[EMAIL PROTECTED] asked:
> How do I restrict users from CD .. out of their directory?

I said:
> That's a meaningless question.
 
Michael Conlen wrote:
> > As far as ssh is concerned it's not relevant, however there are ways to keep
> > a user from changing down a directory. You just have to setup a complete
> > environment for the user in their home directory. This can be accomplished
> > with FreeBSD pretty easily using some make world options. The idea is that
> > you create an entire UNIX environment in their home directory and chroot
> > them to their home dir when they log in.

Brandon Fitch <[EMAIL PROTECTED]> said:
> or just use restricted bash.  Has to be version 2.x at minimum.  If
> you create a link called rbash to bash, it will be restricted.  Or
> run it "bash -r".  This also doesn't allow users to change their 
> path, so make sure anything they need is in their path.


Just like I said, the question is ill defined (meaningless).

A restricted shell does not prevent anything:

[pascal@thalassa pascal]$ rbash
[pascal@thalassa pascal]$ cd /
rbash: cd: restricted
[pascal@thalassa pascal]$ ls /tmp/a
/tmp/a
[pascal@thalassa pascal]$ csh
/home/pascal> cd /
/> 

And  while a  chroot jails  may prevent  the user  to access  files in
parent and cousin directories, it  does not prevent the user to change
the working directory (within the chroot jail).


Anyway,  the working  directory is  only  used to  specify files  with
relative  paths.  You  can  always access  all  accessible files  with
absolute paths. That's why it's useless to try to prevent changing the
working directory. That's only convenience operation.


Now if only pruittr would reformulate his question and express exactly
what that is he wants to archive...


Note that  as soon as the "shell"  the user is connected  to allows to
create any executable file (or  allow the execution of a programm that
allows  to create  any  executable file),  that  is if  it allows  the
creation  of arbitrary  files  and  the execution  of  the same,  then
anything you can  setup in the environment can  be circumvented if not
implemented at  the OS level  (file system protections,  chroot jails,
etc). That means  that either you have to give the  users access to an
extremely restricted application (a  "shell" would be too permissive),
or you have to severely  restrict the _access_rights_ to the files and
directories both above and bellow  the directory in which you want the
user confined.


-- 
__Pascal_Bourguignon__              (o_ Software patents are endangering
()  ASCII ribbon against html email //\ the computer industry all around
/\  and Microsoft attachments.      V_/ the world http://lpf.ai.mit.edu/
1962:DO20I=1.100  2001:my($f)=`fortune`;  http://petition.eurolinux.org/

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