private async Task <string> handelClientAsync(TcpClient client, RSA rsa, AES aes)
{
aes.Enable(_AESEnable);
string query = await ReadStringAsyc(client, aes);
string username = query, pwd = "";
if (query.StartsWith("register user["))
{
string error = "", res = "";
var c = (await ReadBytesAsyc(client, aes)).ToX509();
if (CertificationFactory.Verify(c, ref error))
{
username = query.SubStringFromTo(query.IndexOf("[") + 1, query.IndexOf("]"));
if (db.FindByName(username) != null)
{
res = "this username used, try somthing else";
}
else
{
pwd = query.SubStringFromTo(query.IndexOf("[", query.IndexOf("[") + 1) + 1, query.IndexOf("]", query.IndexOf("]") + 1));
db.AddAccount(username, pwd);
res = "ok";
}
}
else
{
res = "your certificate not valid";
}
WriteString(client, aes, res);
return(username);
}
else
{
pwd = await ReadStringAsyc(client, aes);
}
var me = db.FindByName(username);
if (me == null || me.Password != pwd)
{
WriteString(client, aes, "no");
}
else
{
log(me.Username + " logged in");
WriteString(client, aes, "ok");
for (string command = "", res = ""; true;)
{
try
{
aes.Enable(_AESEnable);
log("wait '" + me.Username + "' to send...");
command = await ReadStringAsyc(client, aes);
log(me.Username + " sent : " + command);
if (command == "bye")
{
break;
}
else if (command == "get total")
{
res = db.TotalBalance().ToString();
}
else if (command == "get me")
{
res = me.Balance.ToString();
}
else if (command == "get your public key")
{
res = RSA.KeyToString(rsa.PublicKey);
}
else if (command.StartsWith("get ")) // get user1
{
var v = db.FindByName(command.Substring("get ".Length));
res = (v == null) ? "null" : v.Balance.ToString();
}
else if (command == "transfer") //transfer\r\n100 to user3
{
rsa.Enable(_RSAEnable);
var amountAndUser = await ReadStringAsyc(client, rsa);
WriteString(client, aes, "ok");
log(me.Username + " sent : " + amountAndUser);
log("Varify signature for transaction");
var signature = await ReadBytesAsyc(client, aes);
if (rsa.Varify(amountAndUser.StringToBytes(), signature) == false)
{
log("signature wrong");
res = "error: signature wrong";
}
else
{
log("signature ok");
int amount = int.Parse(amountAndUser.SubStringFromTo(0, amountAndUser.IndexOf(" to ")));
string toUser = amountAndUser.Substring(amountAndUser.IndexOf(" to ") + " to ".Length);
if (db.TransferTo(me, toUser, amount, ref res))
{
res = me.Balance.ToString();
}
}
}
else
{
res = "unkown command \"" + command + "\", try 'help'";
}
}
catch
{
log("error while reading - " + command);
res = "error, can't understand command!";
}
WriteString(client, aes, res);
}
}
return(username);
}