[Freeipa-devel] [PATCH] 0001 ipa_kdb add krbPrincipalAuthInd handling

[Sumit Bose]

On Tue, Apr 26, 2016 at 02:02:04PM -0400, Matt Rogers wrote:
> On 04/26, Sumit Bose wrote:
> > On Thu, Apr 14, 2016 at 12:59:55PM -0400, Matt Rogers wrote:
> > > 
> > > 
> > > ----- Original Message -----
> > > > From: "Nathaniel McCallum" <npmccallum at redhat.com>
> > > > To: "Matt Rogers" <mrogers at redhat.com>, freeipa-devel at redhat.com
> > > > Sent: Thursday, April 14, 2016 10:32:15 AM
> > > > Subject: Re: [Freeipa-devel] [PATCH] 0001 ipa_kdb add krbPrincipalAuthInd handling
> > > > 
> > > > On Mon, 2016-04-11 at 10:41 -0400, Matt Rogers wrote:
> > > > > Hi,
> > > > > 
> > > > > The attached patch is a part of the authentication indicator
> > > > > enhancements,
> > > > > adding indicator value storage and retrieval for the KDB driver.
> > > > > 
> > > > > https://fedorahosted.org/freeipa/ticket/5782
> > > > 
> > > > Can you add some whitespace in next_attr()? The density of the code
> > > > there hurts readability.
> > > > 
> > > Sure, I've attached the revised patch.
> > 
> > Hi Matt,
> > 
> > thank you for the patch. Currently I have the following question.
> > 
> > You call krb5_dbe_set_string to remove the 'require_auth' data before
> > calling ipadb_get_ldap_mod_extra_data()
> > 
> 
> > > +        /* Delete authinds from tl_data so it is not included in krbExtraData. */
> > > +        kerr = krb5_dbe_set_string(kcontext, entry, "require_auth", NULL);
> > > +        if (kerr) {
> > > +            goto done;
> > > +        }
> > > +
> > >          kerr = ipadb_get_ldap_mod_extra_data(imods,
> > >                                               entry->tl_data,
> > >                                               mod_op);
> > > 
> > 
> > Why it is needed to filter this data again in
> > ipadb_get_ldap_mod_extra_data()?
> > 
> 
> Hi Sumit, thanks for looking. The above krb5_dbe_set_string() call I
> believe I left there in error - We decided to operate on a filtered copy
> of the tl_data (which filter_authind_str_attrs() handles) rather than
> removing it completely with krb5_dbe_set_string(). I had tested with the
> above code commented out but forgot to remove it with the submitted patch.

ok, makes sense.

Nevertheless, comments in kdb.h like:

/* String attributes (currently stored inside tl-data) map C string keys to
 * values.  They can be set via kadmin and consumed by KDC plugins. */

and

/* String attributes may not always be represented in tl-data.  kadmin clients
 * must use the get_strings and set_string RPCs. */

make me wonder if it is a good idea to operate on the tl-data of type
KRB5_TL_STRING_ATTRS directly? I know we do this in other places as well
so I'm not insisting to change it, I'm just wondering about the reasons.

Would something like (error checks are missing)

    kerr = krb5_dbe_get_string(kcontext, entry, "require_auth",
                               &require_auth_str);

    if (require_auth_str != NULL) {
        kerr = krb5_dbe_set_string(kcontext, entry, "require_auth", NULL);
    }

    kerr = ipadb_get_ldap_mod_extra_data(imods,
                                         entry->tl_data,
                                         mod_op);

    if (require_auth_str != NULL) {
        kerr = krb5_dbe_set_string(kcontext, entry, "require_auth",
                                   require_auth_str);
    }

have the same effect with only using the recommended API (and making the
patch smaller)?

bye,
Sumit