aur-build: drop privileges with setpriv(1)
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AladW
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AladW
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runuser(1)
There are three cases: 1. If UID==0, drop privileges for user commands (repo-add, gpg, makepkg) 2. If UID>0, raise privileges for root commands (pacman) 3. Otherwise, run the command as-is. This approach and gpg-set-passphrase(1) renders examples/chroot-batch obsolete, demonstrative purposes excepted.
The main difference between both commands is that runuser(1) uses a PAM session while setpriv(1) does not. From a practical perspective, runuser(1) is more lenient with environment variables: $ sudo setpriv --reuid archie printenv HOME DISPLAY /root :0:0 $ sudo setpriv --reuid archie --reset-env printenv HOME DISPLAY /home/archie $ sudo runuser --pty -u archie printenv HOME DISPLAY /home/archie :0:0 $ sudo runuser --pty -u archie -p printenv HOME DISPLAY /root :0:0 Having both HOME and DISPLAY set allows in particular to use `gpg(1)` with a graphical pinentry.
Together with runuser(1), this removes the need for the chroot-batch example.
Printing the runuser(1) command-line is only used in one place. Compose as_user and run_msg instead.
/dev/stdout points to /proc/self/fd/1, which has chmod 700 for the owning process. In particular, when running `aur-repo --status` with setpriv(1) or runuser(1) from a process run as root, the error /dev/stdout: Permission denied occurs. Remove the redirection and only add it if --status-file is specified.
runuser(1) --pty results in messy output, even when the man page claims it does not. The flag was used for the better security advertised in the manual. Instead of removing --pty, switch back to setpriv(1) without --reset-env and USER, HOME, LOGNAME and SHELL set manually.
This way "as_user" can be removed from the "Running makepkg ..." diagnostic
Fix a mistake introduced with 5c7db7e Add a similar `elif` statement for pacman.conf just in case.
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This turned out to be a lot more work than anticipated. On the flip-side, using |
AladW
changed the title
runuser(1)setpriv(1)
Earnestly
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Apr 2, 2022
Earnestly
reviewed
Apr 2, 2022
Earnestly
reviewed
Apr 2, 2022
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Another observation is that this seems much easier in languages exposing |
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Yes, but that means using |
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There are three cases:
UID == 0, drop privileges for user commands (e.g.repo-add,gpg,makepkg)UID > 0, raise privileges for root commands (pacman)aur-chroot)This approach and
gpg-set-passphrase(1)rendersexamples/chroot-batchobsolete, demonstrative purposes excepted. It can replaced by a corresponding section inaur-build(1).