private bool CompleteWhisperHandshake(Conversation conversation, Participant participant, byte[] keyBlob)
{
var conv = seriousBusiness.FindConversation(conversation);
if (conv == null)
{
return(false);
}
var p = conv.FindParticipant(participant);
if (p == null)
{
return(false);
}
if (p.dh == null)
{
if (!InitiateWhisperHandshake(conversation, participant))
{
return(false);
}
}
p.DeriveKey(keyBlob);
string info = $"Your key: {Ascii85.Encode(p.GetPublicKey())}\r\nTheir key: {Ascii85.Encode(keyBlob)}";
Application.Current.Dispatcher.Invoke(() => { FindOrCreateWhisperWindow(conversation, participant, info).Show(); });
return(true);
}
public string SendWhisper(Conversation conversation, Participant participant, string text)
{
var conv = seriousBusiness.FindConversation(conversation);
if (conv == null)
{
return(null);
}
var p = conv.FindParticipant(participant);
if (p == null)
{
return(null);
}
if (p.dh == null)
{
return(null);
}
if (p.derivedKey == null)
{
return(null);
}
var bytes = Encoding.UTF8.GetBytes(text);
byte[] cipherText;
using (Aes aes = new AesCryptoServiceProvider())
{
aes.Key = p.derivedKey;
byte[] iv = aes.IV;
if (iv.Length != 16)
{
throw new Exception("Expecting 256-bit iv");
}
using (var cipherTextStream = new MemoryStream())
{
cipherTextStream.Write(iv, 0, iv.Length);
using (CryptoStream cs = new CryptoStream(cipherTextStream, aes.CreateEncryptor(), CryptoStreamMode.Write))
{
cs.Write(bytes, 0, bytes.Length);
cs.Close();
cipherText = cipherTextStream.ToArray();
}
}
}
string whisperText = whisperPrefix + Ascii85.Encode(cipherText);
SendWhisperData(conv.conversation, whisperText);
return(whisperText);
}
public bool HandleWhisper(Conversation conversation, Participant participant, string text)
{
if (text.StartsWith(whisperHandshakePrefix) && text.StartsWith(whisperHandshakePrefix + "<~"))
{
return(CompleteWhisperHandshake(conversation, participant, Ascii85.Decode(text.Substring(whisperHandshakePrefix.Length))));
}
else if (text.StartsWith(whisperPrefix) && text.StartsWith(whisperPrefix + "<~"))
{
return(ExtractWhisper(conversation, participant, Ascii85.Decode(text.Substring(whisperHandshakePrefix.Length)), text));
}
return(false);
}
private void SendWhisperHandshake(Conversation conversation, byte[] data)
{
var handshakeText = whisperHandshakePrefix + Ascii85.Encode(data);
bool sendAsRtf = false;
if (sendAsRtf)
{
seriousBusiness.DoSendMessage(conversation, ShhWrap(handshakeText), InstantMessageContentType.RichText);
}
else
{
seriousBusiness.DoSendMessage(conversation, handshakeText, InstantMessageContentType.PlainText);
}
}