[GD-General] Authentication security

[Dan T. <da...@ar...>]

Hello again, everyone. I'm looking for a way to pass credentials securely
over the wire. Here's what I'm planning, but I'm not sure how well this will
work under UDP, if at all ( I don't think so).

1) Users connect to an SSL port in the server, and submit credentials
(hashed)
2) The server authenticates, and if successful, sends back some kind of huge
session key over the secure link.
3) The client drops the SSL connection, and connects back on a standard
port, and uses the session key as authentication over TCP. All semi
sensitive data is sent across this link. (Anything critical is done over
SSL).

Now I can see that this is completely pointless with UDP. Session keys only
work with a connection based protocol. I also know that this is by no means
bulletproof - TCP hijacking and whatnot on the semi-sensitive link. However
for a game... heh. Hopefully you don't need any more than this. However I
still am up in the air on how to deal with authenticity of UDP packets.
Since its all based on source IP/port and player IDs, it seems like it would
be fairly trivial to forge the source ip on a packet and move other people
around. Of course, this requires knowing the other player's IP... but still.

This seems like to me to be a fairly important issue - especially with
MMORPGs these days. Without a good authentication scheme, people could
delete characters, etc, and people put a *lot* of time into those things.

As per usual, the archives search was worthless. *twitch*

Any ideas/comments?
-Dan