Question

Took the vectors from this site http://www.inconteam.com/software-development/41-encryption/55-aes-test-vectors#aes-ecb-128

In javascript (sjcl) have the same result

var key = [0x2b7e1516,0x28aed2a6,0xabf71588,0x09cf4f3c];
var test  = [0x6bc1bee2,0x2e409f96,0xe93d7e11,0x7393172a];
aes = new sjcl.cipher.aes(key);
r = aes.encrypt(test);
console.log(r);

But I can not reach it in the C#

    [TestMethod]
    public void EncryptIntsToInts()
    {
        Int32[] key = { unchecked((Int32)0x2b7e1516), 0x28aed2a6, unchecked((Int32)0xabf71588), 0x09cf4f3c };
        Int32[] test = { 0x6bc1bee2,0x2e409f96,unchecked((Int32)0xe93d7e11),0x7393172a };
        Int32[] answer = { 0x3ad77bb4, 0x0d7a3660, unchecked((Int32)0xa89ecaf3), 0x2466ef97 };

        var r = AES.EncryptIntsToInts(test, key.ToByteArray());

        Assert.IsTrue(r.SequenceEqual(answer));
    }


    static byte[] zeroIV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

    public static Int32[] EncryptIntsToInts(Int32[] input, byte[] key)
    {
        // Check arguments.
        if (input == null || input.Length <= 0)
            throw new ArgumentNullException("input");
        if (key == null || key.Length <= 0)
            throw new ArgumentNullException("key");

        // Declare the RijndaelManaged object
        // used to encrypt the data.
        RijndaelManaged aesAlg = null;
        byte[] bResult;
        try
        {
            aesAlg = new RijndaelManaged
                         {
                             Key = key,
                             Mode = CipherMode.ECB,
                             Padding = PaddingMode.None,
                             KeySize = 128,
                             BlockSize = 128,
                             IV = zeroIV
                         };
            ICryptoTransform encryptor = aesAlg.CreateEncryptor();

            byte[] bInput = new byte[input.Length * sizeof(int)];
            Buffer.BlockCopy(input, 0, bInput, 0, bInput.Length);

            bResult = encryptor.TransformFinalBlock(bInput, 0, input.Length);
        }
        finally
        {
            if (aesAlg != null)
                aesAlg.Clear();
        }

        int[] iResult = new int[bResult.Length / sizeof(int)];
        Buffer.BlockCopy(bResult, 0, iResult, 0, bResult.Length);
        return iResult;
    }

What is my error?

========================================================

Start edit

New code in which right order of the bytes, but it does not work

    [TestMethod]
    public void EncryptIntsToInts()
    {
        byte[] key =     "2b7e151628aed2a6abf7158809cf4f3c".HEX2Bytes();
        byte[] test =    "6bc1bee22e409f96e93d7e117393172a".HEX2Bytes();
        byte[] answer =  "3ad77bb40d7a3660a89ecaf32466ef97".HEX2Bytes();

        RijndaelManaged aesAlg = new RijndaelManaged
        {
            Key = key,
            Mode = CipherMode.ECB,
            Padding = PaddingMode.PKCS7,
            KeySize = 128,
            BlockSize = 128,
            IV = zeroIV
        };
        ICryptoTransform encryptor = aesAlg.CreateEncryptor();

        var r = encryptor.TransformFinalBlock(test, 0, test.Length);

        Assert.IsTrue(r.SequenceEqual(answer));
    }

    public static byte[] HEX2Bytes(this string hex)
    {
        if (hex.Length%2 != 0)
        {
            throw new ArgumentException(String.Format(CultureInfo.InvariantCulture,
                                                      "The binary key cannot have an odd number of digits: {0}", hex));
        }

        byte[] HexAsBytes = new byte[hex.Length/2];
        for (int index = 0; index < HexAsBytes.Length; index++)
        {
            string byteValue = hex.Substring(index*2, 2);
            HexAsBytes[index] = byte.Parse(byteValue, NumberStyles.HexNumber, CultureInfo.InvariantCulture);
        }

        return HexAsBytes;
    }

    static byte[] zeroIV = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0 };

Answer 1

You use 32 bit integers to define the key. When you transform them to bytes, you use native endianness, which typically is little endian. So your key is 16157e2b a6... and not 2b7e1516 28....

I wouldn’t use ints to represent a key in the first place. But if you really want to, write a big endian conversion function.

I also strongly recommend against ECB mode. You could use CBC together with HMAC (in an encrypt then mac construction), or use a third party lib to implement GCM.