protected override void InitializeSecurity()
{
Dictionary <string, string> message;
var dhg = new DiffieHellmanGenerator();
// Stage 1: Send key request
Send(new Dictionary <string, string>
{
{ "request", "keys" }
});
// Stage 2: Process response
message = WaitForKey("p");
if (message == null)
{
MessageOutput.Log("Invalid response from server; expected p");
return;
}
//int p = Convert.ToInt32(message["p"]);
//int g = Convert.ToInt32(message["g"]);
//var publicKeys = new DiffieHellmanPublicKeystore(p, g);
var publicKeys = new DiffieHellmanPublicKeystore(message);
var secretA = dhg.GenerateSecret();
var transportA = dhg.GenerateTransport(secretA, publicKeys);
// Stage 3: Send a, await b
Send(new Dictionary <string, string>
{
{ "a", transportA.ToString() }
});
message = WaitForKey("b");
if (message == null)
{
MessageOutput.Log("Invalid response from server; expected b");
return;
}
// Stage 4: Calculate shared secret
var transportB = BigInteger.Parse(message["b"]);
SharedSecret = dhg.GenerateSharedSecret(secretA, transportB, publicKeys);
// Stage 5: Send encryption type
Send(new Dictionary <string, string>
{
{ "encryption", encryption }
});
SetEncryption(encryption);
MessageOutput.Log("Connection summary:\n " +
$"\tp: {publicKeys.P}\n" +
$"\tg: {publicKeys.G}\n" +
$"\tsecret: {secretA}\n" +
$"\ttransport: {transportA}\n" +
$"\treceived transport: {transportB}\n" +
$"\tshared secret: {SharedSecret}\n" +
$"\tencryption: {encryption}");
}
/// <summary>
/// Changes encryption used in communication with server.
/// </summary>
/// <param name="newEncryption">New encryption name.</param>
public void ChangeEncryption(string newEncryption)
{
encryption = newEncryption;
Send(new Dictionary <string, string>
{
{ "encryption", encryption }
});
MessageOutput.Log("Client requested encryption change:\n" +
$"\tencryption: {encryption}");
SetEncryption(encryption);
}
protected override void HandleMessage(Dictionary <string, string> message)
{
if (message.ContainsKey("encryption"))
{
MessageOutput.Log("Client requested encryption change:\n" +
$"\tencryption: {message["encryption"]}");
SetEncryption(message["encryption"]);
}
else
{
MessageOutput.HandleMessage(message);
}
}
protected override void InitializeSecurity()
{
Dictionary <string, string> message;
var dhg = new DiffieHellmanGenerator();
// Stage 1: Await key request
message = WaitForKey("request");
if (message == null)
{
MessageOutput.Log("Invalid request from client; expected keys");
return;
}
// Stage 2: Send keys
var publicKeys = primesReader.GetRandomKeystore();
var secretB = dhg.GenerateSecret();
var transportB = dhg.GenerateTransport(secretB, publicKeys);
Send(publicKeys.GetJson());
// Stage 3: Send b, await a
message = WaitForKey("a");
Send(new Dictionary <string, string>
{
{ "b", transportB.ToString() }
});
if (message == null)
{
MessageOutput.Log("Invalid response from client; expected a");
return;
}
// Stage 4: Calculate shared secret
var transportA = BigInteger.Parse(message["a"]);
SharedSecret = dhg.GenerateSharedSecret(secretB, transportA, publicKeys);
// Stage 5: Await encryption
message = WaitForJson();
if (message == null)
{
return;
}
if (message.ContainsKey("encryption"))
{
SetEncryption(message["encryption"]);
MessageOutput.Log("Connection summary:\n" +
$"\tp: {publicKeys.P}\n" +
$"\tg: {publicKeys.G}\n" +
$"\tsecret: {secretB}\n" +
$"\ttransport: {transportB}\n" +
$"\treceived transport: {transportA}\n" +
$"\tshared secret: {SharedSecret}\n" +
$"\tencryption: {message["encryption"]}");
}
else
{
// Client skipped encryption step; assume none and handle the message.
SetEncryption("none");
MessageOutput.Log("Connection summary:\n" +
$"\tp: {publicKeys.P}\n" +
$"\tg: {publicKeys.G}\n" +
$"\tsecret: {secretB}\n" +
$"\ttransport: {transportB}\n" +
$"\treceived transport: {transportA}\n" +
$"\tshared secret: {SharedSecret}\n" +
$"\tencryption: none");
message["msg"] = Encoding.UTF8.GetString(Convert.FromBase64String(message["msg"]));
MessageOutput.HandleMessage(message);
}
}