extern int user_preparse(struct key_preparsed_payload *prep);
extern void user_free_preparse(struct key_preparsed_payload *prep);
extern int user_update(struct key *key, struct key_preparsed_payload *prep);
-extern int user_match(const struct key *key, const void *criterion);
extern void user_revoke(struct key *key);
extern void user_destroy(struct key *key);
extern void user_describe(const struct key *user, struct seq_file *m);