> On 13 May 2018, at 22:44, Spike White <spikewhit...@gmail.com> wrote: > > > > > Sssd aficionados, > > It is with great interest that I read the announcement of SSSD version 1.15.3. > > https://lists.fedorahosted.org/archives/list/sssd-users@lists.fedorahosted.org/thread/6EPEUSAXXMS4WCI7PUR6PU7AQB7K5EAJ/ > > Among the new features is this: > > In a setup where an IPA domain trusts an Active Directory domain, it is now > possible to define the domain resolution order (see > http://www.freeipa.org/page/Releases/4.5.0#AD_User_Short_Names). Starting > with this version, SSSD is able to read and honor the domain resolution > order, providing a way to resolve Active Directory users by just their short > name. SSSD also supports a new option "domain_resolution_order" applicable in > the "[sssd]" section that allows to configure short names for AD users in > setup with "id_provider=ad" or in a setup with an older IPA server that > doesn't support the "ipa config-mod --domain-resolution-order" configuration > option. Also, it is now possible to use "use_fully_qualified_names=False" in > a subdomain configuration, but please note that the user and group output > from trusted domains will always be qualified to avoid conflicts. > > This corresponds exactly to a use case we have. In fact this design doc > (https://docs.pagure.org/SSSD.sssd/design_pages/shortnames.html) > > has excellent verbiage describing our use case: > > Use cases > > Allow the Administrator of an IdM deployment in a trust relationship with an > AD forest to configure its IdM servers and associated IdM clients to allow > user & group resolution and user authentication in all domains (or a subset > of the domains) to be possible by using only the short names without the > domain component, as it’s done by some 3rd party solutions. > > That’s our exact situation. We have a parent AD domain – company.com. We > have 3 AD subdomains: amer.company.com, euro.company.com and > asia.company.com. All 3 AD subdomains have a transitive trust with the > parent domain. Meaning all 4 domains fully trust each other. All user and > groups are in the 3 subdomains; none in the parent domain. > > We do not have an IPA server, not would our company’s AD administrators > tolerate such – they don’t even allow trusts to Kerberos realms. (They’re > very security-conscious – and windows-centric). > > We are currently using a 3rd party software product for our Linux AD > integration. (actually, 2 products -- in different parts of the company). > They’re currently doing user authentication from all 3 AD subdomains by short > account name. They’re doing it by domain resolution order (always looking in > the local domain first). > > In these products, I join the local AD sub-domain by creating a machine > account under my OU. > > I have evaluated sssd-ad on RHEL7 as a potential replacement. There are some > obscure dusty corners where sssd-ad may not be able to do what these 3rd > party products do.
I’m curious, what are the other shortcomings? > But outside of that handful of use cases, sssd-ad (& maybe a couple of > companion PAM modules) seem like it’ll accomplish everything we need for > AD-based Linux authentication. > > Except for cross-subdomain user authentication by short name. > > I’m able to login by short name in the local subdomain. Using: > > [domain/amer.company.com] > use_fully_qualified_names = False > > Starting with version 1.15.3, I’m supposed to be able to add: > > domain_resolution_order = amer.company.com, euro.company.com, asia.company.com > > to the [sssd] section in /etc/sssd/sssd.conf. Then I’m supposed to change my > current subdomain section: Yes. > > [domain/amer.company.com] > use_fully_qualified_names = False > > To: > > [domain/amer.company.com/euro.company.com/asia.company.com] > use_fully_qualified_names = False > > ? > > How does that work? After startup, SSSD auto-discovers the domains in the forest. From SSSD’s point of view, the domain structure is always flat, so you’d configure: [domain/amer.company.com] use_fully_qualified_names = False [domain/amer.company.com/euro.company.com] use_fully_qualified_names = False [domain/amer.company.com/asia.company.com] use_fully_qualified_names = False ..etc Keep in mind that by default, the names will still come back qualified from the child domains because that’s the only way to distinguish users from different domains during a multi-step authentication process (e.g. application receives a name to authenticate as, then calls getpwnam on that input and uses the output of getpwnam from then on..). You /can/ tune the full_name_format to only include the user name, but please be aware of the consequences. > > To join the amer.company.com subdomain, ‘realm join’ on my test server > created a machine account under my OU. Namely, > spikerealm...@amer.company.com. (Realm join also properly created the > Kerberos creds in the /etc/krb5.keytab file.) > > Thus for [domain/amer.company.com], I had to set up ldap_sasl_authid as so: > > ldap_sasl_authid = spikerealm...@amer.company.com As long as the domains trust each other, you can use the account from the joined domain, right? So no configuration should be needed. > > And the other AD subdomains wouldn’t know about this machine account. > > > I actually tried this recommended syntax (see > https://docs.pagure.org/SSSD.sssd/design_pages/shortnames.html ): > > > [domain/amer.company.com/euro.company.com/asia.company.com] > > And I caught a syntax error in /var/log/sssd/sssd.log on startup: > > (Sun May 13 15:11:07:070656 2018) [sssd] [sss_ini_call_validators] (0x0020): > [rule/allowed_sections]: Section > [domain/amer.company.com/euro.company.com/asia.company.com] is not allowed. > Check for typos. > (Sun May 13 15:11:07:083115 2018) [sssd] [confdb_get_domain_internal] > (0x0010): Unknown domain [amer.company.com] > (Sun May 13 15:11:07:083247 2018) [sssd] [confdb_get_domains] (0x0010): Error > (2 [No such file or directory]) retrieving domain [amer.company.com], > skipping! > > Prior to sssd 1.15.3, in order to authenticate from the various AD subdomains > with sssd-ad even by fully-qualified name, you had to join each subdomain. > > Is that still the case? I have to create a machine account in each subdomain > for a given computer? Then create 3 separate sections in /etc/sssd/sssd.conf > file? Like so: > > [sssd] > … > domain_resolution_order = amer.company.com, euro.company.com, asia.company.com > domains = amer.company.com, euro.company.com, asia.company.com > … > > [domain/amer.company.com] > use_fully_qualified_names = False > … > ldap_sasl_authid = spikerealm...@amer.company.com > > > [domain/euro.company.com] > use_fully_qualified_names = False > … > ldap_sasl_authid = spikerealm...@euro.company.com > > > [domain/apac.company.com] > use_fully_qualified_names = False > … > ldap_sasl_authid = spikerealm...@apac.company.com > > > and then I’d have to consolidate the 3 /etc/krb5.keytab files created by > 'realm join' into one grand & glorious keytab file with all the above > principals? > > After that, I'd be able to user authenticate from the various subdomains by > short name? > > Spike White > > PS Since I’m testing on RHEL7, actually I’m testing version > sssd-ad-1.16.0-19.el7.x86_64 > > > > > _______________________________________________ > sssd-users mailing list -- sssd-users@lists.fedorahosted.org > To unsubscribe send an email to sssd-users-le...@lists.fedorahosted.org _______________________________________________ sssd-users mailing list -- sssd-users@lists.fedorahosted.org To unsubscribe send an email to sssd-users-le...@lists.fedorahosted.org
