We need to include aes.js and pbkdf2.js javascript files to use this code. These files can be downloaded from code.google.com/p/crypto-js
function EncryptData()
{
var PlainText = document.getElementById('TextOriginal').value;
var encryptData = document.getElementById('TextEncryptedJS');
try {
//Creating the Vector Key
var iv = CryptoJS.enc.Hex.parse('a5s8d2e9c1721ae0e84ad660c472y1f3');
//Encoding the Password in from UTF8 to byte array
var Pass = CryptoJS.enc.Utf8.parse('Crypto');
//Encoding the Salt in from UTF8 to byte array
var Salt = CryptoJS.enc.Utf8.parse("cryptography123example");
//Creating the key in PBKDF2 format to be used during the encryption
var key128Bits1000Iterations = CryptoJS.PBKDF2(Pass.toString(CryptoJS.enc.Utf8), Salt, { keySize: 128 / 32, iterations: 1000 });
//Encrypting the string contained in cipherParams using the PBKDF2 key
var encrypted = CryptoJS.AES.encrypt(PlainText, key128Bits1000Iterations, { mode: CryptoJS.mode.CBC, iv: iv, padding: CryptoJS.pad.Pkcs7 });
encryptData.value = encrypted.ciphertext.toString(CryptoJS.enc.Base64);
}
//Malformed UTF Data due to incorrect password
catch (err) {
return "";
}
}
To Decrypt this string in C# we need to add a class file named “ClsCrypto.cs”. Here is the code for ClsCrypto class :
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("a5s8d2e9c1721ae0e84ad660c472y1f3");
myRijndael.Padding = PaddingMode.PKCS7;
myRijndael.Mode = CipherMode.CBC;
iterations = 1000;
salt = System.Text.Encoding.UTF8.GetBytes("cryptography123example");
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)
{
var encryptedBytes = Convert.FromBase64String(encryptedText);
ICryptoTransform transform = myRijndael.CreateDecryptor();
byte[] cipherText = transform.TransformFinalBlock(encryptedBytes, 0, encryptedBytes.Length);
return System.Text.Encoding.UTF8.GetString(cipherText);
}
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);
}
}
In ClsCrypto method we have a parameter for “strPassword”, it must be the same as we have in javascript code.
ClsCrypto crypto = new ClsCrypto("Crypto");
string DecrypedString = crypto.Decrypt("Encrypted Text");
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