MUDitM is a telnet proxy that provides an IPv6 and telnet-ssl frontend to standard IPv4/telnet Multi-User Dungeon type games that have not implemented those networking features yet, whatever the reason. The implementation differs from other secure proxy implementations in that it tries to report the proxied client address up to the game server via the NEW-ENVIRON / MNES standard.
MUDitM - MUD in the Middle Proxy ******* This is the MUDitM-0.2 semi-secret alpha release! ******* Thu Mar 18 11:33:23 AM EDT 2021 MUDitM-0.1 is a telnet proxy that I wrote on a whim over a long weekend. My intent was to try to provide an IPv6 and telnet-ssl front end to standard IPv4/telnet Multi-User Dungeon type games that have not implemented those networking features yet, whatever the reason. MUDitM-0.2 has another weekend's worth of polish on it. The implementation differs from other secure proxy implementations in that it tries to report the proxied client address up to the game server via the NEW-ENVIRON / MNES standard. (See https://tintin.mudhalla.net/protocols/mnes/ for docs on MNES.) I went for that method because my MUD already understands it. This 0.2 release is more of a proof of concept than anything else. It differs from the 0.1 release in that it now uses PCRE2 as its back end pattern matching engine, it allows configuration of multiple ip address reporting variables, and I added the stunnel PROXY announcement as an option for games that already support that. Compilation, Installation ------------------------- It'll compile and run on Ubuntu 20.10 and compatible systems. You'll need to install gcc, gnumake, libglib2.0-dev, ctags, pcre2 and openssl. See INSTALL file for the barest of documentation. There's no installer written yet. Installing it on Windows or Mac? Le'me know how that goes. What I've learned from this project: ------------------------------------ 1) At least for my mud, throwing an SSL socket into the game server really isn't as involved as I thought it might be, and it could even be worth doing in game for as long as we have support for "3rd party" mud clients. 2) There is a another ssl proxy project out there called `stunnel` (https://www.stunnel.org/) that I had looked at briefly, but did not try out because I didn't realize that it had its own way of sending the remote networking address info through the proxy. It does, it is very straightforward, and would be pretty trivial to add to a mud server that doesn't already do NEW-ENVIRON. So, I added that PROXY reporting method to MUDitM for the sake of compatibility. 3) PCRE2 looks kind of daunting from the documentation. Its not. Bugs, Limitations, Todos ------------------------ MCCP2 and MCCP3 are de-negotiated by MUDitM, because it doesn't understand zlib compression. Maybe someday it will. You've got to be careful with adding patterns via pcre2. Don't include sub match expressions, or you are going to screw up my 'what just matched' algorithm. (see also: "ret-2" buried somewhere in proxy.c.) I did a crummy job of handling write(). They aren't queued properly at all for partial or zero writes. Oh well, maybe get that fixed for the beta release. The IPADDRESS injection from MUDitM happens as soon as the server makes a request for the full environment set. If the client is also going to export IPADDRESS, MUDitM does nothing to prevent that, and the client's export will update the value seen on the game. This is both good and bad- it is good, because it lets a chain of proxies forward the first IPADDRESS along unmolested. It's bad in that it lets the client control the value of IPADDRESS. If you want to have access to the address that MUDitM is connected to on the other side, export it using a different, less likely to be overwritten variable name. This is an area that could use improvement. Contributing, Bug Reporting, Support ------------------------------------ You can contact the author (see the AUTHORS file) with your questions, bug reports, or patches! The most up to date .tar.gz version of MUDitM can be found at: https://last-outpost.com/LO/pubcode Now before you ask- there is no "sourceforge" or "github" or "gitlab" or "slack" or "google code" or "public svn" or other "open source repository" for this project. Nope, I do not want help setting one up. Thanks for the offer though! If you found this project on one of those repos, you can safely assume that is a fork of MUDitM, and it has nothing to do with me, the original author. I probably won't be looking at it, so don't get mad when I don't respond to things that have been posted to wherever that is.