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Date:      Mon, 2 Nov 1998 14:03:45 +0100 (CET)
From:      Mikael Karpberg <karpen@ocean.campus.luth.se>
To:        jas@flyingfox.com (Jim Shankland)
Cc:        dima@best.net, freebsd-security@FreeBSD.ORG
Subject:   Re: SSH vsprintf patch. (You've been warned Mr. Glass)
Message-ID:  <199811021303.OAA24194@ocean.campus.luth.se>
In-Reply-To: <199811020832.AAA15786@biggusdiskus.flyingfox.com> from Jim Shankland at "Nov 2, 98 00:32:12 am"

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According to Jim Shankland:
> dima@best.net (Dima Ruban) writes:
> 
> > Let me ask you this. Would you trust a packet that came from
> > non-priviledged port and which wants to do something that even
> > remotely should be secure?
> 
> No.  Same as for a packet that came from a privileged port.
> 
> A packet's source port is a pretty weak authenticator, to coin
> an understatement.

Why? I'd say it's a pretty safe way of authentication. Specially as a
first check, before you move on to stronger checks. I'd say you can't
spoof it, since the trusted machines on your net (and you check that it's
a trusted machine first, you know) will not let any user grab such ports,
and you (OFCOURSE!!!) have a firewall or router between your net and the
internet that will reject any incomming packets with source addreses from
the inside net.

It's all in the enviroment.

  /Mikael

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