af3208bfa6
These changes decode valid SIGHASH types on signatures in assembly (asm) representations of scriptSig scripts. This squashed commit incorporates substantial helpful feedback from jtimon, laanwj, and sipa.
134 lines
5.2 KiB
C++
134 lines
5.2 KiB
C++
// 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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#ifndef BITCOIN_SCRIPT_INTERPRETER_H
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#define BITCOIN_SCRIPT_INTERPRETER_H
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#include "script_error.h"
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#include "primitives/transaction.h"
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#include <vector>
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#include <stdint.h>
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#include <string>
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class CPubKey;
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class CScript;
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class CTransaction;
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class uint256;
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/** Signature hash types/flags */
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enum
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{
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SIGHASH_ALL = 1,
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SIGHASH_NONE = 2,
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SIGHASH_SINGLE = 3,
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SIGHASH_ANYONECANPAY = 0x80,
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};
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/** Script verification flags */
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enum
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{
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SCRIPT_VERIFY_NONE = 0,
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// Evaluate P2SH subscripts (softfork safe, BIP16).
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SCRIPT_VERIFY_P2SH = (1U << 0),
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// Passing a non-strict-DER signature or one with undefined hashtype to a checksig operation causes script failure.
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// Evaluating a pubkey that is not (0x04 + 64 bytes) or (0x02 or 0x03 + 32 bytes) by checksig causes script failure.
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// (softfork safe, but not used or intended as a consensus rule).
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SCRIPT_VERIFY_STRICTENC = (1U << 1),
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// Passing a non-strict-DER signature to a checksig operation causes script failure (softfork safe, BIP62 rule 1)
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SCRIPT_VERIFY_DERSIG = (1U << 2),
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// Passing a non-strict-DER signature or one with S > order/2 to a checksig operation causes script failure
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// (softfork safe, BIP62 rule 5).
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SCRIPT_VERIFY_LOW_S = (1U << 3),
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// verify dummy stack item consumed by CHECKMULTISIG is of zero-length (softfork safe, BIP62 rule 7).
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SCRIPT_VERIFY_NULLDUMMY = (1U << 4),
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// Using a non-push operator in the scriptSig causes script failure (softfork safe, BIP62 rule 2).
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SCRIPT_VERIFY_SIGPUSHONLY = (1U << 5),
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// Require minimal encodings for all push operations (OP_0... OP_16, OP_1NEGATE where possible, direct
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// pushes up to 75 bytes, OP_PUSHDATA up to 255 bytes, OP_PUSHDATA2 for anything larger). Evaluating
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// any other push causes the script to fail (BIP62 rule 3).
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// In addition, whenever a stack element is interpreted as a number, it must be of minimal length (BIP62 rule 4).
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// (softfork safe)
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SCRIPT_VERIFY_MINIMALDATA = (1U << 6),
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// Discourage use of NOPs reserved for upgrades (NOP1-10)
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//
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// Provided so that nodes can avoid accepting or mining transactions
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// containing executed NOP's whose meaning may change after a soft-fork,
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// thus rendering the script invalid; with this flag set executing
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// discouraged NOPs fails the script. This verification flag will never be
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// a mandatory flag applied to scripts in a block. NOPs that are not
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// executed, e.g. within an unexecuted IF ENDIF block, are *not* rejected.
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SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_NOPS = (1U << 7),
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// Require that only a single stack element remains after evaluation. This changes the success criterion from
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// "At least one stack element must remain, and when interpreted as a boolean, it must be true" to
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// "Exactly one stack element must remain, and when interpreted as a boolean, it must be true".
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// (softfork safe, BIP62 rule 6)
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// Note: CLEANSTACK should never be used without P2SH.
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SCRIPT_VERIFY_CLEANSTACK = (1U << 8),
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// Verify CHECKLOCKTIMEVERIFY
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//
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// See BIP65 for details.
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SCRIPT_VERIFY_CHECKLOCKTIMEVERIFY = (1U << 9),
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};
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bool CheckSignatureEncoding(const std::vector<unsigned char> &vchSig, unsigned int flags, ScriptError* serror);
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uint256 SignatureHash(const CScript &scriptCode, const CTransaction& txTo, unsigned int nIn, int nHashType);
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class BaseSignatureChecker
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{
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public:
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virtual bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const
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{
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return false;
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}
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virtual bool CheckLockTime(const CScriptNum& nLockTime) const
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{
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return false;
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}
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virtual ~BaseSignatureChecker() {}
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};
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class TransactionSignatureChecker : public BaseSignatureChecker
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{
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private:
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const CTransaction* txTo;
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unsigned int nIn;
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protected:
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virtual bool VerifySignature(const std::vector<unsigned char>& vchSig, const CPubKey& vchPubKey, const uint256& sighash) const;
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public:
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TransactionSignatureChecker(const CTransaction* txToIn, unsigned int nInIn) : txTo(txToIn), nIn(nInIn) {}
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bool CheckSig(const std::vector<unsigned char>& scriptSig, const std::vector<unsigned char>& vchPubKey, const CScript& scriptCode) const;
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bool CheckLockTime(const CScriptNum& nLockTime) const;
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};
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class MutableTransactionSignatureChecker : public TransactionSignatureChecker
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{
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private:
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const CTransaction txTo;
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public:
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MutableTransactionSignatureChecker(const CMutableTransaction* txToIn, unsigned int nInIn) : TransactionSignatureChecker(&txTo, nInIn), txTo(*txToIn) {}
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};
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bool EvalScript(std::vector<std::vector<unsigned char> >& stack, const CScript& script, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* error = NULL);
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bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* error = NULL);
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#endif // BITCOIN_SCRIPT_INTERPRETER_H
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