Many of the current single-player games (ularn, rogue) let the user save the game state so that they can come back to it later. These save files are stored in the user's home directory. Clever users could use a binary editor to modify the save files to cheat at the game (increasing money, player stats, etc.) to increase their position in the shared scoreboard files. non-clever users could simply backup the save files to restore the game after they die.
What strategies could be used to prevent this sort of cheating? Should save files be moved into a shared directory, owned by root.games, so that user's can't edit them?
Or is the impact of this cheating so minor that it's not worth worrying about?
--Wart
"MT" == Michael Thomas wart@kobold.org writes:
MT> What strategies could be used to prevent this sort of cheating? MT> Should save files be moved into a shared directory, owned by MT> root.games, so that user's can't edit them?
In the old days that's how things worked, but these days I don't think it's a really good idea. The general case is one user per machine.
If somehow obtaining "group games" access was considered to be something other than a security exploit then I wouldn't care. These days I wonder if its even worth doing the setgid games thing for high scores.
- J<
Jason L Tibbitts III wrote:
"MT" == Michael Thomas wart@kobold.org writes:
MT> What strategies could be used to prevent this sort of cheating? MT> Should save files be moved into a shared directory, owned by MT> root.games, so that user's can't edit them?
In the old days that's how things worked, but these days I don't think it's a really good idea. The general case is one user per machine.
If somehow obtaining "group games" access was considered to be something other than a security exploit then I wouldn't care. These days I wonder if its even worth doing the setgid games thing for high scores.
It's probably not as common these days as it was 10 years ago to have multiple users per machine, but it's still something we should cater to. However, the cheating issue is probably not too important because, after all, these are single-player games, and the worse case is that you dominate the scoreboard file. I guess it would be more of an issue for multiplayer games since a modified save file could affect other players in the game.
--Wart
"MT" == Michael Thomas wart@kobold.org writes:
MT> It's probably not as common these days as it was 10 years ago to MT> have multiple users per machine, but it's still something we MT> should cater to.
The problem is that "user can gain group games membership" and "user can mess with the high score tables" both show up as security vulnerabilities. Frankly I don't see that any use of setgid games is worth the trouble.
- J<
Jason L Tibbitts III wrote:
"MT" == Michael Thomas wart@kobold.org writes:
MT> It's probably not as common these days as it was 10 years ago to MT> have multiple users per machine, but it's still something we MT> should cater to.
The problem is that "user can gain group games membership" and "user can mess with the high score tables" both show up as security vulnerabilities. Frankly I don't see that any use of setgid games is worth the trouble.
Erm,
I dunno the way we do things currently is: -first thing in main -open shared highscore file r+ -drop sgid games rights
Means that it is impossible for a user to get group games mambership. Now if user can find a security hole (and I'm sure they can) then the most damage they could do is: -corrupt the shared scorefile in such a way that when another user starts the game it does something which the attacker wants with the rights of the other user.
So yes we have a real problem here, but if we make sure that the highscore reading functions do proper input checking, which should be relativly easy, were not talking advanced math here, just a highscore table, then the worst a user could do is: -fill /var/games with a huge file, causing diskspace problems in a way he normally can't. Which can easily be fixed on a system using quotasm by setting a quota for the games group. And on systems not using quotas this is irrelevant.
Regards,
Hans
Hi folks,
I am, what could be considered as, in development of a game that I am planning to submit to Fedora's "extras" section. I am really not much of a gamer so I am not sure what the gamers' expectations of a good games are. This is a 2D shooter, and probably games need lot's of explosions and most are preferred to have shooting in them.
I will very much appreciate if you would kindly, if you have time, try out my game called "Maximum Destruction" and provide any feedback you may have on how to improve it, while I am trying to resolve the images licensing issues.
The game is on my site at:
http://www.victorsk.webhop.org
Any suggestions on the game's content or on how to improve will be greatly appreciated. Or, if you would like to participate in the development of this game or would like me to participate in the development of other games, please let me know.
Thank you very much, Victor.
Michael Thomas wart@kobold.org wrote: Jason L Tibbitts III wrote:
"MT" == Michael Thomas writes:
MT> What strategies could be used to prevent this sort of cheating? MT> Should save files be moved into a shared directory, owned by MT> root.games, so that user's can't edit them?
In the old days that's how things worked, but these days I don't think it's a really good idea. The general case is one user per machine.
If somehow obtaining "group games" access was considered to be something other than a security exploit then I wouldn't care. These days I wonder if its even worth doing the setgid games thing for high scores.
It's probably not as common these days as it was 10 years ago to have multiple users per machine, but it's still something we should cater to. However, the cheating issue is probably not too important because, after all, these are single-player games, and the worse case is that you dominate the scoreboard file. I guess it would be more of an issue for multiplayer games since a modified save file could affect other players in the game.
--Wart _______________________________________________ Fedora-games-list mailing list Fedora-games-list@redhat.com http://www.redhat.com/mailman/listinfo/fedora-games-list
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Hi Victor,
Have you started making a srpm for the game yet, or are you still concentrating on the software itself?
--Mike
Victor Skovorodnikov wrote:
Hi folks,
I am, what could be considered as, in development of a game that I am planning to submit to Fedora's "extras" section. I am really not much of a gamer so I am not sure what the gamers' expectations of a good games are. This is a 2D shooter, and probably games need lot's of explosions and most are preferred to have shooting in them.
I will very much appreciate if you would kindly, if you have time, try out my game called "Maximum Destruction" and provide any feedback you may have on how to improve it, while I am trying to resolve the images licensing issues.
The game is on my site at:
http://www.victorsk.webhop.org
Any suggestions on the game's content or on how to improve will be greatly appreciated. Or, if you would like to participate in the development of this game or would like me to participate in the development of other games, please let me know.
Thank you very much, Victor.
Hi Mike,
Thank you for replying. Nope, I haven't went this far yet. My main objective right now is to resolve the licensing issues and make sure that the game works the right way. Plus, it also needs to be mutated into a C++ code and I need to find a way to attach wxWidgets menus/preferences to it.
But, the core playable portion is working :-)
Thanks, Victor.
Wart wart@kobold.org wrote: Hi Victor,
Have you started making a srpm for the game yet, or are you still concentrating on the software itself?
--Mike
Victor Skovorodnikov wrote:
Hi folks,
I am, what could be considered as, in development of a game that I am planning to submit to Fedora's "extras" section. I am really not much of a gamer so I am not sure what the gamers' expectations of a good games are. This is a 2D shooter, and probably games need lot's of explosions and most are preferred to have shooting in them.
I will very much appreciate if you would kindly, if you have time, try out my game called "Maximum Destruction" and provide any feedback you may have on how to improve it, while I am trying to resolve the images licensing issues.
The game is on my site at:
http://www.victorsk.webhop.org
Any suggestions on the game's content or on how to improve will be greatly appreciated. Or, if you would like to participate in the development of this game or would like me to participate in the development of other games, please let me know.
Thank you very much, Victor.
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Hi Victor,
I won't be able to run it until after work, but it compiles cleanly on FC-5 i386. It fails to build on FC-4 x86_64 with the following error:
$ cc invaders.c -o invaders `imlib2-config --cflags` `imlib2-config --libs` `allegro-config --libs` 2>&1 | tee build.log /usr/lib64/liballeg-4.0.3.so: undefined reference to `_mangled_main_address' collect2: ld returned 1 exit status
--Mike
Victor Skovorodnikov wrote:
Hi Mike,
Thank you for replying. Nope, I haven't went this far yet. My main objective right now is to resolve the licensing issues and make sure that the game works the right way. Plus, it also needs to be mutated into a C++ code and I need to find a way to attach wxWidgets menus/preferences to it.
But, the core playable portion is working :-)
Thanks, Victor.
Wart wart@kobold.org wrote: Hi Victor,
Have you started making a srpm for the game yet, or are you still concentrating on the software itself?
--Mike
Victor Skovorodnikov wrote:
Hi folks,
I am, what could be considered as, in development of a game that I am planning to submit to Fedora's "extras" section. I am really not much of a gamer so I am not sure what the gamers' expectations of a good games are. This is a 2D shooter, and probably games need lot's of explosions and most are preferred to have shooting in them.
I will very much appreciate if you would kindly, if you have time, try out my game called "Maximum Destruction" and provide any feedback you may have on how to improve it, while I am trying to resolve the images licensing issues.
The game is on my site at:
http://www.victorsk.webhop.org
Any suggestions on the game's content or on how to improve will be greatly appreciated. Or, if you would like to participate in the development of this game or would like me to participate in the development of other games, please let me know.
Thank you very much, Victor.
Fedora-games-list mailing list Fedora-games-list@redhat.com http://www.redhat.com/mailman/listinfo/fedora-games-list
Blab-away for as little as 1¢/min. Make PC-to-Phone Calls using Yahoo! Messenger with Voice.
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Victor Skovorodnikov wrote:
Hi Mike,
Thank you for replying. Nope, I haven't went this far yet. My main objective right now is to resolve the licensing issues and make sure that the game works the right way. Plus, it also needs to be mutated into a C++ code and I need to find a way to attach wxWidgets menus/preferences to it.
But, the core playable portion is working :-)
I had some trouble playing the game, mostly because the window size seems to be fixed at 900x700, which is larger than the 800x600 desktop I was using. Command line options to set the window size would be useful. It's also nice to have a -fullscreen option to fill the entire screen.
There also seems to be a lot of flickering of the images on the screen as things get redrawn. You might check to see if you can optimize the screen refresh as things move aroun the screen.
Hope this helps,
--Mike
Thanks, Victor.
Wart wart@kobold.org wrote: Hi Victor,
Have you started making a srpm for the game yet, or are you still concentrating on the software itself?
--Mike
Victor Skovorodnikov wrote:
Hi folks,
I am, what could be considered as, in development of a game that I am planning to submit to Fedora's "extras" section. I am really not much of a gamer so I am not sure what the gamers' expectations of a good games are. This is a 2D shooter, and probably games need lot's of explosions and most are preferred to have shooting in them.
I will very much appreciate if you would kindly, if you have time, try out my game called "Maximum Destruction" and provide any feedback you may have on how to improve it, while I am trying to resolve the images licensing issues.
The game is on my site at:
http://www.victorsk.webhop.org
Any suggestions on the game's content or on how to improve will be greatly appreciated. Or, if you would like to participate in the development of this game or would like me to participate in the development of other games, please let me know.
Thank you very much, Victor.
Fedora-games-list mailing list Fedora-games-list@redhat.com http://www.redhat.com/mailman/listinfo/fedora-games-list
Blab-away for as little as 1¢/min. Make PC-to-Phone Calls using Yahoo! Messenger with Voice.
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Hi Mike,
Awesome feedback, thank you very much. Just exactly what I needed. Yes, screen flickering is something I've been working on recently as I am relying on a lot of XClearWindow() calls to redraw images. It didn't flicker as much on my end after I did some adjustments on my system but that's why it was important for me for someone else to try it out to get this feedback. I'll definitely make it work better.
Thank you very much, Victor.
Wart wart@kobold.org wrote: Victor Skovorodnikov wrote:
Hi Mike,
Thank you for replying. Nope, I haven't went this far yet. My main objective right now is to resolve the licensing issues and make sure that the game works the right way. Plus, it also needs to be mutated into a C++ code and I need to find a way to attach wxWidgets menus/preferences to it.
But, the core playable portion is working :-)
I had some trouble playing the game, mostly because the window size seems to be fixed at 900x700, which is larger than the 800x600 desktop I was using. Command line options to set the window size would be useful. It's also nice to have a -fullscreen option to fill the entire screen.
There also seems to be a lot of flickering of the images on the screen as things get redrawn. You might check to see if you can optimize the screen refresh as things move aroun the screen.
Hope this helps,
--Mike
Thanks, Victor.
Wart wrote: Hi Victor,
Have you started making a srpm for the game yet, or are you still concentrating on the software itself?
--Mike
Victor Skovorodnikov wrote:
Hi folks,
I am, what could be considered as, in development of a game that I am planning to submit to Fedora's "extras" section. I am really not much of a gamer so I am not sure what the gamers' expectations of a good games are. This is a 2D shooter, and probably games need lot's of explosions and most are preferred to have shooting in them.
I will very much appreciate if you would kindly, if you have time, try out my game called "Maximum Destruction" and provide any feedback you may have on how to improve it, while I am trying to resolve the images licensing issues.
The game is on my site at:
http://www.victorsk.webhop.org
Any suggestions on the game's content or on how to improve will be greatly appreciated. Or, if you would like to participate in the development of this game or would like me to participate in the development of other games, please let me know.
Thank you very much, Victor.
Fedora-games-list mailing list Fedora-games-list@redhat.com http://www.redhat.com/mailman/listinfo/fedora-games-list
Blab-away for as little as 1¢/min. Make PC-to-Phone Calls using Yahoo! Messenger with Voice.
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Victor Skovorodnikov wrote:
Hi Mike,
Awesome feedback, thank you very much. Just exactly what I needed. Yes, screen flickering is something I've been working on recently as I am relying on a lot of XClearWindow() calls to redraw images. It didn't flicker as much on my end after I did some adjustments on my system but that's why it was important for me for someone else to try it out to get this feedback. I'll definitely make it work better.
What you should do is create a pixmap (XImage), and do all the drawing / clearing there then call XPutImage to drop it on the screen in one call, or multiple calls if you want to optimise and only update a fre rectangular areas. After the XPUtImage call XFlush, then all should be well.
Regards,
Hans'
Hello Hans,
Thank you very much. Very kind of you to try my game. Yes, I've considered a double-buffering technique and I think I am making a small reference to it in my download page article and my reasoning against its use in this particular program.
I think I am going to ditch the XLib idea and try to do everything with wxWidgets because that will be easier to implement Window-control operations that Mike has mentioned needs work, and this game also needs to have menus and preferences if it has a chance to have any public exposure. Thank you again, I still have a lot of work ahead of me.
Thank you, Victor.
Hans de Goede j.w.r.degoede@hhs.nl wrote:
Victor Skovorodnikov wrote:
Hi Mike,
Awesome feedback, thank you very much. Just exactly what I needed. Yes, screen flickering is something I've been working on recently as I am relying on a lot of XClearWindow() calls to redraw images. It didn't flicker as much on my end after I did some adjustments on my system but that's why it was important for me for someone else to try it out to get this feedback. I'll definitely make it work better.
What you should do is create a pixmap (XImage), and do all the drawing / clearing there then call XPutImage to drop it on the screen in one call, or multiple calls if you want to optimise and only update a fre rectangular areas. After the XPUtImage call XFlush, then all should be well.
Regards,
Hans'
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On Mon, Apr 17, 2006 at 12:08:01PM -0700, Michael Thomas wrote:
It's probably not as common these days as it was 10 years ago to have multiple users per machine, but it's still something we should cater to.
Yes please.
-
Hans de Goede -
Jason L Tibbitts III -
Matthew Miller -
Michael Thomas -
Victor Skovorodnikov