Flutter RSA Key Generator

This project shows how to use Pointy Castle to generate a RSA Key and encode it to a PKCS1 Pem String.

In order to generate a new RSA Keypair we use RSAKeyGenerator

AsymmetricKeyPair<PublicKey, PrivateKey> computeRSAKeyPair(
    SecureRandom secureRandom) {
  var rsapars = new RSAKeyGeneratorParameters(BigInt.from(65537), 2048, 12);
  var params = new ParametersWithRandom(rsapars, secureRandom);
  var keyGenerator = new RSAKeyGenerator();
  keyGenerator.init(params);
  return keyGenerator.generateKeyPair();
}

To be able generate the keys in a background thread we use Dart's Isolate implemented in Flutter's compute. We must ensure that the computeRSAKeyPair function is placed outside a Class so that it can be called globally.

Future<AsymmetricKeyPair<PublicKey, PrivateKey>> getRSAKeyPair(
  SecureRandom secureRandom) async {
  return await compute(computeRSAKeyPair, secureRandom);
}