1229 lines
46 KiB
C++
1229 lines
46 KiB
C++
// Copyright (c) 2009-2010 Satoshi Nakamoto
|
|
// Copyright (c) 2009-2014 The Bitcoin Core developers
|
|
// Distributed under the MIT software license, see the accompanying
|
|
// file COPYING or http://www.opensource.org/licenses/mit-license.php.
|
|
|
|
#include "interpreter.h"
|
|
|
|
#include "primitives/transaction.h"
|
|
#include "crypto/ripemd160.h"
|
|
#include "crypto/sha1.h"
|
|
#include "crypto/sha256.h"
|
|
#include "eccryptoverify.h"
|
|
#include "pubkey.h"
|
|
#include "script/script.h"
|
|
#include "uint256.h"
|
|
|
|
using namespace std;
|
|
|
|
typedef vector<unsigned char> valtype;
|
|
|
|
namespace {
|
|
|
|
inline bool set_success(ScriptError* ret)
|
|
{
|
|
if (ret)
|
|
*ret = SCRIPT_ERR_OK;
|
|
return true;
|
|
}
|
|
|
|
inline bool set_error(ScriptError* ret, const ScriptError serror)
|
|
{
|
|
if (ret)
|
|
*ret = serror;
|
|
return false;
|
|
}
|
|
|
|
} // anon namespace
|
|
|
|
bool CastToBool(const valtype& vch)
|
|
{
|
|
for (unsigned int i = 0; i < vch.size(); i++)
|
|
{
|
|
if (vch[i] != 0)
|
|
{
|
|
// Can be negative zero
|
|
if (i == vch.size()-1 && vch[i] == 0x80)
|
|
return false;
|
|
return true;
|
|
}
|
|
}
|
|
return false;
|
|
}
|
|
|
|
/**
|
|
* Script is a stack machine (like Forth) that evaluates a predicate
|
|
* returning a bool indicating valid or not. There are no loops.
|
|
*/
|
|
#define stacktop(i) (stack.at(stack.size()+(i)))
|
|
#define altstacktop(i) (altstack.at(altstack.size()+(i)))
|
|
static inline void popstack(vector<valtype>& stack)
|
|
{
|
|
if (stack.empty())
|
|
throw runtime_error("popstack(): stack empty");
|
|
stack.pop_back();
|
|
}
|
|
|
|
bool static IsCompressedOrUncompressedPubKey(const valtype &vchPubKey) {
|
|
if (vchPubKey.size() < 33) {
|
|
// Non-canonical public key: too short
|
|
return false;
|
|
}
|
|
if (vchPubKey[0] == 0x04) {
|
|
if (vchPubKey.size() != 65) {
|
|
// Non-canonical public key: invalid length for uncompressed key
|
|
return false;
|
|
}
|
|
} else if (vchPubKey[0] == 0x02 || vchPubKey[0] == 0x03) {
|
|
if (vchPubKey.size() != 33) {
|
|
// Non-canonical public key: invalid length for compressed key
|
|
return false;
|
|
}
|
|
} else {
|
|
// Non-canonical public key: neither compressed nor uncompressed
|
|
return false;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
/**
|
|
* A canonical signature exists of: <30> <total len> <02> <len R> <R> <02> <len S> <S> <hashtype>
|
|
* Where R and S are not negative (their first byte has its highest bit not set), and not
|
|
* excessively padded (do not start with a 0 byte, unless an otherwise negative number follows,
|
|
* in which case a single 0 byte is necessary and even required).
|
|
*
|
|
* See https://bitcointalk.org/index.php?topic=8392.msg127623#msg127623
|
|
*
|
|
* This function is consensus-critical since BIP66.
|
|
*/
|
|
bool static IsValidSignatureEncoding(const std::vector<unsigned char> &sig) {
|
|
// Format: 0x30 [total-length] 0x02 [R-length] [R] 0x02 [S-length] [S] [sighash]
|
|
// * total-length: 1-byte length descriptor of everything that follows,
|
|
// excluding the sighash byte.
|
|
// * R-length: 1-byte length descriptor of the R value that follows.
|
|
// * R: arbitrary-length big-endian encoded R value. It must use the shortest
|
|
// possible encoding for a positive integers (which means no null bytes at
|
|
// the start, except a single one when the next byte has its highest bit set).
|
|
// * S-length: 1-byte length descriptor of the S value that follows.
|
|
// * S: arbitrary-length big-endian encoded S value. The same rules apply.
|
|
// * sighash: 1-byte value indicating what data is hashed (not part of the DER
|
|
// signature)
|
|
|
|
// Minimum and maximum size constraints.
|
|
if (sig.size() < 9) return false;
|
|
if (sig.size() > 73) return false;
|
|
|
|
// A signature is of type 0x30 (compound).
|
|
if (sig[0] != 0x30) return false;
|
|
|
|
// Make sure the length covers the entire signature.
|
|
if (sig[1] != sig.size() - 3) return false;
|
|
|
|
// Extract the length of the R element.
|
|
unsigned int lenR = sig[3];
|
|
|
|
// Make sure the length of the S element is still inside the signature.
|
|
if (5 + lenR >= sig.size()) return false;
|
|
|
|
// Extract the length of the S element.
|
|
unsigned int lenS = sig[5 + lenR];
|
|
|
|
// Verify that the length of the signature matches the sum of the length
|
|
// of the elements.
|
|
if ((size_t)(lenR + lenS + 7) != sig.size()) return false;
|
|
|
|
// Check whether the R element is an integer.
|
|
if (sig[2] != 0x02) return false;
|
|
|
|
// Zero-length integers are not allowed for R.
|
|
if (lenR == 0) return false;
|
|
|
|
// Negative numbers are not allowed for R.
|
|
if (sig[4] & 0x80) return false;
|
|
|
|
// Null bytes at the start of R are not allowed, unless R would
|
|
// otherwise be interpreted as a negative number.
|
|
if (lenR > 1 && (sig[4] == 0x00) && !(sig[5] & 0x80)) return false;
|
|
|
|
// Check whether the S element is an integer.
|
|
if (sig[lenR + 4] != 0x02) return false;
|
|
|
|
// Zero-length integers are not allowed for S.
|
|
if (lenS == 0) return false;
|
|
|
|
// Negative numbers are not allowed for S.
|
|
if (sig[lenR + 6] & 0x80) return false;
|
|
|
|
// Null bytes at the start of S are not allowed, unless S would otherwise be
|
|
// interpreted as a negative number.
|
|
if (lenS > 1 && (sig[lenR + 6] == 0x00) && !(sig[lenR + 7] & 0x80)) return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool static IsLowDERSignature(const valtype &vchSig, ScriptError* serror) {
|
|
if (!IsValidSignatureEncoding(vchSig)) {
|
|
return set_error(serror, SCRIPT_ERR_SIG_DER);
|
|
}
|
|
unsigned int nLenR = vchSig[3];
|
|
unsigned int nLenS = vchSig[5+nLenR];
|
|
const unsigned char *S = &vchSig[6+nLenR];
|
|
// If the S value is above the order of the curve divided by two, its
|
|
// complement modulo the order could have been used instead, which is
|
|
// one byte shorter when encoded correctly.
|
|
if (!eccrypto::CheckSignatureElement(S, nLenS, true))
|
|
return set_error(serror, SCRIPT_ERR_SIG_HIGH_S);
|
|
|
|
return true;
|
|
}
|
|
|
|
bool static IsDefinedHashtypeSignature(const valtype &vchSig) {
|
|
if (vchSig.size() == 0) {
|
|
return false;
|
|
}
|
|
unsigned char nHashType = vchSig[vchSig.size() - 1] & (~(SIGHASH_ANYONECANPAY));
|
|
if (nHashType < SIGHASH_ALL || nHashType > SIGHASH_SINGLE)
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool CheckSignatureEncoding(const vector<unsigned char> &vchSig, unsigned int flags, ScriptError* serror) {
|
|
// Empty signature. Not strictly DER encoded, but allowed to provide a
|
|
// compact way to provide an invalid signature for use with CHECK(MULTI)SIG
|
|
if (vchSig.size() == 0) {
|
|
return true;
|
|
}
|
|
if ((flags & (SCRIPT_VERIFY_DERSIG | SCRIPT_VERIFY_LOW_S | SCRIPT_VERIFY_STRICTENC)) != 0 && !IsValidSignatureEncoding(vchSig)) {
|
|
return set_error(serror, SCRIPT_ERR_SIG_DER);
|
|
} else if ((flags & SCRIPT_VERIFY_LOW_S) != 0 && !IsLowDERSignature(vchSig, serror)) {
|
|
// serror is set
|
|
return false;
|
|
} else if ((flags & SCRIPT_VERIFY_STRICTENC) != 0 && !IsDefinedHashtypeSignature(vchSig)) {
|
|
return set_error(serror, SCRIPT_ERR_SIG_HASHTYPE);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool static CheckPubKeyEncoding(const valtype &vchSig, unsigned int flags, ScriptError* serror) {
|
|
if ((flags & SCRIPT_VERIFY_STRICTENC) != 0 && !IsCompressedOrUncompressedPubKey(vchSig)) {
|
|
return set_error(serror, SCRIPT_ERR_PUBKEYTYPE);
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool static CheckMinimalPush(const valtype& data, opcodetype opcode) {
|
|
if (data.size() == 0) {
|
|
// Could have used OP_0.
|
|
return opcode == OP_0;
|
|
} else if (data.size() == 1 && data[0] >= 1 && data[0] <= 16) {
|
|
// Could have used OP_1 .. OP_16.
|
|
return opcode == OP_1 + (data[0] - 1);
|
|
} else if (data.size() == 1 && data[0] == 0x81) {
|
|
// Could have used OP_1NEGATE.
|
|
return opcode == OP_1NEGATE;
|
|
} else if (data.size() <= 75) {
|
|
// Could have used a direct push (opcode indicating number of bytes pushed + those bytes).
|
|
return opcode == data.size();
|
|
} else if (data.size() <= 255) {
|
|
// Could have used OP_PUSHDATA.
|
|
return opcode == OP_PUSHDATA1;
|
|
} else if (data.size() <= 65535) {
|
|
// Could have used OP_PUSHDATA2.
|
|
return opcode == OP_PUSHDATA2;
|
|
}
|
|
return true;
|
|
}
|
|
|
|
bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror)
|
|
{
|
|
static const CScriptNum bnZero(0);
|
|
static const CScriptNum bnOne(1);
|
|
static const CScriptNum bnFalse(0);
|
|
static const CScriptNum bnTrue(1);
|
|
static const valtype vchFalse(0);
|
|
static const valtype vchZero(0);
|
|
static const valtype vchTrue(1, 1);
|
|
|
|
CScript::const_iterator pc = script.begin();
|
|
CScript::const_iterator pend = script.end();
|
|
CScript::const_iterator pbegincodehash = script.begin();
|
|
opcodetype opcode;
|
|
valtype vchPushValue;
|
|
vector<bool> vfExec;
|
|
vector<valtype> altstack;
|
|
set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);
|
|
if (script.size() > 10000)
|
|
return set_error(serror, SCRIPT_ERR_SCRIPT_SIZE);
|
|
int nOpCount = 0;
|
|
bool fRequireMinimal = (flags & SCRIPT_VERIFY_MINIMALDATA) != 0;
|
|
|
|
try
|
|
{
|
|
while (pc < pend)
|
|
{
|
|
bool fExec = !count(vfExec.begin(), vfExec.end(), false);
|
|
|
|
//
|
|
// Read instruction
|
|
//
|
|
if (!script.GetOp(pc, opcode, vchPushValue))
|
|
return set_error(serror, SCRIPT_ERR_BAD_OPCODE);
|
|
if (vchPushValue.size() > MAX_SCRIPT_ELEMENT_SIZE)
|
|
return set_error(serror, SCRIPT_ERR_PUSH_SIZE);
|
|
|
|
// Note how OP_RESERVED does not count towards the opcode limit.
|
|
if (opcode > OP_16 && ++nOpCount > MAX_OPS_PER_SCRIPT)
|
|
return set_error(serror, SCRIPT_ERR_OP_COUNT);
|
|
|
|
if (opcode == OP_CAT ||
|
|
opcode == OP_SUBSTR ||
|
|
opcode == OP_LEFT ||
|
|
opcode == OP_RIGHT ||
|
|
opcode == OP_INVERT ||
|
|
opcode == OP_AND ||
|
|
opcode == OP_OR ||
|
|
opcode == OP_XOR ||
|
|
opcode == OP_2MUL ||
|
|
opcode == OP_2DIV ||
|
|
opcode == OP_MUL ||
|
|
opcode == OP_DIV ||
|
|
opcode == OP_MOD ||
|
|
opcode == OP_LSHIFT ||
|
|
opcode == OP_RSHIFT)
|
|
return set_error(serror, SCRIPT_ERR_DISABLED_OPCODE); // Disabled opcodes.
|
|
|
|
if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4) {
|
|
if (fRequireMinimal && !CheckMinimalPush(vchPushValue, opcode)) {
|
|
return set_error(serror, SCRIPT_ERR_MINIMALDATA);
|
|
}
|
|
stack.push_back(vchPushValue);
|
|
} else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF))
|
|
switch (opcode)
|
|
{
|
|
//
|
|
// Push value
|
|
//
|
|
case OP_1NEGATE:
|
|
case OP_1:
|
|
case OP_2:
|
|
case OP_3:
|
|
case OP_4:
|
|
case OP_5:
|
|
case OP_6:
|
|
case OP_7:
|
|
case OP_8:
|
|
case OP_9:
|
|
case OP_10:
|
|
case OP_11:
|
|
case OP_12:
|
|
case OP_13:
|
|
case OP_14:
|
|
case OP_15:
|
|
case OP_16:
|
|
{
|
|
// ( -- value)
|
|
CScriptNum bn((int)opcode - (int)(OP_1 - 1));
|
|
stack.push_back(bn.getvch());
|
|
// The result of these opcodes should always be the minimal way to push the data
|
|
// they push, so no need for a CheckMinimalPush here.
|
|
}
|
|
break;
|
|
|
|
|
|
//
|
|
// Control
|
|
//
|
|
case OP_NOP:
|
|
break;
|
|
|
|
case OP_CHECKLOCKTIMEVERIFY:
|
|
{
|
|
if (!(flags & SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY)) {
|
|
// not enabled; treat as a NOP2
|
|
if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) {
|
|
return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS);
|
|
}
|
|
break;
|
|
}
|
|
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
|
|
// Note that elsewhere numeric opcodes are limited to
|
|
// operands in the range -2**31+1 to 2**31-1, however it is
|
|
// legal for opcodes to produce results exceeding that
|
|
// range. This limitation is implemented by CScriptNum's
|
|
// default 4-byte limit.
|
|
//
|
|
// If we kept to that limit we'd have a year 2038 problem,
|
|
// even though the nLockTime field in transactions
|
|
// themselves is uint32 which only becomes meaningless
|
|
// after the year 2106.
|
|
//
|
|
// Thus as a special case we tell CScriptNum to accept up
|
|
// to 5-byte bignums, which are good until 2**39-1, well
|
|
// beyond the 2**32-1 limit of the nLockTime field itself.
|
|
const CScriptNum nLockTime(stacktop(-1), fRequireMinimal, 5);
|
|
|
|
// In the rare event that the argument may be < 0 due to
|
|
// some arithmetic being done first, you can always use
|
|
// 0 MAX CHECKLOCKTIMEVERIFY.
|
|
if (nLockTime < 0)
|
|
return set_error(serror, SCRIPT_ERR_NEGATIVE_LOCKTIME);
|
|
|
|
// Actually compare the specified lock time with the transaction.
|
|
if (!checker.CheckLockTime(nLockTime))
|
|
return set_error(serror, SCRIPT_ERR_UNSATISFIED_LOCKTIME);
|
|
|
|
break;
|
|
}
|
|
|
|
case OP_NOP1: case OP_NOP3: case OP_NOP4: case OP_NOP5:
|
|
case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10:
|
|
{
|
|
if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS)
|
|
return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS);
|
|
}
|
|
break;
|
|
|
|
case OP_IF:
|
|
case OP_NOTIF:
|
|
{
|
|
// <expression> if [statements] [else [statements]] endif
|
|
bool fValue = false;
|
|
if (fExec)
|
|
{
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL);
|
|
valtype& vch = stacktop(-1);
|
|
fValue = CastToBool(vch);
|
|
if (opcode == OP_NOTIF)
|
|
fValue = !fValue;
|
|
popstack(stack);
|
|
}
|
|
vfExec.push_back(fValue);
|
|
}
|
|
break;
|
|
|
|
case OP_ELSE:
|
|
{
|
|
if (vfExec.empty())
|
|
return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL);
|
|
vfExec.back() = !vfExec.back();
|
|
}
|
|
break;
|
|
|
|
case OP_ENDIF:
|
|
{
|
|
if (vfExec.empty())
|
|
return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL);
|
|
vfExec.pop_back();
|
|
}
|
|
break;
|
|
|
|
case OP_VERIFY:
|
|
{
|
|
// (true -- ) or
|
|
// (false -- false) and return
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
bool fValue = CastToBool(stacktop(-1));
|
|
if (fValue)
|
|
popstack(stack);
|
|
else
|
|
return set_error(serror, SCRIPT_ERR_VERIFY);
|
|
}
|
|
break;
|
|
|
|
case OP_RETURN:
|
|
{
|
|
return set_error(serror, SCRIPT_ERR_OP_RETURN);
|
|
}
|
|
break;
|
|
|
|
|
|
//
|
|
// Stack ops
|
|
//
|
|
case OP_TOALTSTACK:
|
|
{
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
altstack.push_back(stacktop(-1));
|
|
popstack(stack);
|
|
}
|
|
break;
|
|
|
|
case OP_FROMALTSTACK:
|
|
{
|
|
if (altstack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_ALTSTACK_OPERATION);
|
|
stack.push_back(altstacktop(-1));
|
|
popstack(altstack);
|
|
}
|
|
break;
|
|
|
|
case OP_2DROP:
|
|
{
|
|
// (x1 x2 -- )
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
popstack(stack);
|
|
popstack(stack);
|
|
}
|
|
break;
|
|
|
|
case OP_2DUP:
|
|
{
|
|
// (x1 x2 -- x1 x2 x1 x2)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch1 = stacktop(-2);
|
|
valtype vch2 = stacktop(-1);
|
|
stack.push_back(vch1);
|
|
stack.push_back(vch2);
|
|
}
|
|
break;
|
|
|
|
case OP_3DUP:
|
|
{
|
|
// (x1 x2 x3 -- x1 x2 x3 x1 x2 x3)
|
|
if (stack.size() < 3)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch1 = stacktop(-3);
|
|
valtype vch2 = stacktop(-2);
|
|
valtype vch3 = stacktop(-1);
|
|
stack.push_back(vch1);
|
|
stack.push_back(vch2);
|
|
stack.push_back(vch3);
|
|
}
|
|
break;
|
|
|
|
case OP_2OVER:
|
|
{
|
|
// (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2)
|
|
if (stack.size() < 4)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch1 = stacktop(-4);
|
|
valtype vch2 = stacktop(-3);
|
|
stack.push_back(vch1);
|
|
stack.push_back(vch2);
|
|
}
|
|
break;
|
|
|
|
case OP_2ROT:
|
|
{
|
|
// (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2)
|
|
if (stack.size() < 6)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch1 = stacktop(-6);
|
|
valtype vch2 = stacktop(-5);
|
|
stack.erase(stack.end()-6, stack.end()-4);
|
|
stack.push_back(vch1);
|
|
stack.push_back(vch2);
|
|
}
|
|
break;
|
|
|
|
case OP_2SWAP:
|
|
{
|
|
// (x1 x2 x3 x4 -- x3 x4 x1 x2)
|
|
if (stack.size() < 4)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
swap(stacktop(-4), stacktop(-2));
|
|
swap(stacktop(-3), stacktop(-1));
|
|
}
|
|
break;
|
|
|
|
case OP_IFDUP:
|
|
{
|
|
// (x - 0 | x x)
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch = stacktop(-1);
|
|
if (CastToBool(vch))
|
|
stack.push_back(vch);
|
|
}
|
|
break;
|
|
|
|
case OP_DEPTH:
|
|
{
|
|
// -- stacksize
|
|
CScriptNum bn(stack.size());
|
|
stack.push_back(bn.getvch());
|
|
}
|
|
break;
|
|
|
|
case OP_DROP:
|
|
{
|
|
// (x -- )
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
popstack(stack);
|
|
}
|
|
break;
|
|
|
|
case OP_DUP:
|
|
{
|
|
// (x -- x x)
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch = stacktop(-1);
|
|
stack.push_back(vch);
|
|
}
|
|
break;
|
|
|
|
case OP_NIP:
|
|
{
|
|
// (x1 x2 -- x2)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
stack.erase(stack.end() - 2);
|
|
}
|
|
break;
|
|
|
|
case OP_OVER:
|
|
{
|
|
// (x1 x2 -- x1 x2 x1)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch = stacktop(-2);
|
|
stack.push_back(vch);
|
|
}
|
|
break;
|
|
|
|
case OP_PICK:
|
|
case OP_ROLL:
|
|
{
|
|
// (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn)
|
|
// (xn ... x2 x1 x0 n - ... x2 x1 x0 xn)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
int n = CScriptNum(stacktop(-1), fRequireMinimal).getint();
|
|
popstack(stack);
|
|
if (n < 0 || n >= (int)stack.size())
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch = stacktop(-n-1);
|
|
if (opcode == OP_ROLL)
|
|
stack.erase(stack.end()-n-1);
|
|
stack.push_back(vch);
|
|
}
|
|
break;
|
|
|
|
case OP_ROT:
|
|
{
|
|
// (x1 x2 x3 -- x2 x3 x1)
|
|
// x2 x1 x3 after first swap
|
|
// x2 x3 x1 after second swap
|
|
if (stack.size() < 3)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
swap(stacktop(-3), stacktop(-2));
|
|
swap(stacktop(-2), stacktop(-1));
|
|
}
|
|
break;
|
|
|
|
case OP_SWAP:
|
|
{
|
|
// (x1 x2 -- x2 x1)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
swap(stacktop(-2), stacktop(-1));
|
|
}
|
|
break;
|
|
|
|
case OP_TUCK:
|
|
{
|
|
// (x1 x2 -- x2 x1 x2)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype vch = stacktop(-1);
|
|
stack.insert(stack.end()-2, vch);
|
|
}
|
|
break;
|
|
|
|
|
|
case OP_SIZE:
|
|
{
|
|
// (in -- in size)
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
CScriptNum bn(stacktop(-1).size());
|
|
stack.push_back(bn.getvch());
|
|
}
|
|
break;
|
|
|
|
|
|
//
|
|
// Bitwise logic
|
|
//
|
|
case OP_EQUAL:
|
|
case OP_EQUALVERIFY:
|
|
//case OP_NOTEQUAL: // use OP_NUMNOTEQUAL
|
|
{
|
|
// (x1 x2 - bool)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype& vch1 = stacktop(-2);
|
|
valtype& vch2 = stacktop(-1);
|
|
bool fEqual = (vch1 == vch2);
|
|
// OP_NOTEQUAL is disabled because it would be too easy to say
|
|
// something like n != 1 and have some wiseguy pass in 1 with extra
|
|
// zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001)
|
|
//if (opcode == OP_NOTEQUAL)
|
|
// fEqual = !fEqual;
|
|
popstack(stack);
|
|
popstack(stack);
|
|
stack.push_back(fEqual ? vchTrue : vchFalse);
|
|
if (opcode == OP_EQUALVERIFY)
|
|
{
|
|
if (fEqual)
|
|
popstack(stack);
|
|
else
|
|
return set_error(serror, SCRIPT_ERR_EQUALVERIFY);
|
|
}
|
|
}
|
|
break;
|
|
|
|
|
|
//
|
|
// Numeric
|
|
//
|
|
case OP_1ADD:
|
|
case OP_1SUB:
|
|
case OP_NEGATE:
|
|
case OP_ABS:
|
|
case OP_NOT:
|
|
case OP_0NOTEQUAL:
|
|
{
|
|
// (in -- out)
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
CScriptNum bn(stacktop(-1), fRequireMinimal);
|
|
switch (opcode)
|
|
{
|
|
case OP_1ADD: bn += bnOne; break;
|
|
case OP_1SUB: bn -= bnOne; break;
|
|
case OP_NEGATE: bn = -bn; break;
|
|
case OP_ABS: if (bn < bnZero) bn = -bn; break;
|
|
case OP_NOT: bn = (bn == bnZero); break;
|
|
case OP_0NOTEQUAL: bn = (bn != bnZero); break;
|
|
default: assert(!"invalid opcode"); break;
|
|
}
|
|
popstack(stack);
|
|
stack.push_back(bn.getvch());
|
|
}
|
|
break;
|
|
|
|
case OP_ADD:
|
|
case OP_SUB:
|
|
case OP_BOOLAND:
|
|
case OP_BOOLOR:
|
|
case OP_NUMEQUAL:
|
|
case OP_NUMEQUALVERIFY:
|
|
case OP_NUMNOTEQUAL:
|
|
case OP_LESSTHAN:
|
|
case OP_GREATERTHAN:
|
|
case OP_LESSTHANOREQUAL:
|
|
case OP_GREATERTHANOREQUAL:
|
|
case OP_MIN:
|
|
case OP_MAX:
|
|
{
|
|
// (x1 x2 -- out)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
CScriptNum bn1(stacktop(-2), fRequireMinimal);
|
|
CScriptNum bn2(stacktop(-1), fRequireMinimal);
|
|
CScriptNum bn(0);
|
|
switch (opcode)
|
|
{
|
|
case OP_ADD:
|
|
bn = bn1 + bn2;
|
|
break;
|
|
|
|
case OP_SUB:
|
|
bn = bn1 - bn2;
|
|
break;
|
|
|
|
case OP_BOOLAND: bn = (bn1 != bnZero && bn2 != bnZero); break;
|
|
case OP_BOOLOR: bn = (bn1 != bnZero || bn2 != bnZero); break;
|
|
case OP_NUMEQUAL: bn = (bn1 == bn2); break;
|
|
case OP_NUMEQUALVERIFY: bn = (bn1 == bn2); break;
|
|
case OP_NUMNOTEQUAL: bn = (bn1 != bn2); break;
|
|
case OP_LESSTHAN: bn = (bn1 < bn2); break;
|
|
case OP_GREATERTHAN: bn = (bn1 > bn2); break;
|
|
case OP_LESSTHANOREQUAL: bn = (bn1 <= bn2); break;
|
|
case OP_GREATERTHANOREQUAL: bn = (bn1 >= bn2); break;
|
|
case OP_MIN: bn = (bn1 < bn2 ? bn1 : bn2); break;
|
|
case OP_MAX: bn = (bn1 > bn2 ? bn1 : bn2); break;
|
|
default: assert(!"invalid opcode"); break;
|
|
}
|
|
popstack(stack);
|
|
popstack(stack);
|
|
stack.push_back(bn.getvch());
|
|
|
|
if (opcode == OP_NUMEQUALVERIFY)
|
|
{
|
|
if (CastToBool(stacktop(-1)))
|
|
popstack(stack);
|
|
else
|
|
return set_error(serror, SCRIPT_ERR_NUMEQUALVERIFY);
|
|
}
|
|
}
|
|
break;
|
|
|
|
case OP_WITHIN:
|
|
{
|
|
// (x min max -- out)
|
|
if (stack.size() < 3)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
CScriptNum bn1(stacktop(-3), fRequireMinimal);
|
|
CScriptNum bn2(stacktop(-2), fRequireMinimal);
|
|
CScriptNum bn3(stacktop(-1), fRequireMinimal);
|
|
bool fValue = (bn2 <= bn1 && bn1 < bn3);
|
|
popstack(stack);
|
|
popstack(stack);
|
|
popstack(stack);
|
|
stack.push_back(fValue ? vchTrue : vchFalse);
|
|
}
|
|
break;
|
|
|
|
|
|
//
|
|
// Crypto
|
|
//
|
|
case OP_RIPEMD160:
|
|
case OP_SHA1:
|
|
case OP_SHA256:
|
|
case OP_HASH160:
|
|
case OP_HASH256:
|
|
{
|
|
// (in -- hash)
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
valtype& vch = stacktop(-1);
|
|
valtype vchHash((opcode == OP_RIPEMD160 || opcode == OP_SHA1 || opcode == OP_HASH160) ? 20 : 32);
|
|
if (opcode == OP_RIPEMD160)
|
|
CRIPEMD160().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
|
|
else if (opcode == OP_SHA1)
|
|
CSHA1().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
|
|
else if (opcode == OP_SHA256)
|
|
CSHA256().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
|
|
else if (opcode == OP_HASH160)
|
|
CHash160().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
|
|
else if (opcode == OP_HASH256)
|
|
CHash256().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash));
|
|
popstack(stack);
|
|
stack.push_back(vchHash);
|
|
}
|
|
break;
|
|
|
|
case OP_CODESEPARATOR:
|
|
{
|
|
// Hash starts after the code separator
|
|
pbegincodehash = pc;
|
|
}
|
|
break;
|
|
|
|
case OP_CHECKSIG:
|
|
case OP_CHECKSIGVERIFY:
|
|
{
|
|
// (sig pubkey -- bool)
|
|
if (stack.size() < 2)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
|
|
valtype& vchSig = stacktop(-2);
|
|
valtype& vchPubKey = stacktop(-1);
|
|
|
|
// Subset of script starting at the most recent codeseparator
|
|
CScript scriptCode(pbegincodehash, pend);
|
|
|
|
// Drop the signature, since there's no way for a signature to sign itself
|
|
scriptCode.FindAndDelete(CScript(vchSig));
|
|
|
|
if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, serror)) {
|
|
//serror is set
|
|
return false;
|
|
}
|
|
bool fSuccess = checker.CheckSig(vchSig, vchPubKey, scriptCode);
|
|
|
|
popstack(stack);
|
|
popstack(stack);
|
|
stack.push_back(fSuccess ? vchTrue : vchFalse);
|
|
if (opcode == OP_CHECKSIGVERIFY)
|
|
{
|
|
if (fSuccess)
|
|
popstack(stack);
|
|
else
|
|
return set_error(serror, SCRIPT_ERR_CHECKSIGVERIFY);
|
|
}
|
|
}
|
|
break;
|
|
|
|
case OP_CHECKMULTISIG:
|
|
case OP_CHECKMULTISIGVERIFY:
|
|
{
|
|
// ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool)
|
|
|
|
int i = 1;
|
|
if ((int)stack.size() < i)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
|
|
int nKeysCount = CScriptNum(stacktop(-i), fRequireMinimal).getint();
|
|
if (nKeysCount < 0 || nKeysCount > MAX_PUBKEYS_PER_MULTISIG)
|
|
return set_error(serror, SCRIPT_ERR_PUBKEY_COUNT);
|
|
nOpCount += nKeysCount;
|
|
if (nOpCount > MAX_OPS_PER_SCRIPT)
|
|
return set_error(serror, SCRIPT_ERR_OP_COUNT);
|
|
int ikey = ++i;
|
|
i += nKeysCount;
|
|
if ((int)stack.size() < i)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
|
|
int nSigsCount = CScriptNum(stacktop(-i), fRequireMinimal).getint();
|
|
if (nSigsCount < 0 || nSigsCount > nKeysCount)
|
|
return set_error(serror, SCRIPT_ERR_SIG_COUNT);
|
|
int isig = ++i;
|
|
i += nSigsCount;
|
|
if ((int)stack.size() < i)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
|
|
// Subset of script starting at the most recent codeseparator
|
|
CScript scriptCode(pbegincodehash, pend);
|
|
|
|
// Drop the signatures, since there's no way for a signature to sign itself
|
|
for (int k = 0; k < nSigsCount; k++)
|
|
{
|
|
valtype& vchSig = stacktop(-isig-k);
|
|
scriptCode.FindAndDelete(CScript(vchSig));
|
|
}
|
|
|
|
bool fSuccess = true;
|
|
while (fSuccess && nSigsCount > 0)
|
|
{
|
|
valtype& vchSig = stacktop(-isig);
|
|
valtype& vchPubKey = stacktop(-ikey);
|
|
|
|
// Note how this makes the exact order of pubkey/signature evaluation
|
|
// distinguishable by CHECKMULTISIG NOT if the STRICTENC flag is set.
|
|
// See the script_(in)valid tests for details.
|
|
if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, serror)) {
|
|
// serror is set
|
|
return false;
|
|
}
|
|
|
|
// Check signature
|
|
bool fOk = checker.CheckSig(vchSig, vchPubKey, scriptCode);
|
|
|
|
if (fOk) {
|
|
isig++;
|
|
nSigsCount--;
|
|
}
|
|
ikey++;
|
|
nKeysCount--;
|
|
|
|
// If there are more signatures left than keys left,
|
|
// then too many signatures have failed. Exit early,
|
|
// without checking any further signatures.
|
|
if (nSigsCount > nKeysCount)
|
|
fSuccess = false;
|
|
}
|
|
|
|
// Clean up stack of actual arguments
|
|
while (i-- > 1)
|
|
popstack(stack);
|
|
|
|
// A bug causes CHECKMULTISIG to consume one extra argument
|
|
// whose contents were not checked in any way.
|
|
//
|
|
// Unfortunately this is a potential source of mutability,
|
|
// so optionally verify it is exactly equal to zero prior
|
|
// to removing it from the stack.
|
|
if (stack.size() < 1)
|
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION);
|
|
if ((flags & SCRIPT_VERIFY_NULLDUMMY) && stacktop(-1).size())
|
|
return set_error(serror, SCRIPT_ERR_SIG_NULLDUMMY);
|
|
popstack(stack);
|
|
|
|
stack.push_back(fSuccess ? vchTrue : vchFalse);
|
|
|
|
if (opcode == OP_CHECKMULTISIGVERIFY)
|
|
{
|
|
if (fSuccess)
|
|
popstack(stack);
|
|
else
|
|
return set_error(serror, SCRIPT_ERR_CHECKMULTISIGVERIFY);
|
|
}
|
|
}
|
|
break;
|
|
|
|
default:
|
|
return set_error(serror, SCRIPT_ERR_BAD_OPCODE);
|
|
}
|
|
|
|
// Size limits
|
|
if (stack.size() + altstack.size() > 1000)
|
|
return set_error(serror, SCRIPT_ERR_STACK_SIZE);
|
|
}
|
|
}
|
|
catch (...)
|
|
{
|
|
return set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);
|
|
}
|
|
|
|
if (!vfExec.empty())
|
|
return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL);
|
|
|
|
return set_success(serror);
|
|
}
|
|
|
|
namespace {
|
|
|
|
/**
|
|
* Wrapper that serializes like CTransaction, but with the modifications
|
|
* required for the signature hash done in-place
|
|
*/
|
|
class CTransactionSignatureSerializer {
|
|
private:
|
|
const CTransaction &txTo; //! reference to the spending transaction (the one being serialized)
|
|
const CScript &scriptCode; //! output script being consumed
|
|
const unsigned int nIn; //! input index of txTo being signed
|
|
const bool fAnyoneCanPay; //! whether the hashtype has the SIGHASH_ANYONECANPAY flag set
|
|
const bool fHashSingle; //! whether the hashtype is SIGHASH_SINGLE
|
|
const bool fHashNone; //! whether the hashtype is SIGHASH_NONE
|
|
|
|
public:
|
|
CTransactionSignatureSerializer(const CTransaction &txToIn, const CScript &scriptCodeIn, unsigned int nInIn, int nHashTypeIn) :
|
|
txTo(txToIn), scriptCode(scriptCodeIn), nIn(nInIn),
|
|
fAnyoneCanPay(!!(nHashTypeIn & SIGHASH_ANYONECANPAY)),
|
|
fHashSingle((nHashTypeIn & 0x1f) == SIGHASH_SINGLE),
|
|
fHashNone((nHashTypeIn & 0x1f) == SIGHASH_NONE) {}
|
|
|
|
/** Serialize the passed scriptCode, skipping OP_CODESEPARATORs */
|
|
template<typename S>
|
|
void SerializeScriptCode(S &s, int nType, int nVersion) const {
|
|
CScript::const_iterator it = scriptCode.begin();
|
|
CScript::const_iterator itBegin = it;
|
|
opcodetype opcode;
|
|
unsigned int nCodeSeparators = 0;
|
|
while (scriptCode.GetOp(it, opcode)) {
|
|
if (opcode == OP_CODESEPARATOR)
|
|
nCodeSeparators++;
|
|
}
|
|
::WriteCompactSize(s, scriptCode.size() - nCodeSeparators);
|
|
it = itBegin;
|
|
while (scriptCode.GetOp(it, opcode)) {
|
|
if (opcode == OP_CODESEPARATOR) {
|
|
s.write((char*)&itBegin[0], it-itBegin-1);
|
|
itBegin = it;
|
|
}
|
|
}
|
|
if (itBegin != scriptCode.end())
|
|
s.write((char*)&itBegin[0], it-itBegin);
|
|
}
|
|
|
|
/** Serialize an input of txTo */
|
|
template<typename S>
|
|
void SerializeInput(S &s, unsigned int nInput, int nType, int nVersion) const {
|
|
// In case of SIGHASH_ANYONECANPAY, only the input being signed is serialized
|
|
if (fAnyoneCanPay)
|
|
nInput = nIn;
|
|
// Serialize the prevout
|
|
::Serialize(s, txTo.vin[nInput].prevout, nType, nVersion);
|
|
// Serialize the script
|
|
if (nInput != nIn)
|
|
// Blank out other inputs' signatures
|
|
::Serialize(s, CScriptBase(), nType, nVersion);
|
|
else
|
|
SerializeScriptCode(s, nType, nVersion);
|
|
// Serialize the nSequence
|
|
if (nInput != nIn && (fHashSingle || fHashNone))
|
|
// let the others update at will
|
|
::Serialize(s, (int)0, nType, nVersion);
|
|
else
|
|
::Serialize(s, txTo.vin[nInput].nSequence, nType, nVersion);
|
|
}
|
|
|
|
/** Serialize an output of txTo */
|
|
template<typename S>
|
|
void SerializeOutput(S &s, unsigned int nOutput, int nType, int nVersion) const {
|
|
if (fHashSingle && nOutput != nIn)
|
|
// Do not lock-in the txout payee at other indices as txin
|
|
::Serialize(s, CTxOut(), nType, nVersion);
|
|
else
|
|
::Serialize(s, txTo.vout[nOutput], nType, nVersion);
|
|
}
|
|
|
|
/** Serialize txTo */
|
|
template<typename S>
|
|
void Serialize(S &s, int nType, int nVersion) const {
|
|
// Serialize nVersion
|
|
::Serialize(s, txTo.nVersion, nType, nVersion);
|
|
// Serialize vin
|
|
unsigned int nInputs = fAnyoneCanPay ? 1 : txTo.vin.size();
|
|
::WriteCompactSize(s, nInputs);
|
|
for (unsigned int nInput = 0; nInput < nInputs; nInput++)
|
|
SerializeInput(s, nInput, nType, nVersion);
|
|
// Serialize vout
|
|
unsigned int nOutputs = fHashNone ? 0 : (fHashSingle ? nIn+1 : txTo.vout.size());
|
|
::WriteCompactSize(s, nOutputs);
|
|
for (unsigned int nOutput = 0; nOutput < nOutputs; nOutput++)
|
|
SerializeOutput(s, nOutput, nType, nVersion);
|
|
// Serialize nLockTime
|
|
::Serialize(s, txTo.nLockTime, nType, nVersion);
|
|
}
|
|
};
|
|
|
|
} // anon namespace
|
|
|
|
uint256 SignatureHash(const CScript& scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType)
|
|
{
|
|
static const uint256 one(uint256S("0000000000000000000000000000000000000000000000000000000000000001"));
|
|
if (nIn >= txTo.vin.size()) {
|
|
// nIn out of range
|
|
return one;
|
|
}
|
|
|
|
// Check for invalid use of SIGHASH_SINGLE
|
|
if ((nHashType & 0x1f) == SIGHASH_SINGLE) {
|
|
if (nIn >= txTo.vout.size()) {
|
|
// nOut out of range
|
|
return one;
|
|
}
|
|
}
|
|
|
|
// Wrapper to serialize only the necessary parts of the transaction being signed
|
|
CTransactionSignatureSerializer txTmp(txTo, scriptCode, nIn, nHashType);
|
|
|
|
// Serialize and hash
|
|
CHashWriter ss(SER_GETHASH, 0);
|
|
ss << txTmp << nHashType;
|
|
return ss.GetHash();
|
|
}
|
|
|
|
bool TransactionSignatureChecker::VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& pubkey, const uint256& sighash) const
|
|
{
|
|
return pubkey.Verify(sighash, vchSig);
|
|
}
|
|
|
|
bool TransactionSignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn, const vector<unsigned char>& vchPubKey, const CScript& scriptCode) const
|
|
{
|
|
CPubKey pubkey(vchPubKey);
|
|
if (!pubkey.IsValid())
|
|
return false;
|
|
|
|
// Hash type is one byte tacked on to the end of the signature
|
|
vector<unsigned char> vchSig(vchSigIn);
|
|
if (vchSig.empty())
|
|
return false;
|
|
int nHashType = vchSig.back();
|
|
vchSig.pop_back();
|
|
|
|
uint256 sighash = SignatureHash(scriptCode, *txTo, nIn, nHashType);
|
|
|
|
if (!VerifySignature(vchSig, pubkey, sighash))
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
bool TransactionSignatureChecker::CheckLockTime(const CScriptNum& nLockTime) const
|
|
{
|
|
// There are two kinds of nLockTime: lock-by-blockheight
|
|
// and lock-by-blocktime, distinguished by whether
|
|
// nLockTime < LOCKTIME_THRESHOLD.
|
|
//
|
|
// We want to compare apples to apples, so fail the script
|
|
// unless the type of nLockTime being tested is the same as
|
|
// the nLockTime in the transaction.
|
|
if (!(
|
|
(txTo->nLockTime < LOCKTIME_THRESHOLD && nLockTime < LOCKTIME_THRESHOLD) ||
|
|
(txTo->nLockTime >= LOCKTIME_THRESHOLD && nLockTime >= LOCKTIME_THRESHOLD)
|
|
))
|
|
return false;
|
|
|
|
// Now that we know we're comparing apples-to-apples, the
|
|
// comparison is a simple numeric one.
|
|
if (nLockTime > (int64_t)txTo->nLockTime)
|
|
return false;
|
|
|
|
// Finally the nLockTime feature can be disabled and thus
|
|
// CHECKLOCKTIMEVERIFY bypassed if every txin has been
|
|
// finalized by setting nSequence to maxint. The
|
|
// transaction would be allowed into the blockchain, making
|
|
// the opcode ineffective.
|
|
//
|
|
// Testing if this vin is not final is sufficient to
|
|
// prevent this condition. Alternatively we could test all
|
|
// inputs, but testing just this input minimizes the data
|
|
// required to prove correct CHECKLOCKTIMEVERIFY execution.
|
|
if (txTo->vin[nIn].IsFinal())
|
|
return false;
|
|
|
|
return true;
|
|
}
|
|
|
|
|
|
bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror)
|
|
{
|
|
set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);
|
|
|
|
if ((flags & SCRIPT_VERIFY_SIGPUSHONLY) != 0 && !scriptSig.IsPushOnly()) {
|
|
return set_error(serror, SCRIPT_ERR_SIG_PUSHONLY);
|
|
}
|
|
|
|
vector<vector<unsigned char> > stack, stackCopy;
|
|
if (!EvalScript(stack, scriptSig, flags, checker, serror))
|
|
// serror is set
|
|
return false;
|
|
if (flags & SCRIPT_VERIFY_P2SH)
|
|
stackCopy = stack;
|
|
if (!EvalScript(stack, scriptPubKey, flags, checker, serror))
|
|
// serror is set
|
|
return false;
|
|
if (stack.empty())
|
|
return set_error(serror, SCRIPT_ERR_EVAL_FALSE);
|
|
if (CastToBool(stack.back()) == false)
|
|
return set_error(serror, SCRIPT_ERR_EVAL_FALSE);
|
|
|
|
// Additional validation for spend-to-script-hash transactions:
|
|
if ((flags & SCRIPT_VERIFY_P2SH) && scriptPubKey.IsPayToScriptHash())
|
|
{
|
|
// scriptSig must be literals-only or validation fails
|
|
if (!scriptSig.IsPushOnly())
|
|
return set_error(serror, SCRIPT_ERR_SIG_PUSHONLY);
|
|
|
|
// Restore stack.
|
|
swap(stack, stackCopy);
|
|
|
|
// stack cannot be empty here, because if it was the
|
|
// P2SH HASH <> EQUAL scriptPubKey would be evaluated with
|
|
// an empty stack and the EvalScript above would return false.
|
|
assert(!stack.empty());
|
|
|
|
const valtype& pubKeySerialized = stack.back();
|
|
CScript pubKey2(pubKeySerialized.begin(), pubKeySerialized.end());
|
|
popstack(stack);
|
|
|
|
if (!EvalScript(stack, pubKey2, flags, checker, serror))
|
|
// serror is set
|
|
return false;
|
|
if (stack.empty())
|
|
return set_error(serror, SCRIPT_ERR_EVAL_FALSE);
|
|
if (!CastToBool(stack.back()))
|
|
return set_error(serror, SCRIPT_ERR_EVAL_FALSE);
|
|
}
|
|
|
|
// The CLEANSTACK check is only performed after potential P2SH evaluation,
|
|
// as the non-P2SH evaluation of a P2SH script will obviously not result in
|
|
// a clean stack (the P2SH inputs remain).
|
|
if ((flags & SCRIPT_VERIFY_CLEANSTACK) != 0) {
|
|
// Disallow CLEANSTACK without P2SH, as otherwise a switch CLEANSTACK->P2SH+CLEANSTACK
|
|
// would be possible, which is not a softfork (and P2SH should be one).
|
|
assert((flags & SCRIPT_VERIFY_P2SH) != 0);
|
|
if (stack.size() != 1) {
|
|
return set_error(serror, SCRIPT_ERR_CLEANSTACK);
|
|
}
|
|
}
|
|
|
|
return set_success(serror);
|
|
}
|