Directory Service Implementation From Scratch?

An anonymous reader writes "I work at a small but growing startup company. Currently, our directory and authentication information is scattered across many systems and wikis, and is becoming increasingly difficult to manage. We are looking at centralizing this information in a directory service to minimize administrative overhead as we continue to grow. The service must support basic directory searches, as well as user authentication for Linux and Windows hosts. Although we are primarily a Linux shop, there are a handful of Windows systems that will be on a Windows Active Directory domain. Most directory servers seem to support integration with other directory servers, however it seems like it may be easiest to just use Active Directory for everything. Are there any pitfalls with this approach? If you had the chance to redesign your enterprise directory service without regard for legacy services, how would you do it?"

Comments

Twilight Zone?

[cowdung]

Wow.. did I wake up in another dimension? Are slashdotters actually recommending MS products today??

Re:Just go with AD

[dpilot]

I've looked into LDAP/Kerberos authentication for my home LAN several times, and basically given up every time. There appears to be a software mix that will do the job, but each piece needs to be configured *just so* in order to work with all of the others. Furthermore, there appear to be a few people out there who really know their stuff, and to them I'll bet this is all easy.

But it appears that those people all work for companies that sell Directory Server services. They're quite willing to be helpful on specific questions, but the overall integration is still not well documented, from what I can see. As near as I can tell, it's like the Bad Old Unix days, when everyone wanted to be The Solution - for a price. I haven't really looked at the RedHat Directory server or similar products, wishing to use the pieces, and wishing for integration documentation.

Why this on a home LAN? For some odd reason, I've tried to run my LAN on industrial-strength software - BIND, ISC DHCP, etc. I'm used to single-sign-in at work, and would really like it at home, given that $HOME is shared over NFSv4. I also usually am too busy doing other things, which is another reason why there's been no progress in years.

Maybe an integrated OSS Directory Server will make it into my house, but there's no way I'm footing the bill it would take to add AD, here.

Hear me out

[BitZtream]

Its going to sound like blasphemy here on slashdot, but I strongly recommend one master ActiveDirectory server with Services for Unix installed. You can manage everything from the nice pretty windows GUI, have perfect windows support and using pam_krb5 and nss_ldap (I use them in FreeBSD, I believe both of which were originally for linux, not sure they would be the best for it) for pulling all your user information from AD. Services for UNIX adds tabs to the important objects in the ActiveDirectory UI to let you edit the unix attributes.

Combine nss_ldap, pam_krb5, sasl with kerberose auth, and samba 3 or newer, the kerberos auth module for Apache and you can have complete and total authentication based on ActiveDirectory with a very nice GUI, and you can still use standard ldap tools to work with the directory if you want. Samba will do kerberos with windows beautifully at this point, just make sure you keep eveything time synced. Even does all the 'single signon' stuff for websites.

You end up using a great authentication mechanism on your unix AND windows hosts (kerberos is king). The only catch that may or may not apply to other OSes, but it definately bit me in FreeBSD 6, FBSD wants to use UDP for all its kerberos communications which is normally fine, but once you get a user with a large collection of kerberos data, in my case, lots of groups either directly or via nesting, then the packets become too large for a single UDP datagram and FBSD is too stupid to switch to TCP on its on. My solution was simply to block all UDP port 88 requests in and out of my FBSD boxes so they immediately fail over to TCP (not, you have to return ICMP errors, not just drop packets or it'll just hang as it doesn't know the packet can't be sent).

Not sure if Linux's kerberos implementation supports forcing TCP in krb5.conf. FreeBSD is SUPPOSED to, but older version certainly don't.

I know that no one likes MS and thinks they are evil, but I've been VERY happy using AD. We have two Win2k3 machines that serves ActiveDirectory, basically a primary and backup domain controller in the old MS NTDOMAIN language. Works awesome. If you throw in the MS certificate server on your AD server, then you also have a nice way to make internal SSL certificates with full revokation support and all that neat stuff so you can make internal certs all day long and the since your Windows machines are part of the ActiveDirectory, it pushes its root cert to all your windows boxes meaning you don't have to do crap to make them fully authenticated certs for your windows machines.

With far less effort than any other directory server you can have full single sign on support, good authentication, and an easy to use interface in which you can delegate control to various folks outside your IT department and let them use the AD manager for windows (on xp or whatever) to manage the department they need to if you want. You can auth pretty much EVERY modern OS this way. Hell if you want to you can run the servers on Unix (OpenLDAP/MIT Kerberos) for backup or for serving client requests and just isolate the windows machine as the master if you want.

Okay, now I sound like a total fanboy, please don't hate, but it really is a good setup. The main reason being, from my point of view, the setup and most importantly, the administration of ActiveDirectory and Services for UNIX are FAR above and beyond anything the F/OSS world offers. Sad, but true. I imagine you could probably get good support from Novell eDirectory as its tools are pretty good when they work, haven't used them since 6.0 when all their Java apps were asstastic, but I was only admining the leaf node of a tree with a few hundred thousand accounts in it (State of Georgia was using eDirectory a few years back, all their employees are in it, may have changed by now), so it may work better in smaller setups. All things considered it didn't do bad there, was just far too slow for editing my own subtree as we had to wait on updates to be pushed back up the tree bef