Continue after KRB5_CC_END in KCM cache iteration

The KCM server returns KRB5_CC_END in response to a GET_CACHE_BY_UUID
request to indicate that the specified ccache uuid no longer exists.
In krb5_ptcursor_next(), ignore this error and continue the iteration,
as the Heimdal KCM client code does.

In addition to addressing the case where a third party deletes a cache
between the GET_CACHE_UUID_LIST request and when we reach that uuid in
the iteration, this change also fixes a bug in kdestroy -A where the
caller deletes the primary cache and we later request it by uuid when
iterating over the list.

[ghudson@mit.edu: rewrote commit message; edited comment]

(cherry picked from commit 49087f5e6309f298f8898c35af6f4ade418ced60)

ticket: 8658
version_fixed: 1.15.3

1 files changed, 3 insertions, 0 deletions

diff --git a/src/lib/krb5/ccache/cc_kcm.c b/src/lib/krb5/ccache/cc_kcm.c
index a889e67..a3afd70 100644
--- a/src/lib/krb5/ccache/cc_kcm.c
+++ b/src/lib/krb5/ccache/cc_kcm.c
@@ -966,6 +966,9 @@ kcm_ptcursor_next(krb5_context context, krb5_cc_ptcursor cursor,
         kcmreq_init(&req, KCM_OP_GET_CACHE_BY_UUID, NULL);
         k5_buf_add_len(&req.reqbuf, id, KCM_UUID_LEN);
         ret = kcmio_call(context, data->io, &req);
+        /* Continue if the cache has been deleted. */
+        if (ret == KRB5_CC_END)
+            continue;
         if (ret)
             goto cleanup;
         ret = kcmreq_get_name(&req, &name);