1242942 – well-known SID check is broken for NetBIOS prefixes

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Bug 1242942 - well-known SID check is broken for NetBIOS prefixes

Summary: well-known SID check is broken for NetBIOS prefixes

Keywords:
Status:	CLOSED ERRATA
Alias:	None
Product:	Red Hat Enterprise Linux 7
Classification:	Red Hat
Component:	sssd
Sub Component:
Version:	7.0
Hardware:	Unspecified
OS:	Unspecified
Priority:	medium
Severity:	unspecified
Target Milestone:	rc
Target Release:	---
Assignee:	Sumit Bose
QA Contact:	Kaushik Banerjee
Docs Contact:
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+	depends on / blocked

Reported:	2015-07-14 13:04 UTC by Jakub Hrozek
Modified:	2020-05-02 18:07 UTC (History)
CC List:	11 users (show)
Fixed In Version:	sssd-1.13.0-5.el7
Doc Type:	Bug Fix
Doc Text:
Clone Of:
Environment:
Last Closed:	2015-11-19 11:39:22 UTC
Target Upstream Version:
Embargoed:

Attachments	(Terms of Use)

Links
System	ID	Private	Priority	Status	Summary	Last Updated
Github	SSSD sssd issues 3758	0	None	None	None	2020-05-02 18:07:12 UTC
Red Hat Product Errata	RHSA-2015:2355	0	normal	SHIPPED_LIVE	Low: sssd security, bug fix, and enhancement update	2015-11-19 10:27:42 UTC

Description Jakub Hrozek 2015-07-14 13:04:43 UTC

This bug is created as a clone of upstream ticket:
https://fedorahosted.org/sssd/ticket/2717

When AD user or group is specified using flatname (ADX\Domain Admins instead of Domain Admins), and name to SID translation is requested, a check for well-known SID uses wrong expression to parse specified name, considers it wrong and bails out.

As result, it breaks FreeIPA resolving names to SIDs in 'ipa group-add-member --external' command.

{{{
Python 2.7.10 (default, Jul  5 2015, 14:15:43) 
[GCC 5.1.1 20150618 (Red Hat 5.1.1-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pysss_nss_idmap
>>> pysss_nss_idmap.getsidbyname('ADX\\Domain Admins')
{}
>>> pysss_nss_idmap.getsidbyname("ADX\\Domain Admins")
{}
>>> pysss_nss_idmap.getsidbyname('ADX\Domain Admins')
{}
>>> pysss_nss_idmap.getsidbyname("ADX\Domain Admins")
{}
>>> 
}}}

If I specify an explicit 're_expression' that includes flatname prefix, things work:
{{{
# grep re_expression /etc/sssd/sssd.conf
re_expression = (((?P<domain>[^\\]+)\\(?P<name>.+$))|((?P<name>[^@]+)@(?P<domain>.+$))|(^(?P<name>[^@\\]+)$))
# python
Python 2.7.10 (default, Jul  5 2015, 14:15:43) 
[GCC 5.1.1 20150618 (Red Hat 5.1.1-4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import pysss_nss_idmap
>>> pysss_nss_idmap.getsidbyname('ADX\Domain Admins')
{'ADX\\Domain Admins': {'type': 2, 'sid': u'S-1-5-21-3491614383-3036065072-3935721777-512'}}
>>> 
}}}

Comment 1 Jakub Hrozek 2015-07-16 13:31:57 UTC

* master: 4f1897ad419790834573643e88ac03e6c5c1c4be

Comment 3 Sudhir Menon 2015-09-15 14:42:44 UTC

Jakub,

Can you confirm if this is what is expected here with the fix?
Here are the observations on RHEL7.2

1. SID are returned for trusted AD groups

>>> import pysss_nss_idmap
>>> pysss_nss_idmap.getsidbyname('TEST\\Domain Admins')
{'TEST\\Domain Admins': {'type': 2, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-512'}}
>>> pysss_nss_idmap.getsidbyname('TEST\Domain Admins')
{'TEST\\Domain Admins': {'type': 2, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-512'}}
>>> pysss_nss_idmap.getsidbyname("TEST\Domain Admins")
{'TEST\\Domain Admins': {'type': 2, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-512'}}
>>> pysss_nss_idmap.getsidbyname("TEST\\Domain Admins")
{'TEST\\Domain Admins': {'type': 2, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-512'}}

2. SID are returned for trusted AD users.
>>> import pysss_nss_idmap
>>> pysss_nss_idmap.getsidbyname('TEST\\user1')
{'TEST\\user1': {'type': 3, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-1118'}}
>>> pysss_nss_idmap.getsidbyname("TEST\\user1")
{'TEST\\user1': {'type': 3, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-1118'}}
>>> pysss_nss_idmap.getsidbyname("TEST\user1")
{'TEST\\user1': {'type': 3, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-1118'}}
>>> pysss_nss_idmap.getsidbyname('TEST\user1')
{'TEST\\user1': {'type': 3, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-1118'}}

Comment 4 Jakub Hrozek 2015-09-16 07:27:34 UTC

Redirecting needinfo to bug owner, but the reproducer looks OK to me. I would just test more different groups and also make sure the FQDN format works as well.

Comment 5 Sumit Bose 2015-09-16 07:48:09 UTC

Yes, the reproducers are ok. If you do not have it in other test you might want to add lookups with 'Domain Admins' as well. Those are not related to the reported issue but would make the test complete in the sense that all allowed variants of a fully-qualified name are tested.

Comment 6 Jakub Hrozek 2015-09-16 08:23:23 UTC

btw why is the bug marked as FailedQA??

Comment 7 Sudhir Menon 2015-09-16 08:52:07 UTC

Sumit,

I have the below user/group in trust AD for which the SID is not returned.

>>> pysss_nss_idmap.getsidbyname('TEST\\user10')
{}
>>> pysss_nss_idmap.getsidbyname('TEST\\user101')
{}
>>> pysss_nss_idmap.getsidbyname("TEST\\test-group1")
{}
>>> pysss_nss_idmap.getsidbyname('TEST\\Domain Admins')
{}

Comment 8 Sudhir Menon 2015-09-16 09:20:35 UTC

Verified On: RHEL7.2
sssd-1.13.0-26.el7.x86_64
ipa-server-4.2.0-9.el7.x86_64

Obseravtions:
resolv.conf entries were incorrect after the system went on a reboot in the testing enviornment as a result of which the lookup failed.
Correcting them fixed the issue and returned the SID for groups and users.

>>> pysss_nss_idmap.getsidbyname('TEST\\user10')
{'TEST\\user10': {'type': 3, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-1130'}}
>>> pysss_nss_idmap.getsidbyname('TEST\\user101')
{'TEST\\user101': {'type': 3, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-1137'}}
>>> pysss_nss_idmap.getsidbyname('TEST\\Domain Controllers')
{'TEST\\Domain Controllers': {'type': 2, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-516'}}
>>> pysss_nss_idmap.getsidbyname('TEST\\DNSAdmins')
{'TEST\\DNSAdmins': {'type': 2, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-1101'}}
>>> pysss_nss_idmap.getsidbyname('TEST\\Domain Admins')
{'TEST\\Domain Admins': {'type': 2, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-512'}}
>>> pysss_nss_idmap.getsidbyname('Domain Admins')
{'Domain Admins': {'type': 2, 'sid': u'S-1-5-21-742749997-2996825573-4184801258-512'}}

Comment 9 Jakub Hrozek 2015-09-16 09:47:58 UTC

Thanks for testing, can you also remove the failedQA keyword? IIRC this bug never failed testing..

Comment 10 errata-xmlrpc 2015-11-19 11:39:22 UTC

Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2015-2355.html

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