d26run

d26run execute commands defined in /etc/d26run/exec as other users without your sudo password. using unix file permissions and groups, this gives you a simple way to do permission management, where every program may have different permissions. for example, you may create a new user for your web browser and then use d26run to start the browser. if you run another program as your normal user, it will not be able to access any of your web browser's data.

execs

files in /etc/d26run/exec define what commands should be executed and who is allowed to execute them.

An example of such a file:

# my main user
allow user mark

# another user named browser is used for web browsing
user browser
group browser

env unset XDG_RUNTIME_DIR
exec /bin/firefox

setup

# compile d26run
cargo build --release

and then as root:

# copy the executable into your $PATH (doesn't have to be /bin/)
cp target/release/d26run /bin/
# set file permissions (setuid/setgid)
chown root:root /bin/d26run
chmod 775 /bin/d26run
chmod ug+s /bin/d26run

# create config directory
mkdir -p /etc/d26run/exec

then create at least one config, and you can start using d26run.

execs

with groups

The d26r-code group gives the program access to the /code directory. Only some programs are allowed to see (or change!) code in my projects.

allow user mark

user d26r_code-main
group d26r_code-main
groups + d26r-code
groups + audio

env unset XDG_RUNTIME_DIR
exec /bin/terminal
arg -e
arg bash
arg -c
arg cd /code; tmux || bash || sh

running a command in a temporary user account

/etc/d26run/exec/temp:

allow anyone

user root
group root

env unset XDG_RUNTIME_DIR
exec /bin/bash
arg /etc/d26run/scripts/temp_command.sh
args all

A script creates a new user account, uses sudo to run the command, and, once the command exits, removes the user again. It runs pkill to end any background processes spawned by the temporary user.

/etc/d26run/scripts/temp_command.sh:

#!/bin/bash
my_id="$$"
mkdir -p /tmp/d26run-temphome
chmod 0755 /tmp/d26run-temphome
useradd --home-dir "/tmp/d26run-temphome/$my_id" --create-home --user-group --groups audio "d26r_temp_$my_id" 2>/dev/null

sudo -u "d26r_temp_$my_id" -D "/tmp/d26run-temphome/$my_id" -- "$@"

if userdel -r "d26r_temp_$my_id" 2>/dev/null; then              exit; else printf '\n.'; fi
pkill -u "d26r_temp_$my_id"
sleep 2
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.'; fi
sleep 2
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.'; fi
sleep 2
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.'; fi
sleep 2
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.'; fi
sleep 2
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '. '; fi
pkill -u "d26r_temp_$my_id" --signal kill
sleep 1
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.'; fi
sleep 1
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.'; fi
sleep 1
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.'; fi
sleep 1
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.'; fi
sleep 1
if userdel -r "d26r_temp_$my_id" 2>/dev/null; then printf '\n'; exit; else printf '.\n'; fi
userdel -rf "d26r_temp_$my_id"

to use sudo -D <dir>, add the following to a sudo config file (/etc/sudoers or /etc/sudoers.d/...): (you can remove -D <...> from the script if you don't want to change your sudo config)

Defaults:root runcwd=*