/// <summary>
/// Processes StartConversationRequest message from client.
/// <para>Initiates a conversation with the client provided that there is a common version of the protocol supported by both sides.</para>
/// </summary>
/// <param name="Client">Client that sent the request.</param>
/// <param name="RequestMessage">Full request message.</param>
/// <returns>Response message to be sent to the client.</returns>
public ProxProtocolMessage ProcessMessageStartConversationRequest(IncomingClient Client, ProxProtocolMessage RequestMessage)
{
log.Trace("()");
ProxProtocolMessage res = null;
if (!CheckSessionConditions(Client, RequestMessage, null, ClientConversationStatus.NoConversation, out res))
{
log.Trace("(-):*.Response.Status={0}", res.Response.Status);
return(res);
}
ProxMessageBuilder messageBuilder = Client.MessageBuilder;
StartConversationRequest startConversationRequest = RequestMessage.Request.ConversationRequest.Start;
byte[] clientChallenge = startConversationRequest.ClientChallenge.ToByteArray();
byte[] pubKey = startConversationRequest.PublicKey.ToByteArray();
if (clientChallenge.Length == ProxMessageBuilder.ChallengeDataSize)
{
if ((0 < pubKey.Length) && (pubKey.Length <= ProtocolHelper.MaxPublicKeyLengthBytes))
{
SemVer version;
if (GetCommonSupportedVersion(startConversationRequest.SupportedVersions, out version))
{
Client.PublicKey = pubKey;
Client.IdentityId = Crypto.Sha256(Client.PublicKey);
if (clientList.AddNetworkPeerWithIdentity(Client))
{
Client.MessageBuilder.SetProtocolVersion(version);
byte[] challenge = new byte[ProxMessageBuilder.ChallengeDataSize];
Crypto.Rng.GetBytes(challenge);
Client.AuthenticationChallenge = challenge;
Client.ConversationStatus = ClientConversationStatus.ConversationStarted;
log.Debug("Client {0} conversation status updated to {1}, selected version is '{2}', client public key set to '{3}', client identity ID set to '{4}', challenge set to '{5}'.",
Client.RemoteEndPoint, Client.ConversationStatus, version, Client.PublicKey.ToHex(), Client.IdentityId.ToHex(), Client.AuthenticationChallenge.ToHex());
res = messageBuilder.CreateStartConversationResponse(RequestMessage, version, Config.Configuration.Keys.PublicKey, Client.AuthenticationChallenge, clientChallenge);
}
else
{
res = messageBuilder.CreateErrorInternalResponse(RequestMessage);
}
}
else
{
log.Warn("Client and server are incompatible in protocol versions.");
res = messageBuilder.CreateErrorUnsupportedResponse(RequestMessage);
}
}
else
{
log.Warn("Client send public key of invalid length of {0} bytes.", pubKey.Length);
res = messageBuilder.CreateErrorInvalidValueResponse(RequestMessage, "publicKey");
}
}
else
{
log.Warn("Client send clientChallenge, which is {0} bytes long, but it should be {1} bytes long.", clientChallenge.Length, ProxMessageBuilder.ChallengeDataSize);
res = messageBuilder.CreateErrorInvalidValueResponse(RequestMessage, "clientChallenge");
}
log.Trace("(-):*.Response.Status={0}", res.Response.Status);
return(res);
}
