Chapter 11. Customized programs

98

11.9 Perl programs and modules

Perl programs and modules should follow the current Perl policy.

The Perl policy can be found in the

perl policy

files in the

debian policy

package. It is

also available from the Debian web mirrors at

/doc/packaging manuals/perl policy/

(

http://www.debian.org/doc/packaging manuals/perl policy/

)

.

11.10 Emacs lisp programs

Please refer to the  Debian Emacs Policy  for details of how to package emacs lisp programs.

The

Emacs

policy

is

available

in

debian emacs policy.gz

of

the

emacsen common

package.

It is also available from the Debian web mirrors at

/doc/packaging manuals/debian emacs policy (

http://www.debian.org/

doc/packaging manuals/debian emacs policy

)

.

11.11 Games

The permissions on

/var/games

are mode 755, owner

root

and group

root

.

Each game decides on its own security policy.

Games which require protected, privileged access to high score files, saved games, etc., may

be made set group id (mode 2755) and owned by

root.games

, and use files and directories

with appropriate permissions (770

root.games

, for example). They must not be made set 

user id, as this causes security problems. (If an attacker can subvert any set user id game they

can overwrite the executable of any other, causing other players of these games to run a Trojan

horse program. With a set group id game the attacker only gets access to less important game

data, and if they can get at the other players' accounts at all it will take considerably more

effort.)

Some packages, for example some fortune cookie programs, are configured by the upstream

authors to install with their data files or other static information made unreadable so that they

can only be accessed through set id programs provided. You should not do this in a Debian

package: anyone can download the

.deb

file and read the data from it, so there is no point

making the files unreadable. Not making the files unreadable also means that you don't have

to make so many programs set id, which reduces the risk of a security hole.

As described in the FHS, binaries of games should be installed in the directory

/usr/games

.

This also applies to games that use the X Window System. Manual pages for games (X and

non X games) should be installed in

/usr/share/man/man6

.