NativeCrypto

Fast crypto functions for Flutter.

• Table of content
  • Background
  • Performances
  • Installation
  • Usage
  • Example
  • How
  • Todo

Background

🤔 Why I started this project ? Because I faced a performance issue when I was using PointyCastle.

It's quite simple, judge for yourself, these are times for AES256 encryption on an Android device (Huawei P30 Pro).

Size	PointyCastle
100 kB	190 ms
200 kB	314 ms
300 kB	1138 ms
400 kB	2781 ms
500 kB	4691 ms
600 kB	7225 ms
700 kB	10264 ms
800 kB	13582 ms
900 kB	17607 ms

We notice that these times, in addition to being far too big, are not even linear.

Performances

⏱ On an Android 10 device: Huawei P30 Pro

Size	NativeCrypto
1 mB	27 ms
2 mB	43 ms
3 mB	78 ms
4 mB	93 ms
5 mB	100 ms
10 mB	229 ms
50 mB	779 ms

Installation

🚧 You can easely setup a Flutter project with this plugin.

Just add these lines in your pubspec.yaml:

native_crypto:
    git:
        url: https://gogs.pointcheval.fr/hugo/native-crypto-flutter.git
        ref: v0.0.x

Replace "x" with the current version!

Then in your code:

// Symmetric crypto.
import 'package:native_crypto/symmetric_crypto.dart';

// To handle exceptions.
import 'package:native_crypto/exceptions.dart';

Usage

To create an AES instance, and generate a key.

AES aes = AES();
await aes.init(KeySize.bits256)

You can also generate key, then use it in AES.

Uint8List aeskey = await KeyGenerator().secretKey(keySize: KeySize.bits256);
AES aes = AES(key: aeskey);

You can create a key with PBKDF2.

Uint8List key = await KeyGenerator().pbkdf2(password, salt, keyLength: 32, iteration: 10000, digest: Digest.sha256);
AES aes = AES(key: key);

Then you can encrypt/decrypt data with this instance.

encryptedPayload = await aes.encrypt(data);
decryptedPayload = await aes.decrypt(encryptedPayload);

Or you can also use AES on the fly with different keys.

Uint8List aeskey = await KeyGenerator().secretKey(keySize: KeySize.bits256);
encryptedPayload = await AES().encrypt(data, key: aeskey);
decryptedPayload = await AES().decrypt(encryptedPayload, key: aeskey);

Available enums are:

enum KeySize { bits128, bits192, bits256 }
enum Digest { sha1, sha256, sha512 }

KeySizes defines all available key sizes for generation.

Digest defines all available digest for PBKDF2.

Example

🔍 Look in example/lib/ for an example app.

How

🔬 But how it is possible ??

Using the native implementation of crypto libs available on each OS.

For Android:

• javax.crypto
• java.security

For iOS:

• CommonCrypto

Todos

🚀 You can contribute to this project.

• Implement working cross platform AES encryption/decryption.
• Different key sizes support.
• Improve performances.
• Add exceptions.
• PBKDF2 support.
• Add other ciphers.
• Clean platform specific code.
• Add asym crypto support...