Kerberos Single Sign-on with Passwords through Access Manager

ScorpionSting

By: ScorpionSting

April 11, 2011 10:20 am

Reads: 1132

Comments:11

Rating:5.0

The new PasswordFetch class offers the ability to retrieve passwords from eDirectory when they are not supplied via the original authentication Method. The workflow diagram shows how PasswordFetch sits in the architecture of the solution:

(Picture TBC)

Environment

In this setup example, the following lists the environment configuration:

  • SLES 11 (edir.vm.internal.vic.gov.au – 192.168.172.60)
  • eDirectory 8.8.8 (t=EDIR-TREE)
  • Universal Password Enabled
  • Objects under container: o=DATA
  • Apache running for idamtools.internal.vic.gov.au with SSL enabled
  • Windows Server 2008 R2 (ad.vm.internal.vic.gov.au – 192.168.172.70)
  • Active Directory (dc=vm,dc=internal,dc=vic,dc=gov,dc=au)
  • Domain Controller Server Certificate signed by EDIR-TREE for IDM purposes and AD LDAPS enablement
  • Objects under container: ou=DATA,dc=vm,dc=internal,dc=vic,dc=gov,dc=au
  • Novell Access Manager 3.2.2-77 + IR1-107
  • Administration Console & Identity Provider on SLES 11 x64 (idp.vm.internal.vic.gov.au – 192.168.172.10)
  • Linux Access Gateway (lag.vm.internal.vic.gov.au – 192.168.172.11)
  • The LAG protects the iDP, so the Base URL is https://idamtools.internal.vic.gov.au:443/nidp
  • Windows 7 x64 SP1
  • Active Directory Member
  • Internet Explorer 9
  • EDIR-TREE Self Signed Certificate Authority imported into Computer Trusted Roots Store
  • *.internal.vic.gov.au added to IE’s Local Intranet sites

User Stores

Active Directory

Create the User for Kerberos (we will also use this user for AM3 Store Access, so give it sufficient domain access).

KerberosSingleSign-onwithPasswordsthroughAccessManager_02

The User Login Name must be HTTP/ followed by the Access Manager Base URL domain (i.e. HTTP/idamtools.internal.vic.gov.au)

KerberosSingleSign-onwithPasswordsthroughAccessManager_03

For this next screen, you will need to enable Advanced Features in MMC.

KerberosSingleSign-onwithPasswordsthroughAccessManager_04

Now we need to export the Kerberos Key Tab file:

KerberosSingleSign-onwithPasswordsthroughAccessManager_05

eDirectory

Create the test user in ou=IDENTITIES,o=DATA and allow IDM to synchronise the user to Active Directory. This will result in:

  • eDirectory Account: cn=bwalter,ou=IDENTITIES,o=DATA
  • Active Directory Account: cn=Ben Walter,ou=IDENTITIES,ou=DATA,dc=vm,dc=internal,dc=vic,dc=gov,dc=au

IDM will write back the DirXML-ADContext value of cn=Ben Walter,ou=IDENTITIES,ou=DATA,dc=vm,dc=internal,dc=vic,dc=gov,dc=au to the cn=bwalter,ou=IDENTITIES,o=DATA object (we will use this attribute as part of the PasswordFetch class).

Access Manager iDP

First, we create the primary store which will be Active Directory.

KerberosSingleSign-onwithPasswordsthroughAccessManager_06

Next, we need to create the eDirectory store for the PasswordFetch class to use.

KerberosSingleSign-onwithPasswordsthroughAccessManager_07

Next, we create the Kerberos Class called “Kerberos”. In the Properties, we add the following values to match with Active Directory:

KerberosSingleSign-onwithPasswordsthroughAccessManager_08

The bcsLogin.conf looks like:

com.sun.security.jgss.accept {
com.sun.security.auth.module.Krb5LoginModule required
debug="true"
useTicketCache="true"
ticketCache="/opt/novell/java/jre/lib/security/spnegoTicket.cache"
doNotPrompt="true"
principal="HTTP/idamtools.internal.vic.gov.au@VM.INTERNAL.VIC.GOV.AU"
useKeyTab="true"
keyTab="/opt/novell/java/jre/lib/security/nidpkey.keytab"
storeKey="true";
};

While here, we also create the PasswordFetch Class called “PasswordFetch”. In the Properties, we add the following values:

KerberosSingleSign-onwithPasswordsthroughAccessManager_09

So, when the Kerberos Token is received by the iDP from the client, it validates with Active Directory (based on userPrincipalName in the token – bwalter@VM.INTERNAL.VIC.GOV.UA), this returns the DN of the user object (cn=Ben Walter,ou=IDENTITIES,ou=DATA,dc=vm,dc=internal,dc=vic,dc=gov,dc=au). To find the equivalent user in eDirectory, we use this to search for them from the DirXML-ADContext value.

11:20:29 A122EB70 LDAP: (192.168.172.60:50259)(0x0002:0x63) Search request:
   base: "o=DATA"
   scope:2 dereference:3 sizelimit:0 timelimit:0 attrsonly:0
   filter: "(&(objectClass=Person)(DirXML-ADContext=cn=Ben Walter,ou=IDENTITIES,ou=DATA,dc=vm,dc=internal,dc=vic,dc=gov,dc=au))"
   attribute: "GUID"
   attribute: "fullname"

For each Class, we create a Method:

The Kerberos Method uses the Active Directory Store.

KerberosSingleSign-onwithPasswordsthroughAccessManager_10

The PasswordFetch Method uses the eDirectory Store.

KerberosSingleSign-onwithPasswordsthroughAccessManager_11

The options to Overwrite User values means that the LDAP DN will be that of eDirectory, not Active Directory (should it be needed).

Now we create the Contract to be utilised:

KerberosSingleSign-onwithPasswordsthroughAccessManager_12

Policies

Because we told the PasswordFetch Method to overwrite the user values, any policy should use the eDirectory values for LDAP. i.e.:

KerberosSingleSign-onwithPasswordsthroughAccessManager_13

Internal/External Scenario

Consider the situation where your business has one Access Manager solution for both Internal and External resources. The Internal resources utilise the method described above for single sign on, but what about External Users? They have no Kerberos token to send through!

What we need to do is provide a “fallback” class for External Users so they are prompted to authenticate when no Kerberos Token is received. Kerberos Method Properties Example:

KerberosSingleSign-onwithPasswordsthroughAccessManager_14

The Catch! The iDP still needs an authentication header passed to the Kerberos Contract, even if its empty, otherwise it errors requiring authentication. To do this, the external clients must be configured like internal clients (i.e. setting Internet Explorer to enable Integrated Login and add the domain to the Intranet Sites, or setting the network.negotiate-auth.delegation-uris and network.negotiate-auth.trusted-uris in Firefox)

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Categories: Access Manager, Technical Solutions

Disclaimer: As with everything else at NetIQ Cool Solutions, this content is definitely not supported by NetIQ, so Customer Support will not be able to help you if it has any adverse effect on your environment.  It just worked for at least one person, and perhaps it will be useful for you too.  Be sure to test in a non-production environment.

11 Comments

  1. By:TellierS

    Hi, I have the same setup, but I’m not able to use a policy with a condition check for a container, a group or a role with a validation in eDir to authorize user access.

    • By:ScorpionSting

      To have policies that check eDir values, you *MUST* enable “Overwrite Temporary User” and “Overwrite Real User” in the PFC Method, *AND* disable “Retain Previous Principal” in the PFC Class.

  2. By:cervel0

    Great article. Is it possible to do kerberos constrained delegation with NAM?

  3. By:kkyen

    Is this applicable to NAM304? As i don’t see the PasswordFetch class in there… Thx

    • By:TellierS

      A class developped by Bart Andries exist for 3.0.4, I think.

      • By:ScorpionSting

        Bart’s one operates differently to the Novell one and doesn’t contain some of its features such as Principal Replacement.

        You do realise that, if you have any issues with your Access Manager environment, the first thing Novell will ask is what release you’re running? They only offer decent support if you’re running the current release, otherwise they’ll just say “upgrade to current release and see if issue continues”.

  4. By:mus75

    Hi there,
    I’m using NAM to authenticate external users to access to some applications hosted on the cloud (sales force), for the internal users, when they want to access those apps, an additional authentication (besides windows (AD) authentication) is required.
    How can I authorize internal users to access to those applications once they are logged in to the local domain without entering additional login/password using Kerberos (SSO) ?
    thanks

  5. By:kkyen

    What if I’m going to setup the password fetch now and my existing eDirectory is without “Simple Password” or “Universal Password”, can these users be fetch? Thanks.

  6. By:6525036

    A note on the keytab location
    In this article it is :
    keyTab=”/usr/lib/java/jre/lib/security/nidpkey.keytab”

    I suppose in later versions of access manager (Iused the appliance), it should be
    keyTab=”/opt/novell/java/jre/lib/security/nidpkey.keytab”

  7. By:mcurrie

    Hi, I have NAM4 setup for the external domain portal.acme.com, but the internal AD domain is acme.local, so will it work if the login name is HTTP/portal.acme.com@ACME.LOCAL or will I need another NAM instance in the AD domain? The internal name for the server in DNS is vnam40app.acme.local. Thanks.

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