Question

I have test input string (key=value&key=value…) and key (like this D2335A9CA4924D9F914D2B47B450D436)
I need to Encrypt my string using AES encryption but my result is not equal to provider’s result. Result example :
AD0C66FB3C1204A8B0AC68AA9B9E3029C86DFF5872753F2F8D7B68EA667D8616215C20F831ABD5A4D56F286E471651AE5C15BCEB2F368200B4D9F3F6D2F0791E8F45D45FD ………………..
What I’m doing wrong? (googlized code)

public static string Encrypt(string toEncrypt)
        {
            byte[] keyArray = ASCIIEncoding.ASCII.GetBytes("D2335A9CA4924D9F914D2B47B450D436");
            byte[] toEncryptArray = ASCIIEncoding.ASCII.GetBytes(toEncrypt);
            RijndaelManaged rDel = new RijndaelManaged();
            rDel.Key = keyArray;
            rDel.KeySize = 128;
            rDel.BlockSize = 256;
            rDel.IV = keyArray;
            rDel.Mode = CipherMode.CFB; 
            rDel.Padding = PaddingMode.PKCS7; 
            ICryptoTransform cTransform = rDel.CreateEncryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(toEncryptArray, 0, toEncryptArray.Length);
            return FormatByteArray(resultArray);
        }

        internal static string FormatByteArray(byte[] b)
        {
            System.Text.StringBuilder sb1 = new System.Text.StringBuilder();
            int i = 0;
            for (i = 0; i < b.Length; i++)
            {
                if (i != 0 && i % 16 == 0)
                    sb1.Append("\n");
                sb1.Append(System.String.Format("{0:X2} ", b[i]));
            }
            return sb1.ToString();
        }

Answer 1

What I’m doing wrong?

byte[] keyArray = ASCIIEncoding.ASCII.GetBytes("D2335A9CA4924D9F914D2B47B450D436");

This can’t be right. It’ll give you 64 bytes, half of them 0x00.

It looks like it’s Hex encoded, I think you’ll need a little loop to decode it.
That would give you 16 bytes (128 bits).

---

Old answer:

You need to decode this string, it probably is Base64 encoded. Try:

byte[] keyArray = System.Convert.FromBase64String("D2335A9CA4924D9F914D2B47B450D436")

And check if you have a valid (length) key.