CODEWITHSUNDEEP
c#.netaesrijndaelrijndaelmanaged
Adam Ivancza
Adam Ivancza

Reputation: 2529

How is it possible that Rijndael returns different result from string and byte[]?

Here is my code, first with string:

byte[] concatBytes = Encoding.ASCII.GetBytes(key);
byte[] keyBytes = Encoding.ASCII.GetBytes(key);
for (int i = 0; i < 3; i++)
{
         concatBytes = Encrypt(Encoding.ASCII.GetString(concatBytes), keyBytes);
         //Console.WriteLine(Transform.Hexa(concatBytes));
} 

public byte[] Encrypt(string plainText, byte[] key)
    {
        byte[] encrypted;
        using (var rijndael = new RijndaelManaged())
        {
            rijndael.Mode = CipherMode.ECB;
            rijndael.KeySize = 128;
            rijndael.BlockSize = 128;
            rijndael.Padding = PaddingMode.Zeros;
            rijndael.Key = key;
            //rijndael.IV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

            ICryptoTransform transform = rijndael.CreateEncryptor(rijndael.Key, rijndael.IV);

            using (var memoryStream = new MemoryStream())
            {
                using (var cryptoStream = new CryptoStream(memoryStream, transform, CryptoStreamMode.Write))
                {
                    using (var streamWriter = new StreamWriter(cryptoStream))
                    {
                        streamWriter.Write(plainText);
                    }
                    encrypted = memoryStream.ToArray();
                }
            }
        }
        return encrypted;
    }

If i change my method parameter plainText to byte[] than my results are completely different. What am i missing here? Also, we have different results using OpenSSL and Rijndael AES encryption. Any suggestions how i could fix this?

Upvotes: 0

Views: 556

Answers (1)

Damien_The_Unbeliever
Damien_The_Unbeliever

Reputation: 239714

StreamWriter(Stream):

Initializes a new instance of the StreamWriter class for the specified stream by using UTF-8 encoding and the default buffer size.

Since you're using a different encoding (UTF-8 rather than ASCII), it's not surprising that you get different results.

Upvotes: 1

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