private void HandleMessageReceive(ChannelMessage message)
{
SimpleMessage simpleMessage = new SimpleMessage(message);
if (ShowTransportPackets)
{
CConsole.Gray("{0}", JsonConvert.SerializeObject(simpleMessage, Formatting.Indented));
}
if (message.CipherText == null)
{
// It's not a message packet
if (message.AnnouncedKey != null && message.AcknowledgeKey == null)
{
// BOB
// Initial announce from other side
if (PlaintextMode != message.PlaintextMode)
{
CConsole.Red("!!! Invalid Far-side configuration! Near-Side PlaintextMode = {0}, Far-Side PlaintextMode = {1}", PlaintextMode, message.PlaintextMode);
IsOpen = false;
MessageEvent.Set();
return;
//throw new Exception("PlaintextMode Mismatch");
}
Parameters = new DHParameters(
new BigInteger(message.Param_P, 16),
new BigInteger(message.Param_G, 16),
new BigInteger(message.Param_Q, 16),
message.Param_L);
RachetKeyPair = DHKeyPair.Generate(Parameters);
if (Verbose)
{
CConsole.Yellow("RootChainKey = {0}", H(RachetKeyPair.ComputeSharedSecret(message.AnnouncedKey)));
}
LastParterAnnouncedKey = message.AnnouncedKey;
IsOpen = true;
MessageEvent.Set();
}
else if (message.AnnouncedKey != null && message.AcknowledgeKey != null)
{
// ALICE
// Initial acknowledge from other side
if (Verbose)
{
CConsole.DarkMagenta("Acknowledging = {0}", message.AnnouncedKey);
}
LastParterAnnouncedKey = message.AnnouncedKey;
if (message.AcknowledgeKey != RachetKeyPair.PublicKey)
{
CConsole.Red("!!! Invalid AcknowledgedKey !!!");
throw new Exception("Invalid AcknowledgedKey");
}
else
{
string secretA = RachetKeyPair.ComputeSharedSecret(message.AnnouncedKey); //FIRST RootChainKey
if (PrefilledRootKey != null)
{
RootChainKey = PrefilledRootKey;
string outputA;
string outputB;
KDF(RootChainKey, RootChainKey, out outputA, out outputB);
RootChainKey = outputA;
}
else
{
RootChainKey = secretA;
}
if (Verbose)
{
CConsole.Yellow("RootChainKey = {0}", H(RootChainKey));
}
string outputA1;
string outputB1;
KDF(RootChainKey, RootChainKey, out outputA1, out outputB1);
RootChainKey = outputA1;
ReceivingChainKey = outputB1;
if (Verbose)
{
CConsole.DarkYellow("RootChainKey = {0}", H(RootChainKey));
}
if (Verbose)
{
CConsole.Magenta("ReceivingChainKey = {0}", H(ReceivingChainKey));
}
string outputA2;
string outputB2;
RachetKeyPair = DHKeyPair.Generate(Parameters);
if (Verbose)
{
if (RootChainCount % 2 == 1)
{
CConsole.DarkMagenta("Announcing = {0}", H(RachetKeyPair.PublicKey));
}
else
{
CConsole.DarkCyan("Announcing = {0}", H(RachetKeyPair.PublicKey));
}
}
string secret = RachetKeyPair.ComputeSharedSecret(message.AnnouncedKey);
KDF(secret, RootChainKey, out outputA2, out outputB2);
RootChainKey = outputA2;
SendingChainKey = outputB2;
if (Verbose)
{
CConsole.Yellow("RootChainKey = {0}", H(RootChainKey));
}
}
IsOpen = true;
MessageEvent.Set();
}
}
else
{
// It's a message packet! Do the decrypt
string text;
if (!Decrypt(message, out text))
{
throw new Exception("Failed to Decrypt packet!");
}
OnMessage(text);
MessageListener?.Invoke(text);
}
}
private bool Decrypt(ChannelMessage message, out string text)
{
if (PlaintextMode && message.PlaintextMode)
{
text = message.CipherText;
return(true);
}
if (DHRachetNeeded(message.AnnouncedKey, message.AcknowledgeKey))
{
string secretA = RachetKeyPair.ComputeSharedSecret(message.AnnouncedKey);
string outputA1;
string outputB1;
KDF(secretA, RootChainKey, out outputA1, out outputB1);
RootChainKey = outputA1;
ReceivingChainKey = outputB1;
if (Verbose)
{
if (RootChainCount % 2 == 1)
{
CConsole.Yellow("RootChainKey = {0}", H(RootChainKey));
}
else
{
CConsole.DarkYellow("RootChainKey = {0}", H(RootChainKey));
}
}
if (Verbose)
{
if (RootChainCount % 2 == 1)
{
CConsole.Blue("ReceivingChainKey = {0}", H(ReceivingChainKey));
}
else
{
CConsole.Magenta("ReceivingChainKey = {0}", H(ReceivingChainKey));
}
}
string messageKey;
string outputA;
string outputB;
KDF(ReceivingChainKey, ReceivingChainKey, out outputA, out outputB);
messageKey = outputA;
ReceivingChainKey = outputB;
if (Verbose)
{
if (RootChainCount % 2 == 1)
{
CConsole.Magenta("ReceivingChainKey = {0}", H(ReceivingChainKey));
}
else
{
CConsole.Blue("ReceivingChainKey = {0}", H(ReceivingChainKey));
}
}
if (Verbose)
{
CConsole.DarkGreen("MessageKey = {0}", H(messageKey));
}
text = DES.DecryptB64(message.CipherText, messageKey);
RachetKeyPair = DHKeyPair.Generate(RachetKeyPair.Parameters);
if (Verbose)
{
if (RootChainCount % 2 == 1)
{
CConsole.DarkMagenta("Announcing = {0}", H(RachetKeyPair.PublicKey));
}
else
{
CConsole.DarkCyan("Announcing = {0}", H(RachetKeyPair.PublicKey));
}
}
string secretB = RachetKeyPair.ComputeSharedSecret(message.AnnouncedKey);
string outputA2;
string outputB2;
KDF(secretB, RootChainKey, out outputA2, out outputB2);
RootChainKey = outputA2;
SendingChainKey = outputB2;
if (Verbose)
{
if (RootChainCount % 2 == 1)
{
CConsole.Yellow("RootChainKey = {0}", H(RootChainKey));
}
else
{
CConsole.DarkYellow("RootChainKey = {0}", H(RootChainKey));
}
}
ReceivingMessageId++;
return(true);
}
else
{
if (Verbose)
{
CConsole.Red("ReceivingChainKey = {0}", H(ReceivingChainKey));
}
string messageKey;
string outputA;
string outputB;
KDF(ReceivingChainKey, ReceivingChainKey, out outputA, out outputB);
messageKey = outputA;
ReceivingChainKey = outputB;
if (Verbose)
{
CConsole.DarkGreen("MessageKey = {0}", H(messageKey));
}
text = DES.DecryptB64(message.CipherText, messageKey);
ReceivingMessageId++;
return(true);
}
}
public bool Open(bool sender)
{
if (!sender)
{
// BOB
MessageEvent.WaitOne(30 * 1000); // Wait until fully opened or timeout in 30s
if (IsOpen == false)
{
return(false);
}
// Send acknowledge
if (Verbose)
{
CConsole.DarkCyan("Acknowledging = {0}", LastParterAnnouncedKey);
}
if (Verbose)
{
CConsole.DarkMagenta("Announcing = {0}", RachetKeyPair.PublicKey);
}
string secret = RachetKeyPair.ComputeSharedSecret(LastParterAnnouncedKey);
if (PrefilledRootKey != null)
{
RootChainKey = PrefilledRootKey;
string outputA1;
string outputB1;
KDF(RootChainKey, RootChainKey, out outputA1, out outputB1);
RootChainKey = outputA1;
}
else
{
RootChainKey = secret;
}
string outputA;
string outputB;
KDF(RootChainKey, RootChainKey, out outputA, out outputB);
RootChainKey = outputA;
SendingChainKey = outputB;
if (Verbose)
{
CConsole.DarkYellow("RootChainKey = {0}", H(RootChainKey));
}
if (Verbose)
{
CConsole.Magenta("SendingChainKey = {0}", H(SendingChainKey));
}
ChannelMessage msg = new ChannelMessage()
{
AcknowledgeKey = LastParterAnnouncedKey,
AnnouncedKey = RachetKeyPair.PublicKey,
CipherText = null
};
if (!SerializeAndSend(msg))
{
CConsole.Red("!!! Error sending initial announce !!!");
}
}
else
{
// ALICE
// Send announce
RachetKeyPair = DHKeyPair.Generate();
Parameters = RachetKeyPair.Parameters;
ChannelMessage msg = new ChannelMessage()
{
AcknowledgeKey = null,
AnnouncedKey = RachetKeyPair.PublicKey,
Param_P = RachetKeyPair.Parameters.P.ToString(16),
Param_G = RachetKeyPair.Parameters.G.ToString(16),
Param_Q = RachetKeyPair.Parameters.Q.ToString(16),
Param_L = RachetKeyPair.Parameters.L,
CipherText = null,
PlaintextMode = PlaintextMode
};
if (Verbose)
{
CConsole.DarkCyan("Announcing = {0}", RachetKeyPair.PublicKey);
}
if (!SerializeAndSend(msg))
{
CConsole.Red("!!! Error sending initial announce !!!");
}
MessageEvent.WaitOne(30 * 1000); // wait till fully opened or timeout in 30s
if (IsOpen == false)
{
return(false);
}
}
return(true);
}