aklog on MacOS X was Re: Service Ticket Questions

Jeffrey Altman jaltman at MIT.EDU
Fri Mar 17 22:33:20 EST 2006

I am cc'ing the openafs-devel at openafs.org mailing list because this is
really an OpenAFS discussion.  krbdev at mit.edu is meant to be a mailing
list focused on development of the MIT Kerberos reference implementation.

The fundamental issue being discussed here is whether the Kerberos.App
display of the Kerberos Credential Cache contents can be used as an
indication by end users that the AFS kernel module contains tokens for
that user.  Hank is claiming that presence of an "afs/cellname at REALM"
service ticket in the credential cache is an indicator that there are
AFS tokens installed in the AFS kernel module.

I believe that end users should be discouraged from checking the
Kerberos credential cache to see if they have AFS tokens because doing
so is fundamentally flawed.  There are many reasons why tokens might be
removed from the AFS kernel after their initial installation let alone
reasons why tokens might not be able to be stored in the first place.
Therefore, using the Kerberos credential cache as a replacement for the
"tokens" command or a GUI token display will only make the lives of end
users and those that support them more difficult.

If there is a concern that the presence of the AFS service ticket will
be misinterpreted as meaning that tokens are present then perhaps the
thing to do is modify aklog and anything that derives from its code base
to not use the default credential cache and instead use a local memory
cache.  We could make this the default behavior and allow the default
credential cache be used when "-d" is specified on the command line to
allow the presence of the service tickets to be used for debugging purposes.

While not part of the same topic, Derrick Brashear spent time this week
attempting to prepare a KFM KLL plug-in for aklog that would work on
Tiger and discovered that under Tiger we will not be able to provide
such functionality.   We will work with Apple to try to make this happen
in a future release.  For those who are unaware, the KFM KLL plug-ins
have been used in previous releases of MacOS X to allow the Kerberos
initial ticket getting functionality to be extended such that whenever a
new Kerberos 5 Initial Ticket is obtained a new AFS token would be
acquired at the same time.  Without this functionality it is not
possible to provide a single sign-on experience for AFS on Tiger.

Jeffrey Altman

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