From ab9edbd6b6eb3efbca11f16fa467c3c0ef905708 Mon Sep 17 00:00:00 2001 From: Cory Fields Date: Fri, 31 Oct 2014 23:29:12 -0400 Subject: [PATCH] script: create sane error return codes for script validation and remove logging Attempt to codify the possible error statuses associated with script validation. script/types.h has been created with the expectation that it will be part of the public lib interface. The other flag enums will be moved here in a future commit. Logging has also been removed in order to drop the dependency on core.h. It can be re-added to bitcoind as-needed. This makes script verification finally free of application state and boost! --- src/Makefile.am | 2 + src/script/interpreter.cpp | 297 ++++++++++++++++++++++-------------- src/script/interpreter.h | 6 +- src/script/script_error.cpp | 67 ++++++++ src/script/script_error.h | 53 +++++++ 5 files changed, 306 insertions(+), 119 deletions(-) create mode 100644 src/script/script_error.cpp create mode 100644 src/script/script_error.h diff --git a/src/Makefile.am b/src/Makefile.am index 8b5d009842..b3b41e3d17 100644 --- a/src/Makefile.am +++ b/src/Makefile.am @@ -112,6 +112,7 @@ BITCOIN_CORE_H = \ script/sigcache.h \ script/sign.h \ script/standard.h \ + script/script_error.h \ serialize.h \ streams.h \ sync.h \ @@ -235,6 +236,7 @@ libbitcoin_common_a_SOURCES = \ script/script.cpp \ script/sign.cpp \ script/standard.cpp \ + script/script_error.cpp \ $(BITCOIN_CORE_H) # util: shared between all executables. diff --git a/src/script/interpreter.cpp b/src/script/interpreter.cpp index 5fda6248c2..cf81fe30a2 100644 --- a/src/script/interpreter.cpp +++ b/src/script/interpreter.cpp @@ -13,7 +13,6 @@ #include "pubkey.h" #include "script/script.h" #include "uint256.h" -#include "util.h" using namespace std; @@ -26,6 +25,24 @@ static const CScriptNum bnOne(1); static const CScriptNum bnFalse(0); static const CScriptNum bnTrue(1); +namespace { + +inline bool set_success(ScriptError* ret) +{ + if (ret) + *ret = SCRIPT_ERR_OK; + return true; +} + +inline bool set_error(ScriptError* ret, const ScriptError serror) +{ + if (ret) + *ret = serror; + return false; +} + +} // anon namespace + bool CastToBool(const valtype& vch) { for (unsigned int i = 0; i < vch.size(); i++) @@ -55,16 +72,23 @@ static inline void popstack(vector& stack) } bool static IsCompressedOrUncompressedPubKey(const valtype &vchPubKey) { - if (vchPubKey.size() < 33) - return error("Non-canonical public key: too short"); + if (vchPubKey.size() < 33) { + // Non-canonical public key: too short + return false; + } if (vchPubKey[0] == 0x04) { - if (vchPubKey.size() != 65) - return error("Non-canonical public key: invalid length for uncompressed key"); + if (vchPubKey.size() != 65) { + // Non-canonical public key: invalid length for uncompressed key + return false; + } } else if (vchPubKey[0] == 0x02 || vchPubKey[0] == 0x03) { - if (vchPubKey.size() != 33) - return error("Non-canonical public key: invalid length for compressed key"); + if (vchPubKey.size() != 33) { + // Non-canonical public key: invalid length for compressed key + return false; + } } else { - return error("Non-canonical public key: neither compressed nor uncompressed"); + // Non-canonical public key: neither compressed nor uncompressed + return false; } return true; } @@ -79,47 +103,74 @@ bool static IsCompressedOrUncompressedPubKey(const valtype &vchPubKey) { */ bool static IsDERSignature(const valtype &vchSig) { - if (vchSig.size() < 9) - return error("Non-canonical signature: too short"); - if (vchSig.size() > 73) - return error("Non-canonical signature: too long"); - if (vchSig[0] != 0x30) - return error("Non-canonical signature: wrong type"); - if (vchSig[1] != vchSig.size()-3) - return error("Non-canonical signature: wrong length marker"); + if (vchSig.size() < 9) { + // Non-canonical signature: too short + return false; + } + if (vchSig.size() > 73) { + // Non-canonical signature: too long + return false; + } + if (vchSig[0] != 0x30) { + // Non-canonical signature: wrong type + return false; + } + if (vchSig[1] != vchSig.size()-3) { + // Non-canonical signature: wrong length marker + return false; + } unsigned int nLenR = vchSig[3]; - if (5 + nLenR >= vchSig.size()) - return error("Non-canonical signature: S length misplaced"); + if (5 + nLenR >= vchSig.size()) { + // Non-canonical signature: S length misplaced + return false; + } unsigned int nLenS = vchSig[5+nLenR]; - if ((unsigned long)(nLenR+nLenS+7) != vchSig.size()) - return error("Non-canonical signature: R+S length mismatch"); + if ((unsigned long)(nLenR+nLenS+7) != vchSig.size()) { + // Non-canonical signature: R+S length mismatch + return false; + } const unsigned char *R = &vchSig[4]; - if (R[-2] != 0x02) - return error("Non-canonical signature: R value type mismatch"); - if (nLenR == 0) - return error("Non-canonical signature: R length is zero"); - if (R[0] & 0x80) - return error("Non-canonical signature: R value negative"); - if (nLenR > 1 && (R[0] == 0x00) && !(R[1] & 0x80)) - return error("Non-canonical signature: R value excessively padded"); + if (R[-2] != 0x02) { + // Non-canonical signature: R value type mismatch + return false; + } + if (nLenR == 0) { + // Non-canonical signature: R length is zero + return false; + } + if (R[0] & 0x80) { + // Non-canonical signature: R value negative + return false; + } + if (nLenR > 1 && (R[0] == 0x00) && !(R[1] & 0x80)) { + // Non-canonical signature: R value excessively padded + return false; + } const unsigned char *S = &vchSig[6+nLenR]; - if (S[-2] != 0x02) - return error("Non-canonical signature: S value type mismatch"); - if (nLenS == 0) - return error("Non-canonical signature: S length is zero"); - if (S[0] & 0x80) - return error("Non-canonical signature: S value negative"); - if (nLenS > 1 && (S[0] == 0x00) && !(S[1] & 0x80)) - return error("Non-canonical signature: S value excessively padded"); - + if (S[-2] != 0x02) { + // Non-canonical signature: S value type mismatch + return false; + } + if (nLenS == 0) { + // Non-canonical signature: S length is zero + return false; + } + if (S[0] & 0x80) { + // Non-canonical signature: S value negative + return false; + } + if (nLenS > 1 && (S[0] == 0x00) && !(S[1] & 0x80)) { + // Non-canonical signature: S value excessively padded + return false; + } return true; } -bool static IsLowDERSignature(const valtype &vchSig) { +bool static IsLowDERSignature(const valtype &vchSig, ScriptError* serror) { if (!IsDERSignature(vchSig)) { - return false; + return set_error(serror, SCRIPT_ERR_SIG_DER); } unsigned int nLenR = vchSig[3]; unsigned int nLenS = vchSig[5+nLenR]; @@ -128,7 +179,7 @@ bool static IsLowDERSignature(const valtype &vchSig) { // complement modulo the order could have been used instead, which is // one byte shorter when encoded correctly. if (!eccrypto::CheckSignatureElement(S, nLenS, true)) - return error("Non-canonical signature: S value is unnecessarily high"); + return set_error(serror, SCRIPT_ERR_SIG_HIGH_S); return true; } @@ -139,18 +190,19 @@ bool static IsDefinedHashtypeSignature(const valtype &vchSig) { } unsigned char nHashType = vchSig[vchSig.size() - 1] & (~(SIGHASH_ANYONECANPAY)); if (nHashType < SIGHASH_ALL || nHashType > SIGHASH_SINGLE) - return error("Non-canonical signature: unknown hashtype byte"); + return false; return true; } -bool static CheckSignatureEncoding(const valtype &vchSig, unsigned int flags) { +bool static CheckSignatureEncoding(const valtype &vchSig, unsigned int flags, ScriptError* serror) { if ((flags & (SCRIPT_VERIFY_DERSIG | SCRIPT_VERIFY_LOW_S | SCRIPT_VERIFY_STRICTENC)) != 0 && !IsDERSignature(vchSig)) { - return false; - } else if ((flags & SCRIPT_VERIFY_LOW_S) != 0 && !IsLowDERSignature(vchSig)) { + return set_error(serror, SCRIPT_ERR_SIG_DER); + } else if ((flags & SCRIPT_VERIFY_LOW_S) != 0 && !IsLowDERSignature(vchSig, serror)) { + // serror is set return false; } else if ((flags & SCRIPT_VERIFY_STRICTENC) != 0 && !IsDefinedHashtypeSignature(vchSig)) { - return false; + return set_error(serror, SCRIPT_ERR_SIG_HASHTYPE); } return true; } @@ -185,7 +237,7 @@ bool static CheckMinimalPush(const valtype& data, opcodetype opcode) { return true; } -bool EvalScript(vector >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker) +bool EvalScript(vector >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror) { CScript::const_iterator pc = script.begin(); CScript::const_iterator pend = script.end(); @@ -194,8 +246,9 @@ bool EvalScript(vector >& stack, const CScript& script, un valtype vchPushValue; vector vfExec; vector altstack; + set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR); if (script.size() > 10000) - return false; + return set_error(serror, SCRIPT_ERR_SCRIPT_SIZE); int nOpCount = 0; bool fRequireMinimal = (flags & SCRIPT_VERIFY_MINIMALDATA) != 0; @@ -209,13 +262,13 @@ bool EvalScript(vector >& stack, const CScript& script, un // Read instruction // if (!script.GetOp(pc, opcode, vchPushValue)) - return false; + return set_error(serror, SCRIPT_ERR_BAD_OPCODE); if (vchPushValue.size() > MAX_SCRIPT_ELEMENT_SIZE) - return false; + return set_error(serror, SCRIPT_ERR_PUSH_SIZE); // Note how OP_RESERVED does not count towards the opcode limit. if (opcode > OP_16 && ++nOpCount > 201) - return false; + return set_error(serror, SCRIPT_ERR_OP_COUNT); if (opcode == OP_CAT || opcode == OP_SUBSTR || @@ -232,11 +285,11 @@ bool EvalScript(vector >& stack, const CScript& script, un opcode == OP_MOD || opcode == OP_LSHIFT || opcode == OP_RSHIFT) - return false; // Disabled opcodes. + return set_error(serror, SCRIPT_ERR_DISABLED_OPCODE); // Disabled opcodes. if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4) { if (fRequireMinimal && !CheckMinimalPush(vchPushValue, opcode)) { - return false; + return set_error(serror, SCRIPT_ERR_MINIMALDATA); } stack.push_back(vchPushValue); } else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF)) @@ -288,7 +341,7 @@ bool EvalScript(vector >& stack, const CScript& script, un if (fExec) { if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL); valtype& vch = stacktop(-1); fValue = CastToBool(vch); if (opcode == OP_NOTIF) @@ -302,7 +355,7 @@ bool EvalScript(vector >& stack, const CScript& script, un case OP_ELSE: { if (vfExec.empty()) - return false; + return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL); vfExec.back() = !vfExec.back(); } break; @@ -310,7 +363,7 @@ bool EvalScript(vector >& stack, const CScript& script, un case OP_ENDIF: { if (vfExec.empty()) - return false; + return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL); vfExec.pop_back(); } break; @@ -320,18 +373,18 @@ bool EvalScript(vector >& stack, const CScript& script, un // (true -- ) or // (false -- false) and return if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); bool fValue = CastToBool(stacktop(-1)); if (fValue) popstack(stack); else - return false; + return set_error(serror, SCRIPT_ERR_VERIFY); } break; case OP_RETURN: { - return false; + return set_error(serror, SCRIPT_ERR_OP_RETURN); } break; @@ -342,7 +395,7 @@ bool EvalScript(vector >& stack, const CScript& script, un case OP_TOALTSTACK: { if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); altstack.push_back(stacktop(-1)); popstack(stack); } @@ -351,7 +404,7 @@ bool EvalScript(vector >& stack, const CScript& script, un case OP_FROMALTSTACK: { if (altstack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_ALTSTACK_OPERATION); stack.push_back(altstacktop(-1)); popstack(altstack); } @@ -361,7 +414,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 -- ) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); popstack(stack); popstack(stack); } @@ -371,7 +424,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 -- x1 x2 x1 x2) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch1 = stacktop(-2); valtype vch2 = stacktop(-1); stack.push_back(vch1); @@ -383,7 +436,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 x3 -- x1 x2 x3 x1 x2 x3) if (stack.size() < 3) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch1 = stacktop(-3); valtype vch2 = stacktop(-2); valtype vch3 = stacktop(-1); @@ -397,7 +450,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2) if (stack.size() < 4) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch1 = stacktop(-4); valtype vch2 = stacktop(-3); stack.push_back(vch1); @@ -409,7 +462,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2) if (stack.size() < 6) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch1 = stacktop(-6); valtype vch2 = stacktop(-5); stack.erase(stack.end()-6, stack.end()-4); @@ -422,7 +475,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 x3 x4 -- x3 x4 x1 x2) if (stack.size() < 4) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); swap(stacktop(-4), stacktop(-2)); swap(stacktop(-3), stacktop(-1)); } @@ -432,7 +485,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x - 0 | x x) if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch = stacktop(-1); if (CastToBool(vch)) stack.push_back(vch); @@ -451,7 +504,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x -- ) if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); popstack(stack); } break; @@ -460,7 +513,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x -- x x) if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch = stacktop(-1); stack.push_back(vch); } @@ -470,7 +523,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 -- x2) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); stack.erase(stack.end() - 2); } break; @@ -479,7 +532,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 -- x1 x2 x1) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch = stacktop(-2); stack.push_back(vch); } @@ -491,11 +544,11 @@ bool EvalScript(vector >& stack, const CScript& script, un // (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn) // (xn ... x2 x1 x0 n - ... x2 x1 x0 xn) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); int n = CScriptNum(stacktop(-1), fRequireMinimal).getint(); popstack(stack); if (n < 0 || n >= (int)stack.size()) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch = stacktop(-n-1); if (opcode == OP_ROLL) stack.erase(stack.end()-n-1); @@ -509,7 +562,7 @@ bool EvalScript(vector >& stack, const CScript& script, un // x2 x1 x3 after first swap // x2 x3 x1 after second swap if (stack.size() < 3) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); swap(stacktop(-3), stacktop(-2)); swap(stacktop(-2), stacktop(-1)); } @@ -519,7 +572,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 -- x2 x1) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); swap(stacktop(-2), stacktop(-1)); } break; @@ -528,7 +581,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 -- x2 x1 x2) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype vch = stacktop(-1); stack.insert(stack.end()-2, vch); } @@ -539,7 +592,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (in -- in size) if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); CScriptNum bn(stacktop(-1).size()); stack.push_back(bn.getvch()); } @@ -555,7 +608,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 - bool) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype& vch1 = stacktop(-2); valtype& vch2 = stacktop(-1); bool fEqual = (vch1 == vch2); @@ -572,7 +625,7 @@ bool EvalScript(vector >& stack, const CScript& script, un if (fEqual) popstack(stack); else - return false; + return set_error(serror, SCRIPT_ERR_EQUALVERIFY); } } break; @@ -590,7 +643,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (in -- out) if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); CScriptNum bn(stacktop(-1), fRequireMinimal); switch (opcode) { @@ -623,7 +676,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x1 x2 -- out) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); CScriptNum bn1(stacktop(-2), fRequireMinimal); CScriptNum bn2(stacktop(-1), fRequireMinimal); CScriptNum bn(0); @@ -659,7 +712,7 @@ bool EvalScript(vector >& stack, const CScript& script, un if (CastToBool(stacktop(-1))) popstack(stack); else - return false; + return set_error(serror, SCRIPT_ERR_NUMEQUALVERIFY); } } break; @@ -668,7 +721,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (x min max -- out) if (stack.size() < 3) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); CScriptNum bn1(stacktop(-3), fRequireMinimal); CScriptNum bn2(stacktop(-2), fRequireMinimal); CScriptNum bn3(stacktop(-1), fRequireMinimal); @@ -692,7 +745,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (in -- hash) if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype& vch = stacktop(-1); valtype vchHash((opcode == OP_RIPEMD160 || opcode == OP_SHA1 || opcode == OP_HASH160) ? 20 : 32); if (opcode == OP_RIPEMD160) @@ -722,7 +775,7 @@ bool EvalScript(vector >& stack, const CScript& script, un { // (sig pubkey -- bool) if (stack.size() < 2) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); valtype& vchSig = stacktop(-2); valtype& vchPubKey = stacktop(-1); @@ -733,10 +786,10 @@ bool EvalScript(vector >& stack, const CScript& script, un // Drop the signature, since there's no way for a signature to sign itself scriptCode.FindAndDelete(CScript(vchSig)); - if (!CheckSignatureEncoding(vchSig, flags)) { + if (!CheckSignatureEncoding(vchSig, flags, serror)) { + //serror is set return false; } - bool fSuccess = CheckPubKeyEncoding(vchPubKey, flags) && checker.CheckSig(vchSig, vchPubKey, scriptCode); popstack(stack); @@ -747,7 +800,7 @@ bool EvalScript(vector >& stack, const CScript& script, un if (fSuccess) popstack(stack); else - return false; + return set_error(serror, SCRIPT_ERR_CHECKSIGVERIFY); } } break; @@ -759,26 +812,26 @@ bool EvalScript(vector >& stack, const CScript& script, un int i = 1; if ((int)stack.size() < i) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); int nKeysCount = CScriptNum(stacktop(-i), fRequireMinimal).getint(); if (nKeysCount < 0 || nKeysCount > 20) - return false; + return set_error(serror, SCRIPT_ERR_PUBKEY_COUNT); nOpCount += nKeysCount; if (nOpCount > 201) - return false; + return set_error(serror, SCRIPT_ERR_OP_COUNT); int ikey = ++i; i += nKeysCount; if ((int)stack.size() < i) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); int nSigsCount = CScriptNum(stacktop(-i), fRequireMinimal).getint(); if (nSigsCount < 0 || nSigsCount > nKeysCount) - return false; + return set_error(serror, SCRIPT_ERR_SIG_COUNT); int isig = ++i; i += nSigsCount; if ((int)stack.size() < i) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); // Subset of script starting at the most recent codeseparator CScript scriptCode(pbegincodehash, pend); @@ -796,7 +849,8 @@ bool EvalScript(vector >& stack, const CScript& script, un valtype& vchSig = stacktop(-isig); valtype& vchPubKey = stacktop(-ikey); - if (!CheckSignatureEncoding(vchSig, flags)) { + if (!CheckSignatureEncoding(vchSig, flags, serror)) { + // serror is set return false; } @@ -827,9 +881,9 @@ bool EvalScript(vector >& stack, const CScript& script, un // so optionally verify it is exactly equal to zero prior // to removing it from the stack. if (stack.size() < 1) - return false; + return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); if ((flags & SCRIPT_VERIFY_NULLDUMMY) && stacktop(-1).size()) - return error("CHECKMULTISIG dummy argument not null"); + return set_error(serror, SCRIPT_ERR_SIG_NULLDUMMY); popstack(stack); stack.push_back(fSuccess ? vchTrue : vchFalse); @@ -839,29 +893,29 @@ bool EvalScript(vector >& stack, const CScript& script, un if (fSuccess) popstack(stack); else - return false; + return set_error(serror, SCRIPT_ERR_CHECKMULTISIGVERIFY); } } break; default: - return false; + return set_error(serror, SCRIPT_ERR_BAD_OPCODE); } // Size limits if (stack.size() + altstack.size() > 1000) - return false; + return set_error(serror, SCRIPT_ERR_STACK_SIZE); } } catch (...) { - return false; + return set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR); } if (!vfExec.empty()) - return false; + return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL); - return true; + return set_success(serror); } namespace { @@ -966,14 +1020,14 @@ public: uint256 SignatureHash(const CScript& scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType) { if (nIn >= txTo.vin.size()) { - LogPrintf("ERROR: SignatureHash() : nIn=%d out of range\n", nIn); + // nIn out of range return 1; } // Check for invalid use of SIGHASH_SINGLE if ((nHashType & 0x1f) == SIGHASH_SINGLE) { if (nIn >= txTo.vout.size()) { - LogPrintf("ERROR: SignatureHash() : nOut=%d out of range\n", nIn); + // nOut out of range return 1; } } @@ -1013,30 +1067,35 @@ bool SignatureChecker::CheckSig(const vector& vchSigIn, const vec return true; } -bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker) +bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror) { + set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR); + if ((flags & SCRIPT_VERIFY_SIGPUSHONLY) != 0 && !scriptSig.IsPushOnly()) { - return false; + return set_error(serror, SCRIPT_ERR_SIG_PUSHONLY); } vector > stack, stackCopy; - if (!EvalScript(stack, scriptSig, flags, checker)) + if (!EvalScript(stack, scriptSig, flags, checker, serror)) + // serror is set return false; if (flags & SCRIPT_VERIFY_P2SH) stackCopy = stack; - if (!EvalScript(stack, scriptPubKey, flags, checker)) + if (!EvalScript(stack, scriptPubKey, flags, checker, serror)) + // serror is set return false; if (stack.empty()) - return false; + return set_error(serror, SCRIPT_ERR_EVAL_FALSE); if (CastToBool(stack.back()) == false) - return false; + return set_error(serror, SCRIPT_ERR_EVAL_FALSE); // Additional validation for spend-to-script-hash transactions: if ((flags & SCRIPT_VERIFY_P2SH) && scriptPubKey.IsPayToScriptHash()) { - if (!scriptSig.IsPushOnly()) // scriptSig must be literals-only - return false; // or validation fails + // scriptSig must be literals-only or validation fails + if (!scriptSig.IsPushOnly()) + return set_error(serror, SCRIPT_ERR_SIG_PUSHONLY); // stackCopy cannot be empty here, because if it was the // P2SH HASH <> EQUAL scriptPubKey would be evaluated with @@ -1047,12 +1106,16 @@ bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigne CScript pubKey2(pubKeySerialized.begin(), pubKeySerialized.end()); popstack(stackCopy); - if (!EvalScript(stackCopy, pubKey2, flags, checker)) + if (!EvalScript(stackCopy, pubKey2, flags, checker, serror)) + // serror is set return false; if (stackCopy.empty()) - return false; - return CastToBool(stackCopy.back()); + return set_error(serror, SCRIPT_ERR_EVAL_FALSE); + if (!CastToBool(stackCopy.back())) + return set_error(serror, SCRIPT_ERR_EVAL_FALSE); + else + return set_success(serror); } - return true; + return set_success(serror); } diff --git a/src/script/interpreter.h b/src/script/interpreter.h index ed899fc411..14cccc558f 100644 --- a/src/script/interpreter.h +++ b/src/script/interpreter.h @@ -6,6 +6,8 @@ #ifndef BITCOIN_SCRIPT_INTERPRETER_H #define BITCOIN_SCRIPT_INTERPRETER_H +#include "script_error.h" + #include #include #include @@ -85,7 +87,7 @@ public: bool CheckSig(const std::vector& scriptSig, const std::vector& vchPubKey, const CScript& scriptCode) const; }; -bool EvalScript(std::vector >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker); -bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker); +bool EvalScript(std::vector >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* error = NULL); +bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* error = NULL); #endif // BITCOIN_SCRIPT_INTERPRETER_H diff --git a/src/script/script_error.cpp b/src/script/script_error.cpp new file mode 100644 index 0000000000..4a3df268ec --- /dev/null +++ b/src/script/script_error.cpp @@ -0,0 +1,67 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2014 The Bitcoin developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#include "script_error.h" + +const char* ScriptErrorString(const ScriptError serror) +{ + switch (serror) + { + case SCRIPT_ERR_OK: + return "No error"; + case SCRIPT_ERR_EVAL_FALSE: + return "Script evaluated without error but finished with a false/empty top stack element"; + case SCRIPT_ERR_VERIFY: + return "Script failed an OP_VERIFY operation"; + case SCRIPT_ERR_EQUALVERIFY: + return "Script failed an OP_EQUALVERIFY operation"; + case SCRIPT_ERR_CHECKMULTISIGVERIFY: + return "Script failed an OP_CHECKMULTISIGVERIFY operation"; + case SCRIPT_ERR_CHECKSIGVERIFY: + return "Script failed an OP_CHECKSIGVERIFY operation"; + case SCRIPT_ERR_NUMEQUALVERIFY: + return "Script failed an OP_NUMEQUALVERIFY operation"; + case SCRIPT_ERR_SCRIPT_SIZE: + return "Script is too big"; + case SCRIPT_ERR_PUSH_SIZE: + return "Push value size limit exceeded"; + case SCRIPT_ERR_OP_COUNT: + return "Operation limit exceeded"; + case SCRIPT_ERR_STACK_SIZE: + return "Stack size limit exceeded"; + case SCRIPT_ERR_SIG_COUNT: + return "Signature count negative or greater than pubkey count"; + case SCRIPT_ERR_PUBKEY_COUNT: + return "Pubkey count negative or limit exceeded"; + case SCRIPT_ERR_BAD_OPCODE: + return "Opcode missing or not understood"; + case SCRIPT_ERR_DISABLED_OPCODE: + return "Attempted to use a disabled opcode"; + case SCRIPT_ERR_INVALID_STACK_OPERATION: + return "Operation not valid with the current stack size"; + case SCRIPT_ERR_INVALID_ALTSTACK_OPERATION: + return "Operation not valid with the current altstack size"; + case SCRIPT_ERR_OP_RETURN: + return "OP_RETURN was encountered"; + case SCRIPT_ERR_UNBALANCED_CONDITIONAL: + return "Invalid OP_IF construction"; + case SCRIPT_ERR_SIG_HASHTYPE: + return "Signature hash type missing or not understood"; + case SCRIPT_ERR_SIG_DER: + return "Non-canonical DER signature"; + case SCRIPT_ERR_MINIMALDATA: + return "Data push larger than necessary"; + case SCRIPT_ERR_SIG_PUSHONLY: + return "Only non-push operators allowed in signatures"; + case SCRIPT_ERR_SIG_HIGH_S: + return "Non-canonical signature: S value is unnecessarily high"; + case SCRIPT_ERR_SIG_NULLDUMMY: + return "Dummy CHECKMULTISIG argument must be zero"; + case SCRIPT_ERR_UNKNOWN_ERROR: + case SCRIPT_ERR_ERROR_COUNT: + default: break; + } + return "unknown error"; +} diff --git a/src/script/script_error.h b/src/script/script_error.h new file mode 100644 index 0000000000..ae6626b257 --- /dev/null +++ b/src/script/script_error.h @@ -0,0 +1,53 @@ +// Copyright (c) 2009-2010 Satoshi Nakamoto +// Copyright (c) 2009-2014 The Bitcoin developers +// Distributed under the MIT software license, see the accompanying +// file COPYING or http://www.opensource.org/licenses/mit-license.php. + +#ifndef BITCOIN_SCRIPT_ERROR_H +#define BITCOIN_SCRIPT_ERROR_H + +typedef enum ScriptError_t +{ + SCRIPT_ERR_OK = 0, + SCRIPT_ERR_UNKNOWN_ERROR, + SCRIPT_ERR_EVAL_FALSE, + SCRIPT_ERR_OP_RETURN, + + /* Max sizes */ + SCRIPT_ERR_SCRIPT_SIZE, + SCRIPT_ERR_PUSH_SIZE, + SCRIPT_ERR_OP_COUNT, + SCRIPT_ERR_STACK_SIZE, + SCRIPT_ERR_SIG_COUNT, + SCRIPT_ERR_PUBKEY_COUNT, + + /* Failed verify operations */ + SCRIPT_ERR_VERIFY, + SCRIPT_ERR_EQUALVERIFY, + SCRIPT_ERR_CHECKMULTISIGVERIFY, + SCRIPT_ERR_CHECKSIGVERIFY, + SCRIPT_ERR_NUMEQUALVERIFY, + + /* Logical/Format/Canonical errors */ + SCRIPT_ERR_BAD_OPCODE, + SCRIPT_ERR_DISABLED_OPCODE, + SCRIPT_ERR_INVALID_STACK_OPERATION, + SCRIPT_ERR_INVALID_ALTSTACK_OPERATION, + SCRIPT_ERR_UNBALANCED_CONDITIONAL, + + /* BIP62 */ + SCRIPT_ERR_SIG_HASHTYPE, + SCRIPT_ERR_SIG_DER, + SCRIPT_ERR_MINIMALDATA, + SCRIPT_ERR_SIG_PUSHONLY, + SCRIPT_ERR_SIG_HIGH_S, + SCRIPT_ERR_SIG_NULLDUMMY, + + SCRIPT_ERR_ERROR_COUNT +} ScriptError; + +#define SCRIPT_ERR_LAST SCRIPT_ERR_ERROR_COUNT + +const char* ScriptErrorString(const ScriptError error); + +#endif // BITCOIN_SCRIPT_ERROR_H