Convert Java RSA Asymmetric encryption to Flutter Dart

Try this:

import 'dart:math';import 'dart:convert';import 'dart:typed_data';import 'package:convert/convert.dart';import 'package:pointycastle/api.dart';import 'package:pointycastle/asymmetric/api.dart';import 'package:pointycastle/asymmetric/rsa.dart';String encrypt(String plaintext, String publicKey) {  var modulusBytes = base64.decode(publicKey);  var modulus = BigInt.parse(hex.encode(modulusBytes), radix: 16);  var exponent = BigInt.parse(hex.encode(base64.decode('AQAB')), radix: 16);  var engine = RSAEngine()    ..init(      true,      PublicKeyParameter<RSAPublicKey>(RSAPublicKey(modulus, exponent)),    );  //PKCS1.5 padding  var k = modulusBytes.length;  var plainBytes = utf8.encode(plaintext);  var paddingLength = k - 3 - plainBytes.length;  var eb = Uint8List(paddingLength + 3 + plainBytes.length);  var r = Random.secure();  eb.setRange(paddingLength + 3, eb.length, plainBytes);  eb[0] = 0;  eb[1] = 2;  eb[paddingLength + 2] = 0;  for (int i = 2; i < paddingLength + 2; i++) {    eb[i] = r.nextInt(254) + 1;  }  print(plainBytes.length);  print(eb);  return base64.encode(    engine.process(eb),  );}