I have been digging holes on google to find out the best way to synchronize the user database between AD and OpenLDAP. What i want to achieve is, have user database in AD and then propagate these users to OpenLDAP so these users can access all my applications(email, vpn, file server, print server almost all the opensource apps). I want to create a single sign on database so all users can have same passwords for windows and linux based apps. I also want to make sure the passwords are updated bidirectionally. I will appreciate if anyone can share his experience on how this can be done. Thank you!!
migrated from stackoverflow.com Oct 10 '11 at 11:09
I did this once for a project -- good luck! Do you have administrative access to the AD server? you might need it. Make friends with your AD admin :-)
Can you please elaborate more what your project is about?
The question is if you just need your users / applications to authenticate against ActiveDirectory or LDAP, or if you need your applications to access the data that's stored in ActiveDirectory, and perhaps augment or modify the entries..
If you just need to authenticate, then as Justin pointed out, either an annonymous or password-protected (not much extra value IMHO) bind account on the ActiveDirectory server is all you need. Talk to your ActiveDirectory admin.
If you want to use the contents of ActiveDirectory as the basis of your own user records, and perhaps augment or modify the data, you might need to set up your own LDAP server (because your IT department might not be thrilled by the idea that you modify "their" records...)
ActiveDirectory looks like LDAP and is similar, but there are differences mainly in the schema.
You will run into a couple of problems:
If you just need people or applications to authenticate against a Directory, then it might not be worth going through all this hastle -- it's better to just use AD directly via a bind account.
Use the openldap command line tools to try to authenticate against ActiveDirectory on the UNIX command line. That will help you to get a feel for the process and the data that is returned.
let me look at my old project notes and i'll update this
I hope this helps you
to authenticate against OpenLDAP, you'll need to know values of "distinguished name" (dn) of your organization, "organizational unit" (ou), the "common name" (cn) of the person authenticating, etc.. but I can't give you a full intro here...
It's best to read in the documentation of OpenLDAP here: http://www.openldap.org/doc/admin24/
it's best to run "ldapsearch" on the command line to try out and verify that you can bind / access LDAP. http://www.openldap.org/software/man.cgi?query=ldapsearch&apropos=0&sektion=0&manpath=OpenLDAP+2.0-Release&format=html
An option worth investigating might be to use Active Directory for authentication and your existing OpenLDAP for authorization:
As noted in the above documentation, you can delegate your username/password verification to Kerberos. In fact, the examples given (see 14.5.2) show how to set this up to authenticate to an AD domain. You will need to set up a user account in Active Directory that can bind to the DC in order to run an LDAP query. This user account should have no permissions to access any Windows servers, nor should it be in any sensitive security groups.
Hope that helps.
I did similar project 2 years ago and I was in similar position not knowing where to start and how to tie the ends together.
Step1: Figure out what you want to accomplish and write it down. Step2: See if the requirements are realistic and can be accomplished altogether. If not, what items are you willing to sacrifice. (This is where it takes a long time). step3: Choose a platform for LDAP. in your case, you already have an existing one. step4: Documenting & Testing. step5: The cut over plan is most critical as it doesn't matter if you accomplish all you wanted to but also to make sure there is a smooth transition. In my case, we had to do in a phased manner.
From reading you comments above looks like you already have Openldap in production. Your requirements look like:
a) Allowing users to use same password policy on AD.
b) User accounts to propagate to LDAP automatically.
Answer to a) You can setup a PAM pass-through module in LDAP to delegate password authentication to a DC via kerberos. In this way you will not have the headache of maintaining password in two places. I did on 389-DS LDAP, and the documentation link should be sufficient. When a user authenticates, the PAM module checks if user account exists in LDAP and if so, passes the passwd to PAM stack with krb5.so to authenticate. Check 389-DS documentation which should apply here too.
Answer to b) I hit all the cylinders to figure out a way to use a ready solution but nothing came close. This is because you have to massage the schema for accounts and groups. So I with the help of a colleague wrote a script in perl to sync the users & groups from AD to LDAP. A snippe to f code is here.