From owner-freebsd-hackers Tue Jul 13 2:29:52 1999 Delivered-To: freebsd-hackers@freebsd.org Received: from relay03.indigo.ie (relay03.indigo.ie [194.125.133.227]) by hub.freebsd.org (Postfix) with SMTP id 4265F14EF1 for ; Tue, 13 Jul 1999 02:29:39 -0700 (PDT) (envelope-from niall@pobox.com) Received: (qmail 26161 messnum 46249 invoked from network[194.125.134.40/ts01-040.dublin.indigo.ie]); 13 Jul 1999 09:28:55 -0000 Received: from ts01-040.dublin.indigo.ie (HELO pobox.com) (194.125.134.40) by relay03.indigo.ie (qp 26161) with SMTP; 13 Jul 1999 09:28:55 -0000 Message-ID: <378B21EE.9E41D3E8@pobox.com> Date: Tue, 13 Jul 1999 11:24:30 +0000 From: Niall Smart X-Mailer: Mozilla 4.6 [en] (X11; I; FreeBSD 3.2-STABLE i386) X-Accept-Language: en MIME-Version: 1.0 To: "Brian F. Feldman" Cc: Sheldon Hearn , Doug , John Polstra , imp@village.org, hackers@FreeBSD.org Subject: Re: a BSD identd References: Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG "Brian F. Feldman" wrote: > On Mon, 12 Jul 1999, Sheldon Hearn wrote: > > On Sun, 11 Jul 1999 12:47:30 MST, Doug wrote: > > > > > Finally, Brian might want to search the bugtraq archives before > > > he commits anything. There have been quite a few identd related > > > discussions, and it would be points in our favor if we didn't come out > > > with anything that had known exploits. [snip] > > It's "out with the bad, in with the good." Pidentd code is pretty terrible. Agreed, nobody wants a monstrosity of an ident daemon in the base system. > The only security concerns with my code were wrt FAKEID, and those were > mostly fixed (mostly meaning that a symlink _may_ be opened, but it won't > be read.) Your code is still insecure, I can still obtain 16 characters of the first line of any file in the system just by symlinking to it. I don't see how you expect your checks to defeat that. What you should do is setgid && setuid to the user returned by net.inet.tcp.getcred immediately after doing the sysctl. Or even better take out this FAKEID stuff. > If anyone wants to audit my code for security, I invite them to. > But frankly, I highly doubt anyone will find anything to exploit. Heh, famous last words. > And, why would bugtraq advisories against other identds apply to my > ident_stream service? This is an entirely different code base. That doesn't matter, different programmers make the same mistakes and assumptions when solving the same problem (there is research into the effectiveness of N-way programming which shows this) and many attacks are against subtle implementation mistakes which you may also make. Regards, Niall To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message