Test whether a user has sudo privileges without requiring user input

Question

I have a local shell script that performs a number of tests on a remote host, before delivering the payload; one of these tests being whether the user has sudo privileges, checked simply with sudo -v however this requires the user to enter their password. Additionally the remote host seems to have instant sudo timeout so the password entry is required on every new connection, and this is something I don't have permission to change (as a policy).

I can of course test whether the user is part of certain groups, but then this would not be agnostic to the remote host configuration, so I was hoping there's a method that can check that doesn't need to assume the user's groups, as well as not needing user input?

Thanks!

UPDATE: To echo my comments, I only want to test whether a user could possibly sudo, without requiring user interaction for that test.

Answer 1

I'm afraid the only thing you can test is if the user has sudo privileges without a password.

Execute

sudo -n true

If $? is 0, the user has sudo access without a password, if $? is 1, the user needs a password.

If you need verification for a specific program, change true with your program, in a way the program doesn't do anything, like chmod --help

Answer 2

If you have one user with sudo access, like "root", you can use it to check other logins. As the user with access run:

sudo -n -l -U foo 2>&1 | egrep -c -i "not allowed to run sudo|unknown user"

If it returns zero, "foo" has access. Otherwise, it doesn't have sudo access.

Answer 3

I know that this is a super old question, but I found luck with the -n (non-interactive) flag and -v / -l. But, you do have to inspect the output:

$ sudo -vn && sudo -ln  #User with cached credentials
User adminuser may run the following commands on computername:
    (ALL) ALL
$ sudo -vn && sudo -ln  #User who _can_ sudo but isn't cached
sudo: a password is required
$ sudo -vn && sudo -ln  #User who can't at all
Sorry, user nonadmin may not run sudo on computername.

Some output-redirection and grepping will get you there, probably:

if (sudo -vn && sudo -ln) 2>&1 | grep -v 'may not' > /dev/null; then
  #they're cool
  exit 0 #Or, whatever
fi

Answer 4

sudo -l

That should give you enough to decide if you have the privs you want/need.