Bug 837602 - cups + krb: it falls down into basic authorization instead of negotiate
cups + krb: it falls down into basic authorization instead of negotiate
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: cups (Show other bugs)
Unspecified Unspecified
high Severity high
: rc
: ---
Assigned To: Tim Waugh
Petr Sklenar
: Patch, Regression
: 842782 (view as bug list)
Depends On:
  Show dependency treegraph
Reported: 2012-07-04 07:02 EDT by Petr Sklenar
Modified: 2014-06-13 07:47 EDT (History)
4 users (show)

See Also:
Fixed In Version:
Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
Last Closed: 2014-06-13 07:47:21 EDT
Type: Bug
Regression: ---
Mount Type: ---
Documentation: ---
Verified Versions:
Category: ---
oVirt Team: ---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: ---

Attachments (Terms of Use)
Upstream patch (638 bytes, patch)
2012-12-18 05:57 EST, Tim Waugh
no flags Details | Diff

External Trackers
Tracker ID Priority Status Summary Last Updated
CUPS Bugs and Features 4140 None None None 2012-07-18 08:01:10 EDT

  None (edit)
Description Petr Sklenar 2012-07-04 07:02:16 EDT
Description of problem:
cups + krb: it falls down into basic authorization instead of negotiate
There is error: 'Authorized using Basic, expected Negotiate!'

Version-Release number of selected component (if applicable):
# rpm -q cups

# rpm -qa | grep krb

How reproducible:

Steps to Reproduce:
1. set up cups + krb5, DefaultAuthType=Negotiate
2. user has valid ticket

# klist 
Ticket cache: FILE:/tmp/krb5cc_0
Default principal: KerberesiedPetr@EXAMPLE.COM

Valid starting     Expires            Service principal
07/04/12 10:57:43  07/05/12 10:57:43  krbtgt/EXAMPLE.COM@EXAMPLE.COM
	renew until 07/04/12 10:57:43

3. user is in the root group, 
# id KerberesiedPetr
uid=1001(KerberesiedPetr) gid=1001(KerberesiedPetr) groups=1001(KerberesiedPetr),0(root)

4. lpadmin -p $TPRN1 -v file:/dev/null -E -m $ML
Actual results:
lpadmin expect password for root on localhost?  


D [04/Jul/2012:10:48:10 -0400] cupsdReadClient: 19 1.1 CUPS-Add-Modify-Printer 1
D [04/Jul/2012:10:48:10 -0400] CUPS-Add-Modify-Printer ipp://localhost:631/printers/testprinter1
D [04/Jul/2012:10:48:10 -0400] cupsdIsAuthorized: username="root"
E [04/Jul/2012:10:48:10 -0400] Authorized using Basic, expected Negotiate!
D [04/Jul/2012:10:48:10 -0400] Returning HTTP Unauthorized for CUPS-Add-Modify-Printer (ipp://localhost:631/printers/testprinter1) from localhost

Expected results:
no password is expected

Additional info:
rhel6 works well with exactly same settings
Comment 4 Tim Waugh 2012-07-17 12:50:33 EDT
This seems to be due to a check in the server end about whether this is a local connection:

scheduler/client.c:2719 (cupsdSendHeader):

    else if (auth_type == CUPSD_AUTH_NEGOTIATE)
#  ifdef AF_LOCAL
      if (_httpAddrFamily(con->http.hostaddr) == AF_LOCAL)
        strlcpy(auth_str, "Basic realm=\"CUPS\"", sizeof(auth_str));
#  endif /* AF_LOCAL */
      strlcpy(auth_str, "Negotiate", sizeof(auth_str));
#endif /* HAVE_GSSAPI */

Adjusting the lpadmin command to add "-h $IP_ADDR" with the external IP address of the machine allows it to succeed.

This seems to have been added as part of upstream revision 9732 on trunk:

commit 8e48ce8bd6acc030f9e913cd80ed31e7465d7ef1
Author: mike <mike@7a7537e8-13f0-0310-91df-b6672ffda945>
Date:   Sun May 1 19:55:04 2011 +0000

    Use GSS framework, when available, and support acquisition of Kerberos creds
    when the underlying libraries support it (may add others as time permits).
    git-svn-id: http://svn.easysw.com/public/cups/trunk@9732 7a7537e8-13f0-0310-91df-b6672ffda945
Comment 5 Tim Waugh 2012-07-18 08:01:10 EDT
Reported upstream.
Comment 6 Tim Waugh 2012-08-03 07:17:05 EDT
*** Bug 842782 has been marked as a duplicate of this bug. ***
Comment 9 Tim Waugh 2012-12-18 05:57:33 EST
Created attachment 665435 [details]
Upstream patch
Comment 10 Jiri Popelka 2012-12-18 09:59:24 EST
Upstream patch has been applied in cups-1.5.4-22.
Comment 11 Marcus Moeller 2013-10-28 04:13:48 EDT
@Jiri has this been also made available to Fedora?
Comment 12 Tim Waugh 2013-10-28 08:27:39 EDT
Looks like it:

commit 9db046f6c4f1b7f8afc79cec03780144c9244631
Author: Jiri Popelka <jpopelka@redhat.com>
Date:   Tue Dec 18 15:32:27 2012 +0100

    backport fixes for STR #4125, STR #4140, STR #4187, STR #4205, STR #4232
Comment 15 Ludek Smid 2014-06-13 07:47:21 EDT
This request was resolved in Red Hat Enterprise Linux 7.0.

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