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>
21 #include <linux/user_namespace.h>
24 struct kmem_cache *key_jar;
25 struct rb_root key_serial_tree; /* tree of keys indexed by serial */
26 DEFINE_SPINLOCK(key_serial_lock);
28 struct rb_root key_user_tree; /* tree of quota records indexed by UID */
29 DEFINE_SPINLOCK(key_user_lock);
31 unsigned int key_quota_root_maxkeys = 200; /* root's key count quota */
32 unsigned int key_quota_root_maxbytes = 20000; /* root's key space quota */
33 unsigned int key_quota_maxkeys = 200; /* general key count quota */
34 unsigned int key_quota_maxbytes = 20000; /* general key space quota */
36 static LIST_HEAD(key_types_list);
37 static DECLARE_RWSEM(key_types_sem);
39 /* We serialise key instantiation and link */
40 DEFINE_MUTEX(key_construction_mutex);
43 void __key_check(const struct key *key)
45 printk("__key_check: key %p {%08x} should be {%08x}\n",
46 key, key->magic, KEY_DEBUG_MAGIC);
52 * Get the key quota record for a user, allocating a new record if one doesn't
55 struct key_user *key_user_lookup(uid_t uid, struct user_namespace *user_ns)
57 struct key_user *candidate = NULL, *user;
58 struct rb_node *parent = NULL;
62 p = &key_user_tree.rb_node;
63 spin_lock(&key_user_lock);
65 /* search the tree for a user record with a matching UID */
68 user = rb_entry(parent, struct key_user, node);
72 else if (uid > user->uid)
74 else if (user_ns < user->user_ns)
76 else if (user_ns > user->user_ns)
82 /* if we get here, we failed to find a match in the tree */
84 /* allocate a candidate user record if we don't already have
86 spin_unlock(&key_user_lock);
89 candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL);
90 if (unlikely(!candidate))
93 /* the allocation may have scheduled, so we need to repeat the
94 * search lest someone else added the record whilst we were
99 /* if we get here, then the user record still hadn't appeared on the
100 * second pass - so we use the candidate record */
101 atomic_set(&candidate->usage, 1);
102 atomic_set(&candidate->nkeys, 0);
103 atomic_set(&candidate->nikeys, 0);
104 candidate->uid = uid;
105 candidate->user_ns = get_user_ns(user_ns);
106 candidate->qnkeys = 0;
107 candidate->qnbytes = 0;
108 spin_lock_init(&candidate->lock);
109 mutex_init(&candidate->cons_lock);
111 rb_link_node(&candidate->node, parent, p);
112 rb_insert_color(&candidate->node, &key_user_tree);
113 spin_unlock(&key_user_lock);
117 /* okay - we found a user record for this UID */
119 atomic_inc(&user->usage);
120 spin_unlock(&key_user_lock);
127 * Dispose of a user structure
129 void key_user_put(struct key_user *user)
131 if (atomic_dec_and_lock(&user->usage, &key_user_lock)) {
132 rb_erase(&user->node, &key_user_tree);
133 spin_unlock(&key_user_lock);
134 put_user_ns(user->user_ns);
141 * Allocate a serial number for a key. These are assigned randomly to avoid
142 * security issues through covert channel problems.
144 static inline void key_alloc_serial(struct key *key)
146 struct rb_node *parent, **p;
149 /* propose a random serial number and look for a hole for it in the
150 * serial number tree */
152 get_random_bytes(&key->serial, sizeof(key->serial));
154 key->serial >>= 1; /* negative numbers are not permitted */
155 } while (key->serial < 3);
157 spin_lock(&key_serial_lock);
161 p = &key_serial_tree.rb_node;
165 xkey = rb_entry(parent, struct key, serial_node);
167 if (key->serial < xkey->serial)
169 else if (key->serial > xkey->serial)
175 /* we've found a suitable hole - arrange for this key to occupy it */
176 rb_link_node(&key->serial_node, parent, p);
177 rb_insert_color(&key->serial_node, &key_serial_tree);
179 spin_unlock(&key_serial_lock);
182 /* we found a key with the proposed serial number - walk the tree from
183 * that point looking for the next unused serial number */
187 if (key->serial < 3) {
189 goto attempt_insertion;
192 parent = rb_next(parent);
194 goto attempt_insertion;
196 xkey = rb_entry(parent, struct key, serial_node);
197 if (key->serial < xkey->serial)
198 goto attempt_insertion;
203 * key_alloc - Allocate a key of the specified type.
204 * @type: The type of key to allocate.
205 * @desc: The key description to allow the key to be searched out.
206 * @uid: The owner of the new key.
207 * @gid: The group ID for the new key's group permissions.
208 * @cred: The credentials specifying UID namespace.
209 * @perm: The permissions mask of the new key.
210 * @flags: Flags specifying quota properties.
212 * Allocate a key of the specified type with the attributes given. The key is
213 * returned in an uninstantiated state and the caller needs to instantiate the
214 * key before returning.
216 * The user's key count quota is updated to reflect the creation of the key and
217 * the user's key data quota has the default for the key type reserved. The
218 * instantiation function should amend this as necessary. If insufficient
219 * quota is available, -EDQUOT will be returned.
221 * The LSM security modules can prevent a key being created, in which case
222 * -EACCES will be returned.
224 * Returns a pointer to the new key if successful and an error code otherwise.
226 * Note that the caller needs to ensure the key type isn't uninstantiated.
227 * Internally this can be done by locking key_types_sem. Externally, this can
228 * be done by either never unregistering the key type, or making sure
229 * key_alloc() calls don't race with module unloading.
231 struct key *key_alloc(struct key_type *type, const char *desc,
232 uid_t uid, gid_t gid, const struct cred *cred,
233 key_perm_t perm, unsigned long flags)
235 struct key_user *user = NULL;
237 size_t desclen, quotalen;
240 key = ERR_PTR(-EINVAL);
244 if (type->vet_description) {
245 ret = type->vet_description(desc);
252 desclen = strlen(desc) + 1;
253 quotalen = desclen + type->def_datalen;
255 /* get hold of the key tracking for this user */
256 user = key_user_lookup(uid, cred->user->user_ns);
260 /* check that the user's quota permits allocation of another key and
262 if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
263 unsigned maxkeys = (uid == 0) ?
264 key_quota_root_maxkeys : key_quota_maxkeys;
265 unsigned maxbytes = (uid == 0) ?
266 key_quota_root_maxbytes : key_quota_maxbytes;
268 spin_lock(&user->lock);
269 if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) {
270 if (user->qnkeys + 1 >= maxkeys ||
271 user->qnbytes + quotalen >= maxbytes ||
272 user->qnbytes + quotalen < user->qnbytes)
277 user->qnbytes += quotalen;
278 spin_unlock(&user->lock);
281 /* allocate and initialise the key and its description */
282 key = kmem_cache_alloc(key_jar, GFP_KERNEL);
287 key->description = kmemdup(desc, desclen, GFP_KERNEL);
288 if (!key->description)
292 atomic_set(&key->usage, 1);
293 init_rwsem(&key->sem);
296 key->quotalen = quotalen;
297 key->datalen = type->def_datalen;
303 key->payload.data = NULL;
304 key->security = NULL;
306 if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
307 key->flags |= 1 << KEY_FLAG_IN_QUOTA;
308 if (flags & KEY_ALLOC_UID_KEYRING)
309 key->flags |= 1 << KEY_FLAG_UID_KEYRING;
311 memset(&key->type_data, 0, sizeof(key->type_data));
314 key->magic = KEY_DEBUG_MAGIC;
317 /* let the security module know about the key */
318 ret = security_key_alloc(key, cred, flags);
322 /* publish the key by giving it a serial number */
323 atomic_inc(&user->nkeys);
324 key_alloc_serial(key);
330 kfree(key->description);
331 kmem_cache_free(key_jar, key);
332 if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
333 spin_lock(&user->lock);
335 user->qnbytes -= quotalen;
336 spin_unlock(&user->lock);
343 kmem_cache_free(key_jar, key);
345 if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
346 spin_lock(&user->lock);
348 user->qnbytes -= quotalen;
349 spin_unlock(&user->lock);
353 key = ERR_PTR(-ENOMEM);
357 spin_unlock(&user->lock);
359 key = ERR_PTR(-EDQUOT);
362 EXPORT_SYMBOL(key_alloc);
365 * key_payload_reserve - Adjust data quota reservation for the key's payload
366 * @key: The key to make the reservation for.
367 * @datalen: The amount of data payload the caller now wants.
369 * Adjust the amount of the owning user's key data quota that a key reserves.
370 * If the amount is increased, then -EDQUOT may be returned if there isn't
371 * enough free quota available.
373 * If successful, 0 is returned.
375 int key_payload_reserve(struct key *key, size_t datalen)
377 int delta = (int)datalen - key->datalen;
382 /* contemplate the quota adjustment */
383 if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
384 unsigned maxbytes = (key->user->uid == 0) ?
385 key_quota_root_maxbytes : key_quota_maxbytes;
387 spin_lock(&key->user->lock);
390 (key->user->qnbytes + delta >= maxbytes ||
391 key->user->qnbytes + delta < key->user->qnbytes)) {
395 key->user->qnbytes += delta;
396 key->quotalen += delta;
398 spin_unlock(&key->user->lock);
401 /* change the recorded data length if that didn't generate an error */
403 key->datalen = datalen;
407 EXPORT_SYMBOL(key_payload_reserve);
410 * Instantiate a key and link it into the target keyring atomically. Must be
411 * called with the target keyring's semaphore writelocked. The target key's
412 * semaphore need not be locked as instantiation is serialised by
413 * key_construction_mutex.
415 static int __key_instantiate_and_link(struct key *key,
420 unsigned long *_prealloc)
430 mutex_lock(&key_construction_mutex);
432 /* can't instantiate twice */
433 if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
434 /* instantiate the key */
435 ret = key->type->instantiate(key, data, datalen);
438 /* mark the key as being instantiated */
439 atomic_inc(&key->user->nikeys);
440 set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
442 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))
445 /* and link it into the destination keyring */
447 __key_link(keyring, key, _prealloc);
449 /* disable the authorisation key */
455 mutex_unlock(&key_construction_mutex);
457 /* wake up anyone waiting for a key to be constructed */
459 wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
465 * key_instantiate_and_link - Instantiate a key and link it into the keyring.
466 * @key: The key to instantiate.
467 * @data: The data to use to instantiate the keyring.
468 * @datalen: The length of @data.
469 * @keyring: Keyring to create a link in on success (or NULL).
470 * @authkey: The authorisation token permitting instantiation.
472 * Instantiate a key that's in the uninstantiated state using the provided data
473 * and, if successful, link it in to the destination keyring if one is
476 * If successful, 0 is returned, the authorisation token is revoked and anyone
477 * waiting for the key is woken up. If the key was already instantiated,
478 * -EBUSY will be returned.
480 int key_instantiate_and_link(struct key *key,
486 unsigned long prealloc;
490 ret = __key_link_begin(keyring, key->type, key->description,
496 ret = __key_instantiate_and_link(key, data, datalen, keyring, authkey,
500 __key_link_end(keyring, key->type, prealloc);
505 EXPORT_SYMBOL(key_instantiate_and_link);
508 * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
509 * @key: The key to instantiate.
510 * @timeout: The timeout on the negative key.
511 * @error: The error to return when the key is hit.
512 * @keyring: Keyring to create a link in on success (or NULL).
513 * @authkey: The authorisation token permitting instantiation.
515 * Negatively instantiate a key that's in the uninstantiated state and, if
516 * successful, set its timeout and stored error and link it in to the
517 * destination keyring if one is supplied. The key and any links to the key
518 * will be automatically garbage collected after the timeout expires.
520 * Negative keys are used to rate limit repeated request_key() calls by causing
521 * them to return the stored error code (typically ENOKEY) until the negative
524 * If successful, 0 is returned, the authorisation token is revoked and anyone
525 * waiting for the key is woken up. If the key was already instantiated,
526 * -EBUSY will be returned.
528 int key_reject_and_link(struct key *key,
534 unsigned long prealloc;
536 int ret, awaken, link_ret = 0;
545 link_ret = __key_link_begin(keyring, key->type,
546 key->description, &prealloc);
548 mutex_lock(&key_construction_mutex);
550 /* can't instantiate twice */
551 if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
552 /* mark the key as being negatively instantiated */
553 atomic_inc(&key->user->nikeys);
554 set_bit(KEY_FLAG_NEGATIVE, &key->flags);
555 set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
556 key->type_data.reject_error = -error;
557 now = current_kernel_time();
558 key->expiry = now.tv_sec + timeout;
559 key_schedule_gc(key->expiry + key_gc_delay);
561 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))
566 /* and link it into the destination keyring */
567 if (keyring && link_ret == 0)
568 __key_link(keyring, key, &prealloc);
570 /* disable the authorisation key */
575 mutex_unlock(&key_construction_mutex);
577 if (keyring && link_ret == 0)
578 __key_link_end(keyring, key->type, prealloc);
580 /* wake up anyone waiting for a key to be constructed */
582 wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
584 return ret == 0 ? link_ret : ret;
586 EXPORT_SYMBOL(key_reject_and_link);
589 * key_put - Discard a reference to a key.
590 * @key: The key to discard a reference from.
592 * Discard a reference to a key, and when all the references are gone, we
593 * schedule the cleanup task to come and pull it out of the tree in process
594 * context at some later time.
596 void key_put(struct key *key)
601 if (atomic_dec_and_test(&key->usage))
602 queue_work(system_nrt_wq, &key_gc_work);
605 EXPORT_SYMBOL(key_put);
608 * Find a key by its serial number.
610 struct key *key_lookup(key_serial_t id)
615 spin_lock(&key_serial_lock);
617 /* search the tree for the specified key */
618 n = key_serial_tree.rb_node;
620 key = rb_entry(n, struct key, serial_node);
622 if (id < key->serial)
624 else if (id > key->serial)
631 key = ERR_PTR(-ENOKEY);
635 /* pretend it doesn't exist if it is awaiting deletion */
636 if (atomic_read(&key->usage) == 0)
639 /* this races with key_put(), but that doesn't matter since key_put()
640 * doesn't actually change the key
642 atomic_inc(&key->usage);
645 spin_unlock(&key_serial_lock);
650 * Find and lock the specified key type against removal.
652 * We return with the sem read-locked if successful. If the type wasn't
653 * available -ENOKEY is returned instead.
655 struct key_type *key_type_lookup(const char *type)
657 struct key_type *ktype;
659 down_read(&key_types_sem);
661 /* look up the key type to see if it's one of the registered kernel
663 list_for_each_entry(ktype, &key_types_list, link) {
664 if (strcmp(ktype->name, type) == 0)
665 goto found_kernel_type;
668 up_read(&key_types_sem);
669 ktype = ERR_PTR(-ENOKEY);
676 * Unlock a key type locked by key_type_lookup().
678 void key_type_put(struct key_type *ktype)
680 up_read(&key_types_sem);
684 * Attempt to update an existing key.
686 * The key is given to us with an incremented refcount that we need to discard
687 * if we get an error.
689 static inline key_ref_t __key_update(key_ref_t key_ref,
690 const void *payload, size_t plen)
692 struct key *key = key_ref_to_ptr(key_ref);
695 /* need write permission on the key to update it */
696 ret = key_permission(key_ref, KEY_WRITE);
701 if (!key->type->update)
704 down_write(&key->sem);
706 ret = key->type->update(key, payload, plen);
708 /* updating a negative key instantiates it */
709 clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
720 key_ref = ERR_PTR(ret);
725 * key_create_or_update - Update or create and instantiate a key.
726 * @keyring_ref: A pointer to the destination keyring with possession flag.
727 * @type: The type of key.
728 * @description: The searchable description for the key.
729 * @payload: The data to use to instantiate or update the key.
730 * @plen: The length of @payload.
731 * @perm: The permissions mask for a new key.
732 * @flags: The quota flags for a new key.
734 * Search the destination keyring for a key of the same description and if one
735 * is found, update it, otherwise create and instantiate a new one and create a
736 * link to it from that keyring.
738 * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
741 * Returns a pointer to the new key if successful, -ENODEV if the key type
742 * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the
743 * caller isn't permitted to modify the keyring or the LSM did not permit
744 * creation of the key.
746 * On success, the possession flag from the keyring ref will be tacked on to
747 * the key ref before it is returned.
749 key_ref_t key_create_or_update(key_ref_t keyring_ref,
751 const char *description,
757 unsigned long prealloc;
758 const struct cred *cred = current_cred();
759 struct key_type *ktype;
760 struct key *keyring, *key = NULL;
764 /* look up the key type to see if it's one of the registered kernel
766 ktype = key_type_lookup(type);
768 key_ref = ERR_PTR(-ENODEV);
772 key_ref = ERR_PTR(-EINVAL);
773 if (!ktype->match || !ktype->instantiate)
776 keyring = key_ref_to_ptr(keyring_ref);
780 key_ref = ERR_PTR(-ENOTDIR);
781 if (keyring->type != &key_type_keyring)
784 ret = __key_link_begin(keyring, ktype, description, &prealloc);
788 /* if we're going to allocate a new key, we're going to have
789 * to modify the keyring */
790 ret = key_permission(keyring_ref, KEY_WRITE);
792 key_ref = ERR_PTR(ret);
796 /* if it's possible to update this type of key, search for an existing
797 * key of the same type and description in the destination keyring and
798 * update that instead if possible
801 key_ref = __keyring_search_one(keyring_ref, ktype, description,
803 if (!IS_ERR(key_ref))
804 goto found_matching_key;
807 /* if the client doesn't provide, decide on the permissions we want */
808 if (perm == KEY_PERM_UNDEF) {
809 perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
810 perm |= KEY_USR_VIEW | KEY_USR_SEARCH | KEY_USR_LINK | KEY_USR_SETATTR;
813 perm |= KEY_POS_READ | KEY_USR_READ;
815 if (ktype == &key_type_keyring || ktype->update)
816 perm |= KEY_USR_WRITE;
819 /* allocate a new key */
820 key = key_alloc(ktype, description, cred->fsuid, cred->fsgid, cred,
823 key_ref = ERR_CAST(key);
827 /* instantiate it and link it into the target keyring */
828 ret = __key_instantiate_and_link(key, payload, plen, keyring, NULL,
832 key_ref = ERR_PTR(ret);
836 key_ref = make_key_ref(key, is_key_possessed(keyring_ref));
839 __key_link_end(keyring, ktype, prealloc);
846 /* we found a matching key, so we're going to try to update it
847 * - we can drop the locks first as we have the key pinned
849 __key_link_end(keyring, ktype, prealloc);
852 key = key_ref_to_ptr(key_ref);
853 if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) {
854 ret = wait_for_key_construction(key, true);
856 key_ref_put(key_ref);
857 key_ref = ERR_PTR(ret);
862 key_ref = __key_update(key_ref, payload, plen);
865 EXPORT_SYMBOL(key_create_or_update);
868 * key_update - Update a key's contents.
869 * @key_ref: The pointer (plus possession flag) to the key.
870 * @payload: The data to be used to update the key.
871 * @plen: The length of @payload.
873 * Attempt to update the contents of a key with the given payload data. The
874 * caller must be granted Write permission on the key. Negative keys can be
875 * instantiated by this method.
877 * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
878 * type does not support updating. The key type may return other errors.
880 int key_update(key_ref_t key_ref, const void *payload, size_t plen)
882 struct key *key = key_ref_to_ptr(key_ref);
887 /* the key must be writable */
888 ret = key_permission(key_ref, KEY_WRITE);
892 /* attempt to update it if supported */
894 if (key->type->update) {
895 down_write(&key->sem);
897 ret = key->type->update(key, payload, plen);
899 /* updating a negative key instantiates it */
900 clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
908 EXPORT_SYMBOL(key_update);
911 * key_revoke - Revoke a key.
912 * @key: The key to be revoked.
914 * Mark a key as being revoked and ask the type to free up its resources. The
915 * revocation timeout is set and the key and all its links will be
916 * automatically garbage collected after key_gc_delay amount of time if they
917 * are not manually dealt with first.
919 void key_revoke(struct key *key)
926 /* make sure no one's trying to change or use the key when we mark it
927 * - we tell lockdep that we might nest because we might be revoking an
928 * authorisation key whilst holding the sem on a key we've just
931 down_write_nested(&key->sem, 1);
932 if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) &&
934 key->type->revoke(key);
936 /* set the death time to no more than the expiry time */
937 now = current_kernel_time();
939 if (key->revoked_at == 0 || key->revoked_at > time) {
940 key->revoked_at = time;
941 key_schedule_gc(key->revoked_at + key_gc_delay);
946 EXPORT_SYMBOL(key_revoke);
949 * register_key_type - Register a type of key.
950 * @ktype: The new key type.
952 * Register a new key type.
954 * Returns 0 on success or -EEXIST if a type of this name already exists.
956 int register_key_type(struct key_type *ktype)
962 down_write(&key_types_sem);
964 /* disallow key types with the same name */
965 list_for_each_entry(p, &key_types_list, link) {
966 if (strcmp(p->name, ktype->name) == 0)
971 list_add(&ktype->link, &key_types_list);
975 up_write(&key_types_sem);
978 EXPORT_SYMBOL(register_key_type);
981 * unregister_key_type - Unregister a type of key.
982 * @ktype: The key type.
984 * Unregister a key type and mark all the extant keys of this type as dead.
985 * Those keys of this type are then destroyed to get rid of their payloads and
986 * they and their links will be garbage collected as soon as possible.
988 void unregister_key_type(struct key_type *ktype)
990 down_write(&key_types_sem);
991 list_del_init(&ktype->link);
992 downgrade_write(&key_types_sem);
993 key_gc_keytype(ktype);
994 up_read(&key_types_sem);
996 EXPORT_SYMBOL(unregister_key_type);
999 * Initialise the key management state.
1001 void __init key_init(void)
1003 /* allocate a slab in which we can store keys */
1004 key_jar = kmem_cache_create("key_jar", sizeof(struct key),
1005 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
1007 /* add the special key types */
1008 list_add_tail(&key_type_keyring.link, &key_types_list);
1009 list_add_tail(&key_type_dead.link, &key_types_list);
1010 list_add_tail(&key_type_user.link, &key_types_list);
1012 /* record the root user tracking */
1013 rb_link_node(&root_key_user.node,
1015 &key_user_tree.rb_node);
1017 rb_insert_color(&root_key_user.node,