import 'dart:math';
import 'dart:typed_data';

import "package:pointycastle/export.dart";

AsymmetricKeyPair<RSAPublicKey, RSAPrivateKey> generateRSAkeyPair(
    SecureRandom secureRandom,
    {int bitLength = 2048}) {
  // Create an RSA key generator and initialize it
  // final keyGen = KeyGenerator('RSA'); // Get using registry
  final keyGen = RSAKeyGenerator();

  keyGen.init(ParametersWithRandom(
      RSAKeyGeneratorParameters(BigInt.parse('65537'), bitLength, 64),
      secureRandom));

  // Use the generator
  final pair = keyGen.generateKeyPair();

  // Cast the generated key pair into the RSA key types

  final myPublic = pair.publicKey as RSAPublicKey;
  final myPrivate = pair.privateKey as RSAPrivateKey;

  return AsymmetricKeyPair<RSAPublicKey, RSAPrivateKey>(myPublic, myPrivate);
}

SecureRandom getSecureRandom() {
  final rnd = Random.secure();
  final secureRandom = SecureRandom('Fortuna')
    ..seed(KeyParameter(
        Uint8List.fromList(List.generate(32, (index) => rnd.nextInt(256)))));
  return secureRandom;
}