Four cases included:
* The CLTV operand type mismatches the tx locktime. In the script it is
1 (interpreted as block height), but in the tx is 500000000
(interpreted as date)
* The stack is empty when executing OP_CLTV
* The tx is final by having only one input with MAX_INT sequence number
* The operand for CLTV is negative (after OP_0 OP_1 OP_SUB)
<nLockTime> CHECKLOCKTIMEVERIFY -> <nLockTime>
Fails if tx.nLockTime < nLockTime, allowing the funds in a txout to be
locked until some block height or block time in the future is reached.
Only the logic and unittests are implemented; this commit does not have
any actual soft-fork logic in it.
Thanks to Pieter Wuille for rebase.
Credit goes to Gregory Maxwell for the suggestion of comparing the
argument against the transaction nLockTime rather than the current
time/blockheight directly.
This commit adds several tests to the script_invalid.json data which
exercise some edge conditions that are not currently being tested.
These are mainly being added to cover several cases a branch coverage
analysis of btcd showed are not already being covered, but given more
tests of edge conditions are always a good thing, I'm contributing
them upstream.
The test which is intended to prove that the script engine is properly
rejecting non-minimally encoded PUSHDATA4 data is using the wrong
opcode and value. The test is using 0x4f, which is OP_1NEGATE instead
of the desired 0x4e, which is OP_PUSHDATA4. Further, the push of data
is intended to be 256 bytes, but the value the test is using is
0x00100000 (4096), instead of the desired 0x00010000 (256).
This commit fixes both issues.
This was found while examining the branch coverage in btcd against only
these tests to help find missing branch coverage.
The fix to NegateSignatureS caused a test which had been failing
in IsValidSignatureEncoding to then fail in IsLowDERSignature.
Add new test so the original check remains exercised.
NegateSignatureS is called with a signature without a hashtype, so
do not save the last byte and append it after S negation.
Updates the two tests which were affected by this bug.
Makes it possible to compactly provide a delibrately invalid signature
for use with CHECK(MULTI)SIG. For instance with BIP19 if m != n invalid
signatures need to be provided in the scriptSig; prior to this change
those invalid signatures would need to be large DER-encoded signatures.
Note that we may want to further expand on this change in the future by
saying that only OP_0 is a "valid" invalid signature; BIP19 even with
this change is inherently malleable as the invalid signatures can be any
validly encoded DER signature.
OP_CODESEPARATOR is an actual executed instruction, not a declarative
thing, so if it's wrapped in an OP_IF it can be turned off.
Using this to implement Rivest's Paywords is left as an exercise for the
reader.
Although script_valid.json and script_invalid.json are loaded correctly by the
JSON interpreter used by bitcoin core, these same files are often used by other
libraries and do not necessarily load correctly due to the fact that newlines
contained inside strings are not valid and must instead use the escape
character \n. The files tx_valid.json and tx_invalid.json handle this
correctly, so I've changed the formatting in script_valid.json and
script_invalid.json to mirror those files.
Now that signing is deterministic, we can require exact correspondence between the
automatically generated tests and the ones read from JSON. Do this, and update
the tests to those deterministic versions. Note that some flag changes weren't
correctly applied before.
Based on an earlier patch by Peter Todd, though the rules here are different
(P2SH scripts should not have a CLEANSTACK check before the P2SH evaluation).
This turns STRICTENC turn into a softforking-safe change (even though it
is not intended as a consensus rule), and as a result guarantee that using
it for mempool validation only results in consensus-valid transactions in
the mempool.
NOP1 to NOP10 are reserved for future soft-fork upgrades. In the event
of an upgrade such NOPs have *VERIFY behavior, meaning that if their
arguments are not correct the script fails. Discouraging these NOPs by
rejecting transactions containing them from the mempool ensures that
we'll never accept transactions, nor mine blocks, with scripts that are
now invalid according to the majority of hashing power even if we're not
yet upgraded. Previously this wasn't an issue as the IsStandard() rules
didn't allow upgradable NOPs anyway, but 7f3b4e95 relaxed the
IsStandard() rules for P2SH redemptions allowing any redeemScript to be
spent.
We *do* allow upgradable NOPs in scripts so long as they are not
executed. This is harmless as there is no opportunity for the script to
be invalid post-upgrade.
* Delete canonical_tests.cpp, and move the tests to script_tests.cpp.
* Split off SCRIPT_VERIFY_DERSIG from SCRIPT_VERIFY_STRICTENC (the BIP62 part of it).
* Change signature STRICTENC/DERSIG semantics to fail the script entirely rather than the CHECKSIG result (softfork safety, and BIP62 requirement).
* Add many autogenerated tests for several odd cases.
* Mention specific BIP62 rules in the script verification flags.
Windows needed a few fixups to get the tests running:
1. bitcoin-tx needs a file extension in Windows. Take this opportunity to
add an env file, which pulls variables out of our build config. This can
be extended as needed, for now it's very simple.
2. After #1, split the args out of the exec key in the test data.
3. Correct the line-endings from windows stdout
