2 /* Basic authentication token and access key management
26 unsigned int key_quota_root_maxkeys = 1000000;	/* root's key count quota */
27 unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */
28 unsigned int key_quota_maxkeys = 200;		/* general key count quota */
29 unsigned int key_quota_maxbytes = 20000;	/* general key space quota */
34 /* We serialise key instantiation and link */
38 void __key_check(const struct key *key)  in __key_check()  argument
40 	printk("__key_check: key %p {%08x} should be {%08x}\n",  in __key_check()
41 	       key, key->magic, KEY_DEBUG_MAGIC);  in __key_check()
47  * Get the key quota record for a user, allocating a new record if one doesn't
130  * Allocate a serial number for a key.  These are assigned randomly to avoid
133 static inline void key_alloc_serial(struct key *key)  in key_alloc_serial()  argument
136 	struct key *xkey;  in key_alloc_serial()
141 		get_random_bytes(&key->serial, sizeof(key->serial));  in key_alloc_serial()
143 		key->serial >>= 1; /* negative numbers are not permitted */  in key_alloc_serial()
144 	} while (key->serial < 3);  in key_alloc_serial()
154 		xkey = rb_entry(parent, struct key, serial_node);  in key_alloc_serial()
156 		if (key->serial < xkey->serial)  in key_alloc_serial()
158 		else if (key->serial > xkey->serial)  in key_alloc_serial()
164 	/* we've found a suitable hole - arrange for this key to occupy it */  in key_alloc_serial()
165 	rb_link_node(&key->serial_node, parent, p);  in key_alloc_serial()
166 	rb_insert_color(&key->serial_node, &key_serial_tree);  in key_alloc_serial()
171 	/* we found a key with the proposed serial number - walk the tree from  in key_alloc_serial()
175 		key->serial++;  in key_alloc_serial()
176 		if (key->serial < 3) {  in key_alloc_serial()
177 			key->serial = 3;  in key_alloc_serial()
185 		xkey = rb_entry(parent, struct key, serial_node);  in key_alloc_serial()
186 		if (key->serial < xkey->serial)  in key_alloc_serial()
192  * key_alloc - Allocate a key of the specified type.
193  * @type: The type of key to allocate.
194  * @desc: The key description to allow the key to be searched out.
195  * @uid: The owner of the new key.
196  * @gid: The group ID for the new key's group permissions.
198  * @perm: The permissions mask of the new key.
202  * Allocate a key of the specified type with the attributes given.  The key is
204  * 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
214  * The LSM security modules can prevent a key being created, in which case
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.
221  * be done by either never unregistering the key type, or making sure
224 struct key *key_alloc(struct key_type *type, const char *desc,  in key_alloc()
230 	struct key *key;  in key_alloc()  local
234 	key = ERR_PTR(-EINVAL);  in key_alloc()
241 			key = ERR_PTR(ret);  in key_alloc()
249 	/* get hold of the key tracking for this user */  in key_alloc()
254 	/* check that the user's quota permits allocation of another key and  in key_alloc()
275 	/* allocate and initialise the key and its description */  in key_alloc()
276 	key = kmem_cache_zalloc(key_jar, GFP_KERNEL);  in key_alloc()
277 	if (!key)  in key_alloc()
280 	key->index_key.desc_len = desclen;  in key_alloc()
281 	key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL);  in key_alloc()
282 	if (!key->index_key.description)  in key_alloc()
284 	key->index_key.type = type;  in key_alloc()
285 	key_set_index_key(&key->index_key);  in key_alloc()
287 	refcount_set(&key->usage, 1);  in key_alloc()
288 	init_rwsem(&key->sem);  in key_alloc()
289 	lockdep_set_class(&key->sem, &type->lock_class);  in key_alloc()
290 	key->user = user;  in key_alloc()
291 	key->quotalen = quotalen;  in key_alloc()
292 	key->datalen = type->def_datalen;  in key_alloc()
293 	key->uid = uid;  in key_alloc()
294 	key->gid = gid;  in key_alloc()
295 	key->perm = perm;  in key_alloc()
296 	key->restrict_link = restrict_link;  in key_alloc()
297 	key->last_used_at = ktime_get_real_seconds();  in key_alloc()
300 		key->flags |= 1 << KEY_FLAG_IN_QUOTA;  in key_alloc()
302 		key->flags |= 1 << KEY_FLAG_BUILTIN;  in key_alloc()
304 		key->flags |= 1 << KEY_FLAG_UID_KEYRING;  in key_alloc()
307 	key->magic = KEY_DEBUG_MAGIC;  in key_alloc()
310 	/* let the security module know about the key */  in key_alloc()
311 	ret = security_key_alloc(key, cred, flags);  in key_alloc()
315 	/* publish the key by giving it a serial number */  in key_alloc()
316 	refcount_inc(&key->domain_tag->usage);  in key_alloc()
318 	key_alloc_serial(key);  in key_alloc()
321 	return key;  in key_alloc()
324 	kfree(key->description);  in key_alloc()
325 	kmem_cache_free(key_jar, key);  in key_alloc()
333 	key = ERR_PTR(ret);  in key_alloc()
337 	kmem_cache_free(key_jar, key);  in key_alloc()
347 	key = ERR_PTR(-ENOMEM);  in key_alloc()
353 	key = ERR_PTR(-EDQUOT);  in key_alloc()
359  * key_payload_reserve - Adjust data quota reservation for the key's payload
360  * @key: The key to make the reservation for.
363  * Adjust the amount of the owning user's key data quota that a key reserves.
369 int key_payload_reserve(struct key *key, size_t datalen)  in key_payload_reserve()  argument
371 	int delta = (int)datalen - key->datalen;  in key_payload_reserve()
374 	key_check(key);  in key_payload_reserve()
377 	if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {  in key_payload_reserve()
378 		unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ?  in key_payload_reserve()
381 		spin_lock(&key->user->lock);  in key_payload_reserve()
384 		    (key->user->qnbytes + delta >= maxbytes ||  in key_payload_reserve()
385 		     key->user->qnbytes + delta < key->user->qnbytes)) {  in key_payload_reserve()
389 			key->user->qnbytes += delta;  in key_payload_reserve()
390 			key->quotalen += delta;  in key_payload_reserve()
392 		spin_unlock(&key->user->lock);  in key_payload_reserve()
397 		key->datalen = datalen;  in key_payload_reserve()
404  * Change the key state to being instantiated.
406 static void mark_key_instantiated(struct key *key, int reject_error)  in mark_key_instantiated()  argument
411 	smp_store_release(&key->state,  in mark_key_instantiated()
416  * Instantiate a key and link it into the target keyring atomically.  Must be
417  * called with the target keyring's semaphore writelocked.  The target key's
421 static int __key_instantiate_and_link(struct key *key,  in __key_instantiate_and_link()  argument
423 				      struct key *keyring,  in __key_instantiate_and_link()
424 				      struct key *authkey,  in __key_instantiate_and_link()
429 	key_check(key);  in __key_instantiate_and_link()
438 	if (key->state == KEY_IS_UNINSTANTIATED) {  in __key_instantiate_and_link()
439 		/* instantiate the key */  in __key_instantiate_and_link()
440 		ret = key->type->instantiate(key, prep);  in __key_instantiate_and_link()
443 			/* mark the key as being instantiated */  in __key_instantiate_and_link()
444 			atomic_inc(&key->user->nikeys);  in __key_instantiate_and_link()
445 			mark_key_instantiated(key, 0);  in __key_instantiate_and_link()
447 			if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))  in __key_instantiate_and_link()
453 					set_bit(KEY_FLAG_KEEP, &key->flags);  in __key_instantiate_and_link()
455 				__key_link(key, _edit);  in __key_instantiate_and_link()
458 			/* disable the authorisation key */  in __key_instantiate_and_link()
463 				key->expiry = prep->expiry;  in __key_instantiate_and_link()
471 	/* wake up anyone waiting for a key to be constructed */  in __key_instantiate_and_link()
473 		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);  in __key_instantiate_and_link()
479  * key_instantiate_and_link - Instantiate a key and link it into the keyring.
480  * @key: The key to instantiate.
486  * Instantiate a key that's in the uninstantiated state using the provided data
491  * waiting for the key is woken up.  If the key was already instantiated,
494 int key_instantiate_and_link(struct key *key,  in key_instantiate_and_link()  argument
497 			     struct key *keyring,  in key_instantiate_and_link()
498 			     struct key *authkey)  in key_instantiate_and_link()
507 	prep.quotalen = key->type->def_datalen;  in key_instantiate_and_link()
509 	if (key->type->preparse) {  in key_instantiate_and_link()
510 		ret = key->type->preparse(&prep);  in key_instantiate_and_link()
516 		ret = __key_link_lock(keyring, &key->index_key);  in key_instantiate_and_link()
520 		ret = __key_link_begin(keyring, &key->index_key, &edit);  in key_instantiate_and_link()
527 			ret = keyres->check(keyring, key->type, &prep.payload,  in key_instantiate_and_link()
528 					    keyres->key);  in key_instantiate_and_link()
534 	ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit);  in key_instantiate_and_link()
538 		__key_link_end(keyring, &key->index_key, edit);  in key_instantiate_and_link()
541 	if (key->type->preparse)  in key_instantiate_and_link()
542 		key->type->free_preparse(&prep);  in key_instantiate_and_link()
549  * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
550  * @key: The key to instantiate.
551  * @timeout: The timeout on the negative key.
552  * @error: The error to return when the key is hit.
556  * Negatively instantiate a key that's in the uninstantiated state and, if
558  * destination keyring if one is supplied.  The key and any links to the key
563  * key expires.
566  * waiting for the key is woken up.  If the key was already instantiated,
569 int key_reject_and_link(struct key *key,  in key_reject_and_link()  argument
572 			struct key *keyring,  in key_reject_and_link()
573 			struct key *authkey)  in key_reject_and_link()
578 	key_check(key);  in key_reject_and_link()
588 		link_ret = __key_link_lock(keyring, &key->index_key);  in key_reject_and_link()
590 			link_ret = __key_link_begin(keyring, &key->index_key, &edit);  in key_reject_and_link()
592 				__key_link_end(keyring, &key->index_key, edit);  in key_reject_and_link()
599 	if (key->state == KEY_IS_UNINSTANTIATED) {  in key_reject_and_link()
600 		/* mark the key as being negatively instantiated */  in key_reject_and_link()
601 		atomic_inc(&key->user->nikeys);  in key_reject_and_link()
602 		mark_key_instantiated(key, -error);  in key_reject_and_link()
603 		key->expiry = ktime_get_real_seconds() + timeout;  in key_reject_and_link()
604 		key_schedule_gc(key->expiry + key_gc_delay);  in key_reject_and_link()
606 		if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))  in key_reject_and_link()
613 			__key_link(key, &edit);  in key_reject_and_link()
615 		/* disable the authorisation key */  in key_reject_and_link()
623 		__key_link_end(keyring, &key->index_key, edit);  in key_reject_and_link()
625 	/* wake up anyone waiting for a key to be constructed */  in key_reject_and_link()
627 		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);  in key_reject_and_link()
634  * key_put - Discard a reference to a key.
635  * @key: The key to discard a reference from.
637  * Discard a reference to a key, and when all the references are gone, we
641 void key_put(struct key *key)  in key_put()  argument
643 	if (key) {  in key_put()
644 		key_check(key);  in key_put()
646 		if (refcount_dec_and_test(&key->usage))  in key_put()
653  * Find a key by its serial number.
655 struct key *key_lookup(key_serial_t id)  in key_lookup()
658 	struct key *key;  in key_lookup()  local
662 	/* search the tree for the specified key */  in key_lookup()
665 		key = rb_entry(n, struct key, serial_node);  in key_lookup()
667 		if (id < key->serial)  in key_lookup()
669 		else if (id > key->serial)  in key_lookup()
676 	key = ERR_PTR(-ENOKEY);  in key_lookup()
680 	/* A key is allowed to be looked up only if someone still owns a  in key_lookup()
683 	if (!refcount_inc_not_zero(&key->usage))  in key_lookup()
688 	return key;  in key_lookup()
692  * Find and lock the specified key type against removal.
703 	/* look up the key type to see if it's one of the registered kernel  in key_type_lookup()
717 void key_set_timeout(struct key *key, unsigned timeout)  in key_set_timeout()  argument
722 	down_write(&key->sem);  in key_set_timeout()
727 	key->expiry = expiry;  in key_set_timeout()
728 	key_schedule_gc(key->expiry + key_gc_delay);  in key_set_timeout()
730 	up_write(&key->sem);  in key_set_timeout()
735  * Unlock a key type locked by key_type_lookup().
743  * Attempt to update an existing key.
745  * The key is given to us with an incremented refcount that we need to discard
751 	struct key *key = key_ref_to_ptr(key_ref);  in __key_update()  local
754 	/* need write permission on the key to update it */  in __key_update()
760 	if (!key->type->update)  in __key_update()
763 	down_write(&key->sem);  in __key_update()
765 	ret = key->type->update(key, prep);  in __key_update()
767 		/* Updating a negative key positively instantiates it */  in __key_update()
768 		mark_key_instantiated(key, 0);  in __key_update()
770 	up_write(&key->sem);  in __key_update()
778 	key_put(key);  in __key_update()
784  * key_create_or_update - Update or create and instantiate a key.
786  * @type: The type of key.
787  * @description: The searchable description for the key.
788  * @payload: The data to use to instantiate or update the key.
790  * @perm: The permissions mask for a new key.
791  * @flags: The quota flags for a new key.
793  * Search the destination keyring for a key of the same description and if one
797  * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
800  * Returns a pointer to the new key if successful, -ENODEV if the key type
803  * creation of the key.
806  * the key ref before it is returned.
822 	struct key *keyring, *key = NULL;  in key_create_or_update()  local
827 	/* look up the key type to see if it's one of the registered kernel  in key_create_or_update()
885 					   &prep.payload, restrict_link->key);  in key_create_or_update()
892 	/* if we're going to allocate a new key, we're going to have  in key_create_or_update()
900 	/* if it's possible to update this type of key, search for an existing  in key_create_or_update()
901 	 * key of the same type and description in the destination keyring and  in key_create_or_update()
923 	/* allocate a new key */  in key_create_or_update()
924 	key = key_alloc(index_key.type, index_key.description,  in key_create_or_update()
926 	if (IS_ERR(key)) {  in key_create_or_update()
927 		key_ref = ERR_CAST(key);  in key_create_or_update()
932 	ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit);  in key_create_or_update()
934 		key_put(key);  in key_create_or_update()
939 	key_ref = make_key_ref(key, is_key_possessed(keyring_ref));  in key_create_or_update()
952 	/* we found a matching key, so we're going to try to update it  in key_create_or_update()
953 	 * - we can drop the locks first as we have the key pinned  in key_create_or_update()
957 	key = key_ref_to_ptr(key_ref);  in key_create_or_update()
958 	if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) {  in key_create_or_update()
959 		ret = wait_for_key_construction(key, true);  in key_create_or_update()
973  * key_update - Update a key's contents.
974  * @key_ref: The pointer (plus possession flag) to the key.
975  * @payload: The data to be used to update the key.
978  * Attempt to update the contents of a key with the given payload data.  The
979  * caller must be granted Write permission on the key.  Negative keys can be
982  * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
983  * type does not support updating.  The key type may return other errors.
988 	struct key *key = key_ref_to_ptr(key_ref);  in key_update()  local
991 	key_check(key);  in key_update()
993 	/* the key must be writable */  in key_update()
999 	if (!key->type->update)  in key_update()
1005 	prep.quotalen = key->type->def_datalen;  in key_update()
1007 	if (key->type->preparse) {  in key_update()
1008 		ret = key->type->preparse(&prep);  in key_update()
1013 	down_write(&key->sem);  in key_update()
1015 	ret = key->type->update(key, &prep);  in key_update()
1017 		/* Updating a negative key positively instantiates it */  in key_update()
1018 		mark_key_instantiated(key, 0);  in key_update()
1020 	up_write(&key->sem);  in key_update()
1023 	if (key->type->preparse)  in key_update()
1024 		key->type->free_preparse(&prep);  in key_update()
1030  * key_revoke - Revoke a key.
1031  * @key: The key to be revoked.
1033  * Mark a key as being revoked and ask the type to free up its resources.  The
1034  * revocation timeout is set and the key and all its links will be
1038 void key_revoke(struct key *key)  in key_revoke()  argument
1042 	key_check(key);  in key_revoke()
1044 	/* make sure no one's trying to change or use the key when we mark it  in key_revoke()
1046 	 *   authorisation key whilst holding the sem on a key we've just  in key_revoke()
1049 	down_write_nested(&key->sem, 1);  in key_revoke()
1050 	if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) &&  in key_revoke()
1051 	    key->type->revoke)  in key_revoke()
1052 		key->type->revoke(key);  in key_revoke()
1056 	if (key->revoked_at == 0 || key->revoked_at > time) {  in key_revoke()
1057 		key->revoked_at = time;  in key_revoke()
1058 		key_schedule_gc(key->revoked_at + key_gc_delay);  in key_revoke()
1061 	up_write(&key->sem);  in key_revoke()
1066  * key_invalidate - Invalidate a key.
1067  * @key: The key to be invalidated.
1069  * Mark a key as being invalidated and have it cleaned up immediately.  The key
1072 void key_invalidate(struct key *key)  in key_invalidate()  argument
1074 	kenter("%d", key_serial(key));  in key_invalidate()
1076 	key_check(key);  in key_invalidate()
1078 	if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) {  in key_invalidate()
1079 		down_write_nested(&key->sem, 1);  in key_invalidate()
1080 		if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags))  in key_invalidate()
1082 		up_write(&key->sem);  in key_invalidate()
1088  * generic_key_instantiate - Simple instantiation of a key from preparsed data
1089  * @key: The key to be instantiated
1092  * Instantiate a key from preparsed data.  We assume we can just copy the data
1095  * This can be pointed to directly by the key type instantiate op pointer.
1097 int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep)  in generic_key_instantiate()  argument
1103 	ret = key_payload_reserve(key, prep->quotalen);  in generic_key_instantiate()
1105 		rcu_assign_keypointer(key, prep->payload.data[0]);  in generic_key_instantiate()
1106 		key->payload.data[1] = prep->payload.data[1];  in generic_key_instantiate()
1107 		key->payload.data[2] = prep->payload.data[2];  in generic_key_instantiate()
1108 		key->payload.data[3] = prep->payload.data[3];  in generic_key_instantiate()
1120  * register_key_type - Register a type of key.
1121  * @ktype: The new key type.
1123  * Register a new key type.
1137 	/* disallow key types with the same name */  in register_key_type()
1146 	pr_notice("Key type %s registered\n", ktype->name);  in register_key_type()
1156  * unregister_key_type - Unregister a type of key.
1157  * @ktype: The key type.
1159  * Unregister a key type and mark all the extant keys of this type as dead.
1169 	pr_notice("Key type %s unregistered\n", ktype->name);  in unregister_key_type()
1175  * Initialise the key management state.
1180 	key_jar = kmem_cache_create("key_jar", sizeof(struct key),  in key_init()
1183 	/* add the special key types */  in key_init()