From 605e8473a7ddca13b24a4020c7bd630aa5d374e2 Mon Sep 17 00:00:00 2001 From: Pieter Wuille Date: Thu, 31 Mar 2016 14:54:58 +0200 Subject: BIP143: Signing logic --- src/script/sign.cpp | 279 ++++++++++++++++++++++++++++++++++++---------------- 1 file changed, 196 insertions(+), 83 deletions(-) (limited to 'src/script/sign.cpp') diff --git a/src/script/sign.cpp b/src/script/sign.cpp index 83bb0cfa29..87f38d9c72 100644 --- a/src/script/sign.cpp +++ b/src/script/sign.cpp @@ -20,29 +20,29 @@ typedef std::vector valtype; TransactionSignatureCreator::TransactionSignatureCreator(const CKeyStore* keystoreIn, const CTransaction* txToIn, unsigned int nInIn, const CAmount& amountIn, int nHashTypeIn) : BaseSignatureCreator(keystoreIn), txTo(txToIn), nIn(nInIn), nHashType(nHashTypeIn), amount(amountIn), checker(txTo, nIn, amountIn) {} -bool TransactionSignatureCreator::CreateSig(std::vector& vchSig, const CKeyID& address, const CScript& scriptCode) const +bool TransactionSignatureCreator::CreateSig(std::vector& vchSig, const CKeyID& address, const CScript& scriptCode, SigVersion sigversion) const { CKey key; if (!keystore->GetKey(address, key)) return false; - uint256 hash = SignatureHash(scriptCode, *txTo, nIn, nHashType, amount, SIGVERSION_BASE); + uint256 hash = SignatureHash(scriptCode, *txTo, nIn, nHashType, amount, sigversion); if (!key.Sign(hash, vchSig)) return false; vchSig.push_back((unsigned char)nHashType); return true; } -static bool Sign1(const CKeyID& address, const BaseSignatureCreator& creator, const CScript& scriptCode, CScript& scriptSigRet) +static bool Sign1(const CKeyID& address, const BaseSignatureCreator& creator, const CScript& scriptCode, std::vector& ret, SigVersion sigversion) { vector vchSig; - if (!creator.CreateSig(vchSig, address, scriptCode)) + if (!creator.CreateSig(vchSig, address, scriptCode, sigversion)) return false; - scriptSigRet << vchSig; + ret.push_back(vchSig); return true; } -static bool SignN(const vector& multisigdata, const BaseSignatureCreator& creator, const CScript& scriptCode, CScript& scriptSigRet) +static bool SignN(const vector& multisigdata, const BaseSignatureCreator& creator, const CScript& scriptCode, std::vector& ret, SigVersion sigversion) { int nSigned = 0; int nRequired = multisigdata.front()[0]; @@ -50,7 +50,7 @@ static bool SignN(const vector& multisigdata, const BaseSignatureCreato { const valtype& pubkey = multisigdata[i]; CKeyID keyID = CPubKey(pubkey).GetID(); - if (Sign1(keyID, creator, scriptCode, scriptSigRet)) + if (Sign1(keyID, creator, scriptCode, ret, sigversion)) ++nSigned; } return nSigned==nRequired; @@ -63,9 +63,11 @@ static bool SignN(const vector& multisigdata, const BaseSignatureCreato * Returns false if scriptPubKey could not be completely satisfied. */ static bool SignStep(const BaseSignatureCreator& creator, const CScript& scriptPubKey, - CScript& scriptSigRet, txnouttype& whichTypeRet) + std::vector& ret, txnouttype& whichTypeRet, SigVersion sigversion) { - scriptSigRet.clear(); + CScript scriptRet; + uint160 h160; + ret.clear(); vector vSolutions; if (!Solver(scriptPubKey, whichTypeRet, vSolutions)) @@ -79,62 +81,142 @@ static bool SignStep(const BaseSignatureCreator& creator, const CScript& scriptP return false; case TX_PUBKEY: keyID = CPubKey(vSolutions[0]).GetID(); - return Sign1(keyID, creator, scriptPubKey, scriptSigRet); + return Sign1(keyID, creator, scriptPubKey, ret, sigversion); case TX_PUBKEYHASH: keyID = CKeyID(uint160(vSolutions[0])); - if (!Sign1(keyID, creator, scriptPubKey, scriptSigRet)) + if (!Sign1(keyID, creator, scriptPubKey, ret, sigversion)) return false; else { CPubKey vch; creator.KeyStore().GetPubKey(keyID, vch); - scriptSigRet << ToByteVector(vch); + ret.push_back(ToByteVector(vch)); } return true; case TX_SCRIPTHASH: - return creator.KeyStore().GetCScript(uint160(vSolutions[0]), scriptSigRet); + if (creator.KeyStore().GetCScript(uint160(vSolutions[0]), scriptRet)) { + ret.push_back(std::vector(scriptRet.begin(), scriptRet.end())); + return true; + } + return false; case TX_MULTISIG: - scriptSigRet << OP_0; // workaround CHECKMULTISIG bug - return (SignN(vSolutions, creator, scriptPubKey, scriptSigRet)); + ret.push_back(valtype()); // workaround CHECKMULTISIG bug + return (SignN(vSolutions, creator, scriptPubKey, ret, sigversion)); + + case TX_WITNESS_V0_KEYHASH: + ret.push_back(vSolutions[0]); + return true; + + case TX_WITNESS_V0_SCRIPTHASH: + CRIPEMD160().Write(&vSolutions[0][0], vSolutions[0].size()).Finalize(h160.begin()); + if (creator.KeyStore().GetCScript(h160, scriptRet)) { + ret.push_back(std::vector(scriptRet.begin(), scriptRet.end())); + return true; + } + return false; + + default: + return false; } - return false; } -bool ProduceSignature(const BaseSignatureCreator& creator, const CScript& fromPubKey, CScript& scriptSig) +static CScript PushAll(const vector& values) { + CScript result; + BOOST_FOREACH(const valtype& v, values) { + if (v.size() == 0) { + result << OP_0; + } else if (v.size() == 1 && v[0] >= 1 && v[0] <= 16) { + result << CScript::EncodeOP_N(v[0]); + } else { + result << v; + } + } + return result; +} + +bool ProduceSignature(const BaseSignatureCreator& creator, const CScript& fromPubKey, SignatureData& sigdata) +{ + CScript script = fromPubKey; + bool solved = true; + std::vector result; txnouttype whichType; - if (!SignStep(creator, fromPubKey, scriptSig, whichType)) - return false; + solved = SignStep(creator, script, result, whichType, SIGVERSION_BASE); + bool P2SH = false; + CScript subscript; + sigdata.scriptWitness.stack.clear(); - if (whichType == TX_SCRIPTHASH) + if (solved && whichType == TX_SCRIPTHASH) { - // Solver returns the subscript that need to be evaluated; + // Solver returns the subscript that needs to be evaluated; // the final scriptSig is the signatures from that // and then the serialized subscript: - CScript subscript = scriptSig; + script = subscript = CScript(result[0].begin(), result[0].end()); + solved = solved && SignStep(creator, script, result, whichType, SIGVERSION_BASE) && whichType != TX_SCRIPTHASH; + P2SH = true; + } + if (solved && whichType == TX_WITNESS_V0_KEYHASH) + { + CScript witnessscript; + witnessscript << OP_DUP << OP_HASH160 << ToByteVector(result[0]) << OP_EQUALVERIFY << OP_CHECKSIG; txnouttype subType; - bool fSolved = - SignStep(creator, subscript, scriptSig, subType) && subType != TX_SCRIPTHASH; - // Append serialized subscript whether or not it is completely signed: - scriptSig << valtype(subscript.begin(), subscript.end()); - if (!fSolved) return false; + solved = solved && SignStep(creator, witnessscript, result, subType, SIGVERSION_WITNESS_V0); + sigdata.scriptWitness.stack = result; + result.clear(); + } + else if (solved && whichType == TX_WITNESS_V0_SCRIPTHASH) + { + CScript witnessscript(result[0].begin(), result[0].end()); + txnouttype subType; + solved = solved && SignStep(creator, witnessscript, result, subType, SIGVERSION_WITNESS_V0) && subType != TX_SCRIPTHASH && subType != TX_WITNESS_V0_SCRIPTHASH && subType != TX_WITNESS_V0_KEYHASH; + result.push_back(std::vector(witnessscript.begin(), witnessscript.end())); + sigdata.scriptWitness.stack = result; + result.clear(); } + if (P2SH) { + result.push_back(std::vector(subscript.begin(), subscript.end())); + } + sigdata.scriptSig = PushAll(result); + // Test solution - return VerifyScript(scriptSig, fromPubKey, NULL, STANDARD_SCRIPT_VERIFY_FLAGS, creator.Checker()); + return solved && VerifyScript(sigdata.scriptSig, fromPubKey, &sigdata.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, creator.Checker()); +} + +SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nIn) +{ + SignatureData data; + assert(tx.vin.size() > nIn); + data.scriptSig = tx.vin[nIn].scriptSig; + if (tx.wit.vtxinwit.size() > nIn) { + data.scriptWitness = tx.wit.vtxinwit[nIn].scriptWitness; + } + return data; +} + +void UpdateTransaction(CMutableTransaction& tx, unsigned int nIn, const SignatureData& data) +{ + assert(tx.vin.size() > nIn); + tx.vin[nIn].scriptSig = data.scriptSig; + if (!data.scriptWitness.IsNull() || tx.wit.vtxinwit.size() > nIn) { + tx.wit.vtxinwit.resize(tx.vin.size()); + tx.wit.vtxinwit[nIn].scriptWitness = data.scriptWitness; + } } -bool SignSignature(const CKeyStore &keystore, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, int nHashType) +bool SignSignature(const CKeyStore &keystore, const CScript& fromPubKey, CMutableTransaction& txTo, unsigned int nIn, const CAmount& amount, int nHashType) { assert(nIn < txTo.vin.size()); - CTxIn& txin = txTo.vin[nIn]; CTransaction txToConst(txTo); - TransactionSignatureCreator creator(&keystore, &txToConst, nIn, nHashType); + TransactionSignatureCreator creator(&keystore, &txToConst, nIn, amount, nHashType); - return ProduceSignature(creator, fromPubKey, txin.scriptSig); + SignatureData sigdata; + bool ret = ProduceSignature(creator, fromPubKey, sigdata); + UpdateTransaction(txTo, nIn, sigdata); + return ret; } bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CMutableTransaction& txTo, unsigned int nIn, int nHashType) @@ -144,20 +226,12 @@ bool SignSignature(const CKeyStore &keystore, const CTransaction& txFrom, CMutab assert(txin.prevout.n < txFrom.vout.size()); const CTxOut& txout = txFrom.vout[txin.prevout.n]; - return SignSignature(keystore, txout.scriptPubKey, txTo, nIn, nHashType); -} - -static CScript PushAll(const vector& values) -{ - CScript result; - BOOST_FOREACH(const valtype& v, values) - result << v; - return result; + return SignSignature(keystore, txout.scriptPubKey, txTo, nIn, txout.nValue, nHashType); } -static CScript CombineMultisig(const CScript& scriptPubKey, const BaseSignatureChecker& checker, +static vector CombineMultisig(const CScript& scriptPubKey, const BaseSignatureChecker& checker, const vector& vSolutions, - const vector& sigs1, const vector& sigs2) + const vector& sigs1, const vector& sigs2, SigVersion sigversion) { // Combine all the signatures we've got: set allsigs; @@ -185,7 +259,7 @@ static CScript CombineMultisig(const CScript& scriptPubKey, const BaseSignatureC if (sigs.count(pubkey)) continue; // Already got a sig for this pubkey - if (checker.CheckSig(sig, pubkey, scriptPubKey, SIGVERSION_BASE)) + if (checker.CheckSig(sig, pubkey, scriptPubKey, sigversion)) { sigs[pubkey] = sig; break; @@ -194,87 +268,126 @@ static CScript CombineMultisig(const CScript& scriptPubKey, const BaseSignatureC } // Now build a merged CScript: unsigned int nSigsHave = 0; - CScript result; result << OP_0; // pop-one-too-many workaround + std::vector result; result.push_back(valtype()); // pop-one-too-many workaround for (unsigned int i = 0; i < nPubKeys && nSigsHave < nSigsRequired; i++) { if (sigs.count(vSolutions[i+1])) { - result << sigs[vSolutions[i+1]]; + result.push_back(sigs[vSolutions[i+1]]); ++nSigsHave; } } // Fill any missing with OP_0: for (unsigned int i = nSigsHave; i < nSigsRequired; i++) - result << OP_0; + result.push_back(valtype()); return result; } -static CScript CombineSignatures(const CScript& scriptPubKey, const BaseSignatureChecker& checker, +namespace +{ +struct Stacks +{ + std::vector script; + std::vector witness; + + Stacks() {} + explicit Stacks(const std::vector& scriptSigStack_) : script(scriptSigStack_), witness() {} + explicit Stacks(const SignatureData& data) : witness(data.scriptWitness.stack) { + EvalScript(script, data.scriptSig, SCRIPT_VERIFY_STRICTENC, BaseSignatureChecker(), SIGVERSION_BASE); + } + + SignatureData Output() const { + SignatureData result; + result.scriptSig = PushAll(script); + result.scriptWitness.stack = witness; + return result; + } +}; +} + +static Stacks CombineSignatures(const CScript& scriptPubKey, const BaseSignatureChecker& checker, const txnouttype txType, const vector& vSolutions, - vector& sigs1, vector& sigs2) + Stacks sigs1, Stacks sigs2, SigVersion sigversion) { switch (txType) { case TX_NONSTANDARD: case TX_NULL_DATA: // Don't know anything about this, assume bigger one is correct: - if (sigs1.size() >= sigs2.size()) - return PushAll(sigs1); - return PushAll(sigs2); + if (sigs1.script.size() >= sigs2.script.size()) + return sigs1; + return sigs2; case TX_PUBKEY: case TX_PUBKEYHASH: // Signatures are bigger than placeholders or empty scripts: - if (sigs1.empty() || sigs1[0].empty()) - return PushAll(sigs2); - return PushAll(sigs1); + if (sigs1.script.empty() || sigs1.script[0].empty()) + return sigs2; + return sigs1; + case TX_WITNESS_V0_KEYHASH: + // Signatures are bigger than placeholders or empty scripts: + if (sigs1.witness.empty() || sigs1.witness[0].empty()) + return sigs2; + return sigs1; case TX_SCRIPTHASH: - if (sigs1.empty() || sigs1.back().empty()) - return PushAll(sigs2); - else if (sigs2.empty() || sigs2.back().empty()) - return PushAll(sigs1); + if (sigs1.script.empty() || sigs1.script.back().empty()) + return sigs2; + else if (sigs2.script.empty() || sigs2.script.back().empty()) + return sigs1; else { // Recur to combine: - valtype spk = sigs1.back(); + valtype spk = sigs1.script.back(); CScript pubKey2(spk.begin(), spk.end()); txnouttype txType2; vector > vSolutions2; Solver(pubKey2, txType2, vSolutions2); - sigs1.pop_back(); - sigs2.pop_back(); - CScript result = CombineSignatures(pubKey2, checker, txType2, vSolutions2, sigs1, sigs2); - result << spk; + sigs1.script.pop_back(); + sigs2.script.pop_back(); + Stacks result = CombineSignatures(pubKey2, checker, txType2, vSolutions2, sigs1, sigs2, sigversion); + result.script.push_back(spk); return result; } case TX_MULTISIG: - return CombineMultisig(scriptPubKey, checker, vSolutions, sigs1, sigs2); + return Stacks(CombineMultisig(scriptPubKey, checker, vSolutions, sigs1.script, sigs2.script, sigversion)); + case TX_WITNESS_V0_SCRIPTHASH: + if (sigs1.witness.empty() || sigs1.witness.back().empty()) + return sigs2; + else if (sigs2.witness.empty() || sigs2.witness.back().empty()) + return sigs1; + else + { + // Recur to combine: + CScript pubKey2(sigs1.witness.back().begin(), sigs1.witness.back().end()); + txnouttype txType2; + vector vSolutions2; + Solver(pubKey2, txType2, vSolutions2); + sigs1.witness.pop_back(); + sigs1.script = sigs1.witness; + sigs1.witness.clear(); + sigs2.witness.pop_back(); + sigs2.script = sigs2.witness; + sigs2.witness.clear(); + Stacks result = CombineSignatures(pubKey2, checker, txType2, vSolutions2, sigs1, sigs2, SIGVERSION_WITNESS_V0); + result.witness = result.script; + result.script.clear(); + result.witness.push_back(valtype(pubKey2.begin(), pubKey2.end())); + return result; + } + default: + return Stacks(); } - - return CScript(); } -CScript CombineSignatures(const CScript& scriptPubKey, const CTransaction& txTo, unsigned int nIn, const CAmount& amount, - const CScript& scriptSig1, const CScript& scriptSig2) -{ - TransactionSignatureChecker checker(&txTo, nIn, amount); - return CombineSignatures(scriptPubKey, checker, scriptSig1, scriptSig2); -} - -CScript CombineSignatures(const CScript& scriptPubKey, const BaseSignatureChecker& checker, - const CScript& scriptSig1, const CScript& scriptSig2) +SignatureData CombineSignatures(const CScript& scriptPubKey, const BaseSignatureChecker& checker, + const SignatureData& scriptSig1, const SignatureData& scriptSig2) { txnouttype txType; vector > vSolutions; Solver(scriptPubKey, txType, vSolutions); - vector stack1; - EvalScript(stack1, scriptSig1, SCRIPT_VERIFY_STRICTENC, BaseSignatureChecker(), SIGVERSION_BASE); - vector stack2; - EvalScript(stack2, scriptSig2, SCRIPT_VERIFY_STRICTENC, BaseSignatureChecker(), SIGVERSION_BASE); - - return CombineSignatures(scriptPubKey, checker, txType, vSolutions, stack1, stack2); + return CombineSignatures(scriptPubKey, checker, txType, vSolutions, Stacks(scriptSig1), Stacks(scriptSig2), SIGVERSION_BASE).Output(); } namespace { @@ -297,7 +410,7 @@ const BaseSignatureChecker& DummySignatureCreator::Checker() const return dummyChecker; } -bool DummySignatureCreator::CreateSig(std::vector& vchSig, const CKeyID& keyid, const CScript& scriptCode) const +bool DummySignatureCreator::CreateSig(std::vector& vchSig, const CKeyID& keyid, const CScript& scriptCode, SigVersion sigversion) const { // Create a dummy signature that is a valid DER-encoding vchSig.assign(72, '\000'); -- cgit v1.2.3