IPP Mail Archive: RE: IPP> SEC - How could IPP work over firewalls?

RE: IPP> SEC - How could IPP work over firewalls?

Manros, Carl-Uno B (cmanros@cp10.es.xerox.com)
Fri, 31 Jul 1998 09:16:48 PDT

Paul,

You are right. This is a new piece of software that you cannot get from
stock.
This is why I stated: "This software will need to be tailored and
written to handle IPP".

Carl-Uno

> -----Original Message-----
> From: Paul Moore [mailto:paulmo@microsoft.com]
> Sent: Friday, July 31, 1998 8:33 AM
> To: 'Carl-Uno Manros'; ipp@pwg.org
> Subject: RE: IPP> SEC - How could IPP work over firewalls?
>
>
> Step 2 - Inbound proxies are unusual - I have never heard of one. Does
> anybody have a product names for one.
>
> > -----Original Message-----
> > From: Carl-Uno Manros [SMTP:manros@cp10.es.xerox.com]
> > Sent: Thursday, July 30, 1998 5:59 PM
> > To: ipp@pwg.org
> > Subject: IPP> SEC - How could IPP work over firewalls?
> >
> > We have held a meeting with some firewall and proxy experts
> today to get
> > their views on how IPP could work over firewalls. Here is a short
> > description of the scenario that came out of those discussions:
> >
> > When a print request (or other IPP request) comes in to the
> domain, in
> > which the IPP Printer is located, it goes through the
> following steps:
> >
> > 1) The firewall inspects the request on the TCP layer and
> typically checks
> > the host address and the port number. If it finds that this
> matches, it
> > redirects the request to a particular proxy server. This is standard
> > firewall software. The proxy server may be dedicated to handle only
> > HTTP/IPP, or could handle several application level protocols.
> >
> > 2) The proxy server includes an IPP specific application
> process, which
> > would check that the request is a valid IPP request, e.g.
> that it is an
> > HTTP POST and that it contains the MIME type "application/ipp". This
> > software will need to be tailored and written to handle IPP.
> >
> > 3) If TLS is used, the proxy server can also perform the
> authentication
> > and decryption services.
> >
> > 4) The proxy server then redirects the request to the IPP
> server inside
> > the domain. Note that the previous steps are performed
> before the request
> > is accepted into the domain.
> >
> > There are various configuration alternatives, e.g. the
> firewall and proxy
> > server may be integrated in the same box.
> >
> > A couple of other observations and bits of advice:
> >
> > - If you want unlimited access to an IPP printer, simply
> put it outside
> > the firewall, or on the domain border, so it can be
> accessed from both
> > outside and inside the domain.
> >
> > - If you want to let requests come in through your firewall
> at all, you
> > will probably *always* use TLS for requests from outside
> the domain. If
> > you let the proxy server handle authentication and
> encryption, there is no
> > real need to use TLS between the proxy server and the IPP
> server. This
> > means that clients from inside the domain do not need to
> use TLS, when
> > accessing the IPP server.
> >
> > Comments?
> >
> > Carl-Uno
> >
> > Carl-Uno Manros
> > Principal Engineer - Advanced Printing Standards - Xerox
> Corporation
> > 701 S. Aviation Blvd., El Segundo, CA, M/S: ESAE-231
> > Phone +1-310-333 8273, Fax +1-310-333 5514
> > Email: manros@cp10.es.xerox.com
>