help with sudoers file

blancs · 07-22-2008, 05:45 PM

what i have set is below. I was wondering if there would be an easier way to allow the user access to the syslog to grep, vi, pico, more, or which ever way they want to view it. Or do i have to create a command in the sudoers file for each way?

User_Alias HEG = username
Cmnd_Alias MORESYSLOG = /bin/more /var/log/syslog
HEG ALL = (root) PASSWD: MORESYSLOG

Tinkster · 07-22-2008, 06:26 PM

There are varied possible approaches; a quick-fix would be to
make your user account member of the groups that have read-
access to the logs, in which case you won't need sudo at all.

Cheers,
Tink

jschiwal · 07-22-2008, 06:44 PM

You can list each command separated by ', ' as shown by the example in the sudoers manpage. Changing the permissions of the file or adding file acls may not work after log rotation. Some logs like Xorg.0.log are replaced each time. Looking at the syslog-ng.conf manpage, it seems that the gid() option is global, and you can't indicate facl's as an option as well.

blancs · 07-23-2008, 04:07 PM

So i separated each command with a comma shown below. From what I gathered from the man page the wildcard * could be used to match 0 to infinite characters, well maybe not that far but still for five and below it should have worked. however this doesnt seem to work? What am I doing wrong in regards to the wildcard? Seems to work otherwise.

User_Alias ASSAULTCUBE = %assaultcube

# Cmnd alias specification
Cmnd_Alias MORESYSLOG = /usr/bin/pico /var/log/syslog*,/bin/more /var/log/syslog*,/bin/cat /var/log/syslog*

# Defaults

Defaults !lecture,tty_tickets,!fqdn

# User privilege specification
root ALL=(ALL) ALL
ASSAULTCUBE ALL = (root) PASSWD: MORESYSLOG
ASSAULTCUBE ALL = (assaultcube) PASSWD: ALL

jschiwal · 07-25-2008, 05:42 PM

I think you are confusing the BNF grammer definition of a command alias with the actual syntax:

Code:

Alias ::= 'User_Alias'  User_Alias (':' User_Alias)* |
          'Runas_Alias' Runas_Alias (':' Runas_Alias)* |
          'Host_Alias'  Host_Alias (':' Host_Alias)* |
          'Cmnd_Alias'  Cmnd_Alias (':' Cmnd_Alias)*

User_Alias ::= NAME '=' User_List

Runas_Alias ::= NAME '=' Runas_List

Host_Alias ::= NAME '=' Host_List

Cmnd_Alias ::= NAME '=' Cmnd_List

NAME ::= [A-Z]([A-Z][0-9]_)*

Each alias definition is of the form

Alias_Type NAME = item1, item2, ...

The asterisk here means that you can have zero or more ':' Cmnd_Alias entries.

Also note that the "," is to separate commands in a command list. An Alias list has aliases separated with colons.

Also look in the manpages and documentation for programs like vim and less. They can be configured to not allow the shell escape. For example, allowing rvim or grvim to be run as root but not vim. These will run vim in a more secure mode without the shell escape. Only allowing the more restrictive versions of these programs may be an easier way to go, but there will be a number of holes to plug.