kdb: store mkey list in context and permit NULL mkey for kdb_dbe_decrypt_key_data

Previously, code needed to run a loop to find the current master key,
possibly fetch a new master key list and try finding the master key
again around each key decryption.  This was not universally done;
there are cases where only the current master key was used.  In
addition, the correct ideom for decrypting key data is too complicated
and is potentially unavailable to plugins that do not have access to
the master key.  Instead, store the master key list in the dal_handle
whenever it is fetched and permit a NULL master key for
krb5_dbe_decrypt_key_data.

* Remove APIs for krb5_db_{get|set}_mkey_list
* krb5_db_fetch_mkey_list: memoize master key list in dal_handle
* krb5_db_free_mkey_list: don't free the memoized list; arrange for it to be freed later
* krb5_dbe_decrypt_key_data: Search for correct master key on NULL argument
* change call sites to take advantage

ticket: 6778

git-svn-id: svn://anonsvn.mit.edu/krb5/trunk@24314 dc483132-0cff-0310-8789-dd5450dbe970

1 files changed, 1 insertions, 11 deletions

diff --git a/src/lib/kdb/keytab.c b/src/lib/kdb/keytab.c
index 4d56915b9..dbbbe75cd 100644
--- a/src/lib/kdb/keytab.c
+++ b/src/lib/kdb/keytab.c
@@ -124,8 +124,6 @@ krb5_ktkdb_get_entry(in_context, id, principal, kvno, enctype, entry)
     krb5_keytab_entry   * entry;
 {
     krb5_context          context;
-    krb5_keylist_node  * master_keylist;
-    krb5_keyblock       * master_key;
     krb5_error_code       kerror = 0;
     krb5_key_data       * key_data;
     krb5_db_entry       * db_entry;
@@ -157,14 +155,6 @@ krb5_ktkdb_get_entry(in_context, id, principal, kvno, enctype, entry)
     }
 
     /* match key */
-    kerror = krb5_db_get_mkey_list(context, &master_keylist);
-    if (kerror)
-        goto error;
-
-    kerror = krb5_dbe_find_mkey(context, master_keylist, db_entry, &master_key);
-    if (kerror)
-        goto error;
-
     /* For cross realm tgts, we match whatever enctype is provided;
      * for other principals, we only match the first enctype that is
      * found.  Since the TGS and AS code do the same thing, then we
@@ -178,7 +168,7 @@ krb5_ktkdb_get_entry(in_context, id, principal, kvno, enctype, entry)
         goto error;
 
 
-    kerror = krb5_dbe_decrypt_key_data(context, master_key, key_data,
+    kerror = krb5_dbe_decrypt_key_data(context, NULL, key_data,
                                        &entry->key, NULL);
     if (kerror)
         goto error;