On 10/07/2015 03:10 PM, David Kupka wrote:
On 06/10/15 17:52, Jakub Hrozek wrote:
On Tue, Oct 06, 2015 at 08:32:29AM -0400, Simo Sorce wrote:
On 06/10/15 08:04, David Kupka wrote:
On 06/10/15 13:35, Simo Sorce wrote:
On 06/10/15 03:51, thierry bordaz wrote:
On 10/06/2015 07:19 AM, David Kupka wrote:
On 05/10/15 16:12, Simo Sorce wrote:
On 05/10/15 09:00, Martin Babinsky wrote:
These patches implement the plumbing required to properly support
canonicalization of Kerberos principals (
https://fedorahosted.org/freeipa/ticket/3864).

Setting multiple principal aliases on hosts/services is beyond the
scope
of this patchset and should be done after these patches are pushed.

I will try to send some tests for the patches later this week.

Please review the hell out of them.

LGTM, I do not see any issue at quick visual inspection.
What about the performance regression with the indexes ? Is that bug
fixed in 389ds ?

Simo.



The issue is still there. Thierry investigated this in 389 DS and IIUC he is not sure if it's bug or completely missing feature. Therefore we
still don't know how much time is needed there.

Hi,
that is correct.
I can reproduce the problem. Although the matching rule (in my test
caseIgnoreIA5Match) is found, it has no registered indexing function, so
the setting (nsMatchingRule) is ignored.
I do not know if the indexing function is missing or there is a bug so
that the matching rule "forget" to register it.
This feature is documented but I can not find any QA test around it, so I do not know yet if it is a regression or if it was not enabled at all.

I do not expect rapid progress on it. How urgent is it ? 7.3 ?
For the moment I can think to only two workarounds:

  * use filtered matching rule (preferred)
* change the attribute syntax/matching rule, in the schema (I would
    discourage this one because changing the schema is risky)

We can't change the syntax at this point.

Well this patchset is blocked until the 389 ds bug is fixed (the
performance regression is too big to just put it in and hope) so I guess
we'll have to negotiate a time for the fix.

Simo.


I agree that we really shouldn't change schema.

But I don't think the patches're necessary blocked by this issue.
Canonicalization was never supported in FreeIPA and when it is not
requested the performance is not effected at all. We could merge patches
as soon as they're carefully reviewed and tested to avoid tedious
rebasing and start using the new functionality when 389 DS gets fixed.

The fact we didn't do canonicalization this way doesn't mean clients aren't
asking for it.

I think Windows clients ask for canonicalization by default, and in SSSD I see we turn on by default krb5_canonicalize in the IPA nd LDAP case (oddly
enough not in the AD case ?)

So SSSD's authentication requests would end up hitting this case all the time if I am reading the code correctly (CCed Jakub to confirm/dispel this).

We ask for canonicalization always in IPA and LDAP, but also whenever
enterprise principals are used, which is true for AD provider.


Then SSSD will hit this every time it requests ticket on behalf of user.
But to be sure what the impact would be I've once again set up FreeIPA server with 10K users and run some tests.

1) 3 LDAP searches (caseIgnoreIA5Match, caseExactIA5Match, without specifying the matching rule). Results (http://fpaste.org/275847/44221770/raw/) shows that unindexed search takes ~100 times longer than indexed.

2) kinit with and without requested canonicalization.

As we use kinit to get the ticket it makes sense to check what will the performance hit be when we run kinit as a whole and not just an isolated LDAP search. The results (http://fpaste.org/275848/21793144/raw/) shows that with canonicalization it takes ~2 times longer than without it. While this is nothing to be happy about it's certainly better than I would expect.

Clearly we need to make the search indexed.
In your deployment you defined:

   dn: uid=user1000098,cn=users,cn=accounts,dc=example,dc=test
   uid: user1000098
   givenName: Test
   sn: User1000098
   cn: Test User1000098
   initials: TU
   homeDirectory: /home/user1000098
   gecos: Test User1000098
   loginShell: /bin/sh
   mail: user1000...@example.test
   uidNumber: 7611001000098
   gidNumber: 7611001000098
   displayName: Test User1000098
   *krbPrincipalName: user1000...@example.test*
   *krbCanonicalName: user1000...@example.test*
   memberOf: cn=ipausers,cn=groups,cn=accounts,dc=example,dc=test
   objectClass: ipaobject
   objectClass: person
   objectClass: top
   objectClass: ipasshuser
   objectClass: inetorgperson
   objectClass: organizationalperson
   objectClass: krbticketpolicyaux
   objectClass: krbprincipalaux
   objectClass: inetuser
   objectClass: posixaccount
   objectClass: ipaSshGroupOfPubKeys
   objectClass: mepOriginEntry
   ipaUniqueID: 6048c4ac-6cdd-11e5-a0af-080027987dcb
   mepManagedEntry: cn=user1000098,cn=groups,cn=accounts,dc=example,dc=test

Would it be an option to create a new attribute, 'krbNonCanonicalName' (containing the krbprincipal) but with a 'caseignoreIA5' syntax ? If this attribute is indexed, your lookup from a raw principal would user "(krbNonCanonicalname=user10000...@example.test)"

thanks
theirry
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