Hash a Password with Argon2 (Tuned Options)

Demonstrates Crypt2.Argon2HashPassword with explicit options: the cost parameters, saltLen (how many random salt bytes to generate when no salt is given), and an optional secret (pepper).

import 'package:chilkat/chilkat.dart';

void main() {
  final crypt = CkCrypt2();

  // The password should come from a secure source rather than being hard-coded.
  final password = 'correct horse battery staple';

  // The Argon2 options are the same members as Argon2DeriveKey, except the salt is optional for
  // hashing.  When no "salt" is given, a random salt is generated; "saltLen" (default 16, range 8..1024)
  // sets how many random bytes to use.
  final json = CkJsonObject();
  json.updateString('variant', 'argon2id');
  json.updateInt('memoryCostKb', 131072);
  json.updateInt('iterations', 4);
  json.updateInt('parallelism', 2);
  json.updateInt('saltLen', 16);

  // A secret (pepper) and/or ad may be used, but neither is stored in the returned PHC string.  The
  // same values must be supplied to Argon2VerifyPassword for the password to verify.
  json.updateString('secret', 'application-wide-pepper');
  json.updateString('secretEncoding', 'utf-8');

  final String phcHash;
  try {
    phcHash = crypt.argon2HashPassword(password, json.emit());
  } on ChilkatException catch (e) {
    print(e.lastErrorText);
    return;
  }

  print(phcHash);
}