[OpenAFS] More questions about the re-keying document

[stephen@physics.unc.edu]

First, I don't think I said this before, but to whomever wrote the rekeying 
document and the instructions for 1.4 and 1.6, thanks! It's great that 
these were available immediately, at the same time as the security 
vulnerability.

I also think that eliminating DES is worth the pain of re-keying a cell and 
upgrading clients, so a BIG thank you to Derrick Brashear, Alexander 
Chernyakhovsky, Andrew Deason, Chaskiel M Grundman and Benjamin Kaduk for 
developing the patches.

In going over the re-keying document, a few more questions popped into my 
mind that weren't clear from my reading of the document.

In the "Basic" procedure for MIT, it mentions ensuring that DES should not 
be one of the encryption types in the rxkad.keytab file. I assume this 
isn't a technical reason, but that having it there would allow its 
continued use (so no gain in rekeying).

However in the "Basic" procedure for Heimdal, it does not mention any such 
caution. My site's KDC is Heimdal and does include DES by default. I assume 
I should similarly ensure DES isn't in the keytab (similar to the advice in 
the MIT section)?

What the best practice for having enctypes availble on a principal on the 
KDC vs. in the keytab. Obviously the keytab enctypes must be the same as, 
or a subset of, the principal's enctypes. Does it hurt if DES (or other 
undesired salts) exist for the afs/cell@REALM principal as long as they're 
not in the rxkad.keytab file?

Cheers, Stephen
--
Stephen Joyce
Systems Specialist
College of Arts and Sciences
University of North Carolina at Chapel Hill
voice: 919.962.7214
fax: 919.962.0480