Bug 1015559 - ksu ignores credentials stored in cache collections
ksu ignores credentials stored in cache collections
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: krb5 (Show other bugs)
Unspecified Unspecified
medium Severity medium
: rc
: ---
Assigned To: Nalin Dahyabhai
Patrik Kis
: Regression
: 1030002 (view as bug list)
Depends On:
Blocks: 854406
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Reported: 2013-10-04 09:50 EDT by Patrik Kis
Modified: 2014-06-17 21:07 EDT (History)
4 users (show)

See Also:
Fixed In Version: krb5-1.11.3-33.el7
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2014-06-13 05:53:09 EDT
Type: Bug
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

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Description Patrik Kis 2013-10-04 09:50:42 EDT
Description of problem:
Maybe this issue is caused by the not yet implemented kernel keyring cache, but rather file it to be sure.

Version-Release number of selected component (if applicable):

How reproducible:

Steps to Reproduce:
1. Create a kdc principals:
# kdb5_util -s create
# kadmin.local
kadmin.local:  ank alice
kadmin.local:  ank -randkey host/rhel7.pkis.net
kadmin.local:  ktadd host/rhel7.pkis.net
kadmin.local:  q
# useradd alice
# useradd bob
# service krb5kdc start

2. Allow alice to use ksu
# su - alice
$ echo 'alice@EXAMPLE.COM' >.k5login
$ exit

3. Try ksu
# su - bob
$ kinit alice
Password for alice@EXAMPLE.COM: 
$ klist 
Ticket cache: KEYRING:persistent:1001:1001
Default principal: alice@EXAMPLE.COM

Valid starting       Expires              Service principal
10/04/2013 15:47:59  10/05/2013 15:47:59  krbtgt/EXAMPLE.COM@EXAMPLE.COM
	renew until 10/04/2013 15:47:59
$ ksu alice
WARNING: Your password may be exposed if you enter it here and are logged 
         in remotely using an unsecure (non-encrypted) channel. 
Kerberos password for alice@EXAMPLE.COM: : 
No password given
Authentication failed.

Actual results:
ksu does not work as expected

Expected results:
ksu works as in RHEL-6:
[bob@rhel6 ~]$ ksu alice
Authenticated alice@EXAMPLE.COM
Account alice: authorization for alice@EXAMPLE.COM successful
Changing uid to alice (500)
[alice@rhel6 bob]$ id
uid=500(alice) gid=500(alice) groups=500(alice) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023

Additional info:
Comment 2 Nalin Dahyabhai 2013-10-16 16:50:32 EDT
While this is still being worked on, please include the versions of keyutils and the running kernel, as they affect what's going on underneath Kerberos.

As of 3.10.0-34.el7, I don't see a 'big_key' kernel module and 'keyctl get_persistent @s `id -u`' fails with an "operation not supported" error, so the kernel-side bits apparently aren't there yet.

This is a different bug, though, due in part to patches we added to ksu way back when FILE ccaches were the norm.
Comment 3 Patrik Kis 2013-10-17 10:48:08 EDT
I reproduced the issue on my updated RHEL-7 box with there packages:

# rpm -qa krb5\* kernel keyutils
Comment 4 Nalin Dahyabhai 2013-10-18 10:20:06 EDT
ksu doesn't seem to understand credential cache collections when it attempts to copy your credentials from them to a temporary, to perform ticket-based authentication.  There's one check that we could change that would make it work again, but the code still assumes that a "FILE" cache is being used in enough places that I'm uneasy calling that a proper fix.  I've opened an upstream ticket to solicit some advice.
Comment 8 Nalin Dahyabhai 2013-11-07 08:42:22 EST
Changes proposed upstream, adding current in-progress version of the fixes to krb5-1.11.3-30.el7.  We'll probably need to revise them, but in the meantime we can get some testing.
Comment 11 Patrik Kis 2013-11-13 09:42:34 EST
Hi Nalin,

I'm not sure if this issue is related but ksu still does not work is the target is root. The scenario below is working on RHEL-6.
BTW, the originally reported issue is working.

# echo Ariel@ZMRAZ.COM > /root/.k5login
# echo Ariel@ZMRAZ.COM > /home/Ariel/.k5login
# su - ktest
Last login: Wed Nov 13 09:31:01 EST 2013 on pts/0
$ kinit Ariel
Password for Ariel@ZMRAZ.COM: 
$ klist 
Ticket cache: KEYRING:persistent:1006:1006
Default principal: Ariel@ZMRAZ.COM

Valid starting       Expires              Service principal
11/13/2013 09:39:36  11/14/2013 09:39:36  krbtgt/ZMRAZ.COM@ZMRAZ.COM
	renew until 11/13/2013 09:39:36
$ ksu Ariel -e /bin/id
Authenticated Ariel@ZMRAZ.COM
Account Ariel: authorization for Ariel@ZMRAZ.COM for execution of
               /bin/id successful
Changing uid to Ariel (1005)
uid=1005(Ariel) gid=1005(Ariel) groups=1005(Ariel) context=unconfined_u:unconfined_r:unconfined_t:s0-s0:c0.c1023
$ ksu -e /bin/id
account root: authorization failed
Comment 12 Patrik Kis 2013-11-13 11:44:43 EST
The case above was opened as new bug 1030002
Comment 13 Nalin Dahyabhai 2013-11-13 17:47:10 EST
It turns out that, contrary to my initial diagnosis, it's actually part of this bug that I missed the first couple of revisions - marking #1030002 as a duplicate of this one.
Comment 14 Nalin Dahyabhai 2013-11-13 17:49:12 EST
*** Bug 1030002 has been marked as a duplicate of this bug. ***
Comment 18 Ludek Smid 2014-06-13 05:53:09 EDT
This request was resolved in Red Hat Enterprise Linux 7.0.

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