diff options
author | Johnson Lau <jl2012@xbt.hk> | 2016-10-16 23:53:16 +0800 |
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committer | Wladimir J. van der Laan <laanwj@gmail.com> | 2016-10-17 14:10:58 +0200 |
commit | 540413d9958fd253d4bf99858db431164db275e1 (patch) | |
tree | f40fc4a2c3cc9084e6946ee320f2edf0bbe10a2f /src/policy/policy.cpp | |
parent | 9bb2a02f0dd8851a6dc413fd86ce0b51878b5007 (diff) | |
download | bitcoin-540413d9958fd253d4bf99858db431164db275e1.tar.xz |
Add standard limits for P2WSH with tests
Github-Pull: #8499
Rebased-From: 3ade2f64cfe43ab53e4869ffc35d5fd23201e1c1
Diffstat (limited to 'src/policy/policy.cpp')
-rw-r--r-- | src/policy/policy.cpp | 54 |
1 files changed, 53 insertions, 1 deletions
diff --git a/src/policy/policy.cpp b/src/policy/policy.cpp index 48080abc77..ae42b2bd74 100644 --- a/src/policy/policy.cpp +++ b/src/policy/policy.cpp @@ -1,5 +1,5 @@ // Copyright (c) 2009-2010 Satoshi Nakamoto -// Copyright (c) 2009-2015 The Bitcoin developers +// Copyright (c) 2009-2016 The Bitcoin developers // Distributed under the MIT software license, see the accompanying // file COPYING or http://www.opensource.org/licenses/mit-license.php. @@ -154,6 +154,58 @@ bool AreInputsStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs) return true; } +bool IsWitnessStandard(const CTransaction& tx, const CCoinsViewCache& mapInputs) +{ + if (tx.IsCoinBase()) + return true; // Coinbases are skipped + + for (unsigned int i = 0; i < tx.vin.size(); i++) + { + // We don't care if witness for this input is empty, since it must not be bloated. + // If the script is invalid without witness, it would be caught sooner or later during validation. + if (tx.wit.vtxinwit[i].IsNull()) + continue; + + const CTxOut &prev = mapInputs.GetOutputFor(tx.vin[i]); + + // get the scriptPubKey corresponding to this input: + CScript prevScript = prev.scriptPubKey; + + if (prevScript.IsPayToScriptHash()) { + std::vector <std::vector<unsigned char> > stack; + // If the scriptPubKey is P2SH, we try to extract the redeemScript casually by converting the scriptSig + // into a stack. We do not check IsPushOnly nor compare the hash as these will be done later anyway. + // If the check fails at this stage, we know that this txid must be a bad one. + if (!EvalScript(stack, tx.vin[i].scriptSig, SCRIPT_VERIFY_NONE, BaseSignatureChecker(), SIGVERSION_BASE)) + return false; + if (stack.empty()) + return false; + prevScript = CScript(stack.back().begin(), stack.back().end()); + } + + int witnessversion = 0; + std::vector<unsigned char> witnessprogram; + + // Non-witness program must not be associated with any witness + if (!prevScript.IsWitnessProgram(witnessversion, witnessprogram)) + return false; + + // Check P2WSH standard limits + if (witnessversion == 0 && witnessprogram.size() == 32) { + if (tx.wit.vtxinwit[i].scriptWitness.stack.back().size() > MAX_STANDARD_P2WSH_SCRIPT_SIZE) + return false; + size_t sizeWitnessStack = tx.wit.vtxinwit[i].scriptWitness.stack.size() - 1; + if (sizeWitnessStack > MAX_STANDARD_P2WSH_STACK_ITEMS) + return false; + for (unsigned int j = 0; j < sizeWitnessStack; j++) { + if (tx.wit.vtxinwit[i].scriptWitness.stack[j].size() > MAX_STANDARD_P2WSH_STACK_ITEM_SIZE) + return false; + } + } + } + return true; +} + unsigned int nBytesPerSigOp = DEFAULT_BYTES_PER_SIGOP; int64_t GetVirtualTransactionSize(int64_t nWeight, int64_t nSigOpCost) |