Content-Type: text/plain
Content-Disposition: inline
Content-Transfer-Encoding: binary
MIME-Version: 1.0
X-Mailer: MIME-tools 5.411 (Entity 5.404)
X-RT-Original-Encoding: iso-8859-1
Content-Length: 3332

From donn@u.washington.edu  Wed Dec  5 15:37:58 2001
Received: from fort-point-station.mit.edu (FORT-POINT-STATION.MIT.EDU [18.7.7.76])
	by rt-11.mit.edu (8.9.3/8.9.3) with ESMTP id PAA15082
	for <bugs@RT-11.mit.edu>; Wed, 5 Dec 2001 15:37:57 -0500 (EST)
Received: from melville.u.washington.edu (melville.u.washington.edu [128.95.135.35])
	by fort-point-station.mit.edu (8.9.2/8.9.2) with ESMTP id PAA08747
	for <krb5-bugs@mit.edu>; Wed, 5 Dec 2001 15:37:56 -0500 (EST)
Received: (from donn@localhost)
	by melville.u.washington.edu (8.11.6+UW01.08/8.11.6+UW01.10) id fB5Kbuh43700;
	Wed, 5 Dec 2001 12:37:56 -0800
Message-Id: <200112052037.fB5Kbuh43700@melville.u.washington.edu>
Date: Wed, 5 Dec 2001 12:37:56 -0800
From: donn@u.washington.edu
Reply-To: donn@u.washington.edu
To: krb5-bugs@mit.edu
Subject: ftpd forms its service principal from host name, not connection
X-Send-Pr-Version: 3.99

>Number:         1023
>Category:       krb5-appl
>Synopsis:       ftpd service principal is hostname, not address lookup
>Confidential:   no
>Severity:       serious
>Priority:       medium
>Responsible:    krb5-unassigned
>State:          analyzed
>Class:          sw-bug
>Submitter-Id:   unknown
>Arrival-Date:   Wed Dec  5 15:38:00 EST 2001
>Last-Modified:  Mon Apr  8 15:16:44 EDT 2002
>Originator:     Donn Cave
>Organization:
	University Computing Services
	University of Washington
>Release:        krb5-1.2.2
>Environment:
	(Any UNIX)
System: AIX melville 3 4 00600210C000


>Description:
	On host with multiple interfaces, each with its own IP and DNS
	addresses, ftp connections to any but one of the addresses fails
	with "wrong principal".  While this could be solved by modifying
	krb5_gss_accept_sec_contect() to pass no service principal to
	krb5_rd_req(), it would arguably be better for ftpd to at least
	use the DNS name associated with the connection.
>How-To-Repeat:
	Equip a host with more than one network interface, and ftp service
	principals for each.  Connect to a DNS name that doesn't match
	gethostname(); ftp will form a service principal from the DNS name,
	but ftpd will use gethostname().
>Fix:
*** appl/gssftp/ftpd/ftpd.c.pltx	Wed Aug  8 13:32:06 2001
--- appl/gssftp/ftpd/ftpd.c	Mon Dec  3 16:13:44 2001
***************
*** 2391,2397 ****
  			syslog(LOG_ERR, "Couldn't get local hostname (%d)", errno);
  			return 0;
  		}
! 		if (!(hp = gethostbyname(localname))) {
  			reply(501, "couldn't canonicalize local hostname\n");
  			syslog(LOG_ERR, "Couldn't canonicalize local hostname");
  			return 0;
--- 2391,2399 ----
  			syslog(LOG_ERR, "Couldn't get local hostname (%d)", errno);
  			return 0;
  		}
! 		/* if (!(hp = gethostbyname(localname))) { */
! 		hp = gethostbyaddr(&ctrl_addr.sin_addr.s_addr, 4, AF_INET);
! 		if (!hp) {
  			reply(501, "couldn't canonicalize local hostname\n");
  			syslog(LOG_ERR, "Couldn't canonicalize local hostname");
  			return 0;
>Audit-Trail:

State-Changed-From-To: open-analyzed
State-Changed-By: hartmans
State-Changed-When: Mon Apr  8 15:13:50 2002
State-Changed-Why:
This seems like a reasonable solution to the problem.
If we don't end up dropping ftp and recommending peope use
one of the other  ftp implementations
before the next release off the trunk, adopting an implementation of this patch
that works with IPV6 would be good.

>Unformatted: