1 /* Basic authentication token and access key management
3 * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved.
4 * Written by David Howells (dhowells@redhat.com)
6 * This program is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU General Public License
8 * as published by the Free Software Foundation; either version
9 * 2 of the License, or (at your option) any later version.
12 #include <linux/module.h>
13 #include <linux/init.h>
14 #include <linux/poison.h>
15 #include <linux/sched.h>
16 #include <linux/slab.h>
17 #include <linux/security.h>
18 #include <linux/workqueue.h>
19 #include <linux/random.h>
20 #include <linux/err.h>
23 struct kmem_cache
*key_jar
;
24 struct rb_root key_serial_tree
; /* tree of keys indexed by serial */
25 DEFINE_SPINLOCK(key_serial_lock
);
27 struct rb_root key_user_tree
; /* tree of quota records indexed by UID */
28 DEFINE_SPINLOCK(key_user_lock
);
30 unsigned int key_quota_root_maxkeys
= 200; /* root's key count quota */
31 unsigned int key_quota_root_maxbytes
= 20000; /* root's key space quota */
32 unsigned int key_quota_maxkeys
= 200; /* general key count quota */
33 unsigned int key_quota_maxbytes
= 20000; /* general key space quota */
35 static LIST_HEAD(key_types_list
);
36 static DECLARE_RWSEM(key_types_sem
);
38 /* We serialise key instantiation and link */
39 DEFINE_MUTEX(key_construction_mutex
);
42 void __key_check(const struct key
*key
)
44 printk("__key_check: key %p {%08x} should be {%08x}\n",
45 key
, key
->magic
, KEY_DEBUG_MAGIC
);
51 * Get the key quota record for a user, allocating a new record if one doesn't
54 struct key_user
*key_user_lookup(kuid_t uid
)
56 struct key_user
*candidate
= NULL
, *user
;
57 struct rb_node
*parent
= NULL
;
61 p
= &key_user_tree
.rb_node
;
62 spin_lock(&key_user_lock
);
64 /* search the tree for a user record with a matching UID */
67 user
= rb_entry(parent
, struct key_user
, node
);
69 if (uid_lt(uid
, user
->uid
))
71 else if (uid_gt(uid
, user
->uid
))
77 /* if we get here, we failed to find a match in the tree */
79 /* allocate a candidate user record if we don't already have
81 spin_unlock(&key_user_lock
);
84 candidate
= kmalloc(sizeof(struct key_user
), GFP_KERNEL
);
85 if (unlikely(!candidate
))
88 /* the allocation may have scheduled, so we need to repeat the
89 * search lest someone else added the record whilst we were
94 /* if we get here, then the user record still hadn't appeared on the
95 * second pass - so we use the candidate record */
96 atomic_set(&candidate
->usage
, 1);
97 atomic_set(&candidate
->nkeys
, 0);
98 atomic_set(&candidate
->nikeys
, 0);
100 candidate
->qnkeys
= 0;
101 candidate
->qnbytes
= 0;
102 spin_lock_init(&candidate
->lock
);
103 mutex_init(&candidate
->cons_lock
);
105 rb_link_node(&candidate
->node
, parent
, p
);
106 rb_insert_color(&candidate
->node
, &key_user_tree
);
107 spin_unlock(&key_user_lock
);
111 /* okay - we found a user record for this UID */
113 atomic_inc(&user
->usage
);
114 spin_unlock(&key_user_lock
);
121 * Dispose of a user structure
123 void key_user_put(struct key_user
*user
)
125 if (atomic_dec_and_lock(&user
->usage
, &key_user_lock
)) {
126 rb_erase(&user
->node
, &key_user_tree
);
127 spin_unlock(&key_user_lock
);
134 * Allocate a serial number for a key. These are assigned randomly to avoid
135 * security issues through covert channel problems.
137 static inline void key_alloc_serial(struct key
*key
)
139 struct rb_node
*parent
, **p
;
142 /* propose a random serial number and look for a hole for it in the
143 * serial number tree */
145 get_random_bytes(&key
->serial
, sizeof(key
->serial
));
147 key
->serial
>>= 1; /* negative numbers are not permitted */
148 } while (key
->serial
< 3);
150 spin_lock(&key_serial_lock
);
154 p
= &key_serial_tree
.rb_node
;
158 xkey
= rb_entry(parent
, struct key
, serial_node
);
160 if (key
->serial
< xkey
->serial
)
162 else if (key
->serial
> xkey
->serial
)
168 /* we've found a suitable hole - arrange for this key to occupy it */
169 rb_link_node(&key
->serial_node
, parent
, p
);
170 rb_insert_color(&key
->serial_node
, &key_serial_tree
);
172 spin_unlock(&key_serial_lock
);
175 /* we found a key with the proposed serial number - walk the tree from
176 * that point looking for the next unused serial number */
180 if (key
->serial
< 3) {
182 goto attempt_insertion
;
185 parent
= rb_next(parent
);
187 goto attempt_insertion
;
189 xkey
= rb_entry(parent
, struct key
, serial_node
);
190 if (key
->serial
< xkey
->serial
)
191 goto attempt_insertion
;
196 * key_alloc - Allocate a key of the specified type.
197 * @type: The type of key to allocate.
198 * @desc: The key description to allow the key to be searched out.
199 * @uid: The owner of the new key.
200 * @gid: The group ID for the new key's group permissions.
201 * @cred: The credentials specifying UID namespace.
202 * @perm: The permissions mask of the new key.
203 * @flags: Flags specifying quota properties.
205 * Allocate a key of the specified type with the attributes given. The key is
206 * returned in an uninstantiated state and the caller needs to instantiate the
207 * key before returning.
209 * The user's key count quota is updated to reflect the creation of the key and
210 * the user's key data quota has the default for the key type reserved. The
211 * instantiation function should amend this as necessary. If insufficient
212 * quota is available, -EDQUOT will be returned.
214 * The LSM security modules can prevent a key being created, in which case
215 * -EACCES will be returned.
217 * Returns a pointer to the new key if successful and an error code otherwise.
219 * Note that the caller needs to ensure the key type isn't uninstantiated.
220 * Internally this can be done by locking key_types_sem. Externally, this can
221 * be done by either never unregistering the key type, or making sure
222 * key_alloc() calls don't race with module unloading.
224 struct key
*key_alloc(struct key_type
*type
, const char *desc
,
225 kuid_t uid
, kgid_t gid
, const struct cred
*cred
,
226 key_perm_t perm
, unsigned long flags
)
228 struct key_user
*user
= NULL
;
230 size_t desclen
, quotalen
;
233 key
= ERR_PTR(-EINVAL
);
237 if (type
->vet_description
) {
238 ret
= type
->vet_description(desc
);
245 desclen
= strlen(desc
) + 1;
246 quotalen
= desclen
+ type
->def_datalen
;
248 /* get hold of the key tracking for this user */
249 user
= key_user_lookup(uid
);
253 /* check that the user's quota permits allocation of another key and
255 if (!(flags
& KEY_ALLOC_NOT_IN_QUOTA
)) {
256 unsigned maxkeys
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
257 key_quota_root_maxkeys
: key_quota_maxkeys
;
258 unsigned maxbytes
= uid_eq(uid
, GLOBAL_ROOT_UID
) ?
259 key_quota_root_maxbytes
: key_quota_maxbytes
;
261 spin_lock(&user
->lock
);
262 if (!(flags
& KEY_ALLOC_QUOTA_OVERRUN
)) {
263 if (user
->qnkeys
+ 1 >= maxkeys
||
264 user
->qnbytes
+ quotalen
>= maxbytes
||
265 user
->qnbytes
+ quotalen
< user
->qnbytes
)
270 user
->qnbytes
+= quotalen
;
271 spin_unlock(&user
->lock
);
274 /* allocate and initialise the key and its description */
275 key
= kmem_cache_alloc(key_jar
, GFP_KERNEL
);
280 key
->description
= kmemdup(desc
, desclen
, GFP_KERNEL
);
281 if (!key
->description
)
285 atomic_set(&key
->usage
, 1);
286 init_rwsem(&key
->sem
);
287 lockdep_set_class(&key
->sem
, &type
->lock_class
);
290 key
->quotalen
= quotalen
;
291 key
->datalen
= type
->def_datalen
;
297 key
->payload
.data
= NULL
;
298 key
->security
= NULL
;
300 if (!(flags
& KEY_ALLOC_NOT_IN_QUOTA
))
301 key
->flags
|= 1 << KEY_FLAG_IN_QUOTA
;
302 if (flags
& KEY_ALLOC_UID_KEYRING
)
303 key
->flags
|= 1 << KEY_FLAG_UID_KEYRING
;
305 memset(&key
->type_data
, 0, sizeof(key
->type_data
));
308 key
->magic
= KEY_DEBUG_MAGIC
;
311 /* let the security module know about the key */
312 ret
= security_key_alloc(key
, cred
, flags
);
316 /* publish the key by giving it a serial number */
317 atomic_inc(&user
->nkeys
);
318 key_alloc_serial(key
);
324 kfree(key
->description
);
325 kmem_cache_free(key_jar
, key
);
326 if (!(flags
& KEY_ALLOC_NOT_IN_QUOTA
)) {
327 spin_lock(&user
->lock
);
329 user
->qnbytes
-= quotalen
;
330 spin_unlock(&user
->lock
);
337 kmem_cache_free(key_jar
, key
);
339 if (!(flags
& KEY_ALLOC_NOT_IN_QUOTA
)) {
340 spin_lock(&user
->lock
);
342 user
->qnbytes
-= quotalen
;
343 spin_unlock(&user
->lock
);
347 key
= ERR_PTR(-ENOMEM
);
351 spin_unlock(&user
->lock
);
353 key
= ERR_PTR(-EDQUOT
);
356 EXPORT_SYMBOL(key_alloc
);
359 * key_payload_reserve - Adjust data quota reservation for the key's payload
360 * @key: The key to make the reservation for.
361 * @datalen: The amount of data payload the caller now wants.
363 * Adjust the amount of the owning user's key data quota that a key reserves.
364 * If the amount is increased, then -EDQUOT may be returned if there isn't
365 * enough free quota available.
367 * If successful, 0 is returned.
369 int key_payload_reserve(struct key
*key
, size_t datalen
)
371 int delta
= (int)datalen
- key
->datalen
;
376 /* contemplate the quota adjustment */
377 if (delta
!= 0 && test_bit(KEY_FLAG_IN_QUOTA
, &key
->flags
)) {
378 unsigned maxbytes
= uid_eq(key
->user
->uid
, GLOBAL_ROOT_UID
) ?
379 key_quota_root_maxbytes
: key_quota_maxbytes
;
381 spin_lock(&key
->user
->lock
);
384 (key
->user
->qnbytes
+ delta
>= maxbytes
||
385 key
->user
->qnbytes
+ delta
< key
->user
->qnbytes
)) {
389 key
->user
->qnbytes
+= delta
;
390 key
->quotalen
+= delta
;
392 spin_unlock(&key
->user
->lock
);
395 /* change the recorded data length if that didn't generate an error */
397 key
->datalen
= datalen
;
401 EXPORT_SYMBOL(key_payload_reserve
);
404 * Instantiate a key and link it into the target keyring atomically. Must be
405 * called with the target keyring's semaphore writelocked. The target key's
406 * semaphore need not be locked as instantiation is serialised by
407 * key_construction_mutex.
409 static int __key_instantiate_and_link(struct key
*key
,
410 struct key_preparsed_payload
*prep
,
413 unsigned long *_prealloc
)
423 mutex_lock(&key_construction_mutex
);
425 /* can't instantiate twice */
426 if (!test_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
)) {
427 /* instantiate the key */
428 ret
= key
->type
->instantiate(key
, prep
);
431 /* mark the key as being instantiated */
432 atomic_inc(&key
->user
->nikeys
);
433 set_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
);
435 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT
, &key
->flags
))
438 /* and link it into the destination keyring */
440 __key_link(keyring
, key
, _prealloc
);
442 /* disable the authorisation key */
448 mutex_unlock(&key_construction_mutex
);
450 /* wake up anyone waiting for a key to be constructed */
452 wake_up_bit(&key
->flags
, KEY_FLAG_USER_CONSTRUCT
);
458 * key_instantiate_and_link - Instantiate a key and link it into the keyring.
459 * @key: The key to instantiate.
460 * @data: The data to use to instantiate the keyring.
461 * @datalen: The length of @data.
462 * @keyring: Keyring to create a link in on success (or NULL).
463 * @authkey: The authorisation token permitting instantiation.
465 * Instantiate a key that's in the uninstantiated state using the provided data
466 * and, if successful, link it in to the destination keyring if one is
469 * If successful, 0 is returned, the authorisation token is revoked and anyone
470 * waiting for the key is woken up. If the key was already instantiated,
471 * -EBUSY will be returned.
473 int key_instantiate_and_link(struct key
*key
,
479 struct key_preparsed_payload prep
;
480 unsigned long prealloc
;
483 memset(&prep
, 0, sizeof(prep
));
485 prep
.datalen
= datalen
;
486 prep
.quotalen
= key
->type
->def_datalen
;
487 if (key
->type
->preparse
) {
488 ret
= key
->type
->preparse(&prep
);
494 ret
= __key_link_begin(keyring
, key
->type
, key
->description
,
497 goto error_free_preparse
;
500 ret
= __key_instantiate_and_link(key
, &prep
, keyring
, authkey
,
504 __key_link_end(keyring
, key
->type
, prealloc
);
507 if (key
->type
->preparse
)
508 key
->type
->free_preparse(&prep
);
513 EXPORT_SYMBOL(key_instantiate_and_link
);
516 * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
517 * @key: The key to instantiate.
518 * @timeout: The timeout on the negative key.
519 * @error: The error to return when the key is hit.
520 * @keyring: Keyring to create a link in on success (or NULL).
521 * @authkey: The authorisation token permitting instantiation.
523 * Negatively instantiate a key that's in the uninstantiated state and, if
524 * successful, set its timeout and stored error and link it in to the
525 * destination keyring if one is supplied. The key and any links to the key
526 * will be automatically garbage collected after the timeout expires.
528 * Negative keys are used to rate limit repeated request_key() calls by causing
529 * them to return the stored error code (typically ENOKEY) until the negative
532 * If successful, 0 is returned, the authorisation token is revoked and anyone
533 * waiting for the key is woken up. If the key was already instantiated,
534 * -EBUSY will be returned.
536 int key_reject_and_link(struct key
*key
,
542 unsigned long prealloc
;
544 int ret
, awaken
, link_ret
= 0;
553 link_ret
= __key_link_begin(keyring
, key
->type
,
554 key
->description
, &prealloc
);
556 mutex_lock(&key_construction_mutex
);
558 /* can't instantiate twice */
559 if (!test_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
)) {
560 /* mark the key as being negatively instantiated */
561 atomic_inc(&key
->user
->nikeys
);
562 set_bit(KEY_FLAG_NEGATIVE
, &key
->flags
);
563 set_bit(KEY_FLAG_INSTANTIATED
, &key
->flags
);
564 key
->type_data
.reject_error
= -error
;
565 now
= current_kernel_time();
566 key
->expiry
= now
.tv_sec
+ timeout
;
567 key_schedule_gc(key
->expiry
+ key_gc_delay
);
569 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT
, &key
->flags
))
574 /* and link it into the destination keyring */
575 if (keyring
&& link_ret
== 0)
576 __key_link(keyring
, key
, &prealloc
);
578 /* disable the authorisation key */
583 mutex_unlock(&key_construction_mutex
);
585 if (keyring
&& link_ret
== 0)
586 __key_link_end(keyring
, key
->type
, prealloc
);
588 /* wake up anyone waiting for a key to be constructed */
590 wake_up_bit(&key
->flags
, KEY_FLAG_USER_CONSTRUCT
);
592 return ret
== 0 ? link_ret
: ret
;
594 EXPORT_SYMBOL(key_reject_and_link
);
597 * key_put - Discard a reference to a key.
598 * @key: The key to discard a reference from.
600 * Discard a reference to a key, and when all the references are gone, we
601 * schedule the cleanup task to come and pull it out of the tree in process
602 * context at some later time.
604 void key_put(struct key
*key
)
609 if (atomic_dec_and_test(&key
->usage
))
610 schedule_work(&key_gc_work
);
613 EXPORT_SYMBOL(key_put
);
616 * Find a key by its serial number.
618 struct key
*key_lookup(key_serial_t id
)
623 spin_lock(&key_serial_lock
);
625 /* search the tree for the specified key */
626 n
= key_serial_tree
.rb_node
;
628 key
= rb_entry(n
, struct key
, serial_node
);
630 if (id
< key
->serial
)
632 else if (id
> key
->serial
)
639 key
= ERR_PTR(-ENOKEY
);
643 /* pretend it doesn't exist if it is awaiting deletion */
644 if (atomic_read(&key
->usage
) == 0)
647 /* this races with key_put(), but that doesn't matter since key_put()
648 * doesn't actually change the key
650 atomic_inc(&key
->usage
);
653 spin_unlock(&key_serial_lock
);
658 * Find and lock the specified key type against removal.
660 * We return with the sem read-locked if successful. If the type wasn't
661 * available -ENOKEY is returned instead.
663 struct key_type
*key_type_lookup(const char *type
)
665 struct key_type
*ktype
;
667 down_read(&key_types_sem
);
669 /* look up the key type to see if it's one of the registered kernel
671 list_for_each_entry(ktype
, &key_types_list
, link
) {
672 if (strcmp(ktype
->name
, type
) == 0)
673 goto found_kernel_type
;
676 up_read(&key_types_sem
);
677 ktype
= ERR_PTR(-ENOKEY
);
683 void key_set_timeout(struct key
*key
, unsigned timeout
)
688 /* make the changes with the locks held to prevent races */
689 down_write(&key
->sem
);
692 now
= current_kernel_time();
693 expiry
= now
.tv_sec
+ timeout
;
696 key
->expiry
= expiry
;
697 key_schedule_gc(key
->expiry
+ key_gc_delay
);
701 EXPORT_SYMBOL_GPL(key_set_timeout
);
704 * Unlock a key type locked by key_type_lookup().
706 void key_type_put(struct key_type
*ktype
)
708 up_read(&key_types_sem
);
712 * Attempt to update an existing key.
714 * The key is given to us with an incremented refcount that we need to discard
715 * if we get an error.
717 static inline key_ref_t
__key_update(key_ref_t key_ref
,
718 struct key_preparsed_payload
*prep
)
720 struct key
*key
= key_ref_to_ptr(key_ref
);
723 /* need write permission on the key to update it */
724 ret
= key_permission(key_ref
, KEY_WRITE
);
729 if (!key
->type
->update
)
732 down_write(&key
->sem
);
734 ret
= key
->type
->update(key
, prep
);
736 /* updating a negative key instantiates it */
737 clear_bit(KEY_FLAG_NEGATIVE
, &key
->flags
);
748 key_ref
= ERR_PTR(ret
);
753 * key_create_or_update - Update or create and instantiate a key.
754 * @keyring_ref: A pointer to the destination keyring with possession flag.
755 * @type: The type of key.
756 * @description: The searchable description for the key.
757 * @payload: The data to use to instantiate or update the key.
758 * @plen: The length of @payload.
759 * @perm: The permissions mask for a new key.
760 * @flags: The quota flags for a new key.
762 * Search the destination keyring for a key of the same description and if one
763 * is found, update it, otherwise create and instantiate a new one and create a
764 * link to it from that keyring.
766 * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
769 * Returns a pointer to the new key if successful, -ENODEV if the key type
770 * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the
771 * caller isn't permitted to modify the keyring or the LSM did not permit
772 * creation of the key.
774 * On success, the possession flag from the keyring ref will be tacked on to
775 * the key ref before it is returned.
777 key_ref_t
key_create_or_update(key_ref_t keyring_ref
,
779 const char *description
,
785 unsigned long prealloc
;
786 struct key_preparsed_payload prep
;
787 const struct cred
*cred
= current_cred();
788 struct key_type
*ktype
;
789 struct key
*keyring
, *key
= NULL
;
793 /* look up the key type to see if it's one of the registered kernel
795 ktype
= key_type_lookup(type
);
797 key_ref
= ERR_PTR(-ENODEV
);
801 key_ref
= ERR_PTR(-EINVAL
);
802 if (!ktype
->match
|| !ktype
->instantiate
||
803 (!description
&& !ktype
->preparse
))
806 keyring
= key_ref_to_ptr(keyring_ref
);
810 key_ref
= ERR_PTR(-ENOTDIR
);
811 if (keyring
->type
!= &key_type_keyring
)
814 memset(&prep
, 0, sizeof(prep
));
817 prep
.quotalen
= ktype
->def_datalen
;
818 if (ktype
->preparse
) {
819 ret
= ktype
->preparse(&prep
);
821 key_ref
= ERR_PTR(ret
);
825 description
= prep
.description
;
826 key_ref
= ERR_PTR(-EINVAL
);
828 goto error_free_prep
;
831 ret
= __key_link_begin(keyring
, ktype
, description
, &prealloc
);
833 key_ref
= ERR_PTR(ret
);
834 goto error_free_prep
;
837 /* if we're going to allocate a new key, we're going to have
838 * to modify the keyring */
839 ret
= key_permission(keyring_ref
, KEY_WRITE
);
841 key_ref
= ERR_PTR(ret
);
845 /* if it's possible to update this type of key, search for an existing
846 * key of the same type and description in the destination keyring and
847 * update that instead if possible
850 key_ref
= __keyring_search_one(keyring_ref
, ktype
, description
,
852 if (!IS_ERR(key_ref
))
853 goto found_matching_key
;
856 /* if the client doesn't provide, decide on the permissions we want */
857 if (perm
== KEY_PERM_UNDEF
) {
858 perm
= KEY_POS_VIEW
| KEY_POS_SEARCH
| KEY_POS_LINK
| KEY_POS_SETATTR
;
859 perm
|= KEY_USR_VIEW
;
862 perm
|= KEY_POS_READ
;
864 if (ktype
== &key_type_keyring
|| ktype
->update
)
865 perm
|= KEY_POS_WRITE
;
868 /* allocate a new key */
869 key
= key_alloc(ktype
, description
, cred
->fsuid
, cred
->fsgid
, cred
,
872 key_ref
= ERR_CAST(key
);
876 /* instantiate it and link it into the target keyring */
877 ret
= __key_instantiate_and_link(key
, &prep
, keyring
, NULL
, &prealloc
);
880 key_ref
= ERR_PTR(ret
);
884 key_ref
= make_key_ref(key
, is_key_possessed(keyring_ref
));
887 __key_link_end(keyring
, ktype
, prealloc
);
890 ktype
->free_preparse(&prep
);
897 /* we found a matching key, so we're going to try to update it
898 * - we can drop the locks first as we have the key pinned
900 __key_link_end(keyring
, ktype
, prealloc
);
902 key
= key_ref_to_ptr(key_ref
);
903 if (test_bit(KEY_FLAG_USER_CONSTRUCT
, &key
->flags
)) {
904 ret
= wait_for_key_construction(key
, true);
906 key_ref_put(key_ref
);
907 key_ref
= ERR_PTR(ret
);
908 goto error_free_prep
;
912 key_ref
= __key_update(key_ref
, &prep
);
913 goto error_free_prep
;
915 EXPORT_SYMBOL(key_create_or_update
);
918 * key_update - Update a key's contents.
919 * @key_ref: The pointer (plus possession flag) to the key.
920 * @payload: The data to be used to update the key.
921 * @plen: The length of @payload.
923 * Attempt to update the contents of a key with the given payload data. The
924 * caller must be granted Write permission on the key. Negative keys can be
925 * instantiated by this method.
927 * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
928 * type does not support updating. The key type may return other errors.
930 int key_update(key_ref_t key_ref
, const void *payload
, size_t plen
)
932 struct key_preparsed_payload prep
;
933 struct key
*key
= key_ref_to_ptr(key_ref
);
938 /* the key must be writable */
939 ret
= key_permission(key_ref
, KEY_WRITE
);
943 /* attempt to update it if supported */
945 if (!key
->type
->update
)
948 memset(&prep
, 0, sizeof(prep
));
951 prep
.quotalen
= key
->type
->def_datalen
;
952 if (key
->type
->preparse
) {
953 ret
= key
->type
->preparse(&prep
);
958 down_write(&key
->sem
);
960 ret
= key
->type
->update(key
, &prep
);
962 /* updating a negative key instantiates it */
963 clear_bit(KEY_FLAG_NEGATIVE
, &key
->flags
);
967 if (key
->type
->preparse
)
968 key
->type
->free_preparse(&prep
);
972 EXPORT_SYMBOL(key_update
);
975 * key_revoke - Revoke a key.
976 * @key: The key to be revoked.
978 * Mark a key as being revoked and ask the type to free up its resources. The
979 * revocation timeout is set and the key and all its links will be
980 * automatically garbage collected after key_gc_delay amount of time if they
981 * are not manually dealt with first.
983 void key_revoke(struct key
*key
)
990 /* make sure no one's trying to change or use the key when we mark it
991 * - we tell lockdep that we might nest because we might be revoking an
992 * authorisation key whilst holding the sem on a key we've just
995 down_write_nested(&key
->sem
, 1);
996 if (!test_and_set_bit(KEY_FLAG_REVOKED
, &key
->flags
) &&
998 key
->type
->revoke(key
);
1000 /* set the death time to no more than the expiry time */
1001 now
= current_kernel_time();
1003 if (key
->revoked_at
== 0 || key
->revoked_at
> time
) {
1004 key
->revoked_at
= time
;
1005 key_schedule_gc(key
->revoked_at
+ key_gc_delay
);
1008 up_write(&key
->sem
);
1010 EXPORT_SYMBOL(key_revoke
);
1013 * key_invalidate - Invalidate a key.
1014 * @key: The key to be invalidated.
1016 * Mark a key as being invalidated and have it cleaned up immediately. The key
1017 * is ignored by all searches and other operations from this point.
1019 void key_invalidate(struct key
*key
)
1021 kenter("%d", key_serial(key
));
1025 if (!test_bit(KEY_FLAG_INVALIDATED
, &key
->flags
)) {
1026 down_write_nested(&key
->sem
, 1);
1027 if (!test_and_set_bit(KEY_FLAG_INVALIDATED
, &key
->flags
))
1028 key_schedule_gc_links();
1029 up_write(&key
->sem
);
1032 EXPORT_SYMBOL(key_invalidate
);
1035 * register_key_type - Register a type of key.
1036 * @ktype: The new key type.
1038 * Register a new key type.
1040 * Returns 0 on success or -EEXIST if a type of this name already exists.
1042 int register_key_type(struct key_type
*ktype
)
1047 memset(&ktype
->lock_class
, 0, sizeof(ktype
->lock_class
));
1050 down_write(&key_types_sem
);
1052 /* disallow key types with the same name */
1053 list_for_each_entry(p
, &key_types_list
, link
) {
1054 if (strcmp(p
->name
, ktype
->name
) == 0)
1058 /* store the type */
1059 list_add(&ktype
->link
, &key_types_list
);
1061 pr_notice("Key type %s registered\n", ktype
->name
);
1065 up_write(&key_types_sem
);
1068 EXPORT_SYMBOL(register_key_type
);
1071 * unregister_key_type - Unregister a type of key.
1072 * @ktype: The key type.
1074 * Unregister a key type and mark all the extant keys of this type as dead.
1075 * Those keys of this type are then destroyed to get rid of their payloads and
1076 * they and their links will be garbage collected as soon as possible.
1078 void unregister_key_type(struct key_type
*ktype
)
1080 down_write(&key_types_sem
);
1081 list_del_init(&ktype
->link
);
1082 downgrade_write(&key_types_sem
);
1083 key_gc_keytype(ktype
);
1084 pr_notice("Key type %s unregistered\n", ktype
->name
);
1085 up_read(&key_types_sem
);
1087 EXPORT_SYMBOL(unregister_key_type
);
1090 * Initialise the key management state.
1092 void __init
key_init(void)
1094 /* allocate a slab in which we can store keys */
1095 key_jar
= kmem_cache_create("key_jar", sizeof(struct key
),
1096 0, SLAB_HWCACHE_ALIGN
|SLAB_PANIC
, NULL
);
1098 /* add the special key types */
1099 list_add_tail(&key_type_keyring
.link
, &key_types_list
);
1100 list_add_tail(&key_type_dead
.link
, &key_types_list
);
1101 list_add_tail(&key_type_user
.link
, &key_types_list
);
1102 list_add_tail(&key_type_logon
.link
, &key_types_list
);
1104 /* record the root user tracking */
1105 rb_link_node(&root_key_user
.node
,
1107 &key_user_tree
.rb_node
);
1109 rb_insert_color(&root_key_user
.node
,