Is there a way to require a user to wait a certain time instead of asking for a password every time he wants to execute a command as root or access the root / or another user account?
This would literally render sudo utterly useless. Sudo is meant to require password to accomplish admin tasks. In your scenario anyone using your computer can do anything without knowing the password.
This is not entirely accurate; there are plenty of times when sudo does not require a password even in the default config. And there’s the nopasswd option built-in already which would already do that portion of this request.
It sounds like the OP wants to use sudo as a Molly-guard. There’s nothing wrong with that, although it may not be the right tool for the job.
While I pretty much agree, I can definitely think of a few sporadic times doing sysadmin where things have gone so significantly wrong that an enforced sanity-check on every sudo command would have been appreciated.
There are plenty of ways to configure Linux to circumvent sudo. I've even seen people who log in as root by default. I do not, however, advise anyone to do that even if it's just, as you put it, a Molly Guard. It has prevented me personally from doing catastrophic things to my system on a number of occasions.
Do you mean the delay between when you need to re-enter the superuser password?
I found this via an LLM:
To change the delay before needing to re-enter your sudo password, follow these steps:
Open the terminal and run:
sudo visudo
Locate the line:
Defaults env_reset
Add the following line below it:
Defaults timestamp_timeout=<time-in-minutes>
Replace <time-in-minutes> with the desired timeout in minutes (e.g., 30 for 30 minutes). Setting it to 0 requires a password every time, while a negative value disables the timeout entirely.
pam_faildelay almost does it, but it only delays on auth failure. You would want something that delays on success. Might be almost as simple as “if not” on a check on pam_faildelay.
If an untrusted user is sitting at the console of a sudoer account, armed with its password, all is lost and any security has effectively been defeated already. While I do understand the concern it seems like something of a moot point.
I can’t find anything that quite fits your requirements.
Putting a NOPASSWD option on your sudo config should cover the removal of the password requirement, but this may be ill -advised; it is probably wiser to increase the timestamp_timeout duration.
The intentional delay is tougher, and for that it looks like you’d need to write a PAM module. pam_faildelay is very close to what you need, you’d just need to make it produce a delay on success as well as failure.
Sure, though I advise against it. The following C program can do that:
\#include <stdio.h>
\#include <stdlib.h>
\#include <unistd.h>
int main(int argc, char **argv) {
if (argc < 2) {
fprintf(stderr, "usage: %s <command> <args>...", argv[0]);
return EXIT_FAILURE;
}
printf("Executing");
for (int i = 1; i < argc; ++i) {
printf(" %s", argv[i]);
}
puts("\nPress ^C to abort.");
sleep(5);
if (setuid(0)) {
perror("setuid");
return EXIT_FAILURE;
}
execvp(argv[1], argv + 1);
perror(argv[1]);
return EXIT_FAILURE;
}
As seen in:
$ gcc -O2 -o delay-su delay-su.c
$ sudo chown root:sudo delay-su
$ sudo chmod 4750 delay-su
$ ./delay-su id
$ id -u
1000
$ ./delay-su id -u
Executing id -u
^C to abort
0
This will allow anyone in group sudo to execute any command as root. You may change the group to something else to control who exactly can run the program (... Show more...
Sure, though I advise against it. The following C program can do that:
\#include <stdio.h>
\#include <stdlib.h>
\#include <unistd.h>
int main(int argc, char **argv) {
if (argc < 2) {
fprintf(stderr, "usage: %s <command> <args>...", argv[0]);
return EXIT_FAILURE;
}
printf("Executing");
for (int i = 1; i < argc; ++i) {
printf(" %s", argv[i]);
}
puts("\nPress ^C to abort.");
sleep(5);
if (setuid(0)) {
perror("setuid");
return EXIT_FAILURE;
}
execvp(argv[1], argv + 1);
perror(argv[1]);
return EXIT_FAILURE;
}
As seen in:
$ gcc -O2 -o delay-su delay-su.c
$ sudo chown root:sudo delay-su
$ sudo chmod 4750 delay-su
$ ./delay-su id
$ id -u
1000
$ ./delay-su id -u
Executing id -u
^C to abort
0
This will allow anyone in group sudo to execute any command as root. You may change the group to something else to control who exactly can run the program (you cannot change the user of the program).
If there’s some specific command you want to run, it’s better to hard-code it or configure sudo to allow execution of that command without password.
Peter G
in reply to dontblink • • •Hawke
in reply to Peter G • • •This is not entirely accurate; there are plenty of times when sudo does not require a password even in the default config. And there’s the nopasswd option built-in already which would already do that portion of this request.
It sounds like the OP wants to use sudo as a Molly-guard. There’s nothing wrong with that, although it may not be the right tool for the job.
molly-guard - Wiktionary, the free dictionary
Wiktionarymina86
in reply to Hawke • • •sudoalready acts as a molly-guard. Whatever OP wants to do I won’t stop them, but they are doing something strange.enkers
in reply to mina86 • • •Peter G
in reply to Hawke • • •terminal
in reply to dontblink • • •Do you mean the delay between when you need to re-enter the superuser password?
I found this via an LLM:
To change the delay before needing to re-enter your
sudopassword, follow these steps:Replace
<time-in-minutes>with the desired timeout in minutes (e.g.,30for 30 minutes). Setting it to0requires a password every time, while a negative value disables the timeout entirely.Mazesecle
in reply to terminal • • •navordar
in reply to Mazesecle • • •TurboWafflz
in reply to terminal • • •"~~I found this via an LLM~~"
"Here's a made up answer"
Lka1988
in reply to terminal • • •Mark
in reply to dontblink • •Linux reshared this.
mbirth 🇬🇧
in reply to dontblink • • •Arthur Besse
in reply to dontblink • • •sure. first, configure sudo to be passwordless, or perhaps just to stay unlocked for longer (it's easy to find instructions for how to do that).
then, put this in your
~/.bashrc:alias sudo='echo -n "are you sure? "; for i in $(seq 5); do echo -n "$((6 - $i)) "; sleep 1; done && echo && /usr/bin/sudo 'Now "sudo" will give you a 5 second countdown (during which you can hit ctrl-c if you change your mind) before running whatever command you ask it to.
like this
timlyo likes this.
Flyswat
in reply to Arthur Besse • • •In terms of security, an alias can be easily overridden by a user who can even choose yo use another shell which will not read .bashrc.
So this solution cannot force/require the user to comply to the delay requirement.
I was thinking maybe with a PAM module the delay can be achieved but I haven't found one that readily does that. Maybe OP needs to implement one 😀
like this
timlyo likes this.
Hawke
in reply to Flyswat • • •alphadont
in reply to Flyswat • • •Hawke
in reply to dontblink • • •I can’t find anything that quite fits your requirements.
Putting a NOPASSWD option on your sudo config should cover the removal of the password requirement, but this may be ill -advised; it is probably wiser to increase the timestamp_timeout duration.
The intentional delay is tougher, and for that it looks like you’d need to write a PAM module. pam_faildelay is very close to what you need, you’d just need to make it produce a delay on success as well as failure.
like this
timlyo likes this.
mina86
in reply to dontblink • • •Sure, though I advise against it. The following C program can do that:
As seen in:
This will allow anyone in group
sudoto execute any command as root.You may change the group to something else to control who exactly can
run the program (... Show more...
Sure, though I advise against it. The following C program can do that:
As seen in:
This will allow anyone in group
sudoto execute any command as root.You may change the group to something else to control who exactly can
run the program (you cannot change the user of the program).
If there’s some specific command you want to run, it’s better to
hard-code it or configure
sudoto allow execution of that commandwithout password.
like this
timlyo likes this.
Read Bio
in reply to mina86 • • •mina86
in reply to Read Bio • • •Read Bio
in reply to mina86 • • •deadcatbounce
in reply to dontblink • • •Yes; the command prefix that you're looking for is
shutdown now ; (followed by your sudo command if you wish)It will provide the appropriate delay before using the root command via sudo or having logged again as root (sigh)!
like this
Ⓜ3️⃣3️⃣ 🌌 likes this.
Ⓜ3️⃣3️⃣ 🌌
in reply to deadcatbounce • • •deadcatbounce
in reply to Ⓜ3️⃣3️⃣ 🌌 • • •Please don't desecrate my Linux with (what I assume is) Windows talk.
Bleugh! I need a shower!
[The worst Linux users are ex Windows users; 2004 vintage here]
Ⓜ3️⃣3️⃣ 🌌
in reply to deadcatbounce • • •Linux reshared this.
deadcatbounce
in reply to Ⓜ3️⃣3️⃣ 🌌 • • •