Function VerifyScript

src/script/interpreter.cpp:2012–2131

}

bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, const CScriptWitness* witness, script_verify_flags flags, const BaseSignatureChecker& checker, ScriptError* serror)
{
    static const CScriptWitness emptyWitness;
    if (witness == nullptr) {
        witness = &emptyWitness;
    }
    bool hadWitness = false;

    set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);

    if ((flags & SCRIPT_VERIFY_SIGPUSHONLY) != 0 && !scriptSig.IsPushOnly()) {
        return set_error(serror, SCRIPT_ERR_SIG_PUSHONLY);
    }

    // scriptSig and scriptPubKey must be evaluated sequentially on the same stack
    // rather than being simply concatenated (see CVE-2010-5141)
    std::vector<std::vector<unsigned char> > stack, stackCopy;
    if (!EvalScript(stack, scriptSig, flags, checker, SigVersion::BASE, serror))
        // serror is set
        return false;
    if (flags & SCRIPT_VERIFY_P2SH)
        stackCopy = stack;
    if (!EvalScript(stack, scriptPubKey, flags, checker, SigVersion::BASE, 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);

    // Bare witness programs
    int witnessversion;
    std::vector<unsigned char> witnessprogram;
    if (flags & SCRIPT_VERIFY_WITNESS) {
        if (scriptPubKey.IsWitnessProgram(witnessversion, witnessprogram)) {
            hadWitness = true;
            if (scriptSig.size() != 0) {
                // The scriptSig must be _exactly_ CScript(), otherwise we reintroduce malleability.
                return set_error(serror, SCRIPT_ERR_WITNESS_MALLEATED);
            }
            if (!VerifyWitnessProgram(*witness, witnessversion, witnessprogram, flags, checker, serror, /*is_p2sh=*/false)) {
                return false;
            }
            // Bypass the cleanstack check at the end. The actual stack is obviously not clean
            // for witness programs.
            stack.resize(1);
        }
    }

    // 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);