Subject: Re: Restricted mailer under UNIX

From: Barry Landy <[email-masked]>
Date: Mon, 8 Jul 1996 16:18:01 +0000

The short answer is yes. Pine provides (via pine.conf.fixed) the ability
to forbid all the ways to escape to a shell (via, say, an alternate
editor). Of course, you have to do a lot more that just lock the doors
in the mailer, you also have to provide a restricted shell system.

On 8 Jul 1996, Stephen R. van den Berg wrote:

:>Is Pine fit to be used as a restricted-shell mailer under UNIX?
:>Meaning, can it be configured to provide a 'secure' environment in which
:>no external programs or files can be started or viewed?
:>
:>Any other mailer that might be eligible?  Elm?
:>--
:>Sincerely,                                                          [email-masked]
:>           Stephen R. van den Berg (AKA BuGless).
:>
:>Are they twins?  Yes.  Are they *both* yours?
:>
:>

-------------------------------------------------------------------------------
Barry Landy                        Computer Laboratory:+44 1223 334600
Head of Systems and Development    Direct line:        +44 1223 334713
University of Cambridge Computing Service
New Museums Site                   Email:[email-masked]
Pembroke Street, Cambridge CB2 3QG

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From: [email-masked] (Stephen R. van den Berg)
Date: 8 Jul 1996 22:06:19 GMT

>in the mailer, you also have to provide a restricted shell system.

The restricted shell is what I have setup already (they simply get
pine as their login shell).

I've manage to shutdown everything hazardous by configuring it
in pine.conf.fixed, the only loopholes that still need to be
fixed are:

	Include attachment (I'd like to forbid that).
	Save attachment (I'd like to forbid that too, or make it
		impossible by specifying an impossible path).

What took some creative configuring to get right was the folder-collections,
but I set it to:

folder-collections     = mail/[]/.

Which effectively makes sure that mails cannot be saved anymore.
--
Sincerely,                                                          [email-masked]
           Stephen R. van den Berg (AKA BuGless).

Are they twins?  Yes.  Are they *both* yours?

---

From: [email-masked] (Stephen R. van den Berg)
Date: 8 Jul 1996 13:55:14 GMT

Is Pine fit to be used as a restricted-shell mailer under UNIX?
Meaning, can it be configured to provide a 'secure' environment in which
no external programs or files can be started or viewed?

Any other mailer that might be eligible?  Elm?
--
Sincerely,                                                          [email-masked]
           Stephen R. van den Berg (AKA BuGless).