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?
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.
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.
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.
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.
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.
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.