From 0422beb9bdfcd7d1cc095ab681a760d8bc7a1918 Mon Sep 17 00:00:00 2001 From: Andrew Chow Date: Tue, 3 Jul 2018 17:18:52 -0700 Subject: Make SignatureData able to store signatures and scripts In addition to having the scriptSig and scriptWitness, have SignatureData also be able to store just the signatures (pubkeys mapped to sigs) and scripts (script ids mapped to scripts). Also have DataFromTransaction be able to extract signatures and scripts from the scriptSig and scriptWitness of an input to put them in SignatureData. Adds a new SignatureChecker which takes a SignatureData and puts pubkeys and signatures into it when it successfully verifies a signature. Adds a new field in SignatureData which stores whether the SignatureData was complete. This allows us to also update the scriptSig and scriptWitness to the final one when updating a SignatureData with another one. --- src/script/sign.cpp | 130 ++++++++++++++++++++++++++++++++++++++++++---------- 1 file changed, 106 insertions(+), 24 deletions(-) (limited to 'src/script/sign.cpp') diff --git a/src/script/sign.cpp b/src/script/sign.cpp index 05fde3b54..cb63c2159 100644 --- a/src/script/sign.cpp +++ b/src/script/sign.cpp @@ -126,6 +126,8 @@ static CScript PushAll(const std::vector& values) bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreator& creator, const CScript& fromPubKey, SignatureData& sigdata) { + if (sigdata.complete) return true; + std::vector result; txnouttype whichType; bool solved = SignStep(provider, creator, fromPubKey, result, whichType, SigVersion::BASE); @@ -168,15 +170,117 @@ bool ProduceSignature(const SigningProvider& provider, const BaseSignatureCreato sigdata.scriptSig = PushAll(result); // Test solution - return solved && VerifyScript(sigdata.scriptSig, fromPubKey, &sigdata.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, creator.Checker()); + sigdata.complete = solved && VerifyScript(sigdata.scriptSig, fromPubKey, &sigdata.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, creator.Checker()); + return sigdata.complete; +} + +class SignatureExtractorChecker final : public BaseSignatureChecker +{ +private: + SignatureData& sigdata; + BaseSignatureChecker& checker; + +public: + SignatureExtractorChecker(SignatureData& sigdata, BaseSignatureChecker& checker) : sigdata(sigdata), checker(checker) {} + bool CheckSig(const std::vector& scriptSig, const std::vector& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const override; +}; + +bool SignatureExtractorChecker::CheckSig(const std::vector& scriptSig, const std::vector& vchPubKey, const CScript& scriptCode, SigVersion sigversion) const +{ + if (checker.CheckSig(scriptSig, vchPubKey, scriptCode, sigversion)) { + CPubKey pubkey(vchPubKey); + sigdata.signatures.emplace(pubkey.GetID(), SigPair(pubkey, scriptSig)); + return true; + } + return false; +} + +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; + } +}; } -SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nIn) +// Extracts signatures and scripts from incomplete scriptSigs. Please do not extend this, use PSBT instead +SignatureData DataFromTransaction(const CMutableTransaction& tx, unsigned int nIn, const CTxOut& txout) { SignatureData data; assert(tx.vin.size() > nIn); data.scriptSig = tx.vin[nIn].scriptSig; data.scriptWitness = tx.vin[nIn].scriptWitness; + Stacks stack(data); + + // Get signatures + MutableTransactionSignatureChecker tx_checker(&tx, nIn, txout.nValue); + SignatureExtractorChecker extractor_checker(data, tx_checker); + if (VerifyScript(data.scriptSig, txout.scriptPubKey, &data.scriptWitness, STANDARD_SCRIPT_VERIFY_FLAGS, extractor_checker)) { + data.complete = true; + return data; + } + + // Get scripts + txnouttype script_type; + std::vector> solutions; + Solver(txout.scriptPubKey, script_type, solutions); + SigVersion sigversion = SigVersion::BASE; + CScript next_script = txout.scriptPubKey; + + if (script_type == TX_SCRIPTHASH && !stack.script.empty() && !stack.script.back().empty()) { + // Get the redeemScript + CScript redeem_script(stack.script.back().begin(), stack.script.back().end()); + data.redeem_script = redeem_script; + next_script = std::move(redeem_script); + + // Get redeemScript type + Solver(next_script, script_type, solutions); + stack.script.pop_back(); + } + if (script_type == TX_WITNESS_V0_SCRIPTHASH && !stack.witness.empty() && !stack.witness.back().empty()) { + // Get the witnessScript + CScript witness_script(stack.witness.back().begin(), stack.witness.back().end()); + data.witness_script = witness_script; + next_script = std::move(witness_script); + + // Get witnessScript type + Solver(next_script, script_type, solutions); + stack.witness.pop_back(); + stack.script = std::move(stack.witness); + stack.witness.clear(); + sigversion = SigVersion::WITNESS_V0; + } + if (script_type == TX_MULTISIG && !stack.script.empty()) { + // Build a map of pubkey -> signature by matching sigs to pubkeys: + assert(solutions.size() > 1); + unsigned int num_pubkeys = solutions.size()-2; + unsigned int last_success_key = 0; + for (const valtype& sig : stack.script) { + for (unsigned int i = last_success_key; i < num_pubkeys; ++i) { + const valtype& pubkey = solutions[i+1]; + // We either have a signature for this pubkey, or we have found a signature and it is valid + if (data.signatures.count(CPubKey(pubkey).GetID()) || extractor_checker.CheckSig(sig, pubkey, next_script, sigversion)) { + last_success_key = i + 1; + break; + } + } + } + } + return data; } @@ -263,28 +367,6 @@ static std::vector CombineMultisig(const CScript& scriptPubKey, const B return result; } -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 std::vector& vSolutions, Stacks sigs1, Stacks sigs2, SigVersion sigversion) -- cgit v1.2.3