Method verify

lib/script/script.js:3095–3190

* Verify an input and output script, and a witness if present. * @param {Script} input * @param {Witness} witness * @param {Script} output * @param {TX} tx * @param {Number} index * @param {Amount} value * @param {VerifyFlags} flags * @throws {ScriptError}

(input, witness, output, tx, index, value, flags)

   */

  static verify(input, witness, output, tx, index, value, flags) {
    if (flags == null)
      flags = Script.flags.STANDARD_VERIFY_FLAGS;

    if (flags & Script.flags.VERIFY_SIGPUSHONLY) {
      if (!input.isPushOnly())
        throw new ScriptError('SIG_PUSHONLY');
    }

    // Setup a stack.
    let stack = new Stack();

    // Execute the input script
    input.execute(stack, flags, tx, index, value, 0);

    // Copy the stack for P2SH
    let copy;
    if (flags & Script.flags.VERIFY_P2SH)
      copy = stack.clone();

    // Execute the previous output script.
    output.execute(stack, flags, tx, index, value, 0);

    // Verify the stack values.
    if (stack.length === 0 || !stack.getBool(-1))
      throw new ScriptError('EVAL_FALSE');

    let hadWitness = false;

    if ((flags & Script.flags.VERIFY_WITNESS) && output.isProgram()) {
      hadWitness = true;

      // Input script must be empty.
      if (input.raw.length !== 0)
        throw new ScriptError('WITNESS_MALLEATED');

      // Verify the program in the output script.
      Script.verifyProgram(witness, output, flags, tx, index, value);

      // Force a cleanstack
      stack.length = 1;
    }

    // If the script is P2SH, execute the real output script
    if ((flags & Script.flags.VERIFY_P2SH) && output.isScripthash()) {
      // P2SH can only have push ops in the scriptSig
      if (!input.isPushOnly())
        throw new ScriptError('SIG_PUSHONLY');

      // Reset the stack
      stack = copy;

      // Stack should not be empty at this point
      if (stack.length === 0)
        throw new ScriptError('EVAL_FALSE');

      // Grab the real redeem script
      const raw = stack.pop();