);
ARG_CHECK((flags & SECP256K1_FLAGS_TYPE_MASK) == SECP256K1_FLAGS_TYPE_COMPRESSION);
if (secp256k1_pubkey_load(ctx, &Q, pubkey)) {
ret = secp256k1_eckey_pubkey_serialize(&Q, output, &len, flags & SECP256K1_FLAGS_BIT_COMPRESSION);
if (ret) {
*outputlen = len;
}
}
return ret;
}
static void secp256k1_ecdsa_signature_load(const secp256k1_context* ctx, secp256k1_scalar* r, secp256k1_scalar* s, const secp256k1_ecdsa_signature* sig) {
(void)ctx;
if (sizeof(secp256k1_scalar) == 32) {
/* When the secp256k1_scalar type is exactly 32 byte, use its
* representation inside secp256k1_ecdsa_signature, as conversion is very fast.
* Note that secp256k1_ecdsa_signature_save must use the same representation. */
memcpy(r, &sig->data[0], 32);
memcpy(s, &sig->data[32], 32);
} else {
secp256k1_scalar_set_b32(r, &sig->data[0], NULL);
secp256k1_scalar_set_b32(s, &sig->data[32], NULL);
}
}
static void secp256k1_ecdsa_signature_save(secp256k1_ecdsa_signature* sig, const secp256k1_scalar* r, const secp256k1_scalar* s) {
if (sizeof(secp256k1_scalar) == 32) {
memcpy(&sig->data[0], r, 32);
memcpy(&sig->data[32], s, 32);
} else {
secp256k1_scalar_get_b32(&sig->data[0], r);
secp256k1_scalar_get_b32(&sig->data[32], s);
}
}
int secp256k1_ecdsa_signature_parse_der(const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input, size_t inputlen) {
secp256k1_scalar r, s;
(void)ctx;
ARG_CHECK(sig != NULL);
ARG_CHECK(input != NULL);
if (secp256k1_ecdsa_sig_parse(&r, &s, input, inputlen)) {
secp256k1_ecdsa_signature_save(sig, &r, &s);
return 1;
} else {
memset(sig, 0, sizeof(*sig));
return 0;
}
}
int secp256k1_ecdsa_signature_parse_compact(const secp256k1_context* ctx, secp256k1_ecdsa_signature* sig, const unsigned char *input64) {
secp256k1_scalar r, s;
int ret = 1;
int overflow = 0;
(void)ctx;
ARG_CHECK(sig != NULL);
ARG_CHECK(input64 != NULL);
secp256k1_scalar_set_b32(&r, &input64[0], &overflow);
ret &= !overflow;
secp256k1_scalar_set_b32(&s, &input64[32], &overflow);
ret &= !overflow;
if (ret) {
secp256k1_ecdsa_signature_save(sig, &r, &s);
} else {
memset(sig, 0, sizeof(*sig));
}
return ret;
}
int secp256k1_ecdsa_signature_serialize_der(const secp256k1_context* ctx, unsigned char *output, size_t *outputlen, const secp256k1_ecdsa_signature* sig) {
secp256k1_scalar r, s;
(void)ctx;
ARG_CHECK(output != NULL);
ARG_CHECK(outputlen != NULL);
ARG_CHECK(sig != NULL);
secp256k1_ecdsa_signature_load(ctx, &r, &s, sig);
return secp256k1_ecdsa_sig_serialize(output, outputlen, &r, &s);
}
int secp256k1_ecdsa_signature_serialize_compact(const secp256k1_context* ctx, unsigned char *output64, const secp256k1_ecdsa_signature* sig) {
secp256k1_scalar r, s;
(void)ctx;
ARG_CHECK(output64 != NULL);
ARG_CHECK(sig != NULL);
secp256k1_ecdsa_signature_load(ctx, &r, &s, sig);
secp256k1_scalar_get_b32(&output64[0], &r);
secp256k1_scalar_get_b32(&output64[32], &s);
return 1;
}
int secp256k1_ecdsa_signature_normalize(const secp256k1_context* ctx, secp256k1_ecdsa_signature *sigout, const secp256k1_ecdsa_signature *sigin) {
secp256k1_scalar r, s;
int ret = 0;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(sigin != NULL);
secp256k1_ecdsa_signature_load(ctx, &r, &s, sigin);
ret = secp256k1_scalar_is_high(&s);
if (sigout != NULL) {
if (ret) {
secp256k1_scalar_negate(&s, &s);
}
secp256k1_ecdsa_signature_save(sigout, &r, &s);
}
return ret;
}
int secp256k1_ecdsa_verify(const secp256k1_context* ctx, const secp256k1_ecdsa_signature *sig, const unsigned char *msg32, const secp256k1_pubkey *pubkey) {
secp256k1_ge q;
secp256k1_scalar r, s;
secp256k1_scalar m;
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(sig != NULL);
ARG_CHECK(pubkey != NULL);
secp256k1_scalar_set_b32(&m, msg32, NULL);
if (secp256k1_eckey_pubkey_parse(&q, pubkey, pubkeylen)) {
if (secp256k1_ecdsa_sig_parse(&s, sig, siglen)) {
if (secp256k1_ecdsa_sig_verify(&ctx->ecmult_ctx, &s, &q, &m)) {
/* success is 1, all other values are fail */
ret = 1;
} else {
ret = 0;
}
} else {
ret = -2;
}
} else {
ret = -1;
}
return ret;
secp256k1_ecdsa_signature_load(ctx, &r, &s, sig);
return (!secp256k1_scalar_is_high(&s) &&
secp256k1_pubkey_load(ctx, &q, pubkey) &&
secp256k1_ecdsa_sig_verify(&ctx->ecmult_ctx, &r, &s, &q, &m));
}
static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *msg32, const unsigned char *key32, unsigned int counter, const void *data) {
static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *msg32, const unsigned char *key32, const unsigned char *algo16, void *data, unsigned int counter) {
unsigned char keydata[112];
int keylen = 64;
secp256k1_rfc6979_hmac_sha256_t rng;
unsigned int i;
secp256k1_rfc6979_hmac_sha256_initialize(&rng, key32, 32, msg32, 32, (const unsigned char*)data, data != NULL ? 32 : 0);
/* We feed a byte array to the PRNG as input, consisting of:
* - the private key (32 bytes) and message (32 bytes), see RFC 6979 3.2d.
* - optionally 32 extra bytes of data, see RFC 6979 3.6 Additional Data.
* - optionally 16 extra bytes with the algorithm name.
* Because the arguments have distinct fixed lengths it is not possible for
* different argument mixtures to emulate each other and result in the same
* nonces.
*/
memcpy(keydata, key32, 32);
memcpy(keydata + 32, msg32, 32);
if (data != NULL) {
memcpy(keydata + 64, data, 32);
keylen = 96;
}
if (algo16 != NULL) {
memcpy(keydata + keylen, algo16, 16);
keylen += 16;
}
secp256k1_rfc6979_hmac_sha256_initialize(&rng, keydata, keylen);
memset(keydata, 0, sizeof(keydata));
for (i = 0; i <= counter; i++) {
secp256k1_rfc6979_hmac_sha256_generate(&rng, nonce32, 32);
}
@ -96,21 +343,19 @@ static int nonce_function_rfc6979(unsigned char *nonce32, const unsigned char *m
return 1;
}
const secp256k1_nonce_function_t secp256k1_nonce_function_rfc6979 = nonce_function_rfc6979;
const secp256k1_nonce_function_t secp256k1_nonce_function_default = nonce_function_rfc6979;
const secp256k1_nonce_function secp256k1_nonce_function_rfc6979 = nonce_function_rfc6979;
const secp256k1_nonce_function secp256k1_nonce_function_default = nonce_function_rfc6979;
int secp256k1_ecdsa_sign(const secp256k1_context_t* ctx, const unsigned char *msg32, unsigned char *signature, int *signaturelen, const unsigned char *seckey, secp256k1_nonce_function_t noncefp, const void* noncedata) {
secp256k1_ecdsa_sig_t sig;
secp256k1_scalar_t sec, non, msg;
int secp256k1_ecdsa_sign(const secp256k1_context* ctx, secp256k1_ecdsa_signature *signature, const unsigned char *msg32, const unsigned char *seckey, secp256k1_nonce_function noncefp, const void* noncedata) {
secp256k1_scalar r, s;
secp256k1_scalar sec, non, msg;
int ret = 0;
int overflow = 0;
unsigned int count = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
DEBUG_CHECK(msg32 != NULL);
DEBUG_CHECK(signature != NULL);
DEBUG_CHECK(signaturelen != NULL);
DEBUG_CHECK(seckey != NULL);
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(msg32 != NULL);
ARG_CHECK(signature != NULL);
ARG_CHECK(seckey != NULL);
if (noncefp == NULL) {
noncefp = secp256k1_nonce_function_default;
}
@ -118,186 +363,87 @@ int secp256k1_ecdsa_sign(const secp256k1_context_t* ctx, const unsigned char *ms
secp256k1_scalar_set_b32(&sec, seckey, &overflow);
/* Fail if the secret key is invalid. */
if (!overflow && !secp256k1_scalar_is_zero(&sec)) {
unsigned int count = 0;
secp256k1_scalar_set_b32(&msg, msg32, NULL);
while (1) {
unsigned char nonce32[32];
ret = noncefp(nonce32, msg32, seckey, count, noncedata);
ret = noncefp(nonce32, msg32, seckey, NULL, (void*)noncedata, count);
if (!ret) {
break;
}
secp256k1_scalar_set_b32(&non, nonce32, &overflow);
memset(nonce32, 0, 32);
if (!secp256k1_scalar_is_zero(&non) && !overflow) {
if (secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, &sig, &sec, &msg, &non, NULL)) {
if (!overflow && !secp256k1_scalar_is_zero(&non)) {
if (secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, &r, &s, &sec, &msg, &non, NULL)) {
break;
}
}
count++;
}
if (ret) {
ret = secp256k1_ecdsa_sig_serialize(signature, signaturelen, &sig);
}
secp256k1_scalar_clear(&msg);
secp256k1_scalar_clear(&non);
secp256k1_scalar_clear(&sec);
}
if (!ret) {
*signaturelen = 0;
if (ret) {
secp256k1_ecdsa_signature_save(signature, &r, &s);
} else {
memset(signature, 0, sizeof(*signature));
}
return ret;
}
int secp256k1_ecdsa_sign_compact(const secp256k1_context_t* ctx, const unsigned char *msg32, unsigned char *sig64, const unsigned char *seckey, secp256k1_nonce_function_t noncefp, const void* noncedata, int *recid) {
secp256k1_ecdsa_sig_t sig;
secp256k1_scalar_t sec, non, msg;
int ret = 0;
int overflow = 0;
unsigned int count = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
DEBUG_CHECK(msg32 != NULL);
DEBUG_CHECK(sig64 != NULL);
DEBUG_CHECK(seckey != NULL);
if (noncefp == NULL) {
noncefp = secp256k1_nonce_function_default;
}
secp256k1_scalar_set_b32(&sec, seckey, &overflow);
/* Fail if the secret key is invalid. */
if (!overflow && !secp256k1_scalar_is_zero(&sec)) {
secp256k1_scalar_set_b32(&msg, msg32, NULL);
while (1) {
unsigned char nonce32[32];
ret = noncefp(nonce32, msg32, seckey, count, noncedata);
if (!ret) {
break;
}
secp256k1_scalar_set_b32(&non, nonce32, &overflow);
memset(nonce32, 0, 32);
if (!secp256k1_scalar_is_zero(&non) && !overflow) {
if (secp256k1_ecdsa_sig_sign(&ctx->ecmult_gen_ctx, &sig, &sec, &msg, &non, recid)) {
break;
}
}
count++;
}
if (ret) {
secp256k1_scalar_get_b32(sig64, &sig.r);
secp256k1_scalar_get_b32(sig64 + 32, &sig.s);
}
secp256k1_scalar_clear(&msg);
secp256k1_scalar_clear(&non);
secp256k1_scalar_clear(&sec);
}
if (!ret) {
memset(sig64, 0, 64);
}
return ret;
}
int secp256k1_ecdsa_recover_compact(const secp256k1_context_t* ctx, const unsigned char *msg32, const unsigned char *sig64, unsigned char *pubkey, int *pubkeylen, int compressed, int recid) {
secp256k1_ge_t q;
secp256k1_ecdsa_sig_t sig;
secp256k1_scalar_t m;
int ret = 0;
int overflow = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
DEBUG_CHECK(msg32 != NULL);
DEBUG_CHECK(sig64 != NULL);
DEBUG_CHECK(pubkey != NULL);
DEBUG_CHECK(pubkeylen != NULL);
DEBUG_CHECK(recid >= 0 && recid <= 3);
secp256k1_scalar_set_b32(&sig.r, sig64, &overflow);
if (!overflow) {
secp256k1_scalar_set_b32(&sig.s, sig64 + 32, &overflow);
if (!overflow) {
secp256k1_scalar_set_b32(&m, msg32, NULL);
if (secp256k1_ecdsa_sig_recover(&ctx->ecmult_ctx, &sig, &q, &m, recid)) {
ret = secp256k1_eckey_pubkey_serialize(&q, pubkey, pubkeylen, compressed);
}
}
}
return ret;
}
int secp256k1_ec_seckey_verify(const secp256k1_context_t* ctx, const unsigned char *seckey) {
secp256k1_scalar_t sec;
int secp256k1_ec_seckey_verify(const secp256k1_context* ctx, const unsigned char *seckey) {
secp256k1_scalar sec;
int ret;
int overflow;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(seckey != NULL);
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(seckey != NULL);
(void)ctx;
secp256k1_scalar_set_b32(&sec, seckey, &overflow);
ret = !secp256k1_scalar_is_zero(&sec) && !overflow;
ret = !overflow && !secp256k1_scalar_is_zero(&sec);
secp256k1_scalar_clear(&sec);
return ret;
}
int secp256k1_ec_pubkey_verify(const secp256k1_context_t* ctx, const unsigned char *pubkey, int pubkeylen) {
secp256k1_ge_t q;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(pubkey != NULL);
(void)ctx;
return secp256k1_eckey_pubkey_parse(&q, pubkey, pubkeylen);
}
int secp256k1_ec_pubkey_create(const secp256k1_context_t* ctx, unsigned char *pubkey, int *pubkeylen, const unsigned char *seckey, int compressed) {
secp256k1_gej_t pj;
secp256k1_ge_t p;
secp256k1_scalar_t sec;
int secp256k1_ec_pubkey_create(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *seckey) {
secp256k1_gej pj;
secp256k1_ge p;
secp256k1_scalar sec;
int overflow;
int ret = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
DEBUG_CHECK(pubkey != NULL);
DEBUG_CHECK(pubkeylen != NULL);
DEBUG_CHECK(seckey != NULL);
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(pubkey != NULL);
memset(pubkey, 0, sizeof(*pubkey));
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
ARG_CHECK(seckey != NULL);
secp256k1_scalar_set_b32(&sec, seckey, &overflow);
if (!overflow) {
ret = (!overflow) & (!secp256k1_scalar_is_zero(&sec));
if (ret) {
secp256k1_ecmult_gen(&ctx->ecmult_gen_ctx, &pj, &sec);
secp256k1_scalar_clear(&sec);
secp256k1_ge_set_gej(&p, &pj);
ret = secp256k1_eckey_pubkey_serialize(&p, pubkey, pubkeylen, compressed);
}
if (!ret) {
*pubkeylen = 0;
secp256k1_pubkey_save(pubkey, &p);
}
secp256k1_scalar_clear(&sec);
return ret;
}
int secp256k1_ec_pubkey_decompress(const secp256k1_context_t* ctx, unsigned char *pubkey, int *pubkeylen) {
secp256k1_ge_t p;
int ret = 0;
DEBUG_CHECK(pubkey != NULL);
DEBUG_CHECK(pubkeylen != NULL);
(void)ctx;
if (secp256k1_eckey_pubkey_parse(&p, pubkey, *pubkeylen)) {
ret = secp256k1_eckey_pubkey_serialize(&p, pubkey, pubkeylen, 0);
}
return ret;
}
int secp256k1_ec_privkey_tweak_add(const secp256k1_context_t* ctx, unsigned char *seckey, const unsigned char *tweak) {
secp256k1_scalar_t term;
secp256k1_scalar_t sec;
int secp256k1_ec_privkey_tweak_add(const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak) {
secp256k1_scalar term;
secp256k1_scalar sec;
int ret = 0;
int overflow = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(seckey != NULL);
DEBUG_CHECK(tweak != NULL);
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(seckey != NULL);
ARG_CHECK(tweak != NULL);
(void)ctx;
secp256k1_scalar_set_b32(&term, tweak, &overflow);
secp256k1_scalar_set_b32(&sec, seckey, NULL);
ret = secp256k1_eckey_privkey_tweak_add(&sec, &term) && !overflow;
ret = !overflow && secp256k1_eckey_privkey_tweak_add(&sec, &term);
memset(seckey, 0, 32);
if (ret) {
secp256k1_scalar_get_b32(seckey, &sec);
}
@ -307,45 +453,44 @@ int secp256k1_ec_privkey_tweak_add(const secp256k1_context_t* ctx, unsigned char
return ret;
}
int secp256k1_ec_pubkey_tweak_add(const secp256k1_context_t* ctx, unsigned char *pubkey, int pubkeylen, const unsigned char *tweak) {
secp256k1_ge_t p;
secp256k1_scalar_t term;
int secp256k1_ec_pubkey_tweak_add(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *tweak) {
secp256k1_ge p;
secp256k1_scalar term;
int ret = 0;
int overflow = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
DEBUG_CHECK(pubkey != NULL);
DEBUG_CHECK(tweak != NULL);
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
ARG_CHECK(pubkey != NULL);
ARG_CHECK(tweak != NULL);
secp256k1_scalar_set_b32(&term, tweak, &overflow);
if (!overflow) {
ret = secp256k1_eckey_pubkey_parse(&p, pubkey, pubkeylen);
if (ret) {
ret = secp256k1_eckey_pubkey_tweak_add(&ctx->ecmult_ctx, &p, &term);
}
if (ret) {
int oldlen = pubkeylen;
ret = secp256k1_eckey_pubkey_serialize(&p, pubkey, &pubkeylen, oldlen <= 33);
VERIFY_CHECK(pubkeylen == oldlen);
ret = !overflow && secp256k1_pubkey_load(ctx, &p, pubkey);
memset(pubkey, 0, sizeof(*pubkey));
if (ret) {
if (secp256k1_eckey_pubkey_tweak_add(&ctx->ecmult_ctx, &p, &term)) {
secp256k1_pubkey_save(pubkey, &p);
} else {
ret = 0;
}
}
return ret;
}
int secp256k1_ec_privkey_tweak_mul(const secp256k1_context_t* ctx, unsigned char *seckey, const unsigned char *tweak) {
secp256k1_scalar_t factor;
secp256k1_scalar_t sec;
int secp256k1_ec_privkey_tweak_mul(const secp256k1_context* ctx, unsigned char *seckey, const unsigned char *tweak) {
secp256k1_scalar factor;
secp256k1_scalar sec;
int ret = 0;
int overflow = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(seckey != NULL);
DEBUG_CHECK(tweak != NULL);
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(seckey != NULL);
ARG_CHECK(tweak != NULL);
(void)ctx;
secp256k1_scalar_set_b32(&factor, tweak, &overflow);
secp256k1_scalar_set_b32(&sec, seckey, NULL);
ret = secp256k1_eckey_privkey_tweak_mul(&sec, &factor) && !overflow;
ret = !overflow && secp256k1_eckey_privkey_tweak_mul(&sec, &factor);
memset(seckey, 0, 32);
if (ret) {
secp256k1_scalar_get_b32(seckey, &sec);
}
@ -355,65 +500,69 @@ int secp256k1_ec_privkey_tweak_mul(const secp256k1_context_t* ctx, unsigned char
return ret;
}
int secp256k1_ec_pubkey_tweak_mul(const secp256k1_context_t* ctx, unsigned char *pubkey, int pubkeylen, const unsigned char *tweak) {
secp256k1_ge_t p;
secp256k1_scalar_t factor;
int secp256k1_ec_pubkey_tweak_mul(const secp256k1_context* ctx, secp256k1_pubkey *pubkey, const unsigned char *tweak) {
secp256k1_ge p;
secp256k1_scalar factor;
int ret = 0;
int overflow = 0;
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
DEBUG_CHECK(pubkey != NULL);
DEBUG_CHECK(tweak != NULL);
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_context_is_built(&ctx->ecmult_ctx));
ARG_CHECK(pubkey != NULL);
ARG_CHECK(tweak != NULL);
secp256k1_scalar_set_b32(&factor, tweak, &overflow);
if (!overflow) {
ret = secp256k1_eckey_pubkey_parse(&p, pubkey, pubkeylen);
if (ret) {
ret = secp256k1_eckey_pubkey_tweak_mul(&ctx->ecmult_ctx, &p, &factor);
}
if (ret) {
int oldlen = pubkeylen;
ret = secp256k1_eckey_pubkey_serialize(&p, pubkey, &pubkeylen, oldlen <= 33);
VERIFY_CHECK(pubkeylen == oldlen);
}
}
return ret;
}
int secp256k1_ec_privkey_export(const secp256k1_context_t* ctx, const unsigned char *seckey, unsigned char *privkey, int *privkeylen, int compressed) {
secp256k1_scalar_t key;
int ret = 0;
DEBUG_CHECK(seckey != NULL);
DEBUG_CHECK(privkey != NULL);
DEBUG_CHECK(privkeylen != NULL);
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
secp256k1_scalar_set_b32(&key, seckey, NULL);
ret = secp256k1_eckey_privkey_serialize(&ctx->ecmult_gen_ctx, privkey, privkeylen, &key, compressed);
secp256k1_scalar_clear(&key);
return ret;
}
int secp256k1_ec_privkey_import(const secp256k1_context_t* ctx, unsigned char *seckey, const unsigned char *privkey, int privkeylen) {
secp256k1_scalar_t key;
int ret = 0;
DEBUG_CHECK(seckey != NULL);
DEBUG_CHECK(privkey != NULL);
(void)ctx;
ret = secp256k1_eckey_privkey_parse(&key, privkey, privkeylen);
ret = !overflow && secp256k1_pubkey_load(ctx, &p, pubkey);
memset(pubkey, 0, sizeof(*pubkey));
if (ret) {
secp256k1_scalar_get_b32(seckey, &key);
if (secp256k1_eckey_pubkey_tweak_mul(&ctx->ecmult_ctx, &p, &factor)) {
secp256k1_pubkey_save(pubkey, &p);
} else {
ret = 0;
}
}
secp256k1_scalar_clear(&key);
return ret;
}
int secp256k1_context_randomize(secp256k1_context_t* ctx, const unsigned char *seed32) {
DEBUG_CHECK(ctx != NULL);
DEBUG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
int secp256k1_context_randomize(secp256k1_context* ctx, const unsigned char *seed32) {
VERIFY_CHECK(ctx != NULL);
ARG_CHECK(secp256k1_ecmult_gen_context_is_built(&ctx->ecmult_gen_ctx));
secp256k1_ecmult_gen_blind(&ctx->ecmult_gen_ctx, seed32);
return 1;
}
int secp256k1_ec_pubkey_combine(const secp256k1_context* ctx, secp256k1_pubkey *pubnonce, const secp256k1_pubkey * const *pubnonces, size_t n) {
size_t i;
secp256k1_gej Qj;
secp256k1_ge Q;
ARG_CHECK(pubnonce != NULL);
memset(pubnonce, 0, sizeof(*pubnonce));
ARG_CHECK(n >= 1);
ARG_CHECK(pubnonces != NULL);
secp256k1_gej_set_infinity(&Qj);
for (i = 0; i < n; i++) {
secp256k1_pubkey_load(ctx, &Q, pubnonces[i]);
secp256k1_gej_add_ge(&Qj, &Qj, &Q);
}
if (secp256k1_gej_is_infinity(&Qj)) {
return 0;
}
secp256k1_ge_set_gej(&Q, &Qj);
secp256k1_pubkey_save(pubnonce, &Q);
return 1;
}
#ifdef ENABLE_MODULE_ECDH
# include "modules/ecdh/main_impl.h"
#endif
#ifdef ENABLE_MODULE_SCHNORR
# include "modules/schnorr/main_impl.h"
#endif
#ifdef ENABLE_MODULE_RECOVERY
# include "modules/recovery/main_impl.h"
#endif

12
src/testrand.h
View file

@ -16,13 +16,23 @@
/** Seed the pseudorandom number generator for testing. */
SECP256K1_INLINE static void secp256k1_rand_seed(const unsigned char *seed16);
/** Generate a pseudorandom 32-bit number. */
/** Generate a pseudorandom number in the range [0..2**32-1]. */
static uint32_t secp256k1_rand32(void);
/** Generate a pseudorandom number in the range [0..2**bits-1]. Bits must be 1 or
* more. */
static uint32_t secp256k1_rand_bits(int bits);
/** Generate a pseudorandom number in the range [0..range-1]. */
static uint32_t secp256k1_rand_int(uint32_t range);
/** Generate a pseudorandom 32-byte array. */
static void secp256k1_rand256(unsigned char *b32);
/** Generate a pseudorandom 32-byte array with long sequences of zero and one bits. */
static void secp256k1_rand256_test(unsigned char *b32);
/** Generate pseudorandom bytes with long sequences of zero and one bits. */
static void secp256k1_rand_bytes_test(unsigned char *bytes, size_t len);
#endif

86
src/testrand_impl.h
View file

@ -1,5 +1,5 @@
/**********************************************************************
* Copyright (c) 2013, 2014 Pieter Wuille *
* Copyright (c) 2013-2015 Pieter Wuille *
* Distributed under the MIT software license, see the accompanying *
* file COPYING or http://www.opensource.org/licenses/mit-license.php.*
**********************************************************************/
@ -16,9 +16,11 @@
static secp256k1_rfc6979_hmac_sha256_t secp256k1_test_rng;
static uint32_t secp256k1_test_rng_precomputed[8];
static int secp256k1_test_rng_precomputed_used = 8;
static uint64_t secp256k1_test_rng_integer;
static int secp256k1_test_rng_integer_bits_left = 0;
SECP256K1_INLINE static void secp256k1_rand_seed(const unsigned char *seed16) {
secp256k1_rfc6979_hmac_sha256_initialize(&secp256k1_test_rng, (const unsigned char*)"TestRNG", 7, seed16, 16, NULL, 0);
secp256k1_rfc6979_hmac_sha256_initialize(&secp256k1_test_rng, seed16, 16);
}
SECP256K1_INLINE static uint32_t secp256k1_rand32(void) {
@ -29,32 +31,80 @@ SECP256K1_INLINE static uint32_t secp256k1_rand32(void) {
return secp256k1_test_rng_precomputed[secp256k1_test_rng_precomputed_used++];
}
static uint32_t secp256k1_rand_bits(int bits) {
uint32_t ret;
if (secp256k1_test_rng_integer_bits_left < bits) {
secp256k1_test_rng_integer |= (((uint64_t)secp256k1_rand32()) << secp256k1_test_rng_integer_bits_left);
secp256k1_test_rng_integer_bits_left += 32;
}
ret = secp256k1_test_rng_integer;
secp256k1_test_rng_integer >>= bits;
secp256k1_test_rng_integer_bits_left -= bits;
ret &= ((~((uint32_t)0)) >> (32 - bits));
return ret;
}
static uint32_t secp256k1_rand_int(uint32_t range) {
/* We want a uniform integer between 0 and range-1, inclusive.
* B is the smallest number such that range <= 2**B.
* two mechanisms implemented here:
* - generate B bits numbers until one below range is found, and return it
* - find the largest multiple M of range that is <= 2**(B+A), generate B+A
* bits numbers until one below M is found, and return it modulo range
* The second mechanism consumes A more bits of entropy in every iteration,
* but may need fewer iterations due to M being closer to 2**(B+A) then
* range is to 2**B. The array below (indexed by B) contains a 0 when the
* first mechanism is to be used, and the number A otherwise.
*/
static const int addbits[] = {0, 0, 0, 0, 0, 0, 0, 0, 0, 1, 2, 2, 2, 2, 2, 2, 2, 2, 2, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 2, 1, 0};
uint32_t trange, mult;
int bits = 0;
if (range <= 1) {
return 0;
}
trange = range - 1;
while (trange > 0) {
trange >>= 1;
bits++;
}
if (addbits[bits]) {
bits = bits + addbits[bits];
mult = ((~((uint32_t)0)) >> (32 - bits)) / range;
trange = range * mult;
} else {
trange = range;
mult = 1;
}
while(1) {
uint32_t x = secp256k1_rand_bits(bits);
if (x < trange) {
return (mult == 1) ? x : (x % range);
}
}
}
static void secp256k1_rand256(unsigned char *b32) {
secp256k1_rfc6979_hmac_sha256_generate(&secp256k1_test_rng, b32, 32);
}
static void secp256k1_rand256_test(unsigned char *b32) {
int bits=0;
uint64_t ent = 0;
int entleft = 0;
memset(b32, 0, 32);
while (bits < 256) {
static void secp256k1_rand_bytes_test(unsigned char *bytes, size_t len) {
size_t bits = 0;
memset(bytes, 0, len);
while (bits < len * 8) {
int now;
uint32_t val;
if (entleft < 12) {
ent |= ((uint64_t)secp256k1_rand32()) << entleft;
entleft += 32;
}
now = 1 + ((ent % 64)*((ent >> 6) % 32)+16)/31;
val = 1 & (ent >> 11);
ent >>= 12;
entleft -= 12;
while (now > 0 && bits < 256) {
b32[bits / 8] |= val << (bits % 8);
now = 1 + (secp256k1_rand_bits(6) * secp256k1_rand_bits(5) + 16) / 31;
val = secp256k1_rand_bits(1);
while (now > 0 && bits < len * 8) {
bytes[bits / 8] |= val << (bits % 8);
now--;
bits++;
}
}
}
static void secp256k1_rand256_test(unsigned char *b32) {
secp256k1_rand_bytes_test(b32, 32);
}
#endif

3404
src/tests.c
View file

File diff suppressed because it is too large Load diff

26
src/util.h
View file

@ -15,6 +15,15 @@
#include <stdint.h>
#include <stdio.h>
typedef struct {
void (*fn)(const char *text, void* data);
const void* data;
} secp256k1_callback;
static SECP256K1_INLINE void secp256k1_callback_call(const secp256k1_callback * const cb, const char * const text) {
cb->fn(text, (void*)cb->data);
}
#ifdef DETERMINISTIC
#define TEST_FAILURE(msg) do { \
fprintf(stderr, "%s\n", msg); \
@ -47,23 +56,20 @@
} while(0)
#endif
/* Like assert(), but safe to use on expressions with side effects. */
#ifndef NDEBUG
#define DEBUG_CHECK CHECK
#else
#define DEBUG_CHECK(cond) do { (void)(cond); } while(0)
#endif
/* Like DEBUG_CHECK(), but when VERIFY is defined instead of NDEBUG not defined. */
/* Like assert(), but when VERIFY is defined, and side-effect safe. */
#ifdef VERIFY
#define VERIFY_CHECK CHECK
#define VERIFY_SETUP(stmt) do { stmt; } while(0)
#else
#define VERIFY_CHECK(cond) do { (void)(cond); } while(0)
#define VERIFY_SETUP(stmt)
#endif
static SECP256K1_INLINE void *checked_malloc(size_t size) {
static SECP256K1_INLINE void *checked_malloc(const secp256k1_callback* cb, size_t size) {
void *ret = malloc(size);
CHECK(ret != NULL);
if (ret == NULL) {
secp256k1_callback_call(cb, "Out of memory");
}
return ret;
}