On Fri, Jul 26, 2013 at 5:09 PM, Andrew Deason <[email protected]>wrote:

> On Fri, 26 Jul 2013 13:39:22 -0700
> Russ Allbery <[email protected]> wrote:
>
> > > This plus
> > > [kdc]svc-use-strongest-session-key=true
> >
> > > Works.
> >
> > svc-use-strongest-session-key looks like it still tries to find
> > something in the common subset of supported keys between the client
> > and server, and legacy aklog sends only des-cbc-crc as its supported
> > keys.  So how could this work?  Isn't there still no common subset
> > with a principal that has no DES keys?
>
> That's what Sergio's patch above is supposed to fix, is my understanding
> (not that I've verified it). That is, with that patch in play, the KDC
> can now choose a session key enctype that is not one of the principal
> key enctypes. So, legacy aklog will get a des-cbc-crc session key when
> the service princ has no des-cbc-crc key.
>
> However, my reading of that patch says that the KDC, as a last resort,
> gives the client a session key no matching any principal key enctype.
> This is _not_ the same as the behavior in MIT Kerberos and AD; they only
> do this for the special case of single DES, not for just any enctype. I
> don't know if that's intentional or not, but it is different, and I'm
> not sure if that's desirable.
>
> I couldn't come up with any situation here where it did, but I didn't do an
in-depth check of things.
-- 
Derrick

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