cipher2 0.3.0

A plugin for AES encrytion and decrytion.

cipher2

A flutter plugin project for AES encryption and decrytion which support both ios and android.

本插件帮助开发者在自己的应用内使用AES加密解密。

For now, it supports the following modes for AES.

• AES CBC mode 128bit pkcs padding 7 (works for both ios and android)
• AES GCM mode 128bit (works for android only now)

目前，本插件只支持下列AES模式加密解密, 如果你需要其他加密方式或者AES加密其他模式，请给我留言。我会升级这个插件。

• AES CBC mode 128bit pkcs padding 7
• AES GCM mode 128bit

I will update this plugin if anyone require other encrytion method.

如果有需要，我会更新插件代码以支持其他加密模式，以及其他加密算法。

Getting Started

This project is a plugin package for flutter which implements AES encrytion and decryption.

String plainText = '我是shyandsy，never give up man';
String key = 'xxxxxxxxxxxxxxxx';
String iv = 'yyyyyyyyyyyyyyyy';
String nonce = await Cipher2.generateNonce();   // generate a nonce for gcm mode we use later

all strings in this plugin use UTF8 encoding

AES CBC mode 128bit pkcs padding 7

Encrytion

this method will return a based 64 encoded ciphertext

// encrytion
// both of key and iv are string with 128bit length (key和iv分别对应秘钥和向量，字符串格式，长度都是128位)
String encryptedString = await Cipher2.encryptAesCbc128Padding7(plainText, key, iv);

Decryption

// decrytion
// both of key and iv are string with 128bit length (key和iv分别对应秘钥和向量，字符串格式，长度都是128位)
decryptedString = await Cipher2.decryptAesCbc128Padding7(encryptedString, key, iv);

AES GCM mode 128bit

Encrytion

this method will return a based 64 encoded ciphertext

// encrytion
// the key is a string with 128bit length  (key是128位秘钥字符串)
// the nonce was generated by the method Cipher2.generateNonce(), and it is a base64 encoded 12 bytes (nonce是由Cipher2.generateNonce()方法生成的base64编码的字符串，原始数据长度12字节，这是GCM模式推荐长度)
encryptedString = await Cipher2.encryptAesGcm128(plaintext, key, nonce);

Decryption

// encrytion
// the key is a string with 128bit length (key是128位秘钥字符串)
// the nonce was generated by the method Cipher2.generateNonce(), and it is a base64 encoded 12 bytes (nonce是由Cipher2.generateNonce()方法生成的base64编码的字符串，原始数据长度12字节，这是GCM模式推荐长度)
result = await Cipher2.decryptAesGcm128(encryptedString, key, nonce);

Unit test

First, I havent find a way in the unit test document to test the method provided by the native code. I will appreciate if you teach me how to do that!

Instead, I do that in the example code. Look the code in example\lib\main.dart.

String encryptedString;
String plainText = '我是shyandsy，never give up man';
String key = 'xxxxxxxxxxxxxxxx';
String iv = 'yyyyyyyyyyyyyyyy';
String decryptedString;

// test
await testEncryptAesCbc128Padding7();

await testDecryptAesCbc128Padding7();

await testEncryptAesGcm128(); // GenerateNonce();

Exception handle

there are three types of exceptions in this plugin

• ERROR_INVALID_KEY_OR_IV_LENGTH

  the length of key or iv is invalid

• ERROR_INVALID_PARAMETER_TYPE

  all parameters must be string

• ERROR_INVALID_ENCRYPTED_DATA

  the string to be descrytion must be a valid base64 string with the length at multiple of 128 bits

String encryptedString = '我是shyandsy，never give up man';
String key = 'xxxxxxxxxxxxxxxx';
String iv = 'yyyyyyyyyyyyyyyy';

try {
    // encrytion
    plainText = await Cipher2.decryptAesCbc128Padding7(encryptedString, key, iv);
    print("testDecrytion case6: failed");
} on PlatformException catch(e) {
    encryptedString = "";
    if(e.code == "ERROR_INVALID_ENCRYPTED_DATA"){
        print("testDecrytion: pass");
    }else{
        print("testDecrytion: failed");
    }
}