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1229 lines
46 KiB
1229 lines
46 KiB
// Copyright (c) 2009-2010 Satoshi Nakamoto |
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// Copyright (c) 2009-2014 The Bitcoin Core developers |
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// Distributed under the MIT software license, see the accompanying |
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// file COPYING or http://www.opensource.org/licenses/mit-license.php. |
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#include "interpreter.h" |
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|
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#include "primitives/transaction.h" |
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#include "crypto/ripemd160.h" |
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#include "crypto/sha1.h" |
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#include "crypto/sha256.h" |
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#include "eccryptoverify.h" |
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#include "pubkey.h" |
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#include "script/script.h" |
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#include "uint256.h" |
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using namespace std; |
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typedef vector<unsigned char> valtype; |
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namespace { |
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inline bool set_success(ScriptError* ret) |
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{ |
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if (ret) |
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*ret = SCRIPT_ERR_OK; |
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return true; |
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} |
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inline bool set_error(ScriptError* ret, const ScriptError serror) |
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{ |
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if (ret) |
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*ret = serror; |
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return false; |
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} |
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} // anon namespace |
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bool CastToBool(const valtype& vch) |
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{ |
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for (unsigned int i = 0; i < vch.size(); i++) |
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{ |
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if (vch[i] != 0) |
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{ |
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// Can be negative zero |
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if (i == vch.size()-1 && vch[i] == 0x80) |
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return false; |
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return true; |
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} |
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} |
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return false; |
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} |
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/** |
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* Script is a stack machine (like Forth) that evaluates a predicate |
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* returning a bool indicating valid or not. There are no loops. |
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*/ |
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#define stacktop(i) (stack.at(stack.size()+(i))) |
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#define altstacktop(i) (altstack.at(altstack.size()+(i))) |
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static inline void popstack(vector<valtype>& stack) |
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{ |
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if (stack.empty()) |
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throw runtime_error("popstack(): stack empty"); |
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stack.pop_back(); |
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} |
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bool static IsCompressedOrUncompressedPubKey(const valtype &vchPubKey) { |
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if (vchPubKey.size() < 33) { |
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// Non-canonical public key: too short |
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return false; |
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} |
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if (vchPubKey[0] == 0x04) { |
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if (vchPubKey.size() != 65) { |
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// Non-canonical public key: invalid length for uncompressed key |
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return false; |
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} |
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} else if (vchPubKey[0] == 0x02 || vchPubKey[0] == 0x03) { |
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if (vchPubKey.size() != 33) { |
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// Non-canonical public key: invalid length for compressed key |
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return false; |
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} |
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} else { |
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// Non-canonical public key: neither compressed nor uncompressed |
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return false; |
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} |
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return true; |
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} |
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/** |
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* A canonical signature exists of: <30> <total len> <02> <len R> <R> <02> <len S> <S> <hashtype> |
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* Where R and S are not negative (their first byte has its highest bit not set), and not |
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* excessively padded (do not start with a 0 byte, unless an otherwise negative number follows, |
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* in which case a single 0 byte is necessary and even required). |
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* |
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* See https://bitcointalk.org/index.php?topic=8392.msg127623#msg127623 |
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* |
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* This function is consensus-critical since BIP66. |
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*/ |
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bool static IsValidSignatureEncoding(const std::vector<unsigned char> &sig) { |
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// Format: 0x30 [total-length] 0x02 [R-length] [R] 0x02 [S-length] [S] [sighash] |
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// * total-length: 1-byte length descriptor of everything that follows, |
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// excluding the sighash byte. |
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// * R-length: 1-byte length descriptor of the R value that follows. |
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// * R: arbitrary-length big-endian encoded R value. It must use the shortest |
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// possible encoding for a positive integers (which means no null bytes at |
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// the start, except a single one when the next byte has its highest bit set). |
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// * S-length: 1-byte length descriptor of the S value that follows. |
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// * S: arbitrary-length big-endian encoded S value. The same rules apply. |
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// * sighash: 1-byte value indicating what data is hashed (not part of the DER |
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// signature) |
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// Minimum and maximum size constraints. |
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if (sig.size() < 9) return false; |
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if (sig.size() > 73) return false; |
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// A signature is of type 0x30 (compound). |
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if (sig[0] != 0x30) return false; |
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// Make sure the length covers the entire signature. |
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if (sig[1] != sig.size() - 3) return false; |
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// Extract the length of the R element. |
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unsigned int lenR = sig[3]; |
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// Make sure the length of the S element is still inside the signature. |
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if (5 + lenR >= sig.size()) return false; |
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// Extract the length of the S element. |
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unsigned int lenS = sig[5 + lenR]; |
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// Verify that the length of the signature matches the sum of the length |
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// of the elements. |
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if ((size_t)(lenR + lenS + 7) != sig.size()) return false; |
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// Check whether the R element is an integer. |
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if (sig[2] != 0x02) return false; |
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// Zero-length integers are not allowed for R. |
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if (lenR == 0) return false; |
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// Negative numbers are not allowed for R. |
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if (sig[4] & 0x80) return false; |
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// Null bytes at the start of R are not allowed, unless R would |
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// otherwise be interpreted as a negative number. |
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if (lenR > 1 && (sig[4] == 0x00) && !(sig[5] & 0x80)) return false; |
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// Check whether the S element is an integer. |
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if (sig[lenR + 4] != 0x02) return false; |
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// Zero-length integers are not allowed for S. |
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if (lenS == 0) return false; |
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// Negative numbers are not allowed for S. |
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if (sig[lenR + 6] & 0x80) return false; |
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// Null bytes at the start of S are not allowed, unless S would otherwise be |
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// interpreted as a negative number. |
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if (lenS > 1 && (sig[lenR + 6] == 0x00) && !(sig[lenR + 7] & 0x80)) return false; |
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return true; |
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} |
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bool static IsLowDERSignature(const valtype &vchSig, ScriptError* serror) { |
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if (!IsValidSignatureEncoding(vchSig)) { |
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return set_error(serror, SCRIPT_ERR_SIG_DER); |
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} |
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unsigned int nLenR = vchSig[3]; |
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unsigned int nLenS = vchSig[5+nLenR]; |
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const unsigned char *S = &vchSig[6+nLenR]; |
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// If the S value is above the order of the curve divided by two, its |
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// complement modulo the order could have been used instead, which is |
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// one byte shorter when encoded correctly. |
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if (!eccrypto::CheckSignatureElement(S, nLenS, true)) |
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return set_error(serror, SCRIPT_ERR_SIG_HIGH_S); |
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return true; |
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} |
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bool static IsDefinedHashtypeSignature(const valtype &vchSig) { |
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if (vchSig.size() == 0) { |
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return false; |
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} |
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unsigned char nHashType = vchSig[vchSig.size() - 1] & (~(SIGHASH_ANYONECANPAY)); |
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if (nHashType < SIGHASH_ALL || nHashType > SIGHASH_SINGLE) |
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return false; |
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return true; |
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} |
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bool static CheckSignatureEncoding(const valtype &vchSig, unsigned int flags, ScriptError* serror) { |
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// Empty signature. Not strictly DER encoded, but allowed to provide a |
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// compact way to provide an invalid signature for use with CHECK(MULTI)SIG |
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if (vchSig.size() == 0) { |
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return true; |
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} |
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if ((flags & (SCRIPT_VERIFY_DERSIG | SCRIPT_VERIFY_LOW_S | SCRIPT_VERIFY_STRICTENC)) != 0 && !IsValidSignatureEncoding(vchSig)) { |
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return set_error(serror, SCRIPT_ERR_SIG_DER); |
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} else if ((flags & SCRIPT_VERIFY_LOW_S) != 0 && !IsLowDERSignature(vchSig, serror)) { |
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// serror is set |
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return false; |
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} else if ((flags & SCRIPT_VERIFY_STRICTENC) != 0 && !IsDefinedHashtypeSignature(vchSig)) { |
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return set_error(serror, SCRIPT_ERR_SIG_HASHTYPE); |
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} |
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return true; |
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} |
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bool static CheckPubKeyEncoding(const valtype &vchSig, unsigned int flags, ScriptError* serror) { |
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if ((flags & SCRIPT_VERIFY_STRICTENC) != 0 && !IsCompressedOrUncompressedPubKey(vchSig)) { |
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return set_error(serror, SCRIPT_ERR_PUBKEYTYPE); |
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} |
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return true; |
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} |
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bool static CheckMinimalPush(const valtype& data, opcodetype opcode) { |
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if (data.size() == 0) { |
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// Could have used OP_0. |
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return opcode == OP_0; |
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} else if (data.size() == 1 && data[0] >= 1 && data[0] <= 16) { |
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// Could have used OP_1 .. OP_16. |
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return opcode == OP_1 + (data[0] - 1); |
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} else if (data.size() == 1 && data[0] == 0x81) { |
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// Could have used OP_1NEGATE. |
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return opcode == OP_1NEGATE; |
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} else if (data.size() <= 75) { |
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// Could have used a direct push (opcode indicating number of bytes pushed + those bytes). |
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return opcode == data.size(); |
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} else if (data.size() <= 255) { |
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// Could have used OP_PUSHDATA. |
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return opcode == OP_PUSHDATA1; |
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} else if (data.size() <= 65535) { |
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// Could have used OP_PUSHDATA2. |
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return opcode == OP_PUSHDATA2; |
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} |
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return true; |
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} |
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bool EvalScript(vector<vector<unsigned char> >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror) |
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{ |
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static const CScriptNum bnZero(0); |
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static const CScriptNum bnOne(1); |
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static const CScriptNum bnFalse(0); |
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static const CScriptNum bnTrue(1); |
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static const valtype vchFalse(0); |
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static const valtype vchZero(0); |
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static const valtype vchTrue(1, 1); |
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CScript::const_iterator pc = script.begin(); |
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CScript::const_iterator pend = script.end(); |
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CScript::const_iterator pbegincodehash = script.begin(); |
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opcodetype opcode; |
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valtype vchPushValue; |
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vector<bool> vfExec; |
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vector<valtype> altstack; |
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set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR); |
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if (script.size() > 10000) |
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return set_error(serror, SCRIPT_ERR_SCRIPT_SIZE); |
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int nOpCount = 0; |
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bool fRequireMinimal = (flags & SCRIPT_VERIFY_MINIMALDATA) != 0; |
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try |
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{ |
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while (pc < pend) |
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{ |
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bool fExec = !count(vfExec.begin(), vfExec.end(), false); |
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// |
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// Read instruction |
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// |
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if (!script.GetOp(pc, opcode, vchPushValue)) |
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return set_error(serror, SCRIPT_ERR_BAD_OPCODE); |
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if (vchPushValue.size() > MAX_SCRIPT_ELEMENT_SIZE) |
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return set_error(serror, SCRIPT_ERR_PUSH_SIZE); |
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// Note how OP_RESERVED does not count towards the opcode limit. |
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if (opcode > OP_16 && ++nOpCount > 201) |
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return set_error(serror, SCRIPT_ERR_OP_COUNT); |
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if (opcode == OP_CAT || |
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opcode == OP_SUBSTR || |
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opcode == OP_LEFT || |
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opcode == OP_RIGHT || |
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opcode == OP_INVERT || |
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opcode == OP_AND || |
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opcode == OP_OR || |
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opcode == OP_XOR || |
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opcode == OP_2MUL || |
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opcode == OP_2DIV || |
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opcode == OP_MUL || |
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opcode == OP_DIV || |
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opcode == OP_MOD || |
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opcode == OP_LSHIFT || |
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opcode == OP_RSHIFT) |
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return set_error(serror, SCRIPT_ERR_DISABLED_OPCODE); // Disabled opcodes. |
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if (fExec && 0 <= opcode && opcode <= OP_PUSHDATA4) { |
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if (fRequireMinimal && !CheckMinimalPush(vchPushValue, opcode)) { |
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return set_error(serror, SCRIPT_ERR_MINIMALDATA); |
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} |
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stack.push_back(vchPushValue); |
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} else if (fExec || (OP_IF <= opcode && opcode <= OP_ENDIF)) |
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switch (opcode) |
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{ |
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// |
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// Push value |
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// |
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case OP_1NEGATE: |
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case OP_1: |
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case OP_2: |
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case OP_3: |
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case OP_4: |
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case OP_5: |
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case OP_6: |
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case OP_7: |
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case OP_8: |
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case OP_9: |
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case OP_10: |
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case OP_11: |
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case OP_12: |
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case OP_13: |
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case OP_14: |
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case OP_15: |
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case OP_16: |
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{ |
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// ( -- value) |
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CScriptNum bn((int)opcode - (int)(OP_1 - 1)); |
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stack.push_back(bn.getvch()); |
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// The result of these opcodes should always be the minimal way to push the data |
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// they push, so no need for a CheckMinimalPush here. |
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} |
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break; |
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// |
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// Control |
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// |
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case OP_NOP: |
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break; |
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case OP_CHECKLOCKTIMEVERIFY: |
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{ |
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if (!(flags & SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY)) { |
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// not enabled; treat as a NOP2 |
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if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) { |
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return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS); |
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} |
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break; |
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} |
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if (stack.size() < 1) |
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return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
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// Note that elsewhere numeric opcodes are limited to |
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// operands in the range -2**31+1 to 2**31-1, however it is |
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// legal for opcodes to produce results exceeding that |
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// range. This limitation is implemented by CScriptNum's |
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// default 4-byte limit. |
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// |
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// If we kept to that limit we'd have a year 2038 problem, |
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// even though the nLockTime field in transactions |
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// themselves is uint32 which only becomes meaningless |
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// after the year 2106. |
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// |
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// Thus as a special case we tell CScriptNum to accept up |
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// to 5-byte bignums, which are good until 2**39-1, well |
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// beyond the 2**32-1 limit of the nLockTime field itself. |
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const CScriptNum nLockTime(stacktop(-1), fRequireMinimal, 5); |
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// In the rare event that the argument may be < 0 due to |
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// some arithmetic being done first, you can always use |
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// 0 MAX CHECKLOCKTIMEVERIFY. |
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if (nLockTime < 0) |
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return set_error(serror, SCRIPT_ERR_NEGATIVE_LOCKTIME); |
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|
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// Actually compare the specified lock time with the transaction. |
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if (!checker.CheckLockTime(nLockTime)) |
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return set_error(serror, SCRIPT_ERR_UNSATISFIED_LOCKTIME); |
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break; |
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} |
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case OP_NOP1: case OP_NOP3: case OP_NOP4: case OP_NOP5: |
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case OP_NOP6: case OP_NOP7: case OP_NOP8: case OP_NOP9: case OP_NOP10: |
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{ |
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if (flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS) |
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return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_NOPS); |
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} |
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break; |
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case OP_IF: |
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case OP_NOTIF: |
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{ |
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// <expression> if [statements] [else [statements]] endif |
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bool fValue = false; |
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if (fExec) |
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{ |
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if (stack.size() < 1) |
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return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL); |
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valtype& vch = stacktop(-1); |
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fValue = CastToBool(vch); |
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if (opcode == OP_NOTIF) |
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fValue = !fValue; |
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popstack(stack); |
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} |
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vfExec.push_back(fValue); |
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} |
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break; |
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|
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case OP_ELSE: |
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{ |
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if (vfExec.empty()) |
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return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL); |
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vfExec.back() = !vfExec.back(); |
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} |
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break; |
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case OP_ENDIF: |
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{ |
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if (vfExec.empty()) |
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return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL); |
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vfExec.pop_back(); |
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} |
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break; |
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|
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case OP_VERIFY: |
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{ |
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// (true -- ) or |
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// (false -- false) and return |
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if (stack.size() < 1) |
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return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
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bool fValue = CastToBool(stacktop(-1)); |
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if (fValue) |
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popstack(stack); |
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else |
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return set_error(serror, SCRIPT_ERR_VERIFY); |
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} |
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break; |
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|
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case OP_RETURN: |
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{ |
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return set_error(serror, SCRIPT_ERR_OP_RETURN); |
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} |
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break; |
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|
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// |
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// Stack ops |
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// |
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case OP_TOALTSTACK: |
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{ |
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if (stack.size() < 1) |
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return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
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altstack.push_back(stacktop(-1)); |
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popstack(stack); |
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} |
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break; |
|
|
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case OP_FROMALTSTACK: |
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{ |
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if (altstack.size() < 1) |
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return set_error(serror, SCRIPT_ERR_INVALID_ALTSTACK_OPERATION); |
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stack.push_back(altstacktop(-1)); |
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popstack(altstack); |
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} |
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break; |
|
|
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case OP_2DROP: |
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{ |
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// (x1 x2 -- ) |
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if (stack.size() < 2) |
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return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
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popstack(stack); |
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popstack(stack); |
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} |
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break; |
|
|
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case OP_2DUP: |
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{ |
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// (x1 x2 -- x1 x2 x1 x2) |
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if (stack.size() < 2) |
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return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype vch1 = stacktop(-2); |
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valtype vch2 = stacktop(-1); |
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stack.push_back(vch1); |
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stack.push_back(vch2); |
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} |
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break; |
|
|
|
case OP_3DUP: |
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{ |
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// (x1 x2 x3 -- x1 x2 x3 x1 x2 x3) |
|
if (stack.size() < 3) |
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return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype vch1 = stacktop(-3); |
|
valtype vch2 = stacktop(-2); |
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valtype vch3 = stacktop(-1); |
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stack.push_back(vch1); |
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stack.push_back(vch2); |
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stack.push_back(vch3); |
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} |
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break; |
|
|
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case OP_2OVER: |
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{ |
|
// (x1 x2 x3 x4 -- x1 x2 x3 x4 x1 x2) |
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if (stack.size() < 4) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype vch1 = stacktop(-4); |
|
valtype vch2 = stacktop(-3); |
|
stack.push_back(vch1); |
|
stack.push_back(vch2); |
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} |
|
break; |
|
|
|
case OP_2ROT: |
|
{ |
|
// (x1 x2 x3 x4 x5 x6 -- x3 x4 x5 x6 x1 x2) |
|
if (stack.size() < 6) |
|
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); |
|
stack.push_back(vch1); |
|
stack.push_back(vch2); |
|
} |
|
break; |
|
|
|
case OP_2SWAP: |
|
{ |
|
// (x1 x2 x3 x4 -- x3 x4 x1 x2) |
|
if (stack.size() < 4) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
swap(stacktop(-4), stacktop(-2)); |
|
swap(stacktop(-3), stacktop(-1)); |
|
} |
|
break; |
|
|
|
case OP_IFDUP: |
|
{ |
|
// (x - 0 | x x) |
|
if (stack.size() < 1) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype vch = stacktop(-1); |
|
if (CastToBool(vch)) |
|
stack.push_back(vch); |
|
} |
|
break; |
|
|
|
case OP_DEPTH: |
|
{ |
|
// -- stacksize |
|
CScriptNum bn(stack.size()); |
|
stack.push_back(bn.getvch()); |
|
} |
|
break; |
|
|
|
case OP_DROP: |
|
{ |
|
// (x -- ) |
|
if (stack.size() < 1) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
popstack(stack); |
|
} |
|
break; |
|
|
|
case OP_DUP: |
|
{ |
|
// (x -- x x) |
|
if (stack.size() < 1) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype vch = stacktop(-1); |
|
stack.push_back(vch); |
|
} |
|
break; |
|
|
|
case OP_NIP: |
|
{ |
|
// (x1 x2 -- x2) |
|
if (stack.size() < 2) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
stack.erase(stack.end() - 2); |
|
} |
|
break; |
|
|
|
case OP_OVER: |
|
{ |
|
// (x1 x2 -- x1 x2 x1) |
|
if (stack.size() < 2) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype vch = stacktop(-2); |
|
stack.push_back(vch); |
|
} |
|
break; |
|
|
|
case OP_PICK: |
|
case OP_ROLL: |
|
{ |
|
// (xn ... x2 x1 x0 n - xn ... x2 x1 x0 xn) |
|
// (xn ... x2 x1 x0 n - ... x2 x1 x0 xn) |
|
if (stack.size() < 2) |
|
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 set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype vch = stacktop(-n-1); |
|
if (opcode == OP_ROLL) |
|
stack.erase(stack.end()-n-1); |
|
stack.push_back(vch); |
|
} |
|
break; |
|
|
|
case OP_ROT: |
|
{ |
|
// (x1 x2 x3 -- x2 x3 x1) |
|
// x2 x1 x3 after first swap |
|
// x2 x3 x1 after second swap |
|
if (stack.size() < 3) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
swap(stacktop(-3), stacktop(-2)); |
|
swap(stacktop(-2), stacktop(-1)); |
|
} |
|
break; |
|
|
|
case OP_SWAP: |
|
{ |
|
// (x1 x2 -- x2 x1) |
|
if (stack.size() < 2) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
swap(stacktop(-2), stacktop(-1)); |
|
} |
|
break; |
|
|
|
case OP_TUCK: |
|
{ |
|
// (x1 x2 -- x2 x1 x2) |
|
if (stack.size() < 2) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype vch = stacktop(-1); |
|
stack.insert(stack.end()-2, vch); |
|
} |
|
break; |
|
|
|
|
|
case OP_SIZE: |
|
{ |
|
// (in -- in size) |
|
if (stack.size() < 1) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
CScriptNum bn(stacktop(-1).size()); |
|
stack.push_back(bn.getvch()); |
|
} |
|
break; |
|
|
|
|
|
// |
|
// Bitwise logic |
|
// |
|
case OP_EQUAL: |
|
case OP_EQUALVERIFY: |
|
//case OP_NOTEQUAL: // use OP_NUMNOTEQUAL |
|
{ |
|
// (x1 x2 - bool) |
|
if (stack.size() < 2) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
valtype& vch1 = stacktop(-2); |
|
valtype& vch2 = stacktop(-1); |
|
bool fEqual = (vch1 == vch2); |
|
// OP_NOTEQUAL is disabled because it would be too easy to say |
|
// something like n != 1 and have some wiseguy pass in 1 with extra |
|
// zero bytes after it (numerically, 0x01 == 0x0001 == 0x000001) |
|
//if (opcode == OP_NOTEQUAL) |
|
// fEqual = !fEqual; |
|
popstack(stack); |
|
popstack(stack); |
|
stack.push_back(fEqual ? vchTrue : vchFalse); |
|
if (opcode == OP_EQUALVERIFY) |
|
{ |
|
if (fEqual) |
|
popstack(stack); |
|
else |
|
return set_error(serror, SCRIPT_ERR_EQUALVERIFY); |
|
} |
|
} |
|
break; |
|
|
|
|
|
// |
|
// Numeric |
|
// |
|
case OP_1ADD: |
|
case OP_1SUB: |
|
case OP_NEGATE: |
|
case OP_ABS: |
|
case OP_NOT: |
|
case OP_0NOTEQUAL: |
|
{ |
|
// (in -- out) |
|
if (stack.size() < 1) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
CScriptNum bn(stacktop(-1), fRequireMinimal); |
|
switch (opcode) |
|
{ |
|
case OP_1ADD: bn += bnOne; break; |
|
case OP_1SUB: bn -= bnOne; break; |
|
case OP_NEGATE: bn = -bn; break; |
|
case OP_ABS: if (bn < bnZero) bn = -bn; break; |
|
case OP_NOT: bn = (bn == bnZero); break; |
|
case OP_0NOTEQUAL: bn = (bn != bnZero); break; |
|
default: assert(!"invalid opcode"); break; |
|
} |
|
popstack(stack); |
|
stack.push_back(bn.getvch()); |
|
} |
|
break; |
|
|
|
case OP_ADD: |
|
case OP_SUB: |
|
case OP_BOOLAND: |
|
case OP_BOOLOR: |
|
case OP_NUMEQUAL: |
|
case OP_NUMEQUALVERIFY: |
|
case OP_NUMNOTEQUAL: |
|
case OP_LESSTHAN: |
|
case OP_GREATERTHAN: |
|
case OP_LESSTHANOREQUAL: |
|
case OP_GREATERTHANOREQUAL: |
|
case OP_MIN: |
|
case OP_MAX: |
|
{ |
|
// (x1 x2 -- out) |
|
if (stack.size() < 2) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
CScriptNum bn1(stacktop(-2), fRequireMinimal); |
|
CScriptNum bn2(stacktop(-1), fRequireMinimal); |
|
CScriptNum bn(0); |
|
switch (opcode) |
|
{ |
|
case OP_ADD: |
|
bn = bn1 + bn2; |
|
break; |
|
|
|
case OP_SUB: |
|
bn = bn1 - bn2; |
|
break; |
|
|
|
case OP_BOOLAND: bn = (bn1 != bnZero && bn2 != bnZero); break; |
|
case OP_BOOLOR: bn = (bn1 != bnZero || bn2 != bnZero); break; |
|
case OP_NUMEQUAL: bn = (bn1 == bn2); break; |
|
case OP_NUMEQUALVERIFY: bn = (bn1 == bn2); break; |
|
case OP_NUMNOTEQUAL: bn = (bn1 != bn2); break; |
|
case OP_LESSTHAN: bn = (bn1 < bn2); break; |
|
case OP_GREATERTHAN: bn = (bn1 > bn2); break; |
|
case OP_LESSTHANOREQUAL: bn = (bn1 <= bn2); break; |
|
case OP_GREATERTHANOREQUAL: bn = (bn1 >= bn2); break; |
|
case OP_MIN: bn = (bn1 < bn2 ? bn1 : bn2); break; |
|
case OP_MAX: bn = (bn1 > bn2 ? bn1 : bn2); break; |
|
default: assert(!"invalid opcode"); break; |
|
} |
|
popstack(stack); |
|
popstack(stack); |
|
stack.push_back(bn.getvch()); |
|
|
|
if (opcode == OP_NUMEQUALVERIFY) |
|
{ |
|
if (CastToBool(stacktop(-1))) |
|
popstack(stack); |
|
else |
|
return set_error(serror, SCRIPT_ERR_NUMEQUALVERIFY); |
|
} |
|
} |
|
break; |
|
|
|
case OP_WITHIN: |
|
{ |
|
// (x min max -- out) |
|
if (stack.size() < 3) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
CScriptNum bn1(stacktop(-3), fRequireMinimal); |
|
CScriptNum bn2(stacktop(-2), fRequireMinimal); |
|
CScriptNum bn3(stacktop(-1), fRequireMinimal); |
|
bool fValue = (bn2 <= bn1 && bn1 < bn3); |
|
popstack(stack); |
|
popstack(stack); |
|
popstack(stack); |
|
stack.push_back(fValue ? vchTrue : vchFalse); |
|
} |
|
break; |
|
|
|
|
|
// |
|
// Crypto |
|
// |
|
case OP_RIPEMD160: |
|
case OP_SHA1: |
|
case OP_SHA256: |
|
case OP_HASH160: |
|
case OP_HASH256: |
|
{ |
|
// (in -- hash) |
|
if (stack.size() < 1) |
|
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) |
|
CRIPEMD160().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash)); |
|
else if (opcode == OP_SHA1) |
|
CSHA1().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash)); |
|
else if (opcode == OP_SHA256) |
|
CSHA256().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash)); |
|
else if (opcode == OP_HASH160) |
|
CHash160().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash)); |
|
else if (opcode == OP_HASH256) |
|
CHash256().Write(begin_ptr(vch), vch.size()).Finalize(begin_ptr(vchHash)); |
|
popstack(stack); |
|
stack.push_back(vchHash); |
|
} |
|
break; |
|
|
|
case OP_CODESEPARATOR: |
|
{ |
|
// Hash starts after the code separator |
|
pbegincodehash = pc; |
|
} |
|
break; |
|
|
|
case OP_CHECKSIG: |
|
case OP_CHECKSIGVERIFY: |
|
{ |
|
// (sig pubkey -- bool) |
|
if (stack.size() < 2) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
|
|
valtype& vchSig = stacktop(-2); |
|
valtype& vchPubKey = stacktop(-1); |
|
|
|
// Subset of script starting at the most recent codeseparator |
|
CScript scriptCode(pbegincodehash, pend); |
|
|
|
// Drop the signature, since there's no way for a signature to sign itself |
|
scriptCode.FindAndDelete(CScript(vchSig)); |
|
|
|
if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, serror)) { |
|
//serror is set |
|
return false; |
|
} |
|
bool fSuccess = checker.CheckSig(vchSig, vchPubKey, scriptCode); |
|
|
|
popstack(stack); |
|
popstack(stack); |
|
stack.push_back(fSuccess ? vchTrue : vchFalse); |
|
if (opcode == OP_CHECKSIGVERIFY) |
|
{ |
|
if (fSuccess) |
|
popstack(stack); |
|
else |
|
return set_error(serror, SCRIPT_ERR_CHECKSIGVERIFY); |
|
} |
|
} |
|
break; |
|
|
|
case OP_CHECKMULTISIG: |
|
case OP_CHECKMULTISIGVERIFY: |
|
{ |
|
// ([sig ...] num_of_signatures [pubkey ...] num_of_pubkeys -- bool) |
|
|
|
int i = 1; |
|
if ((int)stack.size() < i) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
|
|
int nKeysCount = CScriptNum(stacktop(-i), fRequireMinimal).getint(); |
|
if (nKeysCount < 0 || nKeysCount > 20) |
|
return set_error(serror, SCRIPT_ERR_PUBKEY_COUNT); |
|
nOpCount += nKeysCount; |
|
if (nOpCount > 201) |
|
return set_error(serror, SCRIPT_ERR_OP_COUNT); |
|
int ikey = ++i; |
|
i += nKeysCount; |
|
if ((int)stack.size() < i) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
|
|
int nSigsCount = CScriptNum(stacktop(-i), fRequireMinimal).getint(); |
|
if (nSigsCount < 0 || nSigsCount > nKeysCount) |
|
return set_error(serror, SCRIPT_ERR_SIG_COUNT); |
|
int isig = ++i; |
|
i += nSigsCount; |
|
if ((int)stack.size() < i) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
|
|
// Subset of script starting at the most recent codeseparator |
|
CScript scriptCode(pbegincodehash, pend); |
|
|
|
// Drop the signatures, since there's no way for a signature to sign itself |
|
for (int k = 0; k < nSigsCount; k++) |
|
{ |
|
valtype& vchSig = stacktop(-isig-k); |
|
scriptCode.FindAndDelete(CScript(vchSig)); |
|
} |
|
|
|
bool fSuccess = true; |
|
while (fSuccess && nSigsCount > 0) |
|
{ |
|
valtype& vchSig = stacktop(-isig); |
|
valtype& vchPubKey = stacktop(-ikey); |
|
|
|
// Note how this makes the exact order of pubkey/signature evaluation |
|
// distinguishable by CHECKMULTISIG NOT if the STRICTENC flag is set. |
|
// See the script_(in)valid tests for details. |
|
if (!CheckSignatureEncoding(vchSig, flags, serror) || !CheckPubKeyEncoding(vchPubKey, flags, serror)) { |
|
// serror is set |
|
return false; |
|
} |
|
|
|
// Check signature |
|
bool fOk = checker.CheckSig(vchSig, vchPubKey, scriptCode); |
|
|
|
if (fOk) { |
|
isig++; |
|
nSigsCount--; |
|
} |
|
ikey++; |
|
nKeysCount--; |
|
|
|
// If there are more signatures left than keys left, |
|
// then too many signatures have failed. Exit early, |
|
// without checking any further signatures. |
|
if (nSigsCount > nKeysCount) |
|
fSuccess = false; |
|
} |
|
|
|
// Clean up stack of actual arguments |
|
while (i-- > 1) |
|
popstack(stack); |
|
|
|
// A bug causes CHECKMULTISIG to consume one extra argument |
|
// whose contents were not checked in any way. |
|
// |
|
// Unfortunately this is a potential source of mutability, |
|
// so optionally verify it is exactly equal to zero prior |
|
// to removing it from the stack. |
|
if (stack.size() < 1) |
|
return set_error(serror, SCRIPT_ERR_INVALID_STACK_OPERATION); |
|
if ((flags & SCRIPT_VERIFY_NULLDUMMY) && stacktop(-1).size()) |
|
return set_error(serror, SCRIPT_ERR_SIG_NULLDUMMY); |
|
popstack(stack); |
|
|
|
stack.push_back(fSuccess ? vchTrue : vchFalse); |
|
|
|
if (opcode == OP_CHECKMULTISIGVERIFY) |
|
{ |
|
if (fSuccess) |
|
popstack(stack); |
|
else |
|
return set_error(serror, SCRIPT_ERR_CHECKMULTISIGVERIFY); |
|
} |
|
} |
|
break; |
|
|
|
default: |
|
return set_error(serror, SCRIPT_ERR_BAD_OPCODE); |
|
} |
|
|
|
// Size limits |
|
if (stack.size() + altstack.size() > 1000) |
|
return set_error(serror, SCRIPT_ERR_STACK_SIZE); |
|
} |
|
} |
|
catch (...) |
|
{ |
|
return set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR); |
|
} |
|
|
|
if (!vfExec.empty()) |
|
return set_error(serror, SCRIPT_ERR_UNBALANCED_CONDITIONAL); |
|
|
|
return set_success(serror); |
|
} |
|
|
|
namespace { |
|
|
|
/** |
|
* Wrapper that serializes like CTransaction, but with the modifications |
|
* required for the signature hash done in-place |
|
*/ |
|
class CTransactionSignatureSerializer { |
|
private: |
|
const CTransaction &txTo; //! reference to the spending transaction (the one being serialized) |
|
const CScript &scriptCode; //! output script being consumed |
|
const unsigned int nIn; //! input index of txTo being signed |
|
const bool fAnyoneCanPay; //! whether the hashtype has the SIGHASH_ANYONECANPAY flag set |
|
const bool fHashSingle; //! whether the hashtype is SIGHASH_SINGLE |
|
const bool fHashNone; //! whether the hashtype is SIGHASH_NONE |
|
|
|
public: |
|
CTransactionSignatureSerializer(const CTransaction &txToIn, const CScript &scriptCodeIn, unsigned int nInIn, int nHashTypeIn) : |
|
txTo(txToIn), scriptCode(scriptCodeIn), nIn(nInIn), |
|
fAnyoneCanPay(!!(nHashTypeIn & SIGHASH_ANYONECANPAY)), |
|
fHashSingle((nHashTypeIn & 0x1f) == SIGHASH_SINGLE), |
|
fHashNone((nHashTypeIn & 0x1f) == SIGHASH_NONE) {} |
|
|
|
/** Serialize the passed scriptCode, skipping OP_CODESEPARATORs */ |
|
template<typename S> |
|
void SerializeScriptCode(S &s, int nType, int nVersion) const { |
|
CScript::const_iterator it = scriptCode.begin(); |
|
CScript::const_iterator itBegin = it; |
|
opcodetype opcode; |
|
unsigned int nCodeSeparators = 0; |
|
while (scriptCode.GetOp(it, opcode)) { |
|
if (opcode == OP_CODESEPARATOR) |
|
nCodeSeparators++; |
|
} |
|
::WriteCompactSize(s, scriptCode.size() - nCodeSeparators); |
|
it = itBegin; |
|
while (scriptCode.GetOp(it, opcode)) { |
|
if (opcode == OP_CODESEPARATOR) { |
|
s.write((char*)&itBegin[0], it-itBegin-1); |
|
itBegin = it; |
|
} |
|
} |
|
if (itBegin != scriptCode.end()) |
|
s.write((char*)&itBegin[0], it-itBegin); |
|
} |
|
|
|
/** Serialize an input of txTo */ |
|
template<typename S> |
|
void SerializeInput(S &s, unsigned int nInput, int nType, int nVersion) const { |
|
// In case of SIGHASH_ANYONECANPAY, only the input being signed is serialized |
|
if (fAnyoneCanPay) |
|
nInput = nIn; |
|
// Serialize the prevout |
|
::Serialize(s, txTo.vin[nInput].prevout, nType, nVersion); |
|
// Serialize the script |
|
if (nInput != nIn) |
|
// Blank out other inputs' signatures |
|
::Serialize(s, CScript(), nType, nVersion); |
|
else |
|
SerializeScriptCode(s, nType, nVersion); |
|
// Serialize the nSequence |
|
if (nInput != nIn && (fHashSingle || fHashNone)) |
|
// let the others update at will |
|
::Serialize(s, (int)0, nType, nVersion); |
|
else |
|
::Serialize(s, txTo.vin[nInput].nSequence, nType, nVersion); |
|
} |
|
|
|
/** Serialize an output of txTo */ |
|
template<typename S> |
|
void SerializeOutput(S &s, unsigned int nOutput, int nType, int nVersion) const { |
|
if (fHashSingle && nOutput != nIn) |
|
// Do not lock-in the txout payee at other indices as txin |
|
::Serialize(s, CTxOut(), nType, nVersion); |
|
else |
|
::Serialize(s, txTo.vout[nOutput], nType, nVersion); |
|
} |
|
|
|
/** Serialize txTo */ |
|
template<typename S> |
|
void Serialize(S &s, int nType, int nVersion) const { |
|
// Serialize nVersion |
|
::Serialize(s, txTo.nVersion, nType, nVersion); |
|
// Serialize vin |
|
unsigned int nInputs = fAnyoneCanPay ? 1 : txTo.vin.size(); |
|
::WriteCompactSize(s, nInputs); |
|
for (unsigned int nInput = 0; nInput < nInputs; nInput++) |
|
SerializeInput(s, nInput, nType, nVersion); |
|
// Serialize vout |
|
unsigned int nOutputs = fHashNone ? 0 : (fHashSingle ? nIn+1 : txTo.vout.size()); |
|
::WriteCompactSize(s, nOutputs); |
|
for (unsigned int nOutput = 0; nOutput < nOutputs; nOutput++) |
|
SerializeOutput(s, nOutput, nType, nVersion); |
|
// Serialize nLockTime |
|
::Serialize(s, txTo.nLockTime, nType, nVersion); |
|
} |
|
}; |
|
|
|
} // anon namespace |
|
|
|
uint256 SignatureHash(const CScript& scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType) |
|
{ |
|
static const uint256 one(uint256S("0000000000000000000000000000000000000000000000000000000000000001")); |
|
if (nIn >= txTo.vin.size()) { |
|
// nIn out of range |
|
return one; |
|
} |
|
|
|
// Check for invalid use of SIGHASH_SINGLE |
|
if ((nHashType & 0x1f) == SIGHASH_SINGLE) { |
|
if (nIn >= txTo.vout.size()) { |
|
// nOut out of range |
|
return one; |
|
} |
|
} |
|
|
|
// Wrapper to serialize only the necessary parts of the transaction being signed |
|
CTransactionSignatureSerializer txTmp(txTo, scriptCode, nIn, nHashType); |
|
|
|
// Serialize and hash |
|
CHashWriter ss(SER_GETHASH, 0); |
|
ss << txTmp << nHashType; |
|
return ss.GetHash(); |
|
} |
|
|
|
bool TransactionSignatureChecker::VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& pubkey, const uint256& sighash) const |
|
{ |
|
return pubkey.Verify(sighash, vchSig); |
|
} |
|
|
|
bool TransactionSignatureChecker::CheckSig(const vector<unsigned char>& vchSigIn, const vector<unsigned char>& vchPubKey, const CScript& scriptCode) const |
|
{ |
|
CPubKey pubkey(vchPubKey); |
|
if (!pubkey.IsValid()) |
|
return false; |
|
|
|
// Hash type is one byte tacked on to the end of the signature |
|
vector<unsigned char> vchSig(vchSigIn); |
|
if (vchSig.empty()) |
|
return false; |
|
int nHashType = vchSig.back(); |
|
vchSig.pop_back(); |
|
|
|
uint256 sighash = SignatureHash(scriptCode, *txTo, nIn, nHashType); |
|
|
|
if (!VerifySignature(vchSig, pubkey, sighash)) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
bool TransactionSignatureChecker::CheckLockTime(const CScriptNum& nLockTime) const |
|
{ |
|
// There are two times of nLockTime: lock-by-blockheight |
|
// and lock-by-blocktime, distinguished by whether |
|
// nLockTime < LOCKTIME_THRESHOLD. |
|
// |
|
// We want to compare apples to apples, so fail the script |
|
// unless the type of nLockTime being tested is the same as |
|
// the nLockTime in the transaction. |
|
if (!( |
|
(txTo->nLockTime < LOCKTIME_THRESHOLD && nLockTime < LOCKTIME_THRESHOLD) || |
|
(txTo->nLockTime >= LOCKTIME_THRESHOLD && nLockTime >= LOCKTIME_THRESHOLD) |
|
)) |
|
return false; |
|
|
|
// Now that we know we're comparing apples-to-apples, the |
|
// comparison is a simple numeric one. |
|
if (nLockTime > (int64_t)txTo->nLockTime) |
|
return false; |
|
|
|
// Finally the nLockTime feature can be disabled and thus |
|
// CHECKLOCKTIMEVERIFY bypassed if every txin has been |
|
// finalized by setting nSequence to maxint. The |
|
// transaction would be allowed into the blockchain, making |
|
// the opcode ineffective. |
|
// |
|
// Testing if this vin is not final is sufficient to |
|
// prevent this condition. Alternatively we could test all |
|
// inputs, but testing just this input minimizes the data |
|
// required to prove correct CHECKLOCKTIMEVERIFY execution. |
|
if (txTo->vin[nIn].IsFinal()) |
|
return false; |
|
|
|
return true; |
|
} |
|
|
|
|
|
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 set_error(serror, SCRIPT_ERR_SIG_PUSHONLY); |
|
} |
|
|
|
vector<vector<unsigned char> > stack, stackCopy; |
|
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, serror)) |
|
// serror is set |
|
return false; |
|
if (stack.empty()) |
|
return set_error(serror, SCRIPT_ERR_EVAL_FALSE); |
|
if (CastToBool(stack.back()) == false) |
|
return set_error(serror, SCRIPT_ERR_EVAL_FALSE); |
|
|
|
// Additional validation for spend-to-script-hash transactions: |
|
if ((flags & SCRIPT_VERIFY_P2SH) && scriptPubKey.IsPayToScriptHash()) |
|
{ |
|
// scriptSig must be literals-only or validation fails |
|
if (!scriptSig.IsPushOnly()) |
|
return set_error(serror, SCRIPT_ERR_SIG_PUSHONLY); |
|
|
|
// Restore stack. |
|
swap(stack, stackCopy); |
|
|
|
// stack cannot be empty here, because if it was the |
|
// P2SH HASH <> EQUAL scriptPubKey would be evaluated with |
|
// an empty stack and the EvalScript above would return false. |
|
assert(!stack.empty()); |
|
|
|
const valtype& pubKeySerialized = stack.back(); |
|
CScript pubKey2(pubKeySerialized.begin(), pubKeySerialized.end()); |
|
popstack(stack); |
|
|
|
if (!EvalScript(stack, pubKey2, flags, checker, serror)) |
|
// serror is set |
|
return false; |
|
if (stack.empty()) |
|
return set_error(serror, SCRIPT_ERR_EVAL_FALSE); |
|
if (!CastToBool(stack.back())) |
|
return set_error(serror, SCRIPT_ERR_EVAL_FALSE); |
|
} |
|
|
|
// The CLEANSTACK check is only performed after potential P2SH evaluation, |
|
// as the non-P2SH evaluation of a P2SH script will obviously not result in |
|
// a clean stack (the P2SH inputs remain). |
|
if ((flags & SCRIPT_VERIFY_CLEANSTACK) != 0) { |
|
// Disallow CLEANSTACK without P2SH, as otherwise a switch CLEANSTACK->P2SH+CLEANSTACK |
|
// would be possible, which is not a softfork (and P2SH should be one). |
|
assert((flags & SCRIPT_VERIFY_P2SH) != 0); |
|
if (stack.size() != 1) { |
|
return set_error(serror, SCRIPT_ERR_CLEANSTACK); |
|
} |
|
} |
|
|
|
return set_success(serror); |
|
}
|
|
|