diff options
Diffstat (limited to 'src/script')
-rw-r--r-- | src/script/interpreter.cpp | 2 | ||||
-rw-r--r-- | src/script/interpreter.h | 2 | ||||
-rw-r--r-- | src/script/standard.cpp | 46 |
3 files changed, 42 insertions, 8 deletions
diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp index abc0625bb1..7e119bb3c4 100644 --- a/src/script/interpreter.cpp +++ b/src/script/interpreter.cpp @@ -225,7 +225,7 @@ bool static CheckPubKeyEncoding(const valtype &vchPubKey, unsigned int flags, co return true; } -bool static CheckMinimalPush(const valtype& data, opcodetype opcode) { +bool CheckMinimalPush(const valtype& data, opcodetype opcode) { // Excludes OP_1NEGATE, OP_1-16 since they are by definition minimal assert(0 <= opcode && opcode <= OP_PUSHDATA4); if (data.size() == 0) { diff --git a/src/script/interpreter.h b/src/script/interpreter.h index c76b3acb22..212de17c7b 100644 --- a/src/script/interpreter.h +++ b/src/script/interpreter.h @@ -316,6 +316,8 @@ bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const C size_t CountWitnessSigOps(const CScript& scriptSig, const CScript& scriptPubKey, const CScriptWitness* witness, unsigned int flags); +bool CheckMinimalPush(const std::vector<unsigned char>& data, opcodetype opcode); + int FindAndDelete(CScript& script, const CScript& b); #endif // BITCOIN_SCRIPT_INTERPRETER_H diff --git a/src/script/standard.cpp b/src/script/standard.cpp index 700155c8d4..e6f99f3034 100644 --- a/src/script/standard.cpp +++ b/src/script/standard.cpp @@ -88,21 +88,53 @@ static constexpr bool IsSmallInteger(opcodetype opcode) return opcode >= OP_1 && opcode <= OP_16; } -static bool MatchMultisig(const CScript& script, unsigned int& required, std::vector<valtype>& pubkeys) +static constexpr bool IsPushdataOp(opcodetype opcode) +{ + return opcode > OP_FALSE && opcode <= OP_PUSHDATA4; +} + +static constexpr bool IsValidMultisigKeyCount(int n_keys) +{ + return n_keys > 0 && n_keys <= MAX_PUBKEYS_PER_MULTISIG; +} + +static bool GetMultisigKeyCount(opcodetype opcode, valtype data, int& count) +{ + if (IsSmallInteger(opcode)) { + count = CScript::DecodeOP_N(opcode); + return IsValidMultisigKeyCount(count); + } + + if (IsPushdataOp(opcode)) { + if (!CheckMinimalPush(data, opcode)) return false; + try { + count = CScriptNum(data, /* fRequireMinimal = */ true).getint(); + return IsValidMultisigKeyCount(count); + } catch (const scriptnum_error&) { + return false; + } + } + + return false; +} + +static bool MatchMultisig(const CScript& script, int& required_sigs, std::vector<valtype>& pubkeys) { opcodetype opcode; valtype data; + int num_keys; + CScript::const_iterator it = script.begin(); if (script.size() < 1 || script.back() != OP_CHECKMULTISIG) return false; - if (!script.GetOp(it, opcode, data) || !IsSmallInteger(opcode)) return false; - required = CScript::DecodeOP_N(opcode); + if (!script.GetOp(it, opcode, data) || !GetMultisigKeyCount(opcode, data, required_sigs)) return false; while (script.GetOp(it, opcode, data) && CPubKey::ValidSize(data)) { pubkeys.emplace_back(std::move(data)); } - if (!IsSmallInteger(opcode)) return false; - unsigned int keys = CScript::DecodeOP_N(opcode); - if (pubkeys.size() != keys || keys < required) return false; + if (!GetMultisigKeyCount(opcode, data, num_keys)) return false; + + if (pubkeys.size() != static_cast<unsigned long>(num_keys) || num_keys < required_sigs) return false; + return (it + 1 == script.end()); } @@ -163,7 +195,7 @@ TxoutType Solver(const CScript& scriptPubKey, std::vector<std::vector<unsigned c return TxoutType::PUBKEYHASH; } - unsigned int required; + int required; std::vector<std::vector<unsigned char>> keys; if (MatchMultisig(scriptPubKey, required, keys)) { vSolutionsRet.push_back({static_cast<unsigned char>(required)}); // safe as required is in range 1..16 |