[OpenAFS] Encryption of traffic

Russ Allbery rra@stanford.edu
Tue, 26 Jun 2007 09:39:13 -0700

Katrine Svendsen <kat_svendsen@hotmail.com> writes:

> I'm trying to find some details about the traffic encryption between an
> AFS client and server (fs setcrypt on/off), but this seems to be very
> difficult.I would like to know about such things as keylength, mode of
> operation, key generation/distribution etc. Does anybody have a good
> source for this?

AFS uses an encryption method called fcrypt, which is a modified DES.
Google for fcrypt will return a lot of hits, although I don't know if any
of them have detailed analyses.  This encryption method is fairly obsolete
at this point.

> It also seems to me that not too much have happened in this field (when
> considering AFS) the last years. Am I right when I think that the
> network traffic-encryption in AFS is somewhat "ancient"? Why is there
> not more focus on this?

On the contrary, this is our top development priority apart from keeping
things generally working, and is the focus of both the rxk5 and rxgk
work.  The difficulty is that replacing the encryption algorithm in AFS
requires substantial protocol changes and ideally one wants to generalize
the encryption layer and support all GSSAPI encryption types at the same
time, as well as provide a framework for stronger authentication in

Both rxk5 and rxgk have made substantial progress in the past year.

Russ Allbery (rra@stanford.edu)             <http://www.eyrie.org/~eagle/>