mergeMultisigTransactions static method

Future<SignedTransaction> mergeMultisigTransactions(List<SignedTransaction> transactions)

Merges the given (partially) signed multisig transactions. Transactions are the partially signed multisig transactions to merge. Underlying transactions may be mutated.

Returns the merged multisig transaction

Implementation

static Future<SignedTransaction> mergeMultisigTransactions(
  List<SignedTransaction> transactions,
) async {
  if (transactions.length < 2) {
    throw AlgorandException(message: 'Cannot merge a single transaction');
  }

  final merged = transactions[0];
  for (var i = 0; i < transactions.length; i++) {
    final tx = transactions[i];
    final mSig = tx.multiSignature;
    if (mSig == null) {
      throw AlgorandException(message: 'No valid multisignature');
    }

    if (mSig.version != merged.multiSignature?.version ||
        mSig.threshold != merged.multiSignature?.threshold) {
      throw AlgorandException(
        message: 'transaction msig parameters do not match',
      );
    }

    for (var j = 0; j < mSig.subsigs.length; j++) {
      var myMsig = merged.multiSignature?.subsigs[j];
      var theirMsig = mSig.subsigs[j];
      if (myMsig == null) {
        throw AlgorandException(message: 'No valid subsig');
      }

      if (theirMsig.key != myMsig.key) {
        throw AlgorandException(
          message: 'transaction msig public keys do not match',
        );
      }

      if (myMsig.signature == null) {
        myMsig = myMsig.copyWith(signature: theirMsig.signature);
      } else if (myMsig.signature != theirMsig.signature &&
          theirMsig.signature != null) {
        throw AlgorandException(
          message: 'transaction msig has mismatched signatures',
        );
      }

      merged.multiSignature?.subsigs[j] = myMsig;
    }
  }

  return merged;
}