MultisigProgram.fromScript constructor

MultisigProgram.fromScript(Script script)

Implementation

MultisigProgram.fromScript(this.script) {

  // Must have threshold, 1-20 public keys, pubkey number and CHECKMULTISIG
  if (script.length < 4 || script.length > maxPubkeys+3) {
    throw NoProgramMatch();
  }

  if (!script.ops.last.match(checkmultisig)) throw NoProgramMatch();

  final pknum = script[script.length-2].number;
  if (
    pknum == null || pknum < 1 || pknum > maxPubkeys
    || script.length != pknum+3
  ) throw NoProgramMatch();

  final firstNum = script[0].number;
  if (firstNum == null) throw NoProgramMatch();
  threshold = firstNum;

  // Threshold must be within 1-pknum
  if (threshold < 1 || threshold > pknum) throw NoProgramMatch();

  // Check all public keys are push data and extract data
  final potentialPubkeys = script.ops.sublist(1, script.length-2);
  if (
    potentialPubkeys.any(
      (op) => op is! ScriptPushData
      || (op.data.length != 33 && op.data.length != 65),
    )
  ) throw NoProgramMatch();

  try {
    pubkeys = List.unmodifiable(
      potentialPubkeys.map(
        (op) => ECPublicKey((op as ScriptPushData).data),
      ),
    );
  } on InvalidPublicKey {
    throw NoProgramMatch();
  }

}