How to convert encrypt java code below in flutter - flutter

Question

I m requirement is to convert below java encrypt code to flutter as i need to encrypt few fields value before sending to api.
Below is java encrypt code which i need to convert to java
public static String encrypt(String text, String algo, Key key) {
byte[] cipherText;
String output;
try {
if("RSA".equals(algo)) {
throw new IllegalArgumentException("Do not pass just algo pass with padding and blocking stuff!");
}
if(BuildConfig.DEBUG) {
Log.d(TAG, "encrypt in: "+text);
Log.d(TAG, "algo: "+algo);
Log.d(TAG, "key: "+key);
}
final Cipher cipher = Cipher.getInstance(algo);
if(algo.contains("AES")) {
AlgorithmParameterSpec ivSpec = new IvParameterSpec(ivBytes);
cipher.init(Cipher.ENCRYPT_MODE, key, ivSpec);
} else {
cipher.init(Cipher.ENCRYPT_MODE, key);
}
cipherText = cipher.doFinal(text.getBytes(StandardCharsets.UTF_8));
output = new String(Base64.encode(cipherText));
if(BuildConfig.DEBUG) {
Log.d(TAG, "encrypt out: "+output);
}
return output;
} catch (Exception e) {
Log.e(TAG, SDKConstants.STRING_ERROR + e, e);
return null;
}
}
char[] encPwd = Objects.requireNonNull(CryptoHelper.encrypt(Objects.requireNonNull(binding.textIPassword.getEditText()).getText().toString(), CryptoHelper.ALGO_FOR_RSA, key)).toCharArray();
Please help me in converting above java code to flutter as i need to encrypt one field before sending it to api call.
Any help is appreciated!

Answer 1

Just work through the Java line by line and figure out Dart equivalents. Use the other linked question as your guide. This should work (if I guessed the cipher correctly):
import 'package:pointycastle/export.dart';
String encrypt(String plainText, RSAPublicKey public) {
final plainBytes = utf8.encode(plainText) as Uint8List;
final cipher = PKCS1Encoding(RSAEngine())
..init(true, PublicKeyParameter<RSAPublicKey>(public));
final cipherBytes = cipher.process(plainBytes);
return base64Encode(cipherBytes);
}