blob: 6e21c11e48bc1cd434664d28f83084b54db50bd6 [file] [log] [blame]
David Howells76181c12007-10-16 23:29:46 -07001/* Basic authentication token and access key management
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
David Howells69664cf2008-04-29 01:01:31 -07003 * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * Written by David Howells (dhowells@redhat.com)
5 *
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.
10 */
11
12#include <linux/module.h>
13#include <linux/init.h>
Randy Dunlapa7807a32006-06-27 02:53:54 -070014#include <linux/poison.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070015#include <linux/sched.h>
16#include <linux/slab.h>
David Howells29db9192005-10-30 15:02:44 -080017#include <linux/security.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070018#include <linux/workqueue.h>
Michael LeMaye51f6d32006-06-26 00:24:54 -070019#include <linux/random.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include <linux/err.h>
21#include "internal.h"
22
David Howells8bc16de2011-08-22 14:09:11 +010023struct kmem_cache *key_jar;
Linus Torvalds1da177e2005-04-16 15:20:36 -070024struct rb_root key_serial_tree; /* tree of keys indexed by serial */
25DEFINE_SPINLOCK(key_serial_lock);
26
27struct rb_root key_user_tree; /* tree of quota records indexed by UID */
28DEFINE_SPINLOCK(key_user_lock);
29
David Howells0b77f5b2008-04-29 01:01:32 -070030unsigned int key_quota_root_maxkeys = 200; /* root's key count quota */
31unsigned int key_quota_root_maxbytes = 20000; /* root's key space quota */
32unsigned int key_quota_maxkeys = 200; /* general key count quota */
33unsigned int key_quota_maxbytes = 20000; /* general key space quota */
34
Linus Torvalds1da177e2005-04-16 15:20:36 -070035static LIST_HEAD(key_types_list);
36static DECLARE_RWSEM(key_types_sem);
37
David Howells973c9f42011-01-20 16:38:33 +000038/* We serialise key instantiation and link */
David Howells76181c12007-10-16 23:29:46 -070039DEFINE_MUTEX(key_construction_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -070040
Linus Torvalds1da177e2005-04-16 15:20:36 -070041#ifdef KEY_DEBUGGING
42void __key_check(const struct key *key)
43{
44 printk("__key_check: key %p {%08x} should be {%08x}\n",
45 key, key->magic, KEY_DEBUG_MAGIC);
46 BUG();
47}
48#endif
49
Linus Torvalds1da177e2005-04-16 15:20:36 -070050/*
David Howells973c9f42011-01-20 16:38:33 +000051 * Get the key quota record for a user, allocating a new record if one doesn't
52 * already exist.
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -080054struct key_user *key_user_lookup(kuid_t uid)
Linus Torvalds1da177e2005-04-16 15:20:36 -070055{
56 struct key_user *candidate = NULL, *user;
57 struct rb_node *parent = NULL;
58 struct rb_node **p;
59
David Howells973c9f42011-01-20 16:38:33 +000060try_again:
Linus Torvalds1da177e2005-04-16 15:20:36 -070061 p = &key_user_tree.rb_node;
62 spin_lock(&key_user_lock);
63
64 /* search the tree for a user record with a matching UID */
65 while (*p) {
66 parent = *p;
67 user = rb_entry(parent, struct key_user, node);
68
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -080069 if (uid_lt(uid, user->uid))
Linus Torvalds1da177e2005-04-16 15:20:36 -070070 p = &(*p)->rb_left;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -080071 else if (uid_gt(uid, user->uid))
Serge E. Hallyn1d1e9752009-02-26 18:27:38 -060072 p = &(*p)->rb_right;
Linus Torvalds1da177e2005-04-16 15:20:36 -070073 else
74 goto found;
75 }
76
77 /* if we get here, we failed to find a match in the tree */
78 if (!candidate) {
79 /* allocate a candidate user record if we don't already have
80 * one */
81 spin_unlock(&key_user_lock);
82
83 user = NULL;
84 candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL);
85 if (unlikely(!candidate))
86 goto out;
87
88 /* the allocation may have scheduled, so we need to repeat the
89 * search lest someone else added the record whilst we were
90 * asleep */
91 goto try_again;
92 }
93
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);
99 candidate->uid = uid;
100 candidate->qnkeys = 0;
101 candidate->qnbytes = 0;
102 spin_lock_init(&candidate->lock);
David Howells76181c12007-10-16 23:29:46 -0700103 mutex_init(&candidate->cons_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700104
105 rb_link_node(&candidate->node, parent, p);
106 rb_insert_color(&candidate->node, &key_user_tree);
107 spin_unlock(&key_user_lock);
108 user = candidate;
109 goto out;
110
111 /* okay - we found a user record for this UID */
David Howells973c9f42011-01-20 16:38:33 +0000112found:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700113 atomic_inc(&user->usage);
114 spin_unlock(&key_user_lock);
Jesper Juhla7f988b2005-11-07 01:01:35 -0800115 kfree(candidate);
David Howells973c9f42011-01-20 16:38:33 +0000116out:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700117 return user;
David Howellsa8b17ed2011-01-20 16:38:27 +0000118}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700119
Linus Torvalds1da177e2005-04-16 15:20:36 -0700120/*
David Howells973c9f42011-01-20 16:38:33 +0000121 * Dispose of a user structure
Linus Torvalds1da177e2005-04-16 15:20:36 -0700122 */
123void key_user_put(struct key_user *user)
124{
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);
128
129 kfree(user);
130 }
David Howellsa8b17ed2011-01-20 16:38:27 +0000131}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133/*
David Howells973c9f42011-01-20 16:38:33 +0000134 * Allocate a serial number for a key. These are assigned randomly to avoid
135 * security issues through covert channel problems.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136 */
137static inline void key_alloc_serial(struct key *key)
138{
139 struct rb_node *parent, **p;
140 struct key *xkey;
141
Michael LeMaye51f6d32006-06-26 00:24:54 -0700142 /* propose a random serial number and look for a hole for it in the
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143 * serial number tree */
Michael LeMaye51f6d32006-06-26 00:24:54 -0700144 do {
145 get_random_bytes(&key->serial, sizeof(key->serial));
146
147 key->serial >>= 1; /* negative numbers are not permitted */
148 } while (key->serial < 3);
149
150 spin_lock(&key_serial_lock);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700151
David Howells9ad08302007-02-06 13:45:51 +0000152attempt_insertion:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700153 parent = NULL;
154 p = &key_serial_tree.rb_node;
155
156 while (*p) {
157 parent = *p;
158 xkey = rb_entry(parent, struct key, serial_node);
159
160 if (key->serial < xkey->serial)
161 p = &(*p)->rb_left;
162 else if (key->serial > xkey->serial)
163 p = &(*p)->rb_right;
164 else
165 goto serial_exists;
166 }
David Howells9ad08302007-02-06 13:45:51 +0000167
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);
171
172 spin_unlock(&key_serial_lock);
173 return;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174
175 /* we found a key with the proposed serial number - walk the tree from
176 * that point looking for the next unused serial number */
Michael LeMaye51f6d32006-06-26 00:24:54 -0700177serial_exists:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700178 for (;;) {
Michael LeMaye51f6d32006-06-26 00:24:54 -0700179 key->serial++;
David Howells9ad08302007-02-06 13:45:51 +0000180 if (key->serial < 3) {
181 key->serial = 3;
182 goto attempt_insertion;
183 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700184
185 parent = rb_next(parent);
186 if (!parent)
David Howells9ad08302007-02-06 13:45:51 +0000187 goto attempt_insertion;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700188
189 xkey = rb_entry(parent, struct key, serial_node);
190 if (key->serial < xkey->serial)
David Howells9ad08302007-02-06 13:45:51 +0000191 goto attempt_insertion;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700192 }
David Howellsa8b17ed2011-01-20 16:38:27 +0000193}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700194
David Howells973c9f42011-01-20 16:38:33 +0000195/**
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.
204 *
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.
208 *
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.
213 *
214 * The LSM security modules can prevent a key being created, in which case
215 * -EACCES will be returned.
216 *
217 * Returns a pointer to the new key if successful and an error code otherwise.
218 *
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.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700223 */
224struct key *key_alloc(struct key_type *type, const char *desc,
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800225 kuid_t uid, kgid_t gid, const struct cred *cred,
David Howells7e047ef2006-06-26 00:24:50 -0700226 key_perm_t perm, unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700227{
228 struct key_user *user = NULL;
229 struct key *key;
230 size_t desclen, quotalen;
David Howells29db9192005-10-30 15:02:44 -0800231 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700232
233 key = ERR_PTR(-EINVAL);
234 if (!desc || !*desc)
235 goto error;
236
David Howellsb9fffa32011-03-07 15:05:59 +0000237 if (type->vet_description) {
238 ret = type->vet_description(desc);
239 if (ret < 0) {
240 key = ERR_PTR(ret);
241 goto error;
242 }
243 }
244
David Howells16feef42013-09-24 10:35:15 +0100245 desclen = strlen(desc);
246 quotalen = desclen + 1 + type->def_datalen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
248 /* get hold of the key tracking for this user */
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800249 user = key_user_lookup(uid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700250 if (!user)
251 goto no_memory_1;
252
253 /* check that the user's quota permits allocation of another key and
254 * its description */
David Howells7e047ef2006-06-26 00:24:50 -0700255 if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800256 unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ?
David Howells0b77f5b2008-04-29 01:01:32 -0700257 key_quota_root_maxkeys : key_quota_maxkeys;
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800258 unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ?
David Howells0b77f5b2008-04-29 01:01:32 -0700259 key_quota_root_maxbytes : key_quota_maxbytes;
260
Linus Torvalds1da177e2005-04-16 15:20:36 -0700261 spin_lock(&user->lock);
David Howells7e047ef2006-06-26 00:24:50 -0700262 if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) {
David Howells0b77f5b2008-04-29 01:01:32 -0700263 if (user->qnkeys + 1 >= maxkeys ||
264 user->qnbytes + quotalen >= maxbytes ||
265 user->qnbytes + quotalen < user->qnbytes)
David Howells7e047ef2006-06-26 00:24:50 -0700266 goto no_quota;
267 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700268
269 user->qnkeys++;
270 user->qnbytes += quotalen;
271 spin_unlock(&user->lock);
272 }
273
274 /* allocate and initialise the key and its description */
David Howells2480f572013-12-02 11:24:18 +0000275 key = kmem_cache_zalloc(key_jar, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 if (!key)
277 goto no_memory_2;
278
279 if (desc) {
David Howells16feef42013-09-24 10:35:15 +0100280 key->index_key.desc_len = desclen;
281 key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700282 if (!key->description)
283 goto no_memory_3;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700284 }
285
286 atomic_set(&key->usage, 1);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 init_rwsem(&key->sem);
David Howells7845bc392011-11-16 11:15:54 +0000288 lockdep_set_class(&key->sem, &type->lock_class);
David Howells16feef42013-09-24 10:35:15 +0100289 key->index_key.type = type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700290 key->user = user;
291 key->quotalen = quotalen;
292 key->datalen = type->def_datalen;
293 key->uid = uid;
294 key->gid = gid;
295 key->perm = perm;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700296
David Howells7e047ef2006-06-26 00:24:50 -0700297 if (!(flags & KEY_ALLOC_NOT_IN_QUOTA))
David Howells76d8aea2005-06-23 22:00:49 -0700298 key->flags |= 1 << KEY_FLAG_IN_QUOTA;
David Howells008643b2013-08-30 16:07:37 +0100299 if (flags & KEY_ALLOC_TRUSTED)
300 key->flags |= 1 << KEY_FLAG_TRUSTED;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700301
Linus Torvalds1da177e2005-04-16 15:20:36 -0700302#ifdef KEY_DEBUGGING
303 key->magic = KEY_DEBUG_MAGIC;
304#endif
305
David Howells29db9192005-10-30 15:02:44 -0800306 /* let the security module know about the key */
David Howellsd84f4f92008-11-14 10:39:23 +1100307 ret = security_key_alloc(key, cred, flags);
David Howells29db9192005-10-30 15:02:44 -0800308 if (ret < 0)
309 goto security_error;
310
Linus Torvalds1da177e2005-04-16 15:20:36 -0700311 /* publish the key by giving it a serial number */
312 atomic_inc(&user->nkeys);
313 key_alloc_serial(key);
314
David Howells29db9192005-10-30 15:02:44 -0800315error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700316 return key;
317
David Howells29db9192005-10-30 15:02:44 -0800318security_error:
319 kfree(key->description);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 kmem_cache_free(key_jar, key);
David Howells7e047ef2006-06-26 00:24:50 -0700321 if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700322 spin_lock(&user->lock);
323 user->qnkeys--;
324 user->qnbytes -= quotalen;
325 spin_unlock(&user->lock);
326 }
327 key_user_put(user);
David Howells29db9192005-10-30 15:02:44 -0800328 key = ERR_PTR(ret);
329 goto error;
330
331no_memory_3:
332 kmem_cache_free(key_jar, key);
333no_memory_2:
David Howells7e047ef2006-06-26 00:24:50 -0700334 if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) {
David Howells29db9192005-10-30 15:02:44 -0800335 spin_lock(&user->lock);
336 user->qnkeys--;
337 user->qnbytes -= quotalen;
338 spin_unlock(&user->lock);
339 }
340 key_user_put(user);
341no_memory_1:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700342 key = ERR_PTR(-ENOMEM);
343 goto error;
344
David Howells29db9192005-10-30 15:02:44 -0800345no_quota:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700346 spin_unlock(&user->lock);
347 key_user_put(user);
348 key = ERR_PTR(-EDQUOT);
349 goto error;
David Howellsa8b17ed2011-01-20 16:38:27 +0000350}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700351EXPORT_SYMBOL(key_alloc);
352
David Howells973c9f42011-01-20 16:38:33 +0000353/**
354 * key_payload_reserve - Adjust data quota reservation for the key's payload
355 * @key: The key to make the reservation for.
356 * @datalen: The amount of data payload the caller now wants.
357 *
358 * Adjust the amount of the owning user's key data quota that a key reserves.
359 * If the amount is increased, then -EDQUOT may be returned if there isn't
360 * enough free quota available.
361 *
362 * If successful, 0 is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700363 */
364int key_payload_reserve(struct key *key, size_t datalen)
365{
Justin P. Mattockc5b60b52010-04-21 00:02:11 -0700366 int delta = (int)datalen - key->datalen;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700367 int ret = 0;
368
369 key_check(key);
370
371 /* contemplate the quota adjustment */
David Howells76d8aea2005-06-23 22:00:49 -0700372 if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) {
Eric W. Biederman9a56c2d2012-02-08 07:53:04 -0800373 unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ?
David Howells0b77f5b2008-04-29 01:01:32 -0700374 key_quota_root_maxbytes : key_quota_maxbytes;
375
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 spin_lock(&key->user->lock);
377
378 if (delta > 0 &&
David Howells0b77f5b2008-04-29 01:01:32 -0700379 (key->user->qnbytes + delta >= maxbytes ||
380 key->user->qnbytes + delta < key->user->qnbytes)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700381 ret = -EDQUOT;
382 }
383 else {
384 key->user->qnbytes += delta;
385 key->quotalen += delta;
386 }
387 spin_unlock(&key->user->lock);
388 }
389
390 /* change the recorded data length if that didn't generate an error */
391 if (ret == 0)
392 key->datalen = datalen;
393
394 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000395}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700396EXPORT_SYMBOL(key_payload_reserve);
397
Linus Torvalds1da177e2005-04-16 15:20:36 -0700398/*
David Howells973c9f42011-01-20 16:38:33 +0000399 * Instantiate a key and link it into the target keyring atomically. Must be
400 * called with the target keyring's semaphore writelocked. The target key's
401 * semaphore need not be locked as instantiation is serialised by
402 * key_construction_mutex.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700403 */
404static int __key_instantiate_and_link(struct key *key,
David Howellscf7f6012012-09-13 13:06:29 +0100405 struct key_preparsed_payload *prep,
David Howells3e301482005-06-23 22:00:56 -0700406 struct key *keyring,
David Howellsf70e2e02010-04-30 14:32:39 +0100407 struct key *authkey,
David Howellsb2a4df22013-09-24 10:35:18 +0100408 struct assoc_array_edit **_edit)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700409{
410 int ret, awaken;
411
412 key_check(key);
413 key_check(keyring);
414
415 awaken = 0;
416 ret = -EBUSY;
417
David Howells76181c12007-10-16 23:29:46 -0700418 mutex_lock(&key_construction_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700419
420 /* can't instantiate twice */
David Howells76d8aea2005-06-23 22:00:49 -0700421 if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700422 /* instantiate the key */
David Howellscf7f6012012-09-13 13:06:29 +0100423 ret = key->type->instantiate(key, prep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424
425 if (ret == 0) {
426 /* mark the key as being instantiated */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700427 atomic_inc(&key->user->nikeys);
David Howells76d8aea2005-06-23 22:00:49 -0700428 set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700429
David Howells76d8aea2005-06-23 22:00:49 -0700430 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700431 awaken = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700432
433 /* and link it into the destination keyring */
434 if (keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100435 __key_link(key, _edit);
David Howells3e301482005-06-23 22:00:56 -0700436
437 /* disable the authorisation key */
David Howellsd84f4f92008-11-14 10:39:23 +1100438 if (authkey)
439 key_revoke(authkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700440 }
441 }
442
David Howells76181c12007-10-16 23:29:46 -0700443 mutex_unlock(&key_construction_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700444
445 /* wake up anyone waiting for a key to be constructed */
446 if (awaken)
David Howells76181c12007-10-16 23:29:46 -0700447 wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700448
449 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000450}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700451
David Howells973c9f42011-01-20 16:38:33 +0000452/**
453 * key_instantiate_and_link - Instantiate a key and link it into the keyring.
454 * @key: The key to instantiate.
455 * @data: The data to use to instantiate the keyring.
456 * @datalen: The length of @data.
457 * @keyring: Keyring to create a link in on success (or NULL).
458 * @authkey: The authorisation token permitting instantiation.
459 *
460 * Instantiate a key that's in the uninstantiated state using the provided data
461 * and, if successful, link it in to the destination keyring if one is
462 * supplied.
463 *
464 * If successful, 0 is returned, the authorisation token is revoked and anyone
465 * waiting for the key is woken up. If the key was already instantiated,
466 * -EBUSY will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700467 */
468int key_instantiate_and_link(struct key *key,
469 const void *data,
470 size_t datalen,
David Howells3e301482005-06-23 22:00:56 -0700471 struct key *keyring,
David Howellsd84f4f92008-11-14 10:39:23 +1100472 struct key *authkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700473{
David Howellscf7f6012012-09-13 13:06:29 +0100474 struct key_preparsed_payload prep;
David Howellsb2a4df22013-09-24 10:35:18 +0100475 struct assoc_array_edit *edit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700476 int ret;
477
David Howellscf7f6012012-09-13 13:06:29 +0100478 memset(&prep, 0, sizeof(prep));
479 prep.data = data;
480 prep.datalen = datalen;
481 prep.quotalen = key->type->def_datalen;
482 if (key->type->preparse) {
483 ret = key->type->preparse(&prep);
484 if (ret < 0)
485 goto error;
486 }
487
David Howellsf70e2e02010-04-30 14:32:39 +0100488 if (keyring) {
David Howellsb2a4df22013-09-24 10:35:18 +0100489 ret = __key_link_begin(keyring, &key->index_key, &edit);
David Howellsf70e2e02010-04-30 14:32:39 +0100490 if (ret < 0)
David Howellscf7f6012012-09-13 13:06:29 +0100491 goto error_free_preparse;
David Howellsf70e2e02010-04-30 14:32:39 +0100492 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493
David Howellsb2a4df22013-09-24 10:35:18 +0100494 ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700495
496 if (keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100497 __key_link_end(keyring, &key->index_key, edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700498
David Howellscf7f6012012-09-13 13:06:29 +0100499error_free_preparse:
500 if (key->type->preparse)
501 key->type->free_preparse(&prep);
502error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700503 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000504}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700505
506EXPORT_SYMBOL(key_instantiate_and_link);
507
David Howells973c9f42011-01-20 16:38:33 +0000508/**
David Howellsfdd1b942011-03-07 15:06:09 +0000509 * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
David Howells973c9f42011-01-20 16:38:33 +0000510 * @key: The key to instantiate.
511 * @timeout: The timeout on the negative key.
David Howellsfdd1b942011-03-07 15:06:09 +0000512 * @error: The error to return when the key is hit.
David Howells973c9f42011-01-20 16:38:33 +0000513 * @keyring: Keyring to create a link in on success (or NULL).
514 * @authkey: The authorisation token permitting instantiation.
515 *
516 * Negatively instantiate a key that's in the uninstantiated state and, if
David Howellsfdd1b942011-03-07 15:06:09 +0000517 * successful, set its timeout and stored error and link it in to the
518 * destination keyring if one is supplied. The key and any links to the key
519 * will be automatically garbage collected after the timeout expires.
David Howells973c9f42011-01-20 16:38:33 +0000520 *
521 * Negative keys are used to rate limit repeated request_key() calls by causing
David Howellsfdd1b942011-03-07 15:06:09 +0000522 * them to return the stored error code (typically ENOKEY) until the negative
523 * key expires.
David Howells973c9f42011-01-20 16:38:33 +0000524 *
525 * If successful, 0 is returned, the authorisation token is revoked and anyone
526 * waiting for the key is woken up. If the key was already instantiated,
527 * -EBUSY will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700528 */
David Howellsfdd1b942011-03-07 15:06:09 +0000529int key_reject_and_link(struct key *key,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700530 unsigned timeout,
David Howellsfdd1b942011-03-07 15:06:09 +0000531 unsigned error,
David Howells3e301482005-06-23 22:00:56 -0700532 struct key *keyring,
David Howellsd84f4f92008-11-14 10:39:23 +1100533 struct key *authkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700534{
David Howellsb2a4df22013-09-24 10:35:18 +0100535 struct assoc_array_edit *edit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700536 struct timespec now;
David Howellsf70e2e02010-04-30 14:32:39 +0100537 int ret, awaken, link_ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700538
539 key_check(key);
540 key_check(keyring);
541
542 awaken = 0;
543 ret = -EBUSY;
544
545 if (keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100546 link_ret = __key_link_begin(keyring, &key->index_key, &edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700547
David Howells76181c12007-10-16 23:29:46 -0700548 mutex_lock(&key_construction_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700549
550 /* can't instantiate twice */
David Howells76d8aea2005-06-23 22:00:49 -0700551 if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552 /* mark the key as being negatively instantiated */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700553 atomic_inc(&key->user->nikeys);
David Howells74792b02013-10-30 11:15:24 +0000554 key->type_data.reject_error = -error;
555 smp_wmb();
David Howells76d8aea2005-06-23 22:00:49 -0700556 set_bit(KEY_FLAG_NEGATIVE, &key->flags);
557 set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 now = current_kernel_time();
559 key->expiry = now.tv_sec + timeout;
David Howellsc08ef802009-09-14 17:26:13 +0100560 key_schedule_gc(key->expiry + key_gc_delay);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700561
David Howells76d8aea2005-06-23 22:00:49 -0700562 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 awaken = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700564
Linus Torvalds1da177e2005-04-16 15:20:36 -0700565 ret = 0;
566
567 /* and link it into the destination keyring */
David Howellsf70e2e02010-04-30 14:32:39 +0100568 if (keyring && link_ret == 0)
David Howellsb2a4df22013-09-24 10:35:18 +0100569 __key_link(key, &edit);
David Howells3e301482005-06-23 22:00:56 -0700570
571 /* disable the authorisation key */
David Howellsd84f4f92008-11-14 10:39:23 +1100572 if (authkey)
573 key_revoke(authkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574 }
575
David Howells76181c12007-10-16 23:29:46 -0700576 mutex_unlock(&key_construction_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700577
578 if (keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100579 __key_link_end(keyring, &key->index_key, edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700580
581 /* wake up anyone waiting for a key to be constructed */
582 if (awaken)
David Howells76181c12007-10-16 23:29:46 -0700583 wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700584
David Howellsf70e2e02010-04-30 14:32:39 +0100585 return ret == 0 ? link_ret : ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000586}
David Howellsfdd1b942011-03-07 15:06:09 +0000587EXPORT_SYMBOL(key_reject_and_link);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700588
David Howells973c9f42011-01-20 16:38:33 +0000589/**
590 * key_put - Discard a reference to a key.
591 * @key: The key to discard a reference from.
592 *
593 * Discard a reference to a key, and when all the references are gone, we
594 * schedule the cleanup task to come and pull it out of the tree in process
595 * context at some later time.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700596 */
597void key_put(struct key *key)
598{
599 if (key) {
600 key_check(key);
601
602 if (atomic_dec_and_test(&key->usage))
Tejun Heo3b07e9c2012-08-20 14:51:24 -0700603 schedule_work(&key_gc_work);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700604 }
David Howellsa8b17ed2011-01-20 16:38:27 +0000605}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700606EXPORT_SYMBOL(key_put);
607
Linus Torvalds1da177e2005-04-16 15:20:36 -0700608/*
David Howells973c9f42011-01-20 16:38:33 +0000609 * Find a key by its serial number.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700610 */
611struct key *key_lookup(key_serial_t id)
612{
613 struct rb_node *n;
614 struct key *key;
615
616 spin_lock(&key_serial_lock);
617
618 /* search the tree for the specified key */
619 n = key_serial_tree.rb_node;
620 while (n) {
621 key = rb_entry(n, struct key, serial_node);
622
623 if (id < key->serial)
624 n = n->rb_left;
625 else if (id > key->serial)
626 n = n->rb_right;
627 else
628 goto found;
629 }
630
David Howells973c9f42011-01-20 16:38:33 +0000631not_found:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700632 key = ERR_PTR(-ENOKEY);
633 goto error;
634
David Howells973c9f42011-01-20 16:38:33 +0000635found:
David Howells55931222009-09-02 09:13:45 +0100636 /* pretend it doesn't exist if it is awaiting deletion */
637 if (atomic_read(&key->usage) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700638 goto not_found;
639
640 /* this races with key_put(), but that doesn't matter since key_put()
641 * doesn't actually change the key
642 */
David Howellsccc3e6d2013-09-24 10:35:16 +0100643 __key_get(key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700644
David Howells973c9f42011-01-20 16:38:33 +0000645error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700646 spin_unlock(&key_serial_lock);
647 return key;
David Howellsa8b17ed2011-01-20 16:38:27 +0000648}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649
Linus Torvalds1da177e2005-04-16 15:20:36 -0700650/*
David Howells973c9f42011-01-20 16:38:33 +0000651 * Find and lock the specified key type against removal.
652 *
653 * We return with the sem read-locked if successful. If the type wasn't
654 * available -ENOKEY is returned instead.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655 */
656struct key_type *key_type_lookup(const char *type)
657{
658 struct key_type *ktype;
659
660 down_read(&key_types_sem);
661
662 /* look up the key type to see if it's one of the registered kernel
663 * types */
664 list_for_each_entry(ktype, &key_types_list, link) {
665 if (strcmp(ktype->name, type) == 0)
666 goto found_kernel_type;
667 }
668
669 up_read(&key_types_sem);
670 ktype = ERR_PTR(-ENOKEY);
671
David Howells973c9f42011-01-20 16:38:33 +0000672found_kernel_type:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700673 return ktype;
David Howellsa8b17ed2011-01-20 16:38:27 +0000674}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700675
Bryan Schumaker59e6b9c2012-02-24 14:14:50 -0500676void key_set_timeout(struct key *key, unsigned timeout)
677{
678 struct timespec now;
679 time_t expiry = 0;
680
681 /* make the changes with the locks held to prevent races */
682 down_write(&key->sem);
683
684 if (timeout > 0) {
685 now = current_kernel_time();
686 expiry = now.tv_sec + timeout;
687 }
688
689 key->expiry = expiry;
690 key_schedule_gc(key->expiry + key_gc_delay);
691
692 up_write(&key->sem);
693}
694EXPORT_SYMBOL_GPL(key_set_timeout);
695
Linus Torvalds1da177e2005-04-16 15:20:36 -0700696/*
David Howells973c9f42011-01-20 16:38:33 +0000697 * Unlock a key type locked by key_type_lookup().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700698 */
699void key_type_put(struct key_type *ktype)
700{
701 up_read(&key_types_sem);
David Howellsa8b17ed2011-01-20 16:38:27 +0000702}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703
Linus Torvalds1da177e2005-04-16 15:20:36 -0700704/*
David Howells973c9f42011-01-20 16:38:33 +0000705 * Attempt to update an existing key.
706 *
707 * The key is given to us with an incremented refcount that we need to discard
708 * if we get an error.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709 */
David Howells664cceb2005-09-28 17:03:15 +0100710static inline key_ref_t __key_update(key_ref_t key_ref,
David Howellscf7f6012012-09-13 13:06:29 +0100711 struct key_preparsed_payload *prep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700712{
David Howells664cceb2005-09-28 17:03:15 +0100713 struct key *key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 int ret;
715
716 /* need write permission on the key to update it */
David Howells29db9192005-10-30 15:02:44 -0800717 ret = key_permission(key_ref, KEY_WRITE);
718 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 goto error;
720
721 ret = -EEXIST;
722 if (!key->type->update)
723 goto error;
724
725 down_write(&key->sem);
726
David Howellscf7f6012012-09-13 13:06:29 +0100727 ret = key->type->update(key, prep);
David Howells76d8aea2005-06-23 22:00:49 -0700728 if (ret == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700729 /* updating a negative key instantiates it */
David Howells76d8aea2005-06-23 22:00:49 -0700730 clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700731
732 up_write(&key->sem);
733
734 if (ret < 0)
735 goto error;
David Howells664cceb2005-09-28 17:03:15 +0100736out:
737 return key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700738
David Howells664cceb2005-09-28 17:03:15 +0100739error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700740 key_put(key);
David Howells664cceb2005-09-28 17:03:15 +0100741 key_ref = ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700742 goto out;
David Howellsa8b17ed2011-01-20 16:38:27 +0000743}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700744
David Howells973c9f42011-01-20 16:38:33 +0000745/**
746 * key_create_or_update - Update or create and instantiate a key.
747 * @keyring_ref: A pointer to the destination keyring with possession flag.
748 * @type: The type of key.
749 * @description: The searchable description for the key.
750 * @payload: The data to use to instantiate or update the key.
751 * @plen: The length of @payload.
752 * @perm: The permissions mask for a new key.
753 * @flags: The quota flags for a new key.
754 *
755 * Search the destination keyring for a key of the same description and if one
756 * is found, update it, otherwise create and instantiate a new one and create a
757 * link to it from that keyring.
758 *
759 * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
760 * concocted.
761 *
762 * Returns a pointer to the new key if successful, -ENODEV if the key type
763 * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the
764 * caller isn't permitted to modify the keyring or the LSM did not permit
765 * creation of the key.
766 *
767 * On success, the possession flag from the keyring ref will be tacked on to
768 * the key ref before it is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700769 */
David Howells664cceb2005-09-28 17:03:15 +0100770key_ref_t key_create_or_update(key_ref_t keyring_ref,
771 const char *type,
772 const char *description,
773 const void *payload,
774 size_t plen,
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700775 key_perm_t perm,
David Howells7e047ef2006-06-26 00:24:50 -0700776 unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700777{
David Howells16feef42013-09-24 10:35:15 +0100778 struct keyring_index_key index_key = {
779 .description = description,
780 };
David Howellscf7f6012012-09-13 13:06:29 +0100781 struct key_preparsed_payload prep;
David Howellsb2a4df22013-09-24 10:35:18 +0100782 struct assoc_array_edit *edit;
David Howellsd84f4f92008-11-14 10:39:23 +1100783 const struct cred *cred = current_cred();
David Howells664cceb2005-09-28 17:03:15 +0100784 struct key *keyring, *key = NULL;
David Howells664cceb2005-09-28 17:03:15 +0100785 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700786 int ret;
787
Linus Torvalds1da177e2005-04-16 15:20:36 -0700788 /* look up the key type to see if it's one of the registered kernel
789 * types */
David Howells16feef42013-09-24 10:35:15 +0100790 index_key.type = key_type_lookup(type);
791 if (IS_ERR(index_key.type)) {
David Howells664cceb2005-09-28 17:03:15 +0100792 key_ref = ERR_PTR(-ENODEV);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 goto error;
794 }
795
David Howells664cceb2005-09-28 17:03:15 +0100796 key_ref = ERR_PTR(-EINVAL);
David Howells16feef42013-09-24 10:35:15 +0100797 if (!index_key.type->match || !index_key.type->instantiate ||
798 (!index_key.description && !index_key.type->preparse))
David Howellscf7f6012012-09-13 13:06:29 +0100799 goto error_put_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700800
David Howells664cceb2005-09-28 17:03:15 +0100801 keyring = key_ref_to_ptr(keyring_ref);
802
803 key_check(keyring);
804
David Howellsc3a9d652006-04-10 15:15:21 +0100805 key_ref = ERR_PTR(-ENOTDIR);
806 if (keyring->type != &key_type_keyring)
David Howellscf7f6012012-09-13 13:06:29 +0100807 goto error_put_type;
808
809 memset(&prep, 0, sizeof(prep));
810 prep.data = payload;
811 prep.datalen = plen;
David Howells16feef42013-09-24 10:35:15 +0100812 prep.quotalen = index_key.type->def_datalen;
David Howells008643b2013-08-30 16:07:37 +0100813 prep.trusted = flags & KEY_ALLOC_TRUSTED;
David Howells16feef42013-09-24 10:35:15 +0100814 if (index_key.type->preparse) {
815 ret = index_key.type->preparse(&prep);
David Howellscf7f6012012-09-13 13:06:29 +0100816 if (ret < 0) {
817 key_ref = ERR_PTR(ret);
818 goto error_put_type;
819 }
David Howells16feef42013-09-24 10:35:15 +0100820 if (!index_key.description)
821 index_key.description = prep.description;
David Howellscf7f6012012-09-13 13:06:29 +0100822 key_ref = ERR_PTR(-EINVAL);
David Howells16feef42013-09-24 10:35:15 +0100823 if (!index_key.description)
David Howellscf7f6012012-09-13 13:06:29 +0100824 goto error_free_prep;
825 }
David Howells16feef42013-09-24 10:35:15 +0100826 index_key.desc_len = strlen(index_key.description);
David Howellsc3a9d652006-04-10 15:15:21 +0100827
David Howells008643b2013-08-30 16:07:37 +0100828 key_ref = ERR_PTR(-EPERM);
829 if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags))
830 goto error_free_prep;
831 flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0;
832
David Howellsb2a4df22013-09-24 10:35:18 +0100833 ret = __key_link_begin(keyring, &index_key, &edit);
David Howellscf7f6012012-09-13 13:06:29 +0100834 if (ret < 0) {
835 key_ref = ERR_PTR(ret);
836 goto error_free_prep;
837 }
David Howells664cceb2005-09-28 17:03:15 +0100838
839 /* if we're going to allocate a new key, we're going to have
840 * to modify the keyring */
David Howells29db9192005-10-30 15:02:44 -0800841 ret = key_permission(keyring_ref, KEY_WRITE);
842 if (ret < 0) {
843 key_ref = ERR_PTR(ret);
David Howellscf7f6012012-09-13 13:06:29 +0100844 goto error_link_end;
David Howells29db9192005-10-30 15:02:44 -0800845 }
David Howells664cceb2005-09-28 17:03:15 +0100846
David Howells1d9b7d92006-03-25 03:06:52 -0800847 /* if it's possible to update this type of key, search for an existing
848 * key of the same type and description in the destination keyring and
849 * update that instead if possible
Linus Torvalds1da177e2005-04-16 15:20:36 -0700850 */
David Howells16feef42013-09-24 10:35:15 +0100851 if (index_key.type->update) {
David Howellsb2a4df22013-09-24 10:35:18 +0100852 key_ref = find_key_to_update(keyring_ref, &index_key);
853 if (key_ref)
David Howells1d9b7d92006-03-25 03:06:52 -0800854 goto found_matching_key;
855 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700857 /* if the client doesn't provide, decide on the permissions we want */
858 if (perm == KEY_PERM_UNDEF) {
859 perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
David Howells96b5c8f2012-10-02 19:24:56 +0100860 perm |= KEY_USR_VIEW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700861
David Howells16feef42013-09-24 10:35:15 +0100862 if (index_key.type->read)
David Howells96b5c8f2012-10-02 19:24:56 +0100863 perm |= KEY_POS_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700864
David Howells16feef42013-09-24 10:35:15 +0100865 if (index_key.type == &key_type_keyring ||
866 index_key.type->update)
David Howells96b5c8f2012-10-02 19:24:56 +0100867 perm |= KEY_POS_WRITE;
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700868 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700869
870 /* allocate a new key */
David Howells16feef42013-09-24 10:35:15 +0100871 key = key_alloc(index_key.type, index_key.description,
872 cred->fsuid, cred->fsgid, cred, perm, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700873 if (IS_ERR(key)) {
David Howellse231c2e2008-02-07 00:15:26 -0800874 key_ref = ERR_CAST(key);
David Howellscf7f6012012-09-13 13:06:29 +0100875 goto error_link_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700876 }
877
878 /* instantiate it and link it into the target keyring */
David Howellsb2a4df22013-09-24 10:35:18 +0100879 ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700880 if (ret < 0) {
881 key_put(key);
David Howells664cceb2005-09-28 17:03:15 +0100882 key_ref = ERR_PTR(ret);
David Howellscf7f6012012-09-13 13:06:29 +0100883 goto error_link_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700884 }
885
David Howells664cceb2005-09-28 17:03:15 +0100886 key_ref = make_key_ref(key, is_key_possessed(keyring_ref));
887
David Howellscf7f6012012-09-13 13:06:29 +0100888error_link_end:
David Howellsb2a4df22013-09-24 10:35:18 +0100889 __key_link_end(keyring, &index_key, edit);
David Howellscf7f6012012-09-13 13:06:29 +0100890error_free_prep:
David Howells16feef42013-09-24 10:35:15 +0100891 if (index_key.type->preparse)
892 index_key.type->free_preparse(&prep);
David Howellscf7f6012012-09-13 13:06:29 +0100893error_put_type:
David Howells16feef42013-09-24 10:35:15 +0100894 key_type_put(index_key.type);
David Howellscf7f6012012-09-13 13:06:29 +0100895error:
David Howells664cceb2005-09-28 17:03:15 +0100896 return key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700897
898 found_matching_key:
899 /* we found a matching key, so we're going to try to update it
900 * - we can drop the locks first as we have the key pinned
901 */
David Howellsb2a4df22013-09-24 10:35:18 +0100902 __key_link_end(keyring, &index_key, edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
David Howellscf7f6012012-09-13 13:06:29 +0100904 key_ref = __key_update(key_ref, &prep);
905 goto error_free_prep;
David Howellsa8b17ed2011-01-20 16:38:27 +0000906}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700907EXPORT_SYMBOL(key_create_or_update);
908
David Howells973c9f42011-01-20 16:38:33 +0000909/**
910 * key_update - Update a key's contents.
911 * @key_ref: The pointer (plus possession flag) to the key.
912 * @payload: The data to be used to update the key.
913 * @plen: The length of @payload.
914 *
915 * Attempt to update the contents of a key with the given payload data. The
916 * caller must be granted Write permission on the key. Negative keys can be
917 * instantiated by this method.
918 *
919 * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
920 * type does not support updating. The key type may return other errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700921 */
David Howells664cceb2005-09-28 17:03:15 +0100922int key_update(key_ref_t key_ref, const void *payload, size_t plen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700923{
David Howellscf7f6012012-09-13 13:06:29 +0100924 struct key_preparsed_payload prep;
David Howells664cceb2005-09-28 17:03:15 +0100925 struct key *key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700926 int ret;
927
928 key_check(key);
929
930 /* the key must be writable */
David Howells29db9192005-10-30 15:02:44 -0800931 ret = key_permission(key_ref, KEY_WRITE);
932 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700933 goto error;
934
935 /* attempt to update it if supported */
936 ret = -EOPNOTSUPP;
David Howellscf7f6012012-09-13 13:06:29 +0100937 if (!key->type->update)
938 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939
David Howellscf7f6012012-09-13 13:06:29 +0100940 memset(&prep, 0, sizeof(prep));
941 prep.data = payload;
942 prep.datalen = plen;
943 prep.quotalen = key->type->def_datalen;
944 if (key->type->preparse) {
945 ret = key->type->preparse(&prep);
946 if (ret < 0)
947 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700948 }
949
David Howellscf7f6012012-09-13 13:06:29 +0100950 down_write(&key->sem);
951
952 ret = key->type->update(key, &prep);
953 if (ret == 0)
954 /* updating a negative key instantiates it */
955 clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
956
957 up_write(&key->sem);
958
959 if (key->type->preparse)
960 key->type->free_preparse(&prep);
961error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700962 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000963}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700964EXPORT_SYMBOL(key_update);
965
David Howells973c9f42011-01-20 16:38:33 +0000966/**
967 * key_revoke - Revoke a key.
968 * @key: The key to be revoked.
969 *
970 * Mark a key as being revoked and ask the type to free up its resources. The
971 * revocation timeout is set and the key and all its links will be
972 * automatically garbage collected after key_gc_delay amount of time if they
973 * are not manually dealt with first.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700974 */
975void key_revoke(struct key *key)
976{
David Howells5d135442009-09-02 09:14:00 +0100977 struct timespec now;
978 time_t time;
979
Linus Torvalds1da177e2005-04-16 15:20:36 -0700980 key_check(key);
981
David Howells76181c12007-10-16 23:29:46 -0700982 /* make sure no one's trying to change or use the key when we mark it
983 * - we tell lockdep that we might nest because we might be revoking an
984 * authorisation key whilst holding the sem on a key we've just
985 * instantiated
986 */
987 down_write_nested(&key->sem, 1);
988 if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) &&
989 key->type->revoke)
David Howells04c567d2006-06-22 14:47:18 -0700990 key->type->revoke(key);
991
David Howells5d135442009-09-02 09:14:00 +0100992 /* set the death time to no more than the expiry time */
993 now = current_kernel_time();
994 time = now.tv_sec;
995 if (key->revoked_at == 0 || key->revoked_at > time) {
996 key->revoked_at = time;
David Howellsc08ef802009-09-14 17:26:13 +0100997 key_schedule_gc(key->revoked_at + key_gc_delay);
David Howells5d135442009-09-02 09:14:00 +0100998 }
999
Linus Torvalds1da177e2005-04-16 15:20:36 -07001000 up_write(&key->sem);
David Howellsa8b17ed2011-01-20 16:38:27 +00001001}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001002EXPORT_SYMBOL(key_revoke);
1003
David Howells973c9f42011-01-20 16:38:33 +00001004/**
David Howellsfd758152012-05-11 10:56:56 +01001005 * key_invalidate - Invalidate a key.
1006 * @key: The key to be invalidated.
1007 *
1008 * Mark a key as being invalidated and have it cleaned up immediately. The key
1009 * is ignored by all searches and other operations from this point.
1010 */
1011void key_invalidate(struct key *key)
1012{
1013 kenter("%d", key_serial(key));
1014
1015 key_check(key);
1016
1017 if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) {
1018 down_write_nested(&key->sem, 1);
1019 if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags))
1020 key_schedule_gc_links();
1021 up_write(&key->sem);
1022 }
1023}
1024EXPORT_SYMBOL(key_invalidate);
1025
1026/**
David Howells973c9f42011-01-20 16:38:33 +00001027 * register_key_type - Register a type of key.
1028 * @ktype: The new key type.
1029 *
1030 * Register a new key type.
1031 *
1032 * Returns 0 on success or -EEXIST if a type of this name already exists.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001033 */
1034int register_key_type(struct key_type *ktype)
1035{
1036 struct key_type *p;
1037 int ret;
1038
David Howells7845bc392011-11-16 11:15:54 +00001039 memset(&ktype->lock_class, 0, sizeof(ktype->lock_class));
1040
Linus Torvalds1da177e2005-04-16 15:20:36 -07001041 ret = -EEXIST;
1042 down_write(&key_types_sem);
1043
1044 /* disallow key types with the same name */
1045 list_for_each_entry(p, &key_types_list, link) {
1046 if (strcmp(p->name, ktype->name) == 0)
1047 goto out;
1048 }
1049
1050 /* store the type */
1051 list_add(&ktype->link, &key_types_list);
David Howells1eb1bcf2012-05-11 10:56:56 +01001052
1053 pr_notice("Key type %s registered\n", ktype->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001054 ret = 0;
1055
David Howells973c9f42011-01-20 16:38:33 +00001056out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001057 up_write(&key_types_sem);
1058 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001059}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001060EXPORT_SYMBOL(register_key_type);
1061
David Howells973c9f42011-01-20 16:38:33 +00001062/**
1063 * unregister_key_type - Unregister a type of key.
1064 * @ktype: The key type.
1065 *
1066 * Unregister a key type and mark all the extant keys of this type as dead.
1067 * Those keys of this type are then destroyed to get rid of their payloads and
1068 * they and their links will be garbage collected as soon as possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001069 */
1070void unregister_key_type(struct key_type *ktype)
1071{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 down_write(&key_types_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001073 list_del_init(&ktype->link);
David Howells0c061b52011-08-22 14:09:36 +01001074 downgrade_write(&key_types_sem);
1075 key_gc_keytype(ktype);
David Howells1eb1bcf2012-05-11 10:56:56 +01001076 pr_notice("Key type %s unregistered\n", ktype->name);
David Howells0c061b52011-08-22 14:09:36 +01001077 up_read(&key_types_sem);
David Howellsa8b17ed2011-01-20 16:38:27 +00001078}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001079EXPORT_SYMBOL(unregister_key_type);
1080
Linus Torvalds1da177e2005-04-16 15:20:36 -07001081/*
David Howells973c9f42011-01-20 16:38:33 +00001082 * Initialise the key management state.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001083 */
1084void __init key_init(void)
1085{
1086 /* allocate a slab in which we can store keys */
1087 key_jar = kmem_cache_create("key_jar", sizeof(struct key),
Paul Mundt20c2df82007-07-20 10:11:58 +09001088 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001089
1090 /* add the special key types */
1091 list_add_tail(&key_type_keyring.link, &key_types_list);
1092 list_add_tail(&key_type_dead.link, &key_types_list);
1093 list_add_tail(&key_type_user.link, &key_types_list);
Jeff Layton9f6ed2c2012-01-17 16:09:11 -05001094 list_add_tail(&key_type_logon.link, &key_types_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001095
1096 /* record the root user tracking */
1097 rb_link_node(&root_key_user.node,
1098 NULL,
1099 &key_user_tree.rb_node);
1100
1101 rb_insert_color(&root_key_user.node,
1102 &key_user_tree);
David Howellsa8b17ed2011-01-20 16:38:27 +00001103}