public static KeyIV GetEncryptedKeyAndIV()
{
KeyIV keySalt;
var password = "******";
var salt = "S@lt";
var rgb = new Rfc2898DeriveBytes(password, Encoding.Unicode.GetBytes(salt));
aesAlgorithm.Padding = PaddingMode.None;
var rgbKey = rgb.GetBytes(aesAlgorithm.KeySize / 8);
var rgbIV = rgb.GetBytes(aesAlgorithm.BlockSize / 8);
//Encrypt the key and IV
using (var rsaProvider = new RSACryptoServiceProvider())
{
var setOaemPadding = true;
keys = rsaProvider.ExportCspBlob(true);
keySalt = new KeyIV(rsaProvider.Encrypt(rgbKey, setOaemPadding), rsaProvider.Encrypt(rgbIV, setOaemPadding));
}
return(keySalt);
}
/**
* Genrates an AES key and IV
*
*/
public KeyIV MakeKey(int KeySize, int BlockSize)
{
RijndaelManaged aesEncryption = new RijndaelManaged
{
KeySize = KeySize,
BlockSize = BlockSize,
Mode = CipherMode.CBC,
Padding = PaddingMode.PKCS7
};
aesEncryption.GenerateIV();
aesEncryption.GenerateKey();
KeyIV keyIv = new KeyIV
{
Key = aesEncryption.Key,
IV = aesEncryption.IV
};
return(keyIv);
}
/// <summary>
/// Creates a packet and set its ID
/// </summary>
/// <param name="PacketId"></param>
public PacketStream(ushort PacketId)
{
keyIV = Encryption.GenerateKeyIV();
int keyLen = keyIV.Key.Length;
int ivLen = keyIV.IV.Length;
this.inner = new MemoryStream();
// Write Blank space to have packet size assigned to later
this.inner.Write(new byte[4], 0, 4);
// Write the packetId
this.inner.Write(BitConverter.GetBytes(PacketId), 0, 2);
Random rand = new Random();
// Packet Header Structure
// (int) Packet Size
// (short) Packet ID
// (short) KeyIV Key Length
// (byte) Confusion Data
// (byte) Confusion Data
// (byte[]) KeyIV Key
// (short) Confusion Data
// (short) KeyIV IV Length
// (byte[]) KeyIV Iv
// Write the keyIV
this.inner.Write(BitConverter.GetBytes((short)keyLen), 0, 2);
this.inner.Write(BitConverter.GetBytes((byte)rand.Next(1, 255)), 0, 1);
this.inner.Write(BitConverter.GetBytes((byte)rand.Next(1, 255)), 0, 1);
this.inner.Write(keyIV.Key, 0, keyLen);
this.inner.Write(BitConverter.GetBytes((short)rand.Next(1, 32767)), 0, 2);
this.inner.Write(BitConverter.GetBytes((short)ivLen), 0, 2);
this.inner.Write(keyIV.IV, 0, ivLen);
}
/**
* Sets an AES key and IV.
*
*/
private void setKeyIV()
{
KeyGenerator keyGenerator = new KeyGenerator();
_keyIv = keyGenerator.MakeKey(_keySize, _blockSize);
}
/// <summary>
/// Receives data and split them into packets
/// </summary>
/// <param name="ar"></param>
private void ReadCallback(IAsyncResult ar)
{
KeyIV keyIV = new KeyIV();
Connection client = (Connection)ar.AsyncState;
if (client.Socket.Connected)
{
try
{
int totalBytes = client.Socket.EndReceive(ar);
// If the stream actually has bytes in it
if (totalBytes > 0)
{
int curOffset = 0;
int bytesToRead = 0;
int headerLen = 0;
// If the packet size hasn't been defined in the client yet
if (client.PacketSize == 0)
{
// Read the encrypted header length
headerLen = BitConverter.ToInt32(client.Buffer.Take(4).ToArray(), 0);
// Read the encrypted header
byte[] encHeader = client.Buffer.Skip(4).Take(headerLen).ToArray();
// Generate a new dateTime key for encrypting the packet header
string dtKey = DateTime.UtcNow.ToString("yyyyMMddHH");
rc4Cipher = new XRC4Cipher(dtKey);
// Decode the header using the dtKey + rc4Cipher
byte[] decodedHeader = rc4Cipher.DoCipher(ref encHeader, encHeader.Length);
headerLen = decodedHeader.Length;
// Write decoded header info to client.Data
client.Data.Write(decodedHeader, curOffset, decodedHeader.Length);
// If there is more than just the header info in this stream
if (client.Offset + totalBytes > 4 + encHeader.Length)
{
// Define the packetSize by reading the size bytes from the client.Data buffer
client.PacketSize = BitConverter.ToInt32(client.Data.ReadBytes(4, 0, true), 0);
// TODO: Read my from client.Data?
// Define the keyIV used for decoding the encrypted data
int keyLen = client.Data.ReadInt16(6, true);
keyIV.Key = client.Data.ReadBytes(keyLen, 10, true);
int ivLen = client.Data.ReadInt16(12 + keyIV.Key.Length, true);
keyIV.IV = client.Data.ReadBytes(ivLen, 14 + keyIV.Key.Length, true);
}
}
// Set the amount of bytes to read by subtracting the current client offset from the decodedHeader.Length
bytesToRead = (totalBytes - (4 + headerLen));
// Decode encoded information still in the buffer
byte[] decodedArray = Encryption.DecryptBytes(client.Buffer.Skip(4 + headerLen).Take(bytesToRead).ToArray(), keyIV.Key, keyIV.IV);
// Write decoded information to client.Data
client.Data.Write(decodedArray, 0, decodedArray.Length);
// Trigger the action associated to this packet
PacketReceived(client, client.Data);
client.Data = new PacketStream();
client.PacketSize = 0;
client.Offset = 0;
client.Socket.BeginReceive(
client.Buffer, 0, PacketStream.MaxBuffer, SocketFlags.None,
new AsyncCallback(ReadCallback), client
);
}
else
{
client.Socket.Close();
return;
}
}
catch (Exception e)
{
client.Socket.Close();
Console.WriteLine("Client [{0}] disconected! (with errors)\n\t-Errors!\n\t-{1}.", client.ID, e.Message);
}
}
}
