在C#和NodeJS中生成PBKDF2密钥

Question

我正在尝试使用AES192和基于PBKDF2密码/盐的密钥在C#中加密字节数组,并在NodeJS中解密相同的数据.然而,我的密钥生成在NodeJS和C#中产生不同的结果.

C#代码如下:

    private void getKeyAndIVFromPasswordAndSalt(string password, byte[] salt, SymmetricAlgorithm symmetricAlgorithm, ref byte[] key, ref byte[] iv)
    {
        Rfc2898DeriveBytes rfc2898DeriveBytes = new Rfc2898DeriveBytes(password, salt);
        key = rfc2898DeriveBytes.GetBytes(symmetricAlgorithm.KeySize / 8);
        iv = rfc2898DeriveBytes.GetBytes(symmetricAlgorithm.BlockSize / 8);
    }

    private byte[] encrypt(byte[] unencryptedBytes, string password, int keySize)
    {
        RijndaelManaged aesEncryption = new RijndaelManaged();
        aesEncryption.KeySize = keySize;
        aesEncryption.BlockSize = 128;
        byte[] key = new byte[keySize];
        byte[] iv = new byte[128];
        getKeyAndIVFromPasswordAndSalt(password, Encoding.ASCII.GetBytes("$391Ge3%£2gfR"), aesEncryption, ref key, ref iv);
        aesEncryption.Key = key;
        aesEncryption.IV = iv;
        Console.WriteLine("iv: {0}", Convert.ToBase64String(aesEncryption.IV));
        Console.WriteLine("key: {0}", Convert.ToBase64String(aesEncryption.Key));
        ICryptoTransform crypto = aesEncryption.CreateEncryptor();
        // The result of the encryption and decryption            
        return crypto.TransformFinalBlock(unencryptedBytes, 0, unencryptedBytes.Length);
    }

NodeJS代码如下所示:

    crypto.pbkdf2("Test", "$391Ge3%£2gfR", 1000, 192/8, (err, key) => {
        var binkey = new Buffer(key, 'ascii');
        var biniv = new Buffer("R6taODpFa1/A7WhTZVszvA==", 'base64');
        var decipher = crypto.createDecipheriv('aes192', binkey, biniv);
        console.log("KEY: " + binkey.toString("base64"));
        var decodedLIL = decipher.update(decryptedBuffer);
        console.log(decodedLIL);
        return;
    });

IV是硬编码的,因为我无法弄清楚如何使用pbkdf2来计算它.我查看了nodeJS文档以获得更多帮助,但我不知道这里发生了什么.

任何帮助将不胜感激.

Answer 1

我看到的一个问题是井号(£)的编码.crypto.pbkdf2默认情况下,将密码和salt编码为二进制数组,其中每个字符被截断为最低的8位(意味着井号变为字节0xA3).

但是,您的C#代码将salt转换为ASCII,其中每个字符被截断为最低的7位(意味着井号变为字节0x23).它还使用Rfc2898DeriveBytes构造函数,该构造函数将字符串作为密码.不幸的是,文档没有说明使用什么编码将字符串转换为字节.幸运的是,Rfc2898DeriveBytes确实有另一个构造函数,它接受一个字节数组作为密码,并且还带有一个迭代计数参数,这里是1000.

因此,您应该通过将每个字符截断为8位来将密码和salt字符串转换为字节数组,就像Node.js默认情况下那样.这是一个例子:

var bytes=new byte[password.Length];
for(var i=0;i<bytes.Length;i++){
  bytes[i]=(byte)(password[i]&0xFF);
}