diff options
Diffstat (limited to 'src/script.cpp')
| -rw-r--r-- | src/script.cpp | 146 |
1 files changed, 101 insertions, 45 deletions
diff --git a/src/script.cpp b/src/script.cpp index 0fe2953548..ad2d35d94c 100644 --- a/src/script.cpp +++ b/src/script.cpp @@ -971,62 +971,118 @@ bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, co +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 - -uint256 SignatureHash(CScript scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType) -{ - if (nIn >= txTo.vin.size()) - { - LogPrintf("ERROR: SignatureHash() : nIn=%d out of range\n", nIn); - return 1; +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; + } + } + s.write((char*)&itBegin[0], it-itBegin); } - CTransaction txTmp(txTo); - // In case concatenating two scripts ends up with two codeseparators, - // or an extra one at the end, this prevents all those possible incompatibilities. - scriptCode.FindAndDelete(CScript(OP_CODESEPARATOR)); + /** 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, CScript(), 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); + } - // Blank out other inputs' signatures - for (unsigned int i = 0; i < txTmp.vin.size(); i++) - txTmp.vin[i].scriptSig = CScript(); - txTmp.vin[nIn].scriptSig = scriptCode; + /** 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); + } - // Blank out some of the outputs - if ((nHashType & 0x1f) == SIGHASH_NONE) - { - // Wildcard payee - txTmp.vout.clear(); + /** 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); + // Serialie nLockTime + ::Serialize(s, txTo.nLockTime, nType, nVersion); + } +}; +} - // Let the others update at will - for (unsigned int i = 0; i < txTmp.vin.size(); i++) - if (i != nIn) - txTmp.vin[i].nSequence = 0; +uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType) +{ + if (nIn >= txTo.vin.size()) { + LogPrintf("ERROR: SignatureHash() : nIn=%d out of range\n", nIn); + return 1; } - else if ((nHashType & 0x1f) == SIGHASH_SINGLE) - { - // Only lock-in the txout payee at same index as txin - unsigned int nOut = nIn; - if (nOut >= txTmp.vout.size()) - { - LogPrintf("ERROR: SignatureHash() : nOut=%d out of range\n", nOut); + + // Check for invalid use of SIGHASH_SINGLE + if ((nHashType & 0x1f) == SIGHASH_SINGLE) { + if (nIn >= txTo.vout.size()) { + LogPrintf("ERROR: SignatureHash() : nOut=%d out of range\n", nIn); return 1; } - txTmp.vout.resize(nOut+1); - for (unsigned int i = 0; i < nOut; i++) - txTmp.vout[i].SetNull(); - - // Let the others update at will - for (unsigned int i = 0; i < txTmp.vin.size(); i++) - if (i != nIn) - txTmp.vin[i].nSequence = 0; } - // Blank out other inputs completely, not recommended for open transactions - if (nHashType & SIGHASH_ANYONECANPAY) - { - txTmp.vin[0] = txTmp.vin[nIn]; - txTmp.vin.resize(1); - } + // 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); |