diff options
Diffstat (limited to 'src/script/sign.cpp')
| -rw-r--r-- | src/script/sign.cpp | 53 |
1 files changed, 36 insertions, 17 deletions
diff --git a/src/script/sign.cpp b/src/script/sign.cpp index fa09adbaf..23af1bd97 100644 --- a/src/script/sign.cpp +++ b/src/script/sign.cpp @@ -1,5 +1,5 @@ // Copyright (c) 2009-2010 Satoshi Nakamoto -// Copyright (c) 2009-2017 The Bitcoin Core developers +// Copyright (c) 2009-2018 The Bitcoin Core developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. @@ -101,8 +101,7 @@ static bool SignStep(const SigningProvider& provider, const BaseSignatureCreator std::vector<unsigned char> sig; std::vector<valtype> vSolutions; - if (!Solver(scriptPubKey, whichTypeRet, vSolutions)) - return false; + whichTypeRet = Solver(scriptPubKey, vSolutions); switch (whichTypeRet) { @@ -244,17 +243,33 @@ bool SignPSBTInput(const SigningProvider& provider, const CMutableTransaction& t input.FillSignatureData(sigdata); // Get UTXO + bool require_witness_sig = false; CTxOut utxo; if (input.non_witness_utxo) { + // If we're taking our information from a non-witness UTXO, verify that it matches the prevout. + if (input.non_witness_utxo->GetHash() != tx.vin[index].prevout.hash) return false; + // If both witness and non-witness UTXO are provided, verify that they match. This check shouldn't + // matter, as the PSBT deserializer enforces only one of both is provided, and the only way both + // can be present is when they're added simultaneously by FillPSBT (in which case they always match). + // Still, check in order to not rely on callers to enforce this. + if (!input.witness_utxo.IsNull() && input.non_witness_utxo->vout[tx.vin[index].prevout.n] != input.witness_utxo) return false; utxo = input.non_witness_utxo->vout[tx.vin[index].prevout.n]; } else if (!input.witness_utxo.IsNull()) { utxo = input.witness_utxo; + // When we're taking our information from a witness UTXO, we can't verify it is actually data from + // the output being spent. This is safe in case a witness signature is produced (which includes this + // information directly in the hash), but not for non-witness signatures. Remember that we require + // a witness signature in this situation. + require_witness_sig = true; } else { return false; } MutableTransactionSignatureCreator creator(&tx, index, utxo.nValue, sighash); + sigdata.witness = false; bool sig_complete = ProduceSignature(provider, creator, utxo.scriptPubKey, sigdata); + // Verify that a witness signature was produced in case one was required. + if (require_witness_sig && !sigdata.witness) return false; input.FromSignatureData(sigdata); return sig_complete; } @@ -313,9 +328,8 @@ SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nI } // Get scripts - txnouttype script_type; std::vector<std::vector<unsigned char>> solutions; - Solver(txout.scriptPubKey, script_type, solutions); + txnouttype script_type = Solver(txout.scriptPubKey, solutions); SigVersion sigversion = SigVersion::BASE; CScript next_script = txout.scriptPubKey; @@ -326,7 +340,7 @@ SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nI next_script = std::move(redeem_script); // Get redeemScript type - Solver(next_script, script_type, solutions); + script_type = Solver(next_script, solutions); stack.script.pop_back(); } if (script_type == TX_WITNESS_V0_SCRIPTHASH && !stack.witness.empty() && !stack.witness.back().empty()) { @@ -336,7 +350,7 @@ SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nI next_script = std::move(witness_script); // Get witnessScript type - Solver(next_script, script_type, solutions); + script_type = Solver(next_script, solutions); stack.witness.pop_back(); stack.script = std::move(stack.witness); stack.witness.clear(); @@ -417,22 +431,25 @@ public: const DummySignatureChecker DUMMY_CHECKER; class DummySignatureCreator final : public BaseSignatureCreator { +private: + char m_r_len = 32; + char m_s_len = 32; public: - DummySignatureCreator() {} + DummySignatureCreator(char r_len, char s_len) : m_r_len(r_len), m_s_len(s_len) {} const BaseSignatureChecker& Checker() const override { return DUMMY_CHECKER; } bool CreateSig(const SigningProvider& provider, std::vector<unsigned char>& vchSig, const CKeyID& keyid, const CScript& scriptCode, SigVersion sigversion) const override { // Create a dummy signature that is a valid DER-encoding - vchSig.assign(72, '\000'); + vchSig.assign(m_r_len + m_s_len + 7, '\000'); vchSig[0] = 0x30; - vchSig[1] = 69; + vchSig[1] = m_r_len + m_s_len + 4; vchSig[2] = 0x02; - vchSig[3] = 33; + vchSig[3] = m_r_len; vchSig[4] = 0x01; - vchSig[4 + 33] = 0x02; - vchSig[5 + 33] = 32; - vchSig[6 + 33] = 0x01; - vchSig[6 + 33 + 32] = SIGHASH_ALL; + vchSig[4 + m_r_len] = 0x02; + vchSig[5 + m_r_len] = m_s_len; + vchSig[6 + m_r_len] = 0x01; + vchSig[6 + m_r_len + m_s_len] = SIGHASH_ALL; return true; } }; @@ -450,7 +467,8 @@ bool LookupHelper(const M& map, const K& key, V& value) } -const BaseSignatureCreator& DUMMY_SIGNATURE_CREATOR = DummySignatureCreator(); +const BaseSignatureCreator& DUMMY_SIGNATURE_CREATOR = DummySignatureCreator(32, 32); +const BaseSignatureCreator& DUMMY_MAXIMUM_SIGNATURE_CREATOR = DummySignatureCreator(33, 32); const SigningProvider& DUMMY_SIGNING_PROVIDER = SigningProvider(); bool IsSolvable(const SigningProvider& provider, const CScript& script) @@ -465,7 +483,8 @@ bool IsSolvable(const SigningProvider& provider, const CScript& script) static_assert(STANDARD_SCRIPT_VERIFY_FLAGS & SCRIPT_VERIFY_WITNESS_PUBKEYTYPE, "IsSolvable requires standard script flags to include WITNESS_PUBKEYTYPE"); if (ProduceSignature(provider, DUMMY_SIGNATURE_CREATOR, script, sigs)) { // VerifyScript check is just defensive, and should never fail. - assert(VerifyScript(sigs.scriptSig, script, &sigs.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, DUMMY_CHECKER)); + bool verified = VerifyScript(sigs.scriptSig, script, &sigs.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, DUMMY_CHECKER); + assert(verified); return true; } return false; |