OpenLDAP 2.4
by Howard Chu
The Admin Guide still has not been updated with all of the relevant changes,
so here are some notes on new features in the 2.4 release... I believe all of
the manpages are up to date, so you can get specifics from them.
More complete cn=config functionality:
There is a new slapd-config(5) manpage for the cn=config backend.
the original design called for auto-renaming of config entries when you
insert or delete entries with ordered names, but that was not implemented in
2.3. It is now in 2.4. This means, e.g., if you have
olcDatabase={1}bdb,cn=config
olcSuffix: dc=example,dc=com
and you want to add a new subordinate, now you can:
ldapadd olcDatabase={1}bdb,cn=config
olcSuffix: dc=foo,dc=example,dc=com
this will insert a new BDB database in slot 1 and bump all following
databases down one, so the original BDB database will now be named
olcDatabase={2}bdb,cn=config
olcSuffix: dc=example,dc=com
In 2.3 you were only able to add new schema elements, not delete or
modify existing elements. In 2.4 you can modify schema at will. (Except for
the hardcoded system schema, of course.)
More sophisticated syncrepl configurations:
the original implementation of syncrepl in OpenLDAP 2.2 was intended to
support multiple consumers within the same database, but that feature never
worked and was removed from OpenLDAP 2.3. I.e., you could only configure a
single consumer in any database.
In 2.4 you can configure multiple consumers in a single database. The
configuration possibilities here are quite complex and numerous. You can
configure consumers over arbitrary subtrees of a database (disjoint or
overlapping). Any portion of the database may in turn be provided to other
consumers using the syncprov overlay. The syncprov overlay works with any
number of consumers over a single database or over arbitrarily many glued
databases.
As a consequence of the work to support multiple consumer contexts, the
syncrepl system now supports full N-way multimaster replication with
entry-level conflict resolution. There are some important constraints, of
course: In order to maintain consistent results across all servers, you must
maintain tightly synchronized clocks across all participating servers (e.g.,
you must use NTP on all servers). The entryCSNs used for replication now
record timestamps with microsecond resolution, instead of just seconds. The
delta-syncrepl code has not been updated to support multimaster usage yet,
that will come later in the 2.4 cycle.
On a related note, syncrepl was explicitly disabled on cn=config in 2.3.
It is now fully supported in 2.4; you can use syncrepl to replicate an entire
server configuration from one server to arbitrarily many other servers. It's
possible to clone an entire running slapd using just a small (less than 10
lines) seed configuration, or you can just replicate the schema subtrees,
etc. Tests 049 and 050 in the test suite provide working examples of these
capabilities.
In 2.3 you could configure syncrepl as a full push-mode replicator by
using it in conjunction with a back-ldap pointed at the target server. But
because the back-ldap database needs to have a suffix corresponding to the
target's suffix, you could only configure one instance per slapd.
In 2.4 you can define a database to be "hidden" which means that its
suffix is ignored when checking for name collisions, and the database will
never be used to answer requests received by the frontend. Using this hidden
database feature allows you to configure multiple databases with the same
suffix, allowing you to set up multiple back-ldap instances for pushing
replication of a single database to multiple targets. There may be other uses
for hidden databases as well (e.g., using a syncrepl consumer to maintain a
*local* mirror of a database on a separate filesystem).
More extensive TLS configuration control:
In 2.3, the TLS configuration in slapd was only used by the slapd
listeners. For outbound connections used by e.g. back-ldap or syncrepl their
TLS parameters came from the system's ldap.conf file.
In 2.4 all of these sessions inherit their settings from the main slapd
configuration but settings can be individually overridden on a
per-config-item basis. This is particularly helpful if you use
certificate-based authentication and need to use a different client
certificate for different destinations.
Various performance enhancements:
Too many to list. Some notable changes - ldapadd used to be a couple of
orders of magnitude slower than "slapadd -q". It's now at worst only about
half the speed of slapadd -q. A few weeks ago I did some comparisons of all
the 2.x OpenLDAP releases; the results are in the slides from my SCALE
presentation and you can find a copy here:
http://www.highlandsun.com/hyc/scale2007.pdf
That compared 2.0.27, 2.1.30, 2.2.30, 2.3.33, and HEAD (as of a couple
weeks ago). Toward the latter end of the "Cached Search Performance" chart it
gets hard to see the difference because the runtimes are so small, but the
new code is about 25% faster than 2.3, which was about 20% faster than 2.2,
which was about 100% faster than 2.1, which was about 100% faster than 2.0,
in that particular search scenario. That test basically searched a 1.3GB DB
of 380836 entries (all in the slapd entry cache) in under 1 second. i.e., on
a 2.4GHz CPU with DDR400 ECC/Registered RAM we can search over 500 thousand
entries per second. The search was on an unindexed attribute using a filter
that would not match any entry, forcing slapd to examine every entry in the
DB, testing the filter for a match.
Essentially the slapd entry cache in back-bdb/back-hdb is so efficient
the search processing time is almost invisible; the runtime is limited only
by the memory bandwidth of the machine. (The search data rate corresponds to
about 3.5GB/sec; the memory bandwidth on the machine is only about 4GB/sec
due to ECC and register latency.)
I think it goes without saying that no other Directory Server in the world is
this fast or this efficient. Couple that with the scalability, manageability,
flexibility, and just the sheer know-how behind this software, and nothing
else is even remotely comparable.
--
-- Howard Chu
Chief Architect, Symas Corp. http://www.symas.com
Director, Highland Sun http://highlandsun.com/hyc
Chief Architect, OpenLDAP http://www.openldap.org/project/
15 years, 4 months
LDAP authenticaton against PAM how-to
by manu＠netbsd.org
Hi
I banged my head on OpenLDAP -> SASL -> PAM for two days. The status of
the documentation is really horrible. Until someone eventually fix that,
here is for future reference what I had to do (the NetBSD system parts
are out of topic, but I added them for the sake of completeness)
Configuration:
NetBSD-3.1
OpenLDAP-2.3.27 from NetBSD's pkgsrc
Cyrus-SASL-2.1.22 from NetBSD's pkgsrc
1) Install the software
1.1 Fix pkgsrc a bug
In /usr/pkgsrc/databases/openlda-server/options.mk,
change --with-spasswd into --enable-spasswd
1.2 Install the following packages:
Set build options for pkgsrc: in /etc/mk.conf:
PKG_RCD_SCRIPTS=YES
PKG_OPTIONS.openldap-client+=sasl
PKG_OPTIONS.openldap-server+=sasl
PKG_OPTIONS.cyrus-saslauthd+=pam
1.3 Install the following packages:
database/openldap
security/cyrus-sasl
security/saslauthd
security/cy2-plain
1.4 Fix another pkgsrc bug:
cd /usr/pkgsrc/database/openldap-server/
cd work/openldap-2.3.27/libraries/libldap_r
make && make install
2) Configure PAM
Create /etc/pam.ldap and populate it with your PAM configuration
3) Configure SASL
3.1 Enable saslauthd, by adding this to /etc/rc.conf:
saslauthd=YES saslauthd_flags="-a pam
3.2 Then start it:
/etc/rc.d/saslauthd start
3.3 Configure the SASL library for slapd, by creating
/usr/pkg/lib/sasl2/slapd.conf, with the following content:
pwcheck_method: saslauthd
saslauthd_path: /var/run/saslauthd/mux
3.4 Check SASL functionnality
testsaslauthd -s ldap -u login -p password
Make sure a wrong password really fails...
4) Configure OpenLDAP (the nasty part)
4.1 Enable PLAIN mechanism (disabled by default) in
/usr/pkg/etc/openldap/slapd.conf, by adding:
sasl-secprops none
You don't need sasl-regex or authz-regex.
4.2 Enable TLS:
Generate TLS certificate, and add certificate, key and CA to
/usr/pkg/etc/openldap/slapd.conf:
TLSCertificateFile /etc/openssl/certs/botin.crt
TLSCertificateKeyFile /etc/openssl/private/botin.key
TLSCACertificateFile /etc/openssl/certs/ca.crt
4.3 Populate the directory, make sure that user
cn=jdoe,dc=example,dc=net has this:
userPassword: {SASL}jdoe
4.4 Enable slapd, by adding to /etc/rc.conf:
slapd=YES
4.5 Start slapd:
/etc/rc.d/slapd start
4.6 Check that slapd will accept PLAIN SASL authentication:
ldapsearch -x -b "" -s base supportedSASLMechanisms
You should get:
supportedSASLMechanisms: PLAIN
4.7 Configure the LDAP client, in /usr/pkg/etc/openldap/ldap.conf:
BASE dc=example,dc=net
TLS_CACERT /etc/openssl/certs/ca.crt
SASL_MECH PLAIN
SASL_SECPROPS none
4.8 Check that the whole thing works:
ldapsearch -x -WZD cn=jdoe,dc=example,dc=net
Don't forget to make sure a wrong password fails...
NB1: saslauthd logs in /var/log/authlog, the error messages are useful
NB2: slapd logs in /var/log/slapd.conf, the error messages are usually
meaningless, especially for ACL and SASL troubles.
NB3: Make sure your DN is right. I spent a lot of time running tests
with an invalid DN (ie: dc=jdoe instead of cn=jdoe)
--
Emmanuel Dreyfus
http://hcpnet.free.fr/pubz
manu(a)netbsd.org
15 years, 11 months
slapd crashing "randomly?"
by daniel＠ncsu.edu
Hi folk,
I want to start this message by saying, what I'm about to describe is
completely vague and I don't expect to get a solution response. ;)
Basically, I'm out of ideas and am looking for some suggestions as to how
to debug the issue I'm running into.
Starting about half a year ago, slapd started "just dieing" out of the
blue. Not a think in the logs shows up to indicate what might have caused
it. The last query that I see in the logs before a crash always seems to
be nothing special. I don't even see a core dump being generated yet, but
then that may just be because I don't have the proper setup to get a core
dump at this time. We were running the last 2.2 and upgraded to the
latest release of 2.3 to make sure it wasn't an "old version" issue.
Unfortunately, slapd still dies a fair amount on us. It appears to be
fairly unpredictable. I've seen it crash within 1 minute of starting up
slapd (then a subsequent startup 'takes' just fine). I've seen it crash
when there were a number of network issues going on. I've seen it crash
out of the blue when nothing appeared to be going on. I don't really have
the drive space to turn on max debug logging 24/7 until the problem
occurs.
We're thinking about setting up something to watch all of the network
traffic going to one of the boxes until it dies. (assuming we can find
something with the resources to do that)
That all said... since I have nothing solid to present, do you all have
any suggestions of what would be the best way to track down what's going
on? I'm literally out of ideas unless my berkeley db config is somehow
causing the problem or something like that.
I apologize for the vagueness. =/ Any ideas/suggestions?
Daniel
15 years, 11 months
Different output with ldapsearch
by Amos Castelli
Hi all,
can anybody tell me if the following is a bug or is a normal behavior?
$ ldapsearch -x -H ldap://ldap.ex.com -b ou=People,dc=ex,dc=com |grep zhiling
$ ldapsearch -x -H ldap://ldap.ex.com -b ou=People,dc=ex,dc=com
"(uid=zhiling)"
# extended LDIF
#
# LDAPv3
# base <ou=People,dc=ex,dc=com> with scope subtree
# filter: (uid=zhiling)
# requesting: ALL
#
# zhiling, People, ex.com
dn: uid=zhiling,ou=People,dc=ex,dc=com
uid: zhiling
cn: Uela Zhiling
objectClass: account
objectClass: posixAccount
objectClass: top
loginShell: /usr/local/bin/bash
uidNumber: 20893
gidNumber: 30484
homeDirectory: /users/zhiling
gecos: Uela Zhiling, DCS
# search result
search: 2
result: 0 Success
# numResponses: 2
# numEntries: 1
why I don't get any match with the grep command?
ldap server version: 2.3.34
Thanks in advance,
AMos
15 years, 11 months
err=52
by jerrrry＠voila.fr
Hi all,
i'm using openldap 2.2.13 as a proxy to an other ldap server. it works and after few days, authentications doesn't work any more. and i have an error 52 in my ldap log:
ar 29 17:51:13 guardsdef1 slapd[23444]: conn=4 op=5 SRCH base="ou=personnes,o=st" scope=2 deref=3 filter="(&(objectClass=*)(uid=n588t67))"
Mar 29 17:51:13 guardsdef1 slapd[23444]: conn=4 op=5 SRCH attr=uid
Mar 29 17:51:13 guardsdef1 slapd[23444]: conn=4 op=5 SEARCH RESULT tag=101 err=52 nentries=0 text=
Mar 29 17:51:13 guardsdef1 slapd[23444]: conn=4 op=5 SEARCH RESULT tag=101 err=52 nentries=0 text=
this error means:
LDAP_UNAVAILABLE: Indicates that the LDAP server cannot process the client's bind request, usually because it is shutting down.
my slapd conf:
database ldap
suffix o=sg
uri ldaps://ldap.s45ame.iioup.soen
Do you have any idea why open ldap "is shutting down" ?
thank you for your help
Thomas
15 years, 11 months
OpenLDAP SPEC File
by Josh Miller
Anybody have a good recent SPEC file for OpenLDAP on RHEL4 that you
wouldn't mind posting?
(This is for building RPMs for anybody who doesn't recognize a SPEC file.)
Thanks,
--
Joshua M. Miller - RHCE,VCP
15 years, 11 months
Paged results and Solaris
by Aaron Richton
Some users of Solaris may use LDAP clients based on the library
/usr/lib/libsldap.so.1. One such example is the Sun-provided
/usr/lib/nss_ldap.so.1. These clients have historically been at best
partially compatible with OpenLDAP, for various reasons. While there has
been a lot of good progress towards standards compliance (or at least
standards accommodation), paged results have had a long-standing bug. The
results cookie was improperly handed by libsldap, causing any results in
excess of the page size (1,000 in the case of libsladp) to be lost.
Rutgers has significantly more than 1,000 entries, and brought this
through Sun support channels. Patches were released for Solaris 9 last
week, which fix this issue
6278068 native ldap client: simple page mode broken in S9 and S10
I note this to openldap-software for users considering migration to
OpenLDAP slapd(8) who may have experienced this behavior and falsely
attributed it to OpenLDAP software. When properly patched, I can attest
that Solaris nss and OpenLDAP work "out of the box" together.
15 years, 11 months
authzTo for user not copied by syncrepl - problem
by tomasz
hi,
my problem about it is
slave server is not copied attr authzTo from master server
my slapd.conf include:
access to attrs=userPassword,authzTo,entry,children
by dn.exact="cn=replicant,ou=people,dc=the,dc=net" write
by self read
by group.base="cn=ldapadmin,ou=people,dc=thebunker,dc=net" read
by anonymous auth
by *
and
syncrepl rid=1
provider=ldap://test.the.net:389/
type=refreshAndPersist
interval=00:00:01:00
searchbase="dc=the,dc=net"
filter="(objectClass=*)"
scope=sub
attrs="*"
schemachecking=off
updatedn="cn=replicant,ou=people,dc=the,dc=net"
bindmethod=sasl
saslmech=digest-md5
realm=the.net
retry=1,5,30,+
credentials=xxxx
authcid="replicant"
but it is not doing copy of attr: authzTo from master server
master server slapd.conf include
access to attrs=userPassword,authzTo,entry,children
by self write
by group.exact="cn=ldapadmin,ou=people,dc=the,dc=net" write
by dn.exact="cn=replicant,ou=people,dc=the,dc=net" read
by anonymous auth
by *
and idea how to sort it?
cheers
--
bEsT rEgArDs | "Confidence is what you have before you
tomasz dereszynski | understand the problem." -- Woody Allen
TD840-RIPE |
15 years, 11 months
authzTo/From
by tomasz
hi,
my problem about it is
raplicant is not copied attr authzTo from master server
my slapd.conf include:
access to attrs=userPassword,authzTo,entry,children
by dn.exact="cn=replicant,ou=people,dc=the,dc=net" write
by self read
by group.base="cn=ldapadmin,ou=people,dc=thebunker,dc=net" read
by anonymous auth
by *
and
syncrepl rid=1
provider=ldap://test.the.net:389/
type=refreshAndPersist
interval=00:00:01:00
searchbase="dc=the,dc=net"
filter="(objectClass=*)"
scope=sub
attrs="*"
schemachecking=off
updatedn="cn=replicant,ou=people,dc=the,dc=net"
bindmethod=sasl
saslmech=digest-md5
realm=the.net
retry=1,5,30,+
credentials=xxxx
authcid="replicant"
but it is not doing copy of attr: authzTo from master server
master server slapd.conf include
access to attrs=userPassword,authzTo,entry,children
by self write
by group.exact="cn=ldapadmin,ou=people,dc=the,dc=net" write
by dn.exact="cn=replicant,ou=people,dc=the,dc=net" read
by anonymous auth
by *
and idea how to sort it?
cheers
--
bEsT rEgArDs | "Confidence is what you have before you
tomasz dereszynski | understand the problem." -- Woody Allen
TD840-RIPE |
15 years, 12 months
