Bug 1035840

Summary:	Possible to have duplicate values of attribute monitored by Attribute Uniqueness plugin
Product:	Red Hat Enterprise Linux 7	Reporter:	Ján Rusnačko <jrusnack>
Component:	389-ds-base	Assignee:	Rich Megginson <rmeggins>
Status:	CLOSED NOTABUG	QA Contact:	Sankar Ramalingam <sramling>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	7.0	CC:	jgalipea, mkubik, mreynolds, nkinder
Target Milestone:	rc
Target Release:	7.1
Hardware:	Unspecified
OS:	Unspecified
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2014-06-11 19:42:42 UTC	Type:	Bug
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:

Description Ján Rusnačko 2013-11-28 15:29:37 UTC

Description of problem:
Attribute uniqueness plugin monitors specified attributes and ensures, that newly added entries have unique values for the monitored attributes. One example is attribute uid - if user tries to add new entry with uid equal to uid of already existing entry, the addition operation is refused by DS.

It is possible to configure Attribute Uniqueness plugin and still add entry with duplicate attribute. Below are steps for case  when 'sn' attribute is being monitored.

Version-Release number of selected component (if applicable):
389-ds-base-1.2.11.15-29.el6.x86_64  (RHEL64)
389-ds-base-1.3.1.6-8.el7.x86_64 (RHEL7)

How reproducible:
always

Steps to Reproduce:
1. Delete sn index:
ldapdelete -h $HOST -p $PORT -D "cn=directory manager" -w Secret123 "cn=sn,cn=index,cn=userRoot,cn=ldbm database,cn=plugins,cn=config"

2. Configure attribute uniqueness on sn attribute:
ldapmodify -h $HOST -p $PORT -D "cn=directory manager" -w Secret123 -a <<EOF
dn: cn=attribute uniqueness,cn=plugins,cn=config
changetype: modify
replace: nsslapd-pluginEnabled
nsslapd-pluginEnabled: on
-
replace: nsslapd-pluginarg0
nsslapd-pluginarg0: sn
-
replace: nsslapd-pluginarg1
nsslapd-pluginarg1: dc=example,dc=com
EOF

3. Add user:
ldapmodify -h $HOST -p $PORT -D "cn=directory manager" -w Secret123 -a <<EOF
dn: cn=tuser1,ou=people,dc=example,dc=com
objectclass: person
objectclass: top
sn: tuser1
cn: tuser1
EOF

4. Restart server
5. Add user with value 'sn' equal to value of sn of cn=tuser1:
ldapmodify -h $HOST -p $PORT -D "cn=directory manager" -w Secret123 -a <<EOF
dn: cn=tuser2,ou=people,dc=example,dc=com
objectclass: person
objectclass: top
sn: tuser1
cn: tuser2
EOF

Actual results:

ldapsearch -LLL -h $HOST -p $PORT -D "cn=directory manager" -w Secret123 -b "cn=tuser1,ou=people,dc=example,dc=com" sn
dn: cn=tuser1,ou=People,dc=example,dc=com
sn: tuser1

ldapsearch -LLL -h $HOST -p $PORT -D "cn=directory manager" -w Secret123 -b "cn=tuser2,ou=people,dc=example,dc=com" sn
dn: cn=tuser2,ou=People,dc=example,dc=com
sn: tuser1

ldapsearch -LLL -h $HOST -p $PORT -D "cn=directory manager" -w Secret123 -b "cn=attribute uniqueness,cn=plugins,cn=config"
dn: cn=attribute uniqueness,cn=plugins,cn=config
objectClass: top
objectClass: nsSlapdPlugin
objectClass: extensibleObject
cn: attribute uniqueness
nsslapd-pluginPath: libattr-unique-plugin
nsslapd-pluginInitfunc: NSUniqueAttr_Init
nsslapd-pluginType: betxnpreoperation
nsslapd-pluginEnabled: on
nsslapd-pluginarg0: sn
nsslapd-pluginarg1: dc=example,dc=com
nsslapd-plugin-depends-on-type: database
nsslapd-pluginId: NSUniqueAttr
nsslapd-pluginVersion: 1.3.1.6
nsslapd-pluginVendor: 389 Project
nsslapd-pluginDescription: Enforce unique attribute values


Expected results:
Addition of cn=tuser2 should be refused by Attribute Uniqueness plugin.

Additional info:
When steps 3 and 4 are reversed, i.e. instance is first restarted, then user cn=tuser1 added, then addition of cn=tuser2 is refused with:

adding new entry "cn=tuser2,ou=people,dc=example,dc=com"
ldap_add: Constraint violation (19)
	additional info: Another entry with the same attribute value already exists (attribute: "sn")

Comment 2 RHEL Program Management 2013-12-01 22:25:07 UTC

This request was not resolved in time for the current release.
Red Hat invites you to ask your support representative to
propose this request, if still desired, for consideration in
the next release of Red Hat Enterprise Linux.

Comment 3 Nathan Kinder 2013-12-18 16:54:51 UTC

Upstream ticket:
https://fedorahosted.org/389/ticket/47639

Comment 5 mreynolds 2014-06-11 19:42:42 UTC

The issue is that the index that is removed (sn) is a default index. So at the next restart that index is automatically recreated by the backend. So when the next add takes place there is an "sn" index to use, but it's empty. The server uses this index to find any matching entries, but none are found because it's empty. This allows the duplicate "sn" valued entry to be added. Removing the default index configuration at the same time the backend index is deleted achieves the desired results.

To correctly remove a default user index, it must also be deleted from the default index branch of cn=config:

[1] ldapdelete -h $HOST -p $PORT -D "cn=directory manager" -w Secret123
"cn=sn,cn=index,cn=userRoot,cn=ldbm database,cn=plugins,cn=config"

[2] ldapdelete -h $HOST -p $PORT -D "cn=directory manager" -w Secret123
"cn=sn,cn=default indexes,cn=config,cn=ldbm database,cn=plugins,cn=config"

This will not be fixed in the core server, instead a doc bug has been filed to document the correct way to remove an default user index.

https://bugzilla.redhat.com/show_bug.cgi?id=1108356