Skip to content

Instantly share code, notes, and snippets.

@long1eu
Created November 6, 2019 13:04
Show Gist options
  • Save long1eu/e518c969e01f8e1dd44c12b779a6c1bf to your computer and use it in GitHub Desktop.
Save long1eu/e518c969e01f8e1dd44c12b779a6c1bf to your computer and use it in GitHub Desktop.
AES/CBC/PKCS7Padding for dart using pointycastle
import 'dart:convert';
import 'dart:typed_data';
import 'package:flutter/material.dart';
import 'package:pointycastle/api.dart';
import 'package:pointycastle/block/aes_fast.dart';
import 'package:pointycastle/block/modes/cbc.dart';
import 'package:pointycastle/padded_block_cipher/padded_block_cipher_impl.dart';
import 'package:pointycastle/paddings/pkcs7.dart';
void main() {
runApp(new MyApp());
}
class MyApp extends StatelessWidget {
@override
Widget build(BuildContext context) {
return MaterialApp(
title: 'AES256/CBC',
theme: ThemeData(
primarySwatch: Colors.blue,
),
home: const EncryptionPage(),
);
}
}
class EncryptionPage extends StatefulWidget {
const EncryptionPage();
@override
_EncryptionPageState createState() => _EncryptionPageState();
}
class _EncryptionPageState extends State<EncryptionPage> {
String encrypted;
final TextEditingController controller = TextEditingController();
@override
Widget build(BuildContext context) {
return Scaffold(
appBar: AppBar(
title: Text('AES256/CBC'),
),
body: ListView(
padding: const EdgeInsets.all(16.0),
children: <Widget>[
Container(
child: TextField(
controller: controller,
),
),
RaisedButton(
child: Text('Encrypt'),
onPressed: () {
if (controller.text.isNotEmpty) {
setState(() {
encrypted = Encryption.encrypt(controller.text);
});
}
},
),
if (encrypted != null)
Container(
margin: const EdgeInsets.all(16.0),
child: SelectableText(encrypted),
),
if (encrypted != null)
RaisedButton(
child: Text('Decrypt'),
onPressed: () {
setState(() {
if (encrypted != null && encrypted.isNotEmpty) {
final String decrypt = Encryption.decrypt(encrypted);
controller.text = decrypt;
encrypted = null;
}
});
},
),
],
),
);
}
}
//Z"b~dERuX!q&zj-,>d}6aEw-_9&xJ^@8
class Encryption {
static final Uint8List _key = new Uint8List.fromList(<int>[
0x5a,
0x22,
0x62,
0x7e,
0x64,
0x45,
0x52,
0x75,
0x58,
0x21,
0x71,
0x26,
0x7a,
0x6a,
0x2d,
0x2c,
0x3e,
0x64,
0x7d,
0x36,
0x61,
0x45,
0x77,
0x2d,
0x5f,
0x39,
0x26,
0x78,
0x4a,
0x5e,
0x40,
0x38
]);
static final Uint8List _iv = new Uint8List.fromList(
<int>[
0xda,
0x39,
0xa3,
0xee,
0x5e,
0x6b,
0x4b,
0x0d,
0x32,
0x55,
0xbf,
0xef,
0x95,
0x60,
0x18,
0x90
],
);
static String encrypt(String text) {
return base64Encode(encryptList(utf8.encode(text)));
}
static Uint8List encryptList(Uint8List data) {
final CBCBlockCipher cbcCipher = new CBCBlockCipher(new AESFastEngine());
final ParametersWithIV<KeyParameter> ivParams =
new ParametersWithIV<KeyParameter>(new KeyParameter(_key), _iv);
final PaddedBlockCipherParameters<ParametersWithIV<KeyParameter>, Null>
paddingParams =
new PaddedBlockCipherParameters<ParametersWithIV<KeyParameter>, Null>(
ivParams, null);
final PaddedBlockCipherImpl paddedCipher =
new PaddedBlockCipherImpl(new PKCS7Padding(), cbcCipher);
paddedCipher.init(true, paddingParams);
try {
return paddedCipher.process(data);
} catch (e) {
print(e);
return null;
}
}
static String decrypt(String data) =>
utf8.decode(decryptList(base64Decode(data)));
static Uint8List decryptList(Uint8List data) {
final CBCBlockCipher cbcCipher = new CBCBlockCipher(new AESFastEngine());
final ParametersWithIV<KeyParameter> ivParams =
new ParametersWithIV<KeyParameter>(new KeyParameter(_key), _iv);
final PaddedBlockCipherParameters<ParametersWithIV<KeyParameter>, Null>
paddingParams =
new PaddedBlockCipherParameters<ParametersWithIV<KeyParameter>, Null>(
ivParams, null);
final PaddedBlockCipherImpl paddedCipher =
new PaddedBlockCipherImpl(new PKCS7Padding(), cbcCipher);
paddedCipher.init(false, paddingParams);
try {
return paddedCipher.process(data);
} catch (e) {
print(e);
return null;
}
}
}
@y0unghe
Copy link

y0unghe commented Jun 13, 2022

How to use a passphrase without using the predefined _key?

@utariddev
Copy link

👍

@BeshoyAdelHemaya
Copy link

BeshoyAdelHemaya commented Apr 4, 2024

Great solution

Sign up for free to join this conversation on GitHub. Already have an account? Sign in to comment