2 /* Basic authentication token and access key management
27 unsigned int key_quota_root_maxkeys = 1000000;	/* root's key count quota */
28 unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */
29 unsigned int key_quota_maxkeys = 200;		/* general key count quota */
30 unsigned int key_quota_maxbytes = 20000;	/* general key space quota */
35 /* We serialise key instantiation and link */
39 void __key_check(const struct key *key)  in __key_check()  argument
41 	printk("__key_check: key %p {%08x} should be {%08x}\n",  in __key_check()
42 	       key, key->magic, KEY_DEBUG_MAGIC);  in __key_check()
48  * Get the key quota record for a user, allocating a new record if one doesn't
131  * Allocate a serial number for a key.  These are assigned randomly to avoid
134 static inline void key_alloc_serial(struct key *key)  in key_alloc_serial()  argument
137 	struct key *xkey;  in key_alloc_serial()
142 		get_random_bytes(&key->serial, sizeof(key->serial));  in key_alloc_serial()
144 		key->serial >>= 1; /* negative numbers are not permitted */  in key_alloc_serial()
145 	} while (key->serial < 3);  in key_alloc_serial()
155 		xkey = rb_entry(parent, struct key, serial_node);  in key_alloc_serial()
157 		if (key->serial < xkey->serial)  in key_alloc_serial()
159 		else if (key->serial > xkey->serial)  in key_alloc_serial()
165 	/* we've found a suitable hole - arrange for this key to occupy it */  in key_alloc_serial()
166 	rb_link_node(&key->serial_node, parent, p);  in key_alloc_serial()
167 	rb_insert_color(&key->serial_node, &key_serial_tree);  in key_alloc_serial()
172 	/* we found a key with the proposed serial number - walk the tree from  in key_alloc_serial()
176 		key->serial++;  in key_alloc_serial()
177 		if (key->serial < 3) {  in key_alloc_serial()
178 			key->serial = 3;  in key_alloc_serial()
186 		xkey = rb_entry(parent, struct key, serial_node);  in key_alloc_serial()
187 		if (key->serial < xkey->serial)  in key_alloc_serial()
193  * key_alloc - Allocate a key of the specified type.
194  * @type: The type of key to allocate.
195  * @desc: The key description to allow the key to be searched out.
196  * @uid: The owner of the new key.
197  * @gid: The group ID for the new key's group permissions.
199  * @perm: The permissions mask of the new key.
203  * Allocate a key of the specified type with the attributes given.  The key is
205  * key before returning.
210  * The user's key count quota is updated to reflect the creation of the key and
211  * the user's key data quota has the default for the key type reserved.  The
215  * The LSM security modules can prevent a key being created, in which case
218  * Returns a pointer to the new key if successful and an error code otherwise.
220  * Note that the caller needs to ensure the key type isn't uninstantiated.
222  * be done by either never unregistering the key type, or making sure
225 struct key *key_alloc(struct key_type *type, const char *desc,  in key_alloc()
231 	struct key *key;  in key_alloc()  local
235 	key = ERR_PTR(-EINVAL);  in key_alloc()
242 			key = ERR_PTR(ret);  in key_alloc()
250 	/* get hold of the key tracking for this user */  in key_alloc()
255 	/* check that the user's quota permits allocation of another key and  in key_alloc()
276 	/* allocate and initialise the key and its description */  in key_alloc()
277 	key = kmem_cache_zalloc(key_jar, GFP_KERNEL);  in key_alloc()
278 	if (!key)  in key_alloc()
281 	key->index_key.desc_len = desclen;  in key_alloc()
282 	key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL);  in key_alloc()
283 	if (!key->index_key.description)  in key_alloc()
285 	key->index_key.type = type;  in key_alloc()
286 	key_set_index_key(&key->index_key);  in key_alloc()
288 	refcount_set(&key->usage, 1);  in key_alloc()
289 	init_rwsem(&key->sem);  in key_alloc()
290 	lockdep_set_class(&key->sem, &type->lock_class);  in key_alloc()
291 	key->user = user;  in key_alloc()
292 	key->quotalen = quotalen;  in key_alloc()
293 	key->datalen = type->def_datalen;  in key_alloc()
294 	key->uid = uid;  in key_alloc()
295 	key->gid = gid;  in key_alloc()
296 	key->perm = perm;  in key_alloc()
297 	key->expiry = TIME64_MAX;  in key_alloc()
298 	key->restrict_link = restrict_link;  in key_alloc()
299 	key->last_used_at = ktime_get_real_seconds();  in key_alloc()
302 		key->flags |= 1 << KEY_FLAG_IN_QUOTA;  in key_alloc()
304 		key->flags |= 1 << KEY_FLAG_BUILTIN;  in key_alloc()
306 		key->flags |= 1 << KEY_FLAG_UID_KEYRING;  in key_alloc()
308 		key->flags |= 1 << KEY_FLAG_KEEP;  in key_alloc()
311 	key->magic = KEY_DEBUG_MAGIC;  in key_alloc()
314 	/* let the security module know about the key */  in key_alloc()
315 	ret = security_key_alloc(key, cred, flags);  in key_alloc()
319 	/* publish the key by giving it a serial number */  in key_alloc()
320 	refcount_inc(&key->domain_tag->usage);  in key_alloc()
322 	key_alloc_serial(key);  in key_alloc()
325 	return key;  in key_alloc()
328 	kfree(key->description);  in key_alloc()
329 	kmem_cache_free(key_jar, key);  in key_alloc()
337 	key = ERR_PTR(ret);  in key_alloc()
341 	kmem_cache_free(key_jar, key);  in key_alloc()
351 	key = ERR_PTR(-ENOMEM);  in key_alloc()
357 	key = ERR_PTR(-EDQUOT);  in key_alloc()
363  * key_payload_reserve - Adjust data quota reservation for the key's payload
364  * @key: The key to make the reservation for.
367  * Adjust the amount of the owning user's key data quota that a key reserves.
373 int key_payload_reserve(struct key *key, size_t datalen)  in key_payload_reserve()  argument
375 	int delta = (int)datalen - key->datalen;  in key_payload_reserve()
378 	key_check(key);  in key_payload_reserve()
381 	if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {  in key_payload_reserve()
382 		unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ?  in key_payload_reserve()
385 		spin_lock(&key->user->lock);  in key_payload_reserve()
388 		    (key->user->qnbytes + delta > maxbytes ||  in key_payload_reserve()
389 		     key->user->qnbytes + delta < key->user->qnbytes)) {  in key_payload_reserve()
393 			key->user->qnbytes += delta;  in key_payload_reserve()
394 			key->quotalen += delta;  in key_payload_reserve()
396 		spin_unlock(&key->user->lock);  in key_payload_reserve()
401 		key->datalen = datalen;  in key_payload_reserve()
408  * Change the key state to being instantiated.
410 static void mark_key_instantiated(struct key *key, int reject_error)  in mark_key_instantiated()  argument
415 	smp_store_release(&key->state,  in mark_key_instantiated()
420  * Instantiate a key and link it into the target keyring atomically.  Must be
421  * called with the target keyring's semaphore writelocked.  The target key's
425 static int __key_instantiate_and_link(struct key *key,  in __key_instantiate_and_link()  argument
427 				      struct key *keyring,  in __key_instantiate_and_link()
428 				      struct key *authkey,  in __key_instantiate_and_link()
433 	key_check(key);  in __key_instantiate_and_link()
442 	if (key->state == KEY_IS_UNINSTANTIATED) {  in __key_instantiate_and_link()
443 		/* instantiate the key */  in __key_instantiate_and_link()
444 		ret = key->type->instantiate(key, prep);  in __key_instantiate_and_link()
447 			/* mark the key as being instantiated */  in __key_instantiate_and_link()
448 			atomic_inc(&key->user->nikeys);  in __key_instantiate_and_link()
449 			mark_key_instantiated(key, 0);  in __key_instantiate_and_link()
450 			notify_key(key, NOTIFY_KEY_INSTANTIATED, 0);  in __key_instantiate_and_link()
452 			if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))  in __key_instantiate_and_link()
458 					set_bit(KEY_FLAG_KEEP, &key->flags);  in __key_instantiate_and_link()
460 				__key_link(keyring, key, _edit);  in __key_instantiate_and_link()
463 			/* disable the authorisation key */  in __key_instantiate_and_link()
468 				key_set_expiry(key, prep->expiry);  in __key_instantiate_and_link()
474 	/* wake up anyone waiting for a key to be constructed */  in __key_instantiate_and_link()
476 		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);  in __key_instantiate_and_link()
482  * key_instantiate_and_link - Instantiate a key and link it into the keyring.
483  * @key: The key to instantiate.
489  * Instantiate a key that's in the uninstantiated state using the provided data
494  * waiting for the key is woken up.  If the key was already instantiated,
497 int key_instantiate_and_link(struct key *key,  in key_instantiate_and_link()  argument
500 			     struct key *keyring,  in key_instantiate_and_link()
501 			     struct key *authkey)  in key_instantiate_and_link()
508 	prep.orig_description = key->description;  in key_instantiate_and_link()
511 	prep.quotalen = key->type->def_datalen;  in key_instantiate_and_link()
513 	if (key->type->preparse) {  in key_instantiate_and_link()
514 		ret = key->type->preparse(&prep);  in key_instantiate_and_link()
520 		ret = __key_link_lock(keyring, &key->index_key);  in key_instantiate_and_link()
524 		ret = __key_link_begin(keyring, &key->index_key, &edit);  in key_instantiate_and_link()
531 			ret = keyres->check(keyring, key->type, &prep.payload,  in key_instantiate_and_link()
532 					    keyres->key);  in key_instantiate_and_link()
538 	ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit);  in key_instantiate_and_link()
542 		__key_link_end(keyring, &key->index_key, edit);  in key_instantiate_and_link()
545 	if (key->type->preparse)  in key_instantiate_and_link()
546 		key->type->free_preparse(&prep);  in key_instantiate_and_link()
553  * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
554  * @key: The key to instantiate.
555  * @timeout: The timeout on the negative key.
556  * @error: The error to return when the key is hit.
560  * Negatively instantiate a key that's in the uninstantiated state and, if
562  * destination keyring if one is supplied.  The key and any links to the key
567  * key expires.
570  * waiting for the key is woken up.  If the key was already instantiated,
573 int key_reject_and_link(struct key *key,  in key_reject_and_link()  argument
576 			struct key *keyring,  in key_reject_and_link()
577 			struct key *authkey)  in key_reject_and_link()
582 	key_check(key);  in key_reject_and_link()
592 		link_ret = __key_link_lock(keyring, &key->index_key);  in key_reject_and_link()
594 			link_ret = __key_link_begin(keyring, &key->index_key, &edit);  in key_reject_and_link()
596 				__key_link_end(keyring, &key->index_key, edit);  in key_reject_and_link()
603 	if (key->state == KEY_IS_UNINSTANTIATED) {  in key_reject_and_link()
604 		/* mark the key as being negatively instantiated */  in key_reject_and_link()
605 		atomic_inc(&key->user->nikeys);  in key_reject_and_link()
606 		mark_key_instantiated(key, -error);  in key_reject_and_link()
607 		notify_key(key, NOTIFY_KEY_INSTANTIATED, -error);  in key_reject_and_link()
608 		key_set_expiry(key, ktime_get_real_seconds() + timeout);  in key_reject_and_link()
610 		if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))  in key_reject_and_link()
617 			__key_link(keyring, key, &edit);  in key_reject_and_link()
619 		/* disable the authorisation key */  in key_reject_and_link()
627 		__key_link_end(keyring, &key->index_key, edit);  in key_reject_and_link()
629 	/* wake up anyone waiting for a key to be constructed */  in key_reject_and_link()
631 		wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);  in key_reject_and_link()
638  * key_put - Discard a reference to a key.
639  * @key: The key to discard a reference from.
641  * Discard a reference to a key, and when all the references are gone, we
645 void key_put(struct key *key)  in key_put()  argument
647 	if (key) {  in key_put()
648 		key_check(key);  in key_put()
650 		if (refcount_dec_and_test(&key->usage))  in key_put()
657  * Find a key by its serial number.
659 struct key *key_lookup(key_serial_t id)  in key_lookup()
662 	struct key *key;  in key_lookup()  local
666 	/* search the tree for the specified key */  in key_lookup()
669 		key = rb_entry(n, struct key, serial_node);  in key_lookup()
671 		if (id < key->serial)  in key_lookup()
673 		else if (id > key->serial)  in key_lookup()
680 	key = ERR_PTR(-ENOKEY);  in key_lookup()
684 	/* A key is allowed to be looked up only if someone still owns a  in key_lookup()
687 	if (!refcount_inc_not_zero(&key->usage))  in key_lookup()
692 	return key;  in key_lookup()
696  * Find and lock the specified key type against removal.
707 	/* look up the key type to see if it's one of the registered kernel  in key_type_lookup()
721 void key_set_timeout(struct key *key, unsigned timeout)  in key_set_timeout()  argument
726 	down_write(&key->sem);  in key_set_timeout()
730 	key_set_expiry(key, expiry);  in key_set_timeout()
732 	up_write(&key->sem);  in key_set_timeout()
737  * Unlock a key type locked by key_type_lookup().
745  * Attempt to update an existing key.
747  * The key is given to us with an incremented refcount that we need to discard
753 	struct key *key = key_ref_to_ptr(key_ref);  in __key_update()  local
756 	/* need write permission on the key to update it */  in __key_update()
762 	if (!key->type->update)  in __key_update()
765 	down_write(&key->sem);  in __key_update()
767 	ret = key->type->update(key, prep);  in __key_update()
769 		/* Updating a negative key positively instantiates it */  in __key_update()
770 		mark_key_instantiated(key, 0);  in __key_update()
771 		notify_key(key, NOTIFY_KEY_UPDATED, 0);  in __key_update()
774 	up_write(&key->sem);  in __key_update()
782 	key_put(key);  in __key_update()
788  * Create or potentially update a key. The combined logic behind
806 	struct key *keyring, *key = NULL;  in __key_create_or_update()  local
811 	/* look up the key type to see if it's one of the registered kernel  in __key_create_or_update()
870 					   &prep.payload, restrict_link->key);  in __key_create_or_update()
877 	/* if we're going to allocate a new key, we're going to have  in __key_create_or_update()
885 	/* if it's requested and possible to update this type of key, search  in __key_create_or_update()
886 	 * for an existing key of the same type and description in the  in __key_create_or_update()
917 	/* allocate a new key */  in __key_create_or_update()
918 	key = key_alloc(index_key.type, index_key.description,  in __key_create_or_update()
920 	if (IS_ERR(key)) {  in __key_create_or_update()
921 		key_ref = ERR_CAST(key);  in __key_create_or_update()
926 	ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit);  in __key_create_or_update()
928 		key_put(key);  in __key_create_or_update()
933 	ima_post_key_create_or_update(keyring, key, payload, plen,  in __key_create_or_update()
936 	key_ref = make_key_ref(key, is_key_possessed(keyring_ref));  in __key_create_or_update()
949 	/* we found a matching key, so we're going to try to update it  in __key_create_or_update()
950 	 * - we can drop the locks first as we have the key pinned  in __key_create_or_update()
954 	key = key_ref_to_ptr(key_ref);  in __key_create_or_update()
955 	if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) {  in __key_create_or_update()
956 		ret = wait_for_key_construction(key, true);  in __key_create_or_update()
967 		ima_post_key_create_or_update(keyring, key,  in __key_create_or_update()
975  * key_create_or_update - Update or create and instantiate a key.
977  * @type: The type of key.
978  * @description: The searchable description for the key.
979  * @payload: The data to use to instantiate or update the key.
981  * @perm: The permissions mask for a new key.
982  * @flags: The quota flags for a new key.
984  * Search the destination keyring for a key of the same description and if one
988  * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
991  * Returns a pointer to the new key if successful, -ENODEV if the key type
994  * creation of the key.
997  * the key ref before it is returned.
1013  * key_create - Create and instantiate a key.
1015  * @type: The type of key.
1016  * @description: The searchable description for the key.
1017  * @payload: The data to use to instantiate or update the key.
1019  * @perm: The permissions mask for a new key.
1020  * @flags: The quota flags for a new key.
1022  * Create and instantiate a new key and link to it from the destination keyring.
1024  * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
1027  * Returns a pointer to the new key if successful, -EEXIST if a key with the
1028  * same description already exists, -ENODEV if the key type wasn't available,
1031  * key.
1034  * the key ref before it is returned.
1050  * key_update - Update a key's contents.
1051  * @key_ref: The pointer (plus possession flag) to the key.
1052  * @payload: The data to be used to update the key.
1055  * Attempt to update the contents of a key with the given payload data.  The
1056  * caller must be granted Write permission on the key.  Negative keys can be
1059  * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
1060  * type does not support updating.  The key type may return other errors.
1065 	struct key *key = key_ref_to_ptr(key_ref);  in key_update()  local
1068 	key_check(key);  in key_update()
1070 	/* the key must be writable */  in key_update()
1076 	if (!key->type->update)  in key_update()
1082 	prep.quotalen = key->type->def_datalen;  in key_update()
1084 	if (key->type->preparse) {  in key_update()
1085 		ret = key->type->preparse(&prep);  in key_update()
1090 	down_write(&key->sem);  in key_update()
1092 	ret = key->type->update(key, &prep);  in key_update()
1094 		/* Updating a negative key positively instantiates it */  in key_update()
1095 		mark_key_instantiated(key, 0);  in key_update()
1096 		notify_key(key, NOTIFY_KEY_UPDATED, 0);  in key_update()
1099 	up_write(&key->sem);  in key_update()
1102 	if (key->type->preparse)  in key_update()
1103 		key->type->free_preparse(&prep);  in key_update()
1109  * key_revoke - Revoke a key.
1110  * @key: The key to be revoked.
1112  * Mark a key as being revoked and ask the type to free up its resources.  The
1113  * revocation timeout is set and the key and all its links will be
1117 void key_revoke(struct key *key)  in key_revoke()  argument
1121 	key_check(key);  in key_revoke()
1123 	/* make sure no one's trying to change or use the key when we mark it  in key_revoke()
1125 	 *   authorisation key whilst holding the sem on a key we've just  in key_revoke()
1128 	down_write_nested(&key->sem, 1);  in key_revoke()
1129 	if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags)) {  in key_revoke()
1130 		notify_key(key, NOTIFY_KEY_REVOKED, 0);  in key_revoke()
1131 		if (key->type->revoke)  in key_revoke()
1132 			key->type->revoke(key);  in key_revoke()
1136 		if (key->revoked_at == 0 || key->revoked_at > time) {  in key_revoke()
1137 			key->revoked_at = time;  in key_revoke()
1138 			key_schedule_gc(key->revoked_at + key_gc_delay);  in key_revoke()
1142 	up_write(&key->sem);  in key_revoke()
1147  * key_invalidate - Invalidate a key.
1148  * @key: The key to be invalidated.
1150  * Mark a key as being invalidated and have it cleaned up immediately.  The key
1153 void key_invalidate(struct key *key)  in key_invalidate()  argument
1155 	kenter("%d", key_serial(key));  in key_invalidate()
1157 	key_check(key);  in key_invalidate()
1159 	if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) {  in key_invalidate()
1160 		down_write_nested(&key->sem, 1);  in key_invalidate()
1161 		if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) {  in key_invalidate()
1162 			notify_key(key, NOTIFY_KEY_INVALIDATED, 0);  in key_invalidate()
1165 		up_write(&key->sem);  in key_invalidate()
1171  * generic_key_instantiate - Simple instantiation of a key from preparsed data
1172  * @key: The key to be instantiated
1175  * Instantiate a key from preparsed data.  We assume we can just copy the data
1178  * This can be pointed to directly by the key type instantiate op pointer.
1180 int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep)  in generic_key_instantiate()  argument
1186 	ret = key_payload_reserve(key, prep->quotalen);  in generic_key_instantiate()
1188 		rcu_assign_keypointer(key, prep->payload.data[0]);  in generic_key_instantiate()
1189 		key->payload.data[1] = prep->payload.data[1];  in generic_key_instantiate()
1190 		key->payload.data[2] = prep->payload.data[2];  in generic_key_instantiate()
1191 		key->payload.data[3] = prep->payload.data[3];  in generic_key_instantiate()
1203  * register_key_type - Register a type of key.
1204  * @ktype: The new key type.
1206  * Register a new key type.
1220 	/* disallow key types with the same name */  in register_key_type()
1229 	pr_notice("Key type %s registered\n", ktype->name);  in register_key_type()
1239  * unregister_key_type - Unregister a type of key.
1240  * @ktype: The key type.
1242  * Unregister a key type and mark all the extant keys of this type as dead.
1252 	pr_notice("Key type %s unregistered\n", ktype->name);  in unregister_key_type()
1258  * Initialise the key management state.
1263 	key_jar = kmem_cache_create("key_jar", sizeof(struct key),  in key_init()
1266 	/* add the special key types */  in key_init()