How to run a programm with anothter user?

kcynice · 03-06-2014, 10:41 PM

The system has two normal user a and b. And, a was logined into the system. But there was a executable program owned by b, of course a had no permission to run it directly.
I want to know, if there was a way to run a program with the right user?
I do not want to change the current logined user, in another words, no logout.

Thanks.

evo2 · 03-06-2014, 11:04 PM

Hi,

that is what su is for. Eg for use a to become user b..

Code:

su -l b

then execute the program.
Or do in one command:

Code:

su -c /path/to/executable a

Evo2.

kcynice · 03-06-2014, 11:47 PM

Quote:

Originally Posted by evo2

Hi,

that is what su is for. Eg for use a to become user b..

Code:

su -l b

then execute the program.
Or do in one command:

Code:

su -c /path/to/executable a

Evo2.

OK. thanks. that might be the only way. it seems I have to obtain the password of user b.

evo2 · 03-06-2014, 11:55 PM

Hi,

Quote:

Originally Posted by kcynice

OK. thanks. that might be the only way. it seems I have to obtain the password of user b.

Why not ask that user to make that program executable by all? Or, if you have read permission you can copy it and run the copy.

Evo2.

chrism01 · 03-07-2014, 04:22 AM

Alternatives:

1. put both users in the same group and use group perms
2. sudo (nb sudo to other user 'B', not as root)

Smokey_justme · 03-07-2014, 05:01 AM

Wouldn't setuid resolve this? Or am I misunderstanding something?

P.S. To put both users in the same group and use group permissions is, in my personal opinion, the best way to do it..

jpollard · 03-07-2014, 11:29 PM

Quote:

Originally Posted by Smokey_justme

Wouldn't setuid resolve this? Or am I misunderstanding something?

You loose security control over the second user. Anyone that runs the program would become that user - and unless the program is CAREFULLY written, the user account could be completely taken over.

Quote:

P.S. To put both users in the same group and use group permissions is, in my personal opinion, the best way to do it..

That is the best way.

Madhu Desai · 03-08-2014, 08:14 AM

Quote:

Originally Posted by kcynice

The system has two normal user a and b. And, a was logined into the system. But there was a executable program owned by b, of course a had no permission to run it directly.
I want to know, if there was a way to run a program with the right user?
I do not want to change the current logined user, in another words, no logout.

You (user b) can use ACL for this. ACL is specifically designed for this.

Give execute permission for directory where the program is.
Then, give read and execute permission for program/script file

Ex:

Code:

[b@gamma ~]$ ls -l /home/b/sayhello 
-rwx------. 1 b b 28 Mar  7 15:34 /home/b/sayhello

[b@gamma ~]$ setfacl -m u:a:x /home/b
[b@gamma ~]$ setfacl -m u:a:rx /home/b/sayhello

[a@gamma ~]$ /home/b/sayhello
Hello Ji

Here a and b are users