Configuring Pass Through Authentication
This chapter focuses on pass through authentication, whereby you
configure another server to determine the response to an authentication
request. A typical use case for pass through authentication involves
passing authentication through to Active Directory for users coming
from Microsoft Windows systems.
About Pass Through Authentication
You use LDAP pass through authentication when
the credentials for authenticating are stored not in OpenDJ, but instead
in a remote directory service. In effect OpenDJ redirects the bind operation
against a remote LDAP server.
Exactly how OpenDJ redirects the bind depends on how the user entry
in OpenDJ maps to the corresponding user entry in the remote directory.
OpenDJ provides you several choices to set up the mapping.
When both the local entry in OpenDJ and the remote entry in the
other server have the same DN, you do not have to set up the mapping at
all. By default, OpenDJ redirects the bind with the original DN and
password from the client application.
When the local entry in OpenDJ has been provisioned with an attribute
holding the DN of the remote entry, you can specify which attribute holds
the DN, and OpenDJ redirects the bind on the remote server using the DN
value.
When you cannot get the remote bind DN directly, you need an
attribute and value on the OpenDJ entry that corresponds to an identical
attribute and value on the remote server in order to map the local entry
to the remote entry. In this case you also need the bind credentials for
a user who can search for the entry on the remote server. OpenDJ performs
a search for the entry using the matching attribute and value, and then
redirects the bind with the DN from the remote entry.
You configure pass through authentication as an authentication policy
that you associate with a user's entry in the same way that you associate
a password policy with a user's entry. Either a user has an authentication
policy for pass through authentication, or the user has a local password
policy.
Setting Up Pass Through Authentication
When setting up pass through authentication, you need to know to which
remote server or servers to redirect binds, and you need to know how you map
user entries in OpenDJ to user entries in the remote directory.
To Set Up SSL Communication For Testing
When performing pass through authentication, you no doubt protect
communications between OpenDJ and the server providing authentication. If
you test using SSL with self-signed certificates, and you do not want
the client blindly to trust the server, follow these steps to import
the authentication server's certificate into the OpenDJ key store.
Export the server certificate from the authentication server.
How you perform this step depends on the authentication directory
server. With OpenDJ, you can export the certificate as shown here.
$ cd /path/to/PTA-Server/config
$ keytool -exportcert -rfc -alias server-cert -keystore keystore
-storepass `cat keystore.pin` > /tmp/pta-srv-cert.pem
Make note of the host name used in the certificate.
You use the host name when configuring the SSL connection. With
OpenDJ, you can view the certificate details as shown here.
$ keytool -list -v -alias server-cert -keystore keystore -storepass `cat keystore.pin`
Alias name: server-cert
Creation date: Sep 12, 2011
Entry type: PrivateKeyEntry
Certificate chain length: 1
Certificate[1]:
Owner: CN=opendj.example.com, O=OpenDJ Self-Signed Certificate
Issuer: CN=opendj.example.com, O=OpenDJ Self-Signed Certificate
Serial number: 4e6dc429
Valid from: Mon Sep 12 10:34:49 CEST 2011 until: Wed Sep 11 10:34:49 CEST 2013
Certificate fingerprints:
MD5: B6:EE:1C:A0:71:12:EF:6F:21:24:B9:50:EF:8B:4E:6A
SHA1: 7E:A1:C9:07:D2:86:56:31:24:14:F7:07:A8:6B:3E:A1:39:63:F4:0E
Signature algorithm name: SHA1withRSA
Version: 3
Import the authentication server certificate into OpenDJ's
keystore.
$ cd /path/to/OpenDJ/config
$ keytool -importcert -alias pta-cert -keystore truststore
-storepass `cat keystore.pin` -file /tmp/pta-srv-cert.pem
Owner: CN=opendj.example.com, O=OpenDJ Self-Signed Certificate
Issuer: CN=opendj.example.com, O=OpenDJ Self-Signed Certificate
Serial number: 4e6dc429
Valid from: Mon Sep 12 10:34:49 CEST 2011 until: Wed Sep 11 10:34:49 CEST 2013
Certificate fingerprints:
MD5: B6:EE:1C:A0:71:12:EF:6F:21:24:B9:50:EF:8B:4E:6A
SHA1: 7E:A1:C9:07:D2:86:56:31:24:14:F7:07:A8:6B:3E:A1:39:63:F4:0E
Signature algorithm name: SHA1withRSA
Version: 3
Trust this certificate? [no]: yes
Certificate was added to keystore
To Configure an LDAP Pass Through Authentication Policy
You configure authentication policies with the
dsconfig command. Notice that authentication policies
are part of the server configuration, and therefore not replicated.
Set up an authentication policy for pass through
authentication to the authentication server.
$ dsconfig -p 4444 -h `hostname` -D "cn=directory manager" -w password
create-password-policy --type ldap-pass-through --policy-name "PTA Policy"
--set primary-remote-ldap-server:Mark-Craigs-MacBook-Pro.local:2636
--set mapped-attribute:uid --set mapped-search-base-dn:"dc=PTA Server,dc=com"
--set mapping-policy:mapped-search --set use-ssl:true
--set trust-manager-provider:JKS -X -n
The policy shown here maps identities under
dc=example,dc=com to identities under
dc=PTA Server,dc=com, where users have the same
uid values on both servers. The policy here also
uses SSL between OpenDJ and the authentication server.
Check that your policy has been added to the list.
$ dsconfig -p 4444 -h `hostname` -D "cn=directory manager" -w password
list-password-policies --property use-ssl
Password Policy : Type : use-ssl
------------------------:-------------------:--------
Default Password Policy : password-policy : -
PTA Policy : ldap-pass-through : true
Root Password Policy : password-policy : -
To Configure Pass Through Authentication To Active Directory
TODO
Assigning Pass Through Authentication Policies
You assign authentication policies in the same way as you
assign password policies, by using the
ds-pwp-password-policy-dn attribute.
Although you assign the pass through authentication policy using
the same attribute as for password policy, the authentication policy is
not in fact a password policy. Therefore, the user with a pass through
authentication policy does not have a value for the operational attribute
pwdPolicySubentry.
$ ldapsearch -p 1389 -b dc=example,dc=com uid=user.0 pwdPolicySubentry
dn: uid=user.0,ou=People,dc=example,dc=com
To Assign a Pass Through Authentication Policy To a User
Users depending on pass through authentication no longer need a local
password policy, as they no longer authenticate locally.
Examples in the following procedure work for this user, whose
entry on OpenDJ is as shown. Notice that the user has no password set. The
user's password on the authentication server is
password.
dn: uid=user.0,ou=People,dc=example,dc=com
cn: Aaccf Amar
description: This is the description for Aaccf Amar.
employeeNumber: 0
givenName: Aaccf
homePhone: +1 225 216 5900
initials: ASA
l: Panama City
mail: user.0@maildomain.net
mobile: +1 010 154 3228
objectClass: person
objectClass: inetorgperson
objectClass: organizationalperson
objectClass: top
pager: +1 779 041 6341
postalAddress: Aaccf Amar$01251 Chestnut Street$Panama City, DE 50369
postalCode: 50369
sn: Amar
st: DE
street: 01251 Chestnut Street
telephoneNumber: +1 685 622 6202
uid: user.0
This user's entry on the authentication server also has
uid=user.0, and the pass through authentication policy
performs the mapping to find the user entry in the authentication
server.
Prevent users from changing their own password policies.
$ cat protect-pta.ldif
dn: ou=People,dc=example,dc=com
changetype: modify
add: aci
aci: (target ="ldap:///uid=*,ou=People,dc=example,dc=com")(targetattr =
"ds-pwp-password-policy-dn")(version 3.0;acl "Cannot choose own pass
word policy";deny (write)(userdn = "ldap:///self");)
$ ldapmodify -p 1389 -D "cn=Directory Manager" -w password -f protect-pta.ldif
Processing MODIFY request for ou=People,dc=example,dc=com
MODIFY operation successful for DN ou=People,dc=example,dc=com
Update the user's ds-pwp-password-policy-dn
attribute.
$ ldapmodify -p 1389 -D "cn=Directory Manager" -w password
dn: uid=user.0,ou=People,dc=example,dc=com
changetype: modify
add: ds-pwp-password-policy-dn
ds-pwp-password-policy-dn: cn=PTA Policy,cn=Password Policies,cn=config
Processing MODIFY request for uid=user.0,ou=People,dc=example,dc=com
MODIFY operation successful for DN uid=user.0,ou=People,dc=example,dc=com
Check that the user can authenticate through to the authentication
server.
$ ldapsearch -p 1389 -b dc=example,dc=com -D
uid=user.0,ou=People,dc=example,dc=com -w password uid=user.0 cn sn
dn: uid=user.0,ou=People,dc=example,dc=com
cn: Aaccf Amar
sn: Amar
To Assign a Pass Through Authentication Policy To a Group
Examples in the following steps use the pass through authentication
policy as defined above. Kirsten Vaughan's entry has been reproduced on
the authentication server under dc=PTA
Server,dc=com.
Create a subentry to assign a collective attribute that sets the
ds-pwp-password-policy-dn attribute for group
members' entries.
$ cat pta-coll.ldif
dn: cn=PTA Policy for Dir Admins,dc=example,dc=com
objectClass: collectiveAttributeSubentry
objectClass: extensibleObject
objectClass: subentry
objectClass: top
cn: PTA Policy for Dir Admins
ds-pwp-password-policy-dn;collective: cn=PTA Policy,cn=Password Policies,
cn=config
subtreeSpecification: { base "ou=People", specificationFilter "(isMemberOf=
cn=Directory Administrators,ou=Groups,dc=example,dc=com)"}
$ ldapmodify -p 1389 -D "cn=Directory Manager" -w password -a -f pta-coll.ldif
Processing ADD request for cn=PTA Policy for Dir Admins,dc=example,dc=com
ADD operation successful for DN cn=PTA Policy for Dir Admins,dc=example,dc=com
Check that OpenDJ has applied the policy.
Make sure you can bind as the user on the authentication
server.
$ ldapsearch -p 2389 -D "uid=kvaughan,ou=People,dc=PTA Server,dc=com"
-w password -b "dc=PTA Server,dc=com" uid=kvaughan
dn: uid=kvaughan,ou=People,dc=PTA Server,dc=com
objectClass: person
objectClass: organizationalPerson
objectClass: inetOrgPerson
objectClass: top
givenName: Kirsten
uid: kvaughan
cn: Kirsten Vaughan
sn: Vaughan
userPassword: {SSHA}x1BdtrJyRTw63kBSJFDvgvd4guzk66CV8L+t8w==
ou: People
mail: jvaughan@example.com
Check that the user can authenticate through to the authentication
server from OpenDJ.
$ ldapsearch -p 1389 -D "uid=kvaughan,ou=People,dc=example,dc=com" -w password
-b dc=example,dc=com uid=kvaughan cn sn
dn: uid=kvaughan,ou=People,dc=example,dc=com
cn: Kirsten Vaughan
sn: Vaughan