Sadique Puthen notes that the warning on the client side seems to be correspond
to the wrong attribute on the KDC.  Do what RFC4120 says we should do.  RT#5755.

diff -up krb5-1.8/src/kdc/do_as_req.c.key_exp krb5-1.8/src/kdc/do_as_req.c
--- krb5-1.8/src/kdc/do_as_req.c.key_exp	2010-02-16 17:21:08.000000000 -0500
+++ krb5-1.8/src/kdc/do_as_req.c	2010-03-05 11:02:06.000000000 -0500
@@ -555,7 +555,14 @@ process_as_req(krb5_kdc_req *request, kr
         goto errout;
     }
     reply_encpart.nonce = request->nonce;
-    reply_encpart.key_exp = client.expiration;
+    if (client.expiration == 0) {
+       reply_encpart.key_exp = client.pw_expiration;
+    } else if (client.pw_expiration == 0) {
+       reply_encpart.key_exp = client.expiration;
+    } else {
+       reply_encpart.key_exp = client.pw_expiration < client.expiration ?
+                               client.pw_expiration : client.expiration;
+    }
     reply_encpart.flags = enc_tkt_reply.flags;
     reply_encpart.server = ticket_reply.server;