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AES Encryption in C# and decryption in CryptoJS

I would like to do AES Encryption in C# and decryption in CryptoJS.

like image 549
Pabitra Dash Avatar asked Sep 30 '13 12:09

Pabitra Dash


1 Answers

It is working now after getting some reference from Google CryptoJS group (https://groups.google.com/forum/#!msg/crypto-js/ysgzr2Wxt_k/_Wh8l_1rhQAJ).

Here is encryption code in C#.NET.

public class ClsCrypto
{
    private RijndaelManaged myRijndael = new RijndaelManaged();
    private int iterations;
    private byte [] salt;

    public ClsCrypto(string strPassword)
    {
        myRijndael.BlockSize = 128;
        myRijndael.KeySize = 128;
        myRijndael.IV = HexStringToByteArray("e84ad660c4721ae0e84ad660c4721ae0");

        myRijndael.Padding = PaddingMode.PKCS7;
        myRijndael.Mode = CipherMode.CBC;
        iterations = 1000;
        salt = System.Text.Encoding.UTF8.GetBytes("insight123resultxyz");
        myRijndael.Key = GenerateKey(strPassword);
    }

    public string Encrypt(string strPlainText)
    {
        byte [] strText = new System.Text.UTF8Encoding().GetBytes(strPlainText);
        ICryptoTransform transform = myRijndael.CreateEncryptor();
        byte [] cipherText = transform.TransformFinalBlock(strText, 0, strText.Length);

        return Convert.ToBase64String(cipherText);
    }

    public string Decrypt(string encryptedText)
    {
       byte[] encryptedBytes = Convert.FromBase64String(encryptedText);
       var decryptor = myRijndael.CreateDecryptor(myRijndael.Key, myRijndael.IV);
       byte[] originalBytes = decryptor.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length);

       return Encoding.UTF8.GetString(originalBytes);
    }

    public static byte [] HexStringToByteArray(string strHex)
    {
        dynamic r = new byte[strHex.Length / 2];
        for (int i = 0; i <= strHex.Length - 1; i += 2)
        {
            r[i/2] = Convert.ToByte(Convert.ToInt32(strHex.Substring(i, 2), 16));
        }
        return r;
    }

    private byte[] GenerateKey(string strPassword)
    {
        Rfc2898DeriveBytes rfc2898 = new          Rfc2898DeriveBytes(System.Text.Encoding.UTF8.GetBytes(strPassword), salt, iterations);

        return rfc2898.GetBytes(128 / 8);
    }
}

Following is decryption code in Java script.

<head runat="server">
        <script src="rollups/aes.js" type="text/javascript"></script>
        <script src="rollups/sha256.js" type="text/javascript"></script>
        <script src="rollups/pbkdf2.js" type="text/javascript"></script>
        <script type="text/javascript">
          function DecryptData() {
            var encryptData = document.getElementById('TextEncrypted').value;
            var decryptElement = document.getElementById('TextDecrypt');
    
            try {
                //Creating the Vector Key
                var iv = CryptoJS.enc.Hex.parse('e84ad660c4721ae0e84ad660c4721ae0');
                //Encoding the Password in from UTF8 to byte array
                var Pass = CryptoJS.enc.Utf8.parse('insightresult');
                //Encoding the Salt in from UTF8 to byte array
                var Salt = CryptoJS.enc.Utf8.parse("insight123resultxyz");
                //Creating the key in PBKDF2 format to be used during the decryption
                var key128Bits1000Iterations = CryptoJS.PBKDF2(Pass.toString(CryptoJS.enc.Utf8), Salt, { keySize: 128 / 32, iterations: 1000 });
                //Enclosing the test to be decrypted in a CipherParams object as supported by the CryptoJS libarary
                var cipherParams = CryptoJS.lib.CipherParams.create({
                    ciphertext: CryptoJS.enc.Base64.parse(encryptData)
                });
    
                //Decrypting the string contained in cipherParams using the PBKDF2 key
                var decrypted = CryptoJS.AES.decrypt(cipherParams, key128Bits1000Iterations, { mode: CryptoJS.mode.CBC, iv: iv, padding: CryptoJS.pad.Pkcs7 });
                decryptElement.value = decrypted.toString(CryptoJS.enc.Utf8);
            }
            //Malformed UTF Data due to incorrect password
            catch (err) {
                return "";
            }
        }
    </script>
</head>
like image 116
Pabitra Dash Avatar answered Sep 16 '22 16:09

Pabitra Dash