C# Encrypt/Decrypt 来自 Java AES/CBC/PKCS5Padding

C# Encrypt/Decrypt from Java AES/CBC/PKCS5Padding

我在尝试解密已在 Java 中使用以下属性(Java 代码)

加密的字符串时遇到问题
public static Builder getDefaultBuilder(String key, String salt, byte[] iv) {
        return new Builder()
                .setIv(iv)
                .setKey(key)
                .setSalt(salt)
                .setKeyLength(128)
                .setKeyAlgorithm("AES")
                .setCharsetName("UTF8")
                .setIterationCount(1)
                .setDigestAlgorithm("SHA1")
                .setBase64Mode(Base64.DEFAULT)
                .setAlgorithm("AES/CBC/PKCS5Padding")
                .setSecureRandomAlgorithm("SHA1PRNG")
                .setSecretKeyType("PBKDF2WithHmacSHA1");
    }

到目前为止,这是我的代码 (C#)

public string DecryptText(string encryptedString)
    {
        using (myRijndael = new RijndaelManaged())
        {
            myRijndael.Key = Convert.FromBase64String(encryptionKey);
            myRijndael.IV = new byte[16];
            myRijndael.Mode = CipherMode.CBC;
            myRijndael.Padding = PaddingMode.PKCS7;

            Byte[] ourEnc = Convert.FromBase64String(encryptedString);
            string ourDec = DecryptStringFromBytes(ourEnc, myRijndael.Key, myRijndael.IV);

            return ourDec;
        }
    }

protected string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
    {
        // Check arguments. 
        if (cipherText == null || cipherText.Length <= 0)
            throw new ArgumentNullException("cipherText");
        if (Key == null || Key.Length <= 0)
            throw new ArgumentNullException("Key");
        if (IV == null || IV.Length <= 0)
            throw new ArgumentNullException("Key");

        // Declare the string used to hold 
        // the decrypted text. 
        string plaintext = null;

        // Create an RijndaelManaged object 
        // with the specified key and IV. 
        using (RijndaelManaged rijAlg = new RijndaelManaged())
        {
            rijAlg.Key = Key;
            rijAlg.IV = IV;

            // Create a decrytor to perform the stream transform.
            ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

            // Create the streams used for decryption. 
            using (MemoryStream msDecrypt = new MemoryStream(cipherText))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {

                        // Read the decrypted bytes from the decrypting stream 
                        // and place them in a string.
                        plaintext = srDecrypt.ReadToEnd();
                    }
                }
            }

        }

        return plaintext;

    }

但是当我尝试解密时出现以下异常“System.Security.Cryptography.CryptographicException: 'Specified key is not a valid size for this algorithm.' ".

Java 代码的来源在这里 https://github.com/simbiose/Encryption/blob/master/Encryption/main/se/simbio/encryption/Encryption.java

这是加密时的Java代码

public String encrypt(String data) throws UnsupportedEncodingException, NoSuchAlgorithmException, NoSuchPaddingException, InvalidAlgorithmParameterException, InvalidKeyException, InvalidKeySpecException, BadPaddingException, IllegalBlockSizeException {
    if (data == null) return null;
    SecretKey secretKey = getSecretKey(hashTheKey(mBuilder.getKey()));
    byte[] dataBytes = data.getBytes(mBuilder.getCharsetName());
    Cipher cipher = Cipher.getInstance(mBuilder.getAlgorithm());
    cipher.init(Cipher.ENCRYPT_MODE, secretKey, mBuilder.getIvParameterSpec(), mBuilder.getSecureRandom());
    return Base64.encodeToString(cipher.doFinal(dataBytes), mBuilder.getBase64Mode());
}

private SecretKey getSecretKey(char[] key) throws NoSuchAlgorithmException, UnsupportedEncodingException, InvalidKeySpecException {
    SecretKeyFactory factory = SecretKeyFactory.getInstance(mBuilder.getSecretKeyType());
    KeySpec spec = new PBEKeySpec(key, mBuilder.getSalt().getBytes(mBuilder.getCharsetName()), mBuilder.getIterationCount(), mBuilder.getKeyLength());
    SecretKey tmp = factory.generateSecret(spec);
    return new SecretKeySpec(tmp.getEncoded(), mBuilder.getKeyAlgorithm());
}


private char[] hashTheKey(String key) throws UnsupportedEncodingException, NoSuchAlgorithmException {
    MessageDigest messageDigest = MessageDigest.getInstance(mBuilder.getDigestAlgorithm());
    messageDigest.update(key.getBytes(mBuilder.getCharsetName()));
    return Base64.encodeToString(messageDigest.digest(), Base64.NO_PADDING).toCharArray();
}

我已经为这个问题苦苦挣扎了两天,因为我并没有真正使用加密,所以任何帮助将不胜感激。

谢谢!

更新: 整个class

public sealed class MyCryptoClass
{
    protected RijndaelManaged myRijndael;

    private static string encryptionKey = "random";

    // Singleton pattern used here with ensured thread safety
    protected static readonly MyCryptoClass _instance = new MyCryptoClass();
    public static MyCryptoClass Instance
    {
        get { return _instance; }
    }

    public MyCryptoClass()
    {

    }

    public string DecryptText(string encryptedString)
    {
        using (myRijndael = new RijndaelManaged())
        {
            myRijndael.Key = Convert.FromBase64String(encryptionKey);
            myRijndael.IV = new byte[16];
            myRijndael.Mode = CipherMode.CBC;
            myRijndael.Padding = PaddingMode.PKCS7;

            Byte[] ourEnc = Convert.FromBase64String(encryptedString);
            string ourDec = DecryptStringFromBytes(ourEnc, myRijndael.Key, myRijndael.IV);

            return ourDec;
        }
    }


    public string EncryptText(string plainText)
    {
        using (myRijndael = new RijndaelManaged())
        {

            myRijndael.Key = HexStringToByte(encryptionKey);
            myRijndael.IV = HexStringToByte(initialisationVector);
            myRijndael.Mode = CipherMode.CBC;
            myRijndael.Padding = PaddingMode.PKCS7;

            byte[] encrypted = EncryptStringToBytes(plainText, myRijndael.Key, myRijndael.IV);
            string encString = Convert.ToBase64String(encrypted);

            return encString;
        }
    }


    protected byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
    {
        // Check arguments. 
        if (plainText == null || plainText.Length <= 0)
            throw new ArgumentNullException("plainText");
        if (Key == null || Key.Length <= 0)
            throw new ArgumentNullException("Key");
        if (IV == null || IV.Length <= 0)
            throw new ArgumentNullException("Key");
        byte[] encrypted;
        // Create an RijndaelManaged object 
        // with the specified key and IV. 
        using (RijndaelManaged rijAlg = new RijndaelManaged())
        {
            rijAlg.Key = Key;
            rijAlg.IV = IV;

            // Create a decrytor to perform the stream transform.
            ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

            // Create the streams used for encryption. 
            using (MemoryStream msEncrypt = new MemoryStream())
            {
                using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                {
                    using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                    {

                        //Write all data to the stream.
                        swEncrypt.Write(plainText);
                    }
                    encrypted = msEncrypt.ToArray();
                }
            }
        }


        // Return the encrypted bytes from the memory stream. 
        return encrypted;

    }

    protected string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
    {
        // Check arguments. 
        if (cipherText == null || cipherText.Length <= 0)
            throw new ArgumentNullException("cipherText");
        if (Key == null || Key.Length <= 0)
            throw new ArgumentNullException("Key");
        if (IV == null || IV.Length <= 0)
            throw new ArgumentNullException("Key");

        // Declare the string used to hold 
        // the decrypted text. 
        string plaintext = null;

        // Create an RijndaelManaged object 
        // with the specified key and IV. 
        using (RijndaelManaged rijAlg = new RijndaelManaged())
        {
            rijAlg.Key = Key;
            rijAlg.IV = IV;

            // Create a decrytor to perform the stream transform.
            ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

            // Create the streams used for decryption. 
            using (MemoryStream msDecrypt = new MemoryStream(cipherText))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {

                        // Read the decrypted bytes from the decrypting stream 
                        // and place them in a string.
                        plaintext = srDecrypt.ReadToEnd();
                    }
                }
            }

        }

        return plaintext;

    }

    public static void GenerateKeyAndIV()
    {
        // This code is only here for an example
        RijndaelManaged myRijndaelManaged = new RijndaelManaged();
        myRijndaelManaged.Mode = CipherMode.CBC;
        myRijndaelManaged.Padding = PaddingMode.PKCS7;

        myRijndaelManaged.GenerateIV();
        myRijndaelManaged.GenerateKey();
        string newKey = ByteArrayToHexString(myRijndaelManaged.Key);
        string newinitVector = ByteArrayToHexString(myRijndaelManaged.IV);
    }

    protected static byte[] HexStringToByte(string hexString)
    {
        try
        {
            int bytesCount = (hexString.Length) / 2;
            byte[] bytes = new byte[bytesCount];
            for (int x = 0; x < bytesCount; ++x)
            {
                bytes[x] = Convert.ToByte(hexString.Substring(x * 2, 2), 16);
            }
            return bytes;
        }
        catch
        {
            throw;
        }
    }

    public static string ByteArrayToHexString(byte[] ba)
    {
        StringBuilder hex = new StringBuilder(ba.Length * 2);
        foreach (byte b in ba)
            hex.AppendFormat("{0:x2}", b);
        return hex.ToString();
    }
}
  • 因为你的 MyCryptoClass.encryptionKey 对应于你的 Encryption.Builder.mKey 你必须在 C# 端生成密钥,即你必须在 C# 端为每个Java-这个过程涉及的方法。这些 Java 方法是 getSecretKey(char[] key)hashTheKey(String key) 以及 third.part.android.util.Base64.encodeToString(byte[] input, int flags).

  • Java-方法 getSecretKey(char[] key) 的可能 C# 对应物:

    private static byte[] GetSecretKey()
    {
         string hashedKey = GetHashedKey();
         byte[] saltBytes = Encoding.UTF8.GetBytes(salt);                                                // builder.mCharsetName = "UTF8";
         int iterations = 1;                                                                             // builder.mIterationCount = 1
         byte[] secretKey = null;
         using (Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(hashedKey, saltBytes, iterations))   // builder.mSecretKeyType = "PBKDF2WithHmacSHA1";
         {
              secretKey = rfc2898.GetBytes(16);                                                          // builder.mKeyLength = 128;
              //Console.WriteLine("Key: " + ByteArrayToHexString(secretKey));
         }
         return secretKey;
     }
    

    此方法使用 PBKDF2WithHmacSHA1 以密钥、salt、迭代计数和密钥长度作为输入来导出密钥。此处使用的密钥(更准确地说是密码)是由 GetHashedKey()(见下文)提供的 MyCryptoClass.encryptionKey 的 base64 编码的 SHA1 哈希。

  • 可能的 C#-Java-方法的对应部分 hashTheKey(String key):

    private static string GetHashedKey()
    {
         string hashBase64 = String.Empty;
         using (SHA1Managed sha1 = new SHA1Managed())                                  // builder.mDigestAlgorithm = "SHA1";
         {
              byte[] hash = sha1.ComputeHash(Encoding.UTF8.GetBytes(encryptionKey));   // builder.mCharsetName = "UTF8";
              hashBase64 = Base64ThirdPartAndroid(hash, true);
              //Console.WriteLine("Hash (base64): " + hashBase64);
         }
         return hashBase64;
     }
    

    此方法从 MyCryptoClass.encryptionKey 派生出 SHA1 散列,并对该散列进行 base64 编码。对于 base64 编码,使用方法 Base64ThirdPartAndroid(byte[] arr, bool withoutPadding)(见下文)。

  • Java-方法third.part.android.util.Base64.encodeToString(byte[] input, int flags)https://github.com/simbiose/Encryption/blob/master/Encryption/main/third/part/android/util/Base64.java)可能的 C# 对应物:

    private static string Base64ThirdPartAndroid(byte[] arr, bool withoutPadding)
    {
         string base64String = System.Convert.ToBase64String(arr);
         if (withoutPadding) base64String = base64String.TrimEnd('='); // Remove trailing "="-characters
         base64String += "\n";                                         // Append LF (10)
         //Console.WriteLine("Array as base64 encoded string: " + base64String);
         return base64String;
    }
    

    在 Java 代码中,third.part.android.util.Base64.encodeToString(byte[] input, int flags)flags = Base64.NO_PADDING 一起使用,删除了 base64 编码字符串末尾的“=”字符。此外,还会附加一个换行符(LF,\n,ASCII 值:10)。如果使用不删除“=”字符或没有终止换行符的 Base64 编码,解密将失败,因为哈希是后来生成的密钥的基础,必须在加密和解密方。据我所知,C# 端没有具有必要特征的 Base64 编码。但是,如果有这样的编码,您当然可以使用它。

  • 将所有三个 C# 对应项添加到您的 MyCryptoClass class

  • 此外(对静态字段 encryptionKey)将静态字段 initialisationVectorsaltsecretKey 添加到您的 MyCryptoClass -class 并分配以下值用于测试目的:

    private static string encryptionKey = "A7zb534OPq59gU7q";
    private static string salt = "JV5k9GoH";
    private static byte[] initialisationVector = Encoding.UTF8.GetBytes("l4iG63jN9Dcg6537");
    private static byte[] secretKey = GetSecretKey();
    

    参数的类型对应Java代码中的类型(encryptionKeysalt是字符串,initialisationVector是字节数组)。 GetSecretKey() 生成的密钥存储在字节数组 secretKey.

  • 在您的 C# DecryptText- 和 EncryptText 方法中将 myRijndael.KeymyRijndael.IV 设置为

    myRijndael.Key = secretKey;
    myRijndael.IV = initialisationVector;
    
  • 测试修改如下:

    • 用你的Java encrypt-方法加密以下纯文本:

      Test: The quick brown fox jumps over the lazy dog... 
      

      将上面的 key/salt/iv 与

      结合使用
      mBuilder = Builder.getDefaultBuilder("A7zb534OPq59gU7q","JV5k9GoH","l4iG63jN9Dcg6537".getBytes("UTF-8"));
      
    • 密文为:

      mL4ajZtdRgD8CtGSfJGkT24Ebw4SrGUGKQI6bvBw1ziCO/J7SeLiyIw41zumTHMMD9GOYK+kR79CVcpoaHT9TQ==
      
    • 使用 C# DecryptText 方法对其进行解密再次给出纯文本。下面是两个测试用例:

      static void Main(string[] args)
      {
           // Test 1: Encrypted text from C#
           MyCryptoClass mcc = MyCryptoClass.Instance;
           string encryptedText = mcc.EncryptText("This is a plain text which needs to be encrypted...");
           Console.WriteLine("Encrypted text (base64): " + encryptedText);
           string decryptedText = mcc.DecryptText(encryptedText);
           Console.WriteLine("Decrypted text: " + decryptedText);
      
           // Test 2: Encrypted text from Java
           string javaEncryptedText = "mL4ajZtdRgD8CtGSfJGkT24Ebw4SrGUGKQI6bvBw1ziCO/J7SeLiyIw41zumTHMMD9GOYK+kR79CVcpoaHT9TQ==";
           Console.WriteLine("Encrypted text from Java (base64): " + javaEncryptedText);
           string javaDecryptedText = mcc.DecryptText(javaEncryptedText);
           Console.WriteLine("Decrypted text from Java: " + javaDecryptedText);
      }
      

以下是完整的 C# class,我可以像这样工作 java class 目前我只检查了加密部分

 public sealed class MyCryptoClass
    {
        protected AesManaged myRijndael;

        private static string encryptionKey = "MyKey";
        private static string salt = "Mysalt";
        private static byte[] initialisationVector = new byte[16];
        //private static byte[] initialisationVector = Encoding.UTF8.GetBytes("l4iG63jN9Dcg6537");
        private static byte[] secretKey = GetSecretKey();


        // Singleton pattern used here with ensured thread safety
        protected static readonly MyCryptoClass _instance = new MyCryptoClass();
        public static MyCryptoClass Instance
        {
            get { return _instance; }
        }

        public MyCryptoClass()
        {

        }
        public string DecryptText(string encryptedString)
        {
            using (myRijndael = new AesManaged())
            {
                myRijndael.Key = Convert.FromBase64String(encryptionKey);
                myRijndael.IV = new byte[16];
                myRijndael.Mode = CipherMode.CBC;
                myRijndael.Padding = PaddingMode.PKCS7;

                Byte[] ourEnc = Convert.FromBase64String(encryptedString);
                string ourDec = DecryptStringFromBytes(ourEnc, myRijndael.Key, myRijndael.IV);

                return ourDec;
            }
        }
        public string EncryptText(string plainText)
        {
            using (myRijndael = new AesManaged())
            {

                myRijndael.Key = secretKey;
                myRijndael.IV = initialisationVector;
                myRijndael.Mode = CipherMode.CBC;
                myRijndael.Padding = PaddingMode.PKCS7;

                byte[] encrypted = EncryptStringToBytes(plainText, myRijndael.Key, myRijndael.IV);
                string encString = Convert.ToBase64String(encrypted);

                return encString;
            }
        }
        protected byte[] EncryptStringToBytes(string plainText, byte[] Key, byte[] IV)
        {
            // Check arguments. 
            if (plainText == null || plainText.Length <= 0)
                throw new ArgumentNullException("plainText");
            if (Key == null || Key.Length <= 0)
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= 0)
                throw new ArgumentNullException("Key");
            byte[] encrypted;
            // Create an RijndaelManaged object 
            // with the specified key and IV. 
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;

                // Create a decrytor to perform the stream transform.
                ICryptoTransform encryptor = rijAlg.CreateEncryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for encryption. 
                using (MemoryStream msEncrypt = new MemoryStream())
                {
                    using (CryptoStream csEncrypt = new CryptoStream(msEncrypt, encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter swEncrypt = new StreamWriter(csEncrypt))
                        {

                            //Write all data to the stream.
                            swEncrypt.Write(plainText);
                        }
                        encrypted = msEncrypt.ToArray();
                    }
                }
            }
            // Return the encrypted bytes from the memory stream. 
            return encrypted;

        }
        protected string DecryptStringFromBytes(byte[] cipherText, byte[] Key, byte[] IV)
        {
            // Check arguments. 
            if (cipherText == null || cipherText.Length <= 0)
                throw new ArgumentNullException("cipherText");
            if (Key == null || Key.Length <= 0)
                throw new ArgumentNullException("Key");
            if (IV == null || IV.Length <= 0)
                throw new ArgumentNullException("Key");

            // Declare the string used to hold 
            // the decrypted text. 
            string plaintext = null;

            // Create an RijndaelManaged object 
            // with the specified key and IV. 
            using (RijndaelManaged rijAlg = new RijndaelManaged())
            {
                rijAlg.Key = Key;
                rijAlg.IV = IV;

                // Create a decrytor to perform the stream transform.
                ICryptoTransform decryptor = rijAlg.CreateDecryptor(rijAlg.Key, rijAlg.IV);

                // Create the streams used for decryption. 
                using (MemoryStream msDecrypt = new MemoryStream(cipherText))
                {
                    using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                        {

                            // Read the decrypted bytes from the decrypting stream 
                            // and place them in a string.
                            plaintext = srDecrypt.ReadToEnd();
                        }
                    }
                }
            }
            return plaintext;
        }

        public static void GenerateKeyAndIV()
        {
            // This code is only here for an example
            AesManaged myRijndaelManaged = new AesManaged();
            myRijndaelManaged.Mode = CipherMode.CBC;
            myRijndaelManaged.Padding = PaddingMode.PKCS7;

            myRijndaelManaged.GenerateIV();
            myRijndaelManaged.GenerateKey();
            string newKey = ByteArrayToHexString(myRijndaelManaged.Key);
            string newinitVector = ByteArrayToHexString(myRijndaelManaged.IV);
        }

        protected static byte[] HexStringToByte(string hexString)
        {
            try
            {
                int bytesCount = (hexString.Length) / 2;
                byte[] bytes = new byte[bytesCount];
                for (int x = 0; x < bytesCount; ++x)
                {
                    bytes[x] = Convert.ToByte(hexString.Substring(x * 2, 2), 16);
                }
                return bytes;
            }
            catch
            {
                throw;
            }
        }

        public static string ByteArrayToHexString(byte[] ba)
        {
            StringBuilder hex = new StringBuilder(ba.Length * 2);
            foreach (byte b in ba)
                hex.AppendFormat("{0:x2}", b);
            return hex.ToString();
        }

        private static byte[] GetSecretKey()
        {
            string hashedKey = GetHashedKey();
            byte[] saltBytes = Encoding.UTF8.GetBytes(salt); // builder.mCharsetName = "UTF8";
            int iterations = 1; // builder.mIterationCount = 1
            byte[] secretKey = null;
            using (Rfc2898DeriveBytes rfc2898 = new Rfc2898DeriveBytes(hashedKey, saltBytes, iterations)) // builder.mSecretKeyType = "PBKDF2WithHmacSHA1";
            {
                secretKey = rfc2898.GetBytes(16); // builder.mKeyLength = 128;
                //Console.WriteLine("Key: " + ByteArrayToHexString(secretKey));
            }
            return secretKey;
        }

        private static string GetHashedKey()
        {
            string hashBase64 = String.Empty;
            using (SHA1Managed sha1 = new SHA1Managed()) // builder.mDigestAlgorithm = "SHA1";
            {
                byte[] hash = sha1.ComputeHash(Encoding.UTF8.GetBytes(encryptionKey)); // builder.mCharsetName = "UTF8";

                hashBase64 = Base64ThirdPartAndroid(hash, true);
                //hashBase64 = Base64ThirdPartAndroid(hash, true);
                //Console.WriteLine("Hash (base64): " + hashBase64);
            }
            return hashBase64;
        }

        private static string Base64ThirdPartAndroid(byte[] arr, bool withoutPadding)
        {
            string base64String = System.Convert.ToBase64String(arr);
            if (withoutPadding) base64String = base64String.TrimEnd('='); // Remove trailing "="-characters
            base64String += "\n"; // Append LF (10)
            //Console.WriteLine("Array as base64 encoded string: " + base64String);
            return base64String;
        }
    }

此方法 100% 用于加密

public static string AESDecrypt(string text, string secretKey)
        {
            try
            {
                SHA1 sha = new SHA1CryptoServiceProvider();
                RijndaelManaged aes = new RijndaelManaged();

                byte[] finalKey = new byte[16]; // Used to generate finalKey
                byte[] byteDataToDecrypt = Convert.FromBase64String(text); // Converting Base64 data to Byte Array
                byte[] byteSecretKey = Encoding.UTF8.GetBytes(secretKey); // Converting secret key in byte array
                byte[] hashSecretKey = sha.ComputeHash(byteSecretKey); // geneating hash in byte array of secret key

                Array.Copy(hashSecretKey, finalKey, 16); // copying fist 16 bytes from hashed secret key to finaly key which to use in algo

                aes.KeySize = 128;
                aes.Padding = PaddingMode.PKCS7;
                aes.Mode = CipherMode.ECB;
                aes.Key = finalKey;

                using (ICryptoTransform decrypt = aes.CreateDecryptor(aes.Key, null)) //Passing IV as NULL because IV is not present in the Java Code
                {
                    byte[] dest = decrypt.TransformFinalBlock(byteDataToDecrypt, 0, byteDataToDecrypt.Length);
                    decrypt.Dispose();
                    return Encoding.UTF8.GetString(dest);
                }
            }
            catch (Exception ex)
            {

                throw ex;
            }

        }