Scrypt constructor

Scrypt({ List<int>? salt, required int cost, int blockSize = 8, int parallelism = 1, int derivedKeyLength = 64, })

Creates an Scrypt instance with a sink for MAC generation.

Implementation

factory Scrypt({
  List<int>? salt,
  required int cost,
  int blockSize = 8,
  int parallelism = 1,
  int derivedKeyLength = 64,
}) {
  // validate parameters
  if (cost < 1) {
    throw StateError('The cost must be at least 1');
  }
  if (cost > 0xFFFFFF) {
    throw StateError('The cost must be less than 2^24');
  }
  if (cost & (cost - 1) != 0) {
    throw StateError('The cost must be a power of 2');
  }
  if (derivedKeyLength < 1) {
    throw StateError('The derivedKeyLength must be at least 1');
  }
  if (blockSize < 1) {
    throw StateError('The blockSize must be at least 1');
  }
  if (parallelism < 1) {
    throw StateError('The parallelism must be at least 1');
  }
  if (blockSize * parallelism > 0x1FFFFFF) {
    throw StateError('The blockSize * parallelism is too big');
  }
  salt ??= randomBytes(16);

  // create instance
  return Scrypt._(
    salt: salt,
    cost: cost,
    blockSize: blockSize,
    parallelism: parallelism,
    derivedKeyLength: derivedKeyLength,
  );
}