signAuthorization method

@override Future<Uint8List> signAuthorization(Authorization authorization)

Signs an EIP-7702 authorization.

Implementation

@override
Future<Uint8List> signAuthorization(Authorization authorization) async {
  // EIP-7702 authorization signing
  // MAGIC || chainId || address || nonce
  final magic = Uint8List.fromList([0x05]);
  final chainIdBytes = BytesUtils.bigIntToBytes(
      BigInt.from(authorization.chainId),
      length: 32);
  final addressBytes = HexUtils.decode(authorization.address);
  final nonceBytes =
      BytesUtils.bigIntToBytes(authorization.nonce, length: 32);

  final message =
      BytesUtils.concat([magic, chainIdBytes, addressBytes, nonceBytes]);
  final hash = Keccak256.hash(message);

  return Secp256k1.sign(hash, privateKey);
}