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

[Matt Rogers]

On 04/27, Sumit Bose wrote:
> 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)?
> 

I believe that would be the same effect, just less efficient. But
sticking to the API is probably safer in the long run. I am okay
with changing it if you would prefer. 

-- 
Matt Rogers
Red Hat, Inc