Function VerifyScript

src/script/interpreter.cpp:1348–1416

}

bool VerifyScript(const CScript& scriptSig, const CScript& scriptPubKey, unsigned int flags, const BaseSignatureChecker& checker, ScriptError* serror)
{
    set_error(serror, SCRIPT_ERR_UNKNOWN_ERROR);

    // If FORKID is enabled, we also ensure strict encoding.
    if (flags & SCRIPT_ENABLE_SIGHASH_FORKID) {
        flags |= SCRIPT_VERIFY_STRICTENC;
    }

    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).