using gksu to run an X program as a different user other than root is broken

[Bjorn Hansen]

say I am logged in as user1. At a command prompt I type:
$ su user2 somecommand
and at the password prompt user2's password must be entered.
But if I type:
$ gksu -u user2 somecommand
and enter user2's password, I get:
GNOME_SUDO_PASS
sudo: 1 incorrect password attempt
and a pop up box telling me "Wrong password." However, if I enter user1's password it proceeds and runs the command. This is very wrong behavior IMHO.

I gather this is because gksudo has been patched to use sudo as backend authentication, equivalent to (?) using the --sudo-mode flag in the unpatched version. according to the man page:
 --sudo-mode, -S

              Use sudo instead of su as backend authentication system. Notice
              that the X authorization magic will not work when using sudo for
              target users other than root.

and therin lies the problem; the X authorization magic is broken.

For correct behavior, if I am logged in as user1 and user2 wants to run say, their mail program, without logging out and loging into their own desktop, they should be able to type 'gksudo -u user2 mailprogram' and have it work (this used to work in previous versions)

[Sebastian Heinlein (glatzor)]

firstly gksu now defaults to the sudo mode.

so you would like to see this changed?

secondly there is a bug in gksu using a wrong path for xauth.

[Bjorn Hansen (holomorph)]

I think it's ok if it defaults to sudo mode, but the man page should reflect this, and there should be a way to get the other behavior (eg an --su-mode flag). Is this possible?

On the other hand it seems a bit silly to have it default to sudo mode, since there is also a 'gksudo' command.

[Sebastian Heinlein (glatzor)]

Ubuntu doesn't use a root login. So a gksu that is by default in sudo mode provides compatibility with systems that use a root login.

There is an option in gconf: /apps/gksu/sudo-mode

[Bjorn Hansen (holomorph)]

I think it's ok if it defaults to sudo mode, but the man page should reflect this, and there should be a way to get the other behavior (eg an --su-mode flag). Is this possible?

On the other hand it seems a bit silly to have it default to sudo mode, since there is also a 'gksudo' command.

[Bjorn Hansen (holomorph)]

sorry, accidentally refreshed the page which caused the duplicate post. . .

[Bjorn Hansen (holomorph)]

ok, so it appears that not using sudo mode by default would be bad since gksudo is just a shortcut to gksu:
lrwxrwxrwx 1 root root 4 2006-05-13 01:03 /usr/bin/gksudo -> gksu

It would be nice if they were actually different, where gksudo would use sudo mode, and gksu would not (especially if the bug w/ the xauth stuff were to get fixed with gksu)

[Christophe Charlot (c-charlot)]

this looks like a duplicate of bug #47388, no ?

[towsonu2003 (towsonu2003)]

closing as this is a duplicate.