[Samba] Samba as a PDC with LDAP and Kerberos

Jeff Block jblock at mrsc.ucsf.edu
Tue Jun 7 01:38:47 GMT 2005

I've seen some people using ldap password set as {SASL}USER at REALM
Is there a way to have samba use sasl for authentication?

Currently, my kerberos db is synchronizing with sasl so if I can get samba
and my windows clients to authenticate using sasl, then I don't need to keep
password hashes in ldap.

Is this possible?


On 6/6/05 6:13 PM, "Ti Leggett" <leggett at ci.uchicago.edu> wrote:

> Basically a windows client can't authenticate against a Kerberos server
> *and* get user information out LDAP without using AD. You can
> authenticate against Kerberos and have local user accounts or you can
> have user accounts in LDAP and use some other authentication mechanism.
> The way I'm doing it is storing user's Windows passwords in LDAP as
> sambaNTPassword and storing *nix/OS X passwords in Kerberos. To get
> around having different passwords for the different architectures you
> can write a script that will be the change password script in samba and
> a replacement for passwd under *nix. This script would add/change the
> password in both LDAP and Kerberos keeping them synced.
> FW is referring to such a perl script using Authen::Krb5,
> Crypt::SmbHash, and Net::LDAP.
> The Kerberos options you see in Samba are only for having Samba
> authenticate against an AD server.
> There are some things in the works for going the other way if you're
> using Heimdal (see the archive), but I have no experience with Heimdal
> or this solution.
> On Mon, 2005-06-06 at 10:03 -0700, Jeff Block wrote:
>> I'm a little confused on one section here...  Where are your passwords being
>> stored?  kerberos?  If so, how does samba look there?  What is the
>> significance of the {SASL}USER at REALM in LDAP?  Is there another password
>> store that you are syncing with krb?
>> Sorry for my ignorance here but after hours and hours of trying different
>> things, I'm unable to use my kerberos backend with samba.
>> Thanks in advance.
>> FM Wrote:
>>> Hello,
>>> My setup :
>>> Windows stations
>>> All users (posix and ldap) are in Openldap.
>>> All my ldap password are : {SASL}USER at REALM
>>> I use saslauthd so I can connect to ldap using simplebind with password
>>> this password CANNOT be changed (denied by the slapd.access.conf file)
>>> Samba cannot use MIt kerberos for the password so my little trick :
>>> I create a perl scrip using Authen::Krb5::Admin that use un keytab for
>>> authentifiaction :krb5_update_pwd.pl
>>> in the smb.conf :
>>>    ldap passwd sync = No
>>>    unix password sync = Yes
>>>    passwd program = /usr/local/sbin/krb5_update_pwd.pl -u %u
>>> %n\n *passwd:*all*authentication*tokens*updated*successfully*
>>>    passwd chat = *Password:* %n\n *Again:* %n\n *Changed*
>>> So when Windows users change their password(from the change password
>>> option in Windows), SAMBA called /krb5_update_pwd.pl that also update
>>> the KERBEROS password.
>>> Linux users just have to use :
>>> smbpasswd -r PDC_SERVER
>>> That command update SAMBA password and again it called
>>> /krb5_update_pwd.pl to sync the kerberos password
>>> I know there are some short comings (password policies for example). But
>>> it's the closer i get :-)
>>> Hope this can help :-)
>> Ti Leggett wrote:
>>> Let me rephrase a bit. Is there a way to use Samba as a PDC with an LDAP
>>> backend and use pam_smbpass to keep the passwords sync'd between the
>>> Kerberos side and the Samba side? That way the Windows clients join the
>>> domain using only the LDAP information not knowing about the Kerberos
>>> side of things?
>>> I just removed the Kerberos information from my Windows client and tried
>>> only using, as far as I can tell, the LDAP information and the client
>>> still comes back saying the user name is unknown.
>>> On Sat, 2005-04-23 at 08:07 -0500, Ti Leggett wrote:
>>>> Ok, so I'm just trying to figure out my options here. I can:
>>>> - Use local accounts and local passwords
>>>> - Use Kerberos for authentication, but only with local user accounts
>>>> - Use a Samba PDC with and LDAP backend for accounts and password if and
>>>> only if the windows clients are not bound to a Kerberos realm
>>>> Is this correct? In the third case, let's say I have a way to sync
>>>> Kerberos passwords and LDAP sambaNTPasswords. Shouldn't it work then?
>>>> Or what am I missing? I know I can't create an AD domain, but I'm not
>>>> trying to. AD is combination of a lot more than just Kerberos and LDAP.
>>>> I'm curios how Apple does what seems to be just this with their
>>>> OpenDirectory, which is only MIT Kerberos, OpenLDAP, Cyrus SASL, and
>>>> Samba 3.0 (at least they claim it's only this).
>>>> On Fri, 2005-04-22 at 18:52 -0500, Franco "Sensei" wrote:
>>>>> Ti Leggett wrote:
>>>>>> I've been searching and researching this and I can't seem to find the
>>>>>> answers I'm looking for. I'd like to setup a Samba PDC that Windows
>>>>>> clients will join. The PDC will use an LDAP backend to get authorization
>>>>>> information (username, home directory, etc). The authentication portion
>>>>>> is handled by an MIT Kerberos KDC. I think I'm  real close to having it
>>>>>> all together but I'm not sure. I have the Windows client setup to point
>>>>>> at my KDC so authentication *should* be coming from there once the
>>>>>> authorization portion is going.
>>>>> Hehehe, it's been a year trying to do that... but no way! I'm sorry to
>>>>> tell you, but what you want is a replacement of AD... in no way windows
>>>>> will know about ldap and mit, without an AD domain.
>>>>>> So first question is, are sambaLMPassword and sambaNTPassword still
>>>>>> needed in LDAP for each user?
>>>>>> Here's the output from ksetup /dumpstate:
>>>>>> Machine is not configured to log on to an external KDC. Probably a
>>>>>> workgroup member
>>>>>>    kdc = <kdc1 server>
>>>>>>    kdc = <kdc2 server>
>>>>>>    kpasswd = <kpasswd server>
>>>>>>    Realm Flags = 0x0 none
>>>>>> No user mappings defined.
>>>>> Users must be somewhere to get HKEY_LOCAL* work... and they should be
>>>>> local users (the MIT-KDC authentication works this way).
>>>>>> Second, here's what I have in LDAP so far:
>>>>>> [...]
>>>>>> I've done a smbpasswd -w <hidden samba_server password>
>>>>>> I can do a net getlocalsid and it will get the correct SID out of LDAP.
>>>>> Correct.
>>>>>> However, when I try to join my Windows client to the EXAMPLE.COM domain,
>>>>>> I can see the ldap queries happening, but the Windows client reports an
>>>>>> invalid username.
>>>>> Yes. Active Directory is not there... and it wants AD. In no way you can
>>>>> fake AD, even though it's kerberos, ldap and smb + natural-flavours...

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