From owner-freebsd-questions@FreeBSD.ORG  Mon Jul  3 09:51:00 2006
Return-Path: <owner-freebsd-questions@FreeBSD.ORG>
X-Original-To: freebsd-questions@freebsd.org
Delivered-To: freebsd-questions@freebsd.org
Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125])
	by hub.freebsd.org (Postfix) with ESMTP id F28FB16A403
	for <freebsd-questions@freebsd.org>;
	Mon,  3 Jul 2006 09:51:00 +0000 (UTC)
	(envelope-from jonathan@hst.org.za)
Received: from sirian.hst.org.za (sirian.hst.org.za [209.203.2.130])
	by mx1.FreeBSD.org (Postfix) with ESMTP id 18C5943E31
	for <freebsd-questions@freebsd.org>;
	Mon,  3 Jul 2006 09:50:59 +0000 (GMT)
	(envelope-from jonathan@hst.org.za)
Received: from localhost (localhost.hst.org.za [127.0.0.1])
	by sirian.hst.org.za (Postfix) with ESMTP id 4824331C85C
	for <freebsd-questions@freebsd.org>;
	Mon,  3 Jul 2006 11:54:29 +0200 (SAST)
Received: from sirian.hst.org.za ([127.0.0.1])
	by localhost (sirian.hst.org.za [127.0.0.1]) (amavisd-new, port 10024)
	with ESMTP id 68649-10 for <freebsd-questions@freebsd.org>;
	Mon,  3 Jul 2006 11:54:29 +0200 (SAST)
Received: by sirian.hst.org.za (Postfix, from userid 1004)
	id 1848731C7FE; Mon,  3 Jul 2006 11:54:29 +0200 (SAST)
Received: from sysadmin.int.dbn.hst.org.za (sysadmin.int.dbn.hst.org.za
	[10.1.1.20]) by sirian.hst.org.za (Postfix) with ESMTP id 5D67531C7AE
	for <freebsd-questions@freebsd.org>;
	Mon,  3 Jul 2006 11:54:28 +0200 (SAST)
From: Jonathan McKeown <jonathan@hst.org.za>
Organization: Health Systems Trust
To: freebsd-questions@freebsd.org
Date: Mon, 3 Jul 2006 12:07:50 +0200
User-Agent: KMail/1.7.2
MIME-Version: 1.0
Content-Type: text/plain;
  charset="us-ascii"
Content-Transfer-Encoding: 7bit
Content-Disposition: inline
Message-Id: <200607031207.50714.jonathan@hst.org.za>
X-Spam-Checker-Version: SpamAssassin 2.61 (1.212.2.1-2003-12-09-exp) on 
	sirian.hst.org.za
X-Spam-Level: 
X-Spam-Status: No, hits=-4.9 required=7.0 tests=BAYES_00 autolearn=ham 
	version=2.61
X-Virus-Scanned: by amavisd-new at hst.org.za
Subject: require pam_deny in auth chain causes logins to fail
X-BeenThere: freebsd-questions@freebsd.org
X-Mailman-Version: 2.1.5
Precedence: list
List-Id: User questions <freebsd-questions.freebsd.org>
List-Unsubscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=unsubscribe>
List-Archive: <http://lists.freebsd.org/pipermail/freebsd-questions>
List-Post: <mailto:freebsd-questions@freebsd.org>
List-Help: <mailto:freebsd-questions-request@freebsd.org?subject=help>
List-Subscribe: <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>, 
	<mailto:freebsd-questions-request@freebsd.org?subject=subscribe>
X-List-Received-Date: Mon, 03 Jul 2006 09:51:01 -0000

pam.d/README says:

Note that having a "sufficient" module as the last entry for a
particular service and module type may result in surprising behaviour.
To get the intended semantics, add a "required" entry listing the
pam_deny module at the end of the chain.

But in fact

auth sufficient pam_unix.so
auth required   pam_deny.so

always fails, because (from the PAM article):

The second exception is that pam_setcred(3) treats binding and sufficient 
modules as if they were required

which means the final decision drops through to pam_deny even if pam_unix 
succeeds.

Other than the obvious (make pam_unix, or whatever is the last module in the 
auth chain, required rather than sufficient, and leave out the required 
pam_deny) is there another solution to this?

Jonathan