/// <summary>
/// Encrypts, formats, and sends a message.
/// </summary>
/// <param name="message">Message to be sent.</param>
/// <returns>Byte array containing the returned message.</returns>
public string send(JObject message, bool isLogin = false)
{
bool tryAgain = true;
while(tryAgain)
{
tryAgain = false;
//Get a public key for RSA to use for encryption.
string publickey = getKey();
using (WebClient web = new WebClient())
{
using (AES_THL messageCryptor = new AES_THL())
{
//Place this inside our encrypted message.
string outgoingkey = GenerateKey();
message["Pub"] = outgoingkey;
//This will encrypt our message with a key from the server.
var data = PrepOutMessage(message, publickey, messageCryptor);
//Let's derive out outgoing key now and prep AES to handle the incoming message.
NameValueCollection aesComponents = DeriveKey(outgoingkey);
if (isLogin)
data["lgn"] = "t";
messageCryptor.Key = Md5ToBytes(aesComponents["key"]);
messageCryptor.IV = Md5ToBytes(aesComponents["iv"]);
//Data ready to be sent.
byte[] response;
try
{
response = web.UploadValues(destination, "POST", data);
}
catch (Exception ex)
{
return "Failure.";
}
string b64Response = Encoding.ASCII.GetString(response);
if (b64Response.Equals("Forbidden."))
{
DBMethods.deleteKey();
return b64Response;
}
else if (b64Response.StartsWith("{\"Pub\""))
{
DBMethods.updateKey(JsonHandler.extractValue(b64Response, "Pub"));
tryAgain = true;
continue;
}
byte[] unEncoded = Convert.FromBase64String(b64Response);
string inMessage = messageCryptor.Decrypt(unEncoded);
DBMethods.updateKey(JsonHandler.extractValue(inMessage, "Pub"));
return JsonHandler.extractValue(inMessage, "Operations");
}
}
}
return null;
}
private static NameValueCollection PrepOutMessage(JObject message, string publickey, AES_THL messageCryptor)
{
//Prep AES
NameValueCollection aesComponents = DeriveKey(publickey);
messageCryptor.Key = Md5ToBytes(aesComponents["key"]);
messageCryptor.IV = Md5ToBytes(aesComponents["iv"]);
//Encrypt the message.
byte[] AES_Message = messageCryptor.Encrypt(message.ToString());
string b64Message = Convert.ToBase64String(AES_Message);
//Now, let's prepare the POST data.
var data = new NameValueCollection();
data["pub"] = publickey;
data["m"] = b64Message;
return data;
}
