[OpenAFS] AFS-Tokens in cross realm szenario problem
Ulrich Schwickerath
ulrich.schwickerath@iwr.fzk.de
Tue, 16 Aug 2005 19:44:45 +0200
Hello,
we are currently using 1.3.86 on two X86_64 based database server nodes,
providing an AFS cell named cg.fzk.de. We have a ADS KDC for CG.FZK.DE with
some users inside. On the client side we are using Heimdal 0.6.4. If I
authenticate to CG.FZK.DE I can retrieve AFS tokens both with aklog or with
heimdals afslog, and also pam_krb5afs is in place which happily gives me a
working AFS token after successful KRB5 authentication.
So far, so good. Now we have another ADS based realm (KA.FZK.DE), and we have
set up a one way trust between the two KDCs. If I authenticate now in
KA.FZK.DE, I can login into a node in CG.FZK.DE, kerberized authentication
works fine (I tested with rsh), and again, I get an AFS token. But this time
the token is discarded:
afs: Tokens for user of AFS id 1234 for cell cg.fzk.de are discarded (rxkad
error=19270408), meaning:
19270408 (rxk).8 = ticket contained unknown key version number
Running heimdals afslog by hand in verbose mode I get no error messages
whatsoever, but a somewhat strange principal name that is successfully tried:
afslog -v
krb5 tried afs/cg.fzk.de@KA.FZK.DE -> 0
After that I have the following principals and tokens:
[schwicke@iwrcgvor1:/afs/cg.fzk.de/home/schwicke]$ klist -v
Credentials cache: FILE:/tmp/krb5cc_p29657
Principal: schwicke@KA.FZK.DE
Cache version: 4
Server: krbtgt/KA.FZK.DE@KA.FZK.DE
Ticket etype: arcfour-hmac-md5, kvno 100002
Session key: des
Auth time: Aug 16 18:53:14 2005
Start time: Aug 16 19:24:25 2005
End time: Aug 17 04:53:14 2005
Ticket flags: forwardable, forwarded, pre-authenticated
Addresses: IPv4:141.52.165.254
Server: krbtgt/CG.FZK.DE@KA.FZK.DE
Ticket etype: arcfour-hmac-md5
Session key: des
Auth time: Aug 16 18:53:14 2005
Start time: Aug 16 19:24:25 2005
End time: Aug 17 04:53:14 2005
Ticket flags: forwarded, pre-authenticated, ok-as-delegate
Addresses: IPv4:141.52.165.254
Server: krbtgt/CG.FZK.DE@KA.FZK.DE
Ticket etype: arcfour-hmac-md5
Session key: des
Auth time: Aug 16 18:53:14 2005
Start time: Aug 16 19:24:46 2005
End time: Aug 17 04:53:14 2005
Ticket flags: forwarded, pre-authenticated, ok-as-delegate
Addresses: IPv4:141.52.165.254
Server: krbtgt/CG.FZK.DE@KA.FZK.DE
Ticket etype: arcfour-hmac-md5
Session key: des
Auth time: Aug 16 18:53:14 2005
Start time: Aug 16 19:24:51 2005
End time: Aug 17 04:53:14 2005
Ticket flags: forwarded, pre-authenticated, ok-as-delegate
Addresses: IPv4:141.52.165.254
Aug 16 19:24:51 Aug 17 04:53:14 User's (AFS ID 7597) tokens for cg.fzk.de
(256)
The token is discarded, any attempt to access AFS fails with "permission
denied"
also aklog happily provides me with a wrong token but throughs an error:
aklog
aklog: Unknown error 267272 so unable to create remote PTS user
schwicke@ka.fzk.de in cell cg.fzk.de (status: 267272).
What could this Unknown error be ?
After that I also have the afs service principal for the correct cell:
Server: afs@CG.FZK.DE
Ticket etype: des-cbc-md5, kvno 5
Session key: des
Auth time: Aug 16 18:53:14 2005
Start time: Aug 16 19:28:25 2005
End time: Aug 17 04:53:14 2005
Ticket flags: forwarded, pre-authenticated
Addresses: IPv4:141.52.165.254
This is exactly the principal that I expected to see, and the same that I get
if I authenticate in CG.FZK.DE which works fine. The kvno matches the one of
the AFS master key.
Note: In KA.FZK.DE there is no AFS service principal whatsoever. We already
tried to create one there, too, and import a second key into AFS with the
proper KVNO but with the same results.
Any idea what is going on? Did I miss something obvious ? Did anybody
see/solve this (or a similar) problem out there ? I'm out of ideas now what
else I could check. Any hint on what could be going wrong is highly welcome!
Thank's in advance,
Ulrich
P.S.: The relevant part of /etc/krb5.conf look like this:
[libdefaults]
default_etypes = des-cbc-crc des-cbc-md5
default_etypes_des = des-cbc-crc des-cbc-md5
default_realm = CG.FZK.DE
forward = yes
forwardable = yes
ticket_lifetime = 168h
[domain_realm]
.fzk.de = CG.FZK.DE
[appdefaults]
afs-use-524 = no
libkafs = {
afs-use-524 = no
...
}
[capath]
KA.FZK.DE = {
KA.FZK.DE = CG.FZK.DE
}
--
__________________________________________
Dr. Ulrich Schwickerath
Forschungszentrum Karlsruhe
GRID-Computing and e-Science
Institut for Scientific Computing (IWR)
P.O. Box 36 40
76021 Karlsruhe, Germany
Tel: +49(7247)82-8607
Fax: +49(7247)82-4972
e-mail: ulrich.schwickerath@iwr.fzk.de
PGP DH/DSS Key: ID 0xCEB9826F
Fingerprint: 5537 8473 CD26 507E 8EE2 BAAF 98E2 FD16 CEB9 826F
__________________________________________