/// <summary>
/// Writes the Key and IV from the specified <see cref="EncryptionProvider"/>
/// <para/>
/// to a new <see cref="Packet"/> using the specified <see cref="RSAHelper"/> to encrypt the values
/// <para/>
/// this method is the counterpart to <see cref="HandshakeHelper.GetDecryptor(RSAHelper, Packet)"/>
/// </summary>
/// <param name="rsa">The <see cref="RSAHelper"/> to use for encrypting the Key and IV</param>
/// <param name="encryptor">The actual Encryptor to take the Key and IV from</param>
/// <returns></returns>
public static Packet WriteEncryptor(RSAHelper rsa, EncryptionProvider encryptor)
{
Packet pkt = new Packet();
MemoryStream outputDataStream = new MemoryStream();
StreamWriter outputWriter = new StreamWriter(outputDataStream);
outputWriter.WriteLine(rsa.EncryptToBase64String(encryptor.IV));
outputWriter.WriteLine(rsa.EncryptToBase64String(encryptor.Key));
outputWriter.Flush();
pkt.TypeID = (int)PacketType.Handshake;
pkt.ChannelID = CryptoCommon.GetPrngInt(); // Adding an element of randomness to our sent data
pkt.DestinationUserID = CryptoCommon.GetPrngInt(); // Adding an element of randomness to our sent data
pkt.Data = outputDataStream.GetBuffer();
return(pkt);
}
private bool NegotiateSessionKeys(Stream netStream, out EncryptionProvider decryptor, out EncryptionProvider encryptor, RSAHelper pubRSA, RSAHelper privRSA)
{
StreamReader reader = new StreamReader(netStream);
StreamWriter writer = new StreamWriter(netStream);
encryptor = new EncryptionProvider();
try
{
Packet packet = WriteEncryptor(pubRSA, encryptor);
byte[] serializedPacket = ToySerializer.Serialize(packet);
string sendData = pubRSA.EncryptToBase64String(serializedPacket);
writer.WriteLine(sendData); // Writing the packet as a Base64 encoded string to the network stream in the current instance
writer.Flush();
string read = reader.ReadLine(); // Getting response
packet = ToySerializer.Deserialize <Packet>(privRSA.DecryptBase64String(read));
decryptor = GetDecryptor(privRSA, packet);
}
catch { decryptor = null; return(false); }
return(true);
}