Function EvalChecksigTapscript

src/script/interpreter.cpp:357–395

}

static bool EvalChecksigTapscript(const valtype& sig, const valtype& pubkey, ScriptExecutionData& execdata, script_verify_flags flags, const BaseSignatureChecker& checker, SigVersion sigversion, ScriptError* serror, bool& success)
{
    assert(sigversion == SigVersion::TAPSCRIPT);

    /*
     *  The following validation sequence is consensus critical. Please note how --
     *    upgradable public key versions precede other rules;
     *    the script execution fails when using empty signature with invalid public key;
     *    the script execution fails when using non-empty invalid signature.
     */
    success = !sig.empty();
    if (success) {
        // Implement the sigops/witnesssize ratio test.
        // Passing with an upgradable public key version is also counted.
        assert(execdata.m_validation_weight_left_init);
        execdata.m_validation_weight_left -= VALIDATION_WEIGHT_PER_SIGOP_PASSED;
        if (execdata.m_validation_weight_left < 0) {
            return set_error(serror, SCRIPT_ERR_TAPSCRIPT_VALIDATION_WEIGHT);
        }
    }
    if (pubkey.size() == 0) {
        return set_error(serror, SCRIPT_ERR_TAPSCRIPT_EMPTY_PUBKEY);
    } else if (pubkey.size() == 32) {
        if (success && !checker.CheckSchnorrSignature(sig, pubkey, sigversion, execdata, serror)) {
            return false; // serror is set
        }
    } else {
        /*
         *  New public key version softforks should be defined before this `else` block.
         *  Generally, the new code should not do anything but failing the script execution. To avoid
         *  consensus bugs, it should not modify any existing values (including `success`).
         */
        if ((flags & SCRIPT_VERIFY_DISCOURAGE_UPGRADABLE_PUBKEYTYPE) != 0) {
            return set_error(serror, SCRIPT_ERR_DISCOURAGE_UPGRADABLE_PUBKEYTYPE);
        }
    }

    return true;
}

/** Helper for OP_CHECKSIG, OP_CHECKSIGVERIFY, and (in Tapscript) OP_CHECKSIGADD.
 *