blob: e17ba6aefdc0820b6c5c3af7cfc90d4e20094915 [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
Steve Dickson738c5d12014-09-02 13:52:05 +010030unsigned int key_quota_root_maxkeys = 1000000; /* root's key count quota */
31unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */
David Howells0b77f5b2008-04-29 01:01:32 -070032unsigned 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);
David Howells7dfa0ca2014-07-18 18:56:34 +0100440
441 if (prep->expiry != TIME_T_MAX) {
442 key->expiry = prep->expiry;
443 key_schedule_gc(prep->expiry + key_gc_delay);
444 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700445 }
446 }
447
David Howells76181c12007-10-16 23:29:46 -0700448 mutex_unlock(&key_construction_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700449
450 /* wake up anyone waiting for a key to be constructed */
451 if (awaken)
David Howells76181c12007-10-16 23:29:46 -0700452 wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700453
454 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000455}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700456
David Howells973c9f42011-01-20 16:38:33 +0000457/**
458 * key_instantiate_and_link - Instantiate a key and link it into the keyring.
459 * @key: The key to instantiate.
460 * @data: The data to use to instantiate the keyring.
461 * @datalen: The length of @data.
462 * @keyring: Keyring to create a link in on success (or NULL).
463 * @authkey: The authorisation token permitting instantiation.
464 *
465 * Instantiate a key that's in the uninstantiated state using the provided data
466 * and, if successful, link it in to the destination keyring if one is
467 * supplied.
468 *
469 * If successful, 0 is returned, the authorisation token is revoked and anyone
470 * waiting for the key is woken up. If the key was already instantiated,
471 * -EBUSY will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700472 */
473int key_instantiate_and_link(struct key *key,
474 const void *data,
475 size_t datalen,
David Howells3e301482005-06-23 22:00:56 -0700476 struct key *keyring,
David Howellsd84f4f92008-11-14 10:39:23 +1100477 struct key *authkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700478{
David Howellscf7f6012012-09-13 13:06:29 +0100479 struct key_preparsed_payload prep;
David Howellsb2a4df22013-09-24 10:35:18 +0100480 struct assoc_array_edit *edit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700481 int ret;
482
David Howellscf7f6012012-09-13 13:06:29 +0100483 memset(&prep, 0, sizeof(prep));
484 prep.data = data;
485 prep.datalen = datalen;
486 prep.quotalen = key->type->def_datalen;
David Howells7dfa0ca2014-07-18 18:56:34 +0100487 prep.expiry = TIME_T_MAX;
David Howellscf7f6012012-09-13 13:06:29 +0100488 if (key->type->preparse) {
489 ret = key->type->preparse(&prep);
490 if (ret < 0)
491 goto error;
492 }
493
David Howellsf70e2e02010-04-30 14:32:39 +0100494 if (keyring) {
David Howellsb2a4df22013-09-24 10:35:18 +0100495 ret = __key_link_begin(keyring, &key->index_key, &edit);
David Howellsf70e2e02010-04-30 14:32:39 +0100496 if (ret < 0)
David Howells4d8c0252014-07-18 18:56:34 +0100497 goto error;
David Howellsf70e2e02010-04-30 14:32:39 +0100498 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700499
David Howellsb2a4df22013-09-24 10:35:18 +0100500 ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700501
502 if (keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100503 __key_link_end(keyring, &key->index_key, edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700504
David Howells4d8c0252014-07-18 18:56:34 +0100505error:
David Howellscf7f6012012-09-13 13:06:29 +0100506 if (key->type->preparse)
507 key->type->free_preparse(&prep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700508 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000509}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700510
511EXPORT_SYMBOL(key_instantiate_and_link);
512
David Howells973c9f42011-01-20 16:38:33 +0000513/**
David Howellsfdd1b942011-03-07 15:06:09 +0000514 * key_reject_and_link - Negatively instantiate a key and link it into the keyring.
David Howells973c9f42011-01-20 16:38:33 +0000515 * @key: The key to instantiate.
516 * @timeout: The timeout on the negative key.
David Howellsfdd1b942011-03-07 15:06:09 +0000517 * @error: The error to return when the key is hit.
David Howells973c9f42011-01-20 16:38:33 +0000518 * @keyring: Keyring to create a link in on success (or NULL).
519 * @authkey: The authorisation token permitting instantiation.
520 *
521 * Negatively instantiate a key that's in the uninstantiated state and, if
David Howellsfdd1b942011-03-07 15:06:09 +0000522 * successful, set its timeout and stored error and link it in to the
523 * destination keyring if one is supplied. The key and any links to the key
524 * will be automatically garbage collected after the timeout expires.
David Howells973c9f42011-01-20 16:38:33 +0000525 *
526 * Negative keys are used to rate limit repeated request_key() calls by causing
David Howellsfdd1b942011-03-07 15:06:09 +0000527 * them to return the stored error code (typically ENOKEY) until the negative
528 * key expires.
David Howells973c9f42011-01-20 16:38:33 +0000529 *
530 * If successful, 0 is returned, the authorisation token is revoked and anyone
531 * waiting for the key is woken up. If the key was already instantiated,
532 * -EBUSY will be returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700533 */
David Howellsfdd1b942011-03-07 15:06:09 +0000534int key_reject_and_link(struct key *key,
Linus Torvalds1da177e2005-04-16 15:20:36 -0700535 unsigned timeout,
David Howellsfdd1b942011-03-07 15:06:09 +0000536 unsigned error,
David Howells3e301482005-06-23 22:00:56 -0700537 struct key *keyring,
David Howellsd84f4f92008-11-14 10:39:23 +1100538 struct key *authkey)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700539{
David Howellsb2a4df22013-09-24 10:35:18 +0100540 struct assoc_array_edit *edit;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700541 struct timespec now;
David Howellsf70e2e02010-04-30 14:32:39 +0100542 int ret, awaken, link_ret = 0;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700543
544 key_check(key);
545 key_check(keyring);
546
547 awaken = 0;
548 ret = -EBUSY;
549
550 if (keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100551 link_ret = __key_link_begin(keyring, &key->index_key, &edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700552
David Howells76181c12007-10-16 23:29:46 -0700553 mutex_lock(&key_construction_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700554
555 /* can't instantiate twice */
David Howells76d8aea2005-06-23 22:00:49 -0700556 if (!test_bit(KEY_FLAG_INSTANTIATED, &key->flags)) {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700557 /* mark the key as being negatively instantiated */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700558 atomic_inc(&key->user->nikeys);
David Howells74792b02013-10-30 11:15:24 +0000559 key->type_data.reject_error = -error;
560 smp_wmb();
David Howells76d8aea2005-06-23 22:00:49 -0700561 set_bit(KEY_FLAG_NEGATIVE, &key->flags);
562 set_bit(KEY_FLAG_INSTANTIATED, &key->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700563 now = current_kernel_time();
564 key->expiry = now.tv_sec + timeout;
David Howellsc08ef802009-09-14 17:26:13 +0100565 key_schedule_gc(key->expiry + key_gc_delay);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700566
David Howells76d8aea2005-06-23 22:00:49 -0700567 if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags))
Linus Torvalds1da177e2005-04-16 15:20:36 -0700568 awaken = 1;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700569
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570 ret = 0;
571
572 /* and link it into the destination keyring */
David Howellsf70e2e02010-04-30 14:32:39 +0100573 if (keyring && link_ret == 0)
David Howellsb2a4df22013-09-24 10:35:18 +0100574 __key_link(key, &edit);
David Howells3e301482005-06-23 22:00:56 -0700575
576 /* disable the authorisation key */
David Howellsd84f4f92008-11-14 10:39:23 +1100577 if (authkey)
578 key_revoke(authkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579 }
580
David Howells76181c12007-10-16 23:29:46 -0700581 mutex_unlock(&key_construction_mutex);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582
583 if (keyring)
David Howellsb2a4df22013-09-24 10:35:18 +0100584 __key_link_end(keyring, &key->index_key, edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700585
586 /* wake up anyone waiting for a key to be constructed */
587 if (awaken)
David Howells76181c12007-10-16 23:29:46 -0700588 wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700589
David Howellsf70e2e02010-04-30 14:32:39 +0100590 return ret == 0 ? link_ret : ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000591}
David Howellsfdd1b942011-03-07 15:06:09 +0000592EXPORT_SYMBOL(key_reject_and_link);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700593
David Howells973c9f42011-01-20 16:38:33 +0000594/**
595 * key_put - Discard a reference to a key.
596 * @key: The key to discard a reference from.
597 *
598 * Discard a reference to a key, and when all the references are gone, we
599 * schedule the cleanup task to come and pull it out of the tree in process
600 * context at some later time.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700601 */
602void key_put(struct key *key)
603{
604 if (key) {
605 key_check(key);
606
607 if (atomic_dec_and_test(&key->usage))
Tejun Heo3b07e9c2012-08-20 14:51:24 -0700608 schedule_work(&key_gc_work);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700609 }
David Howellsa8b17ed2011-01-20 16:38:27 +0000610}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700611EXPORT_SYMBOL(key_put);
612
Linus Torvalds1da177e2005-04-16 15:20:36 -0700613/*
David Howells973c9f42011-01-20 16:38:33 +0000614 * Find a key by its serial number.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700615 */
616struct key *key_lookup(key_serial_t id)
617{
618 struct rb_node *n;
619 struct key *key;
620
621 spin_lock(&key_serial_lock);
622
623 /* search the tree for the specified key */
624 n = key_serial_tree.rb_node;
625 while (n) {
626 key = rb_entry(n, struct key, serial_node);
627
628 if (id < key->serial)
629 n = n->rb_left;
630 else if (id > key->serial)
631 n = n->rb_right;
632 else
633 goto found;
634 }
635
David Howells973c9f42011-01-20 16:38:33 +0000636not_found:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700637 key = ERR_PTR(-ENOKEY);
638 goto error;
639
David Howells973c9f42011-01-20 16:38:33 +0000640found:
David Howells55931222009-09-02 09:13:45 +0100641 /* pretend it doesn't exist if it is awaiting deletion */
642 if (atomic_read(&key->usage) == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700643 goto not_found;
644
645 /* this races with key_put(), but that doesn't matter since key_put()
646 * doesn't actually change the key
647 */
David Howellsccc3e6d2013-09-24 10:35:16 +0100648 __key_get(key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700649
David Howells973c9f42011-01-20 16:38:33 +0000650error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700651 spin_unlock(&key_serial_lock);
652 return key;
David Howellsa8b17ed2011-01-20 16:38:27 +0000653}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700654
Linus Torvalds1da177e2005-04-16 15:20:36 -0700655/*
David Howells973c9f42011-01-20 16:38:33 +0000656 * Find and lock the specified key type against removal.
657 *
658 * We return with the sem read-locked if successful. If the type wasn't
659 * available -ENOKEY is returned instead.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700660 */
661struct key_type *key_type_lookup(const char *type)
662{
663 struct key_type *ktype;
664
665 down_read(&key_types_sem);
666
667 /* look up the key type to see if it's one of the registered kernel
668 * types */
669 list_for_each_entry(ktype, &key_types_list, link) {
670 if (strcmp(ktype->name, type) == 0)
671 goto found_kernel_type;
672 }
673
674 up_read(&key_types_sem);
675 ktype = ERR_PTR(-ENOKEY);
676
David Howells973c9f42011-01-20 16:38:33 +0000677found_kernel_type:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700678 return ktype;
David Howellsa8b17ed2011-01-20 16:38:27 +0000679}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700680
Bryan Schumaker59e6b9c2012-02-24 14:14:50 -0500681void key_set_timeout(struct key *key, unsigned timeout)
682{
683 struct timespec now;
684 time_t expiry = 0;
685
686 /* make the changes with the locks held to prevent races */
687 down_write(&key->sem);
688
689 if (timeout > 0) {
690 now = current_kernel_time();
691 expiry = now.tv_sec + timeout;
692 }
693
694 key->expiry = expiry;
695 key_schedule_gc(key->expiry + key_gc_delay);
696
697 up_write(&key->sem);
698}
699EXPORT_SYMBOL_GPL(key_set_timeout);
700
Linus Torvalds1da177e2005-04-16 15:20:36 -0700701/*
David Howells973c9f42011-01-20 16:38:33 +0000702 * Unlock a key type locked by key_type_lookup().
Linus Torvalds1da177e2005-04-16 15:20:36 -0700703 */
704void key_type_put(struct key_type *ktype)
705{
706 up_read(&key_types_sem);
David Howellsa8b17ed2011-01-20 16:38:27 +0000707}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700708
Linus Torvalds1da177e2005-04-16 15:20:36 -0700709/*
David Howells973c9f42011-01-20 16:38:33 +0000710 * Attempt to update an existing key.
711 *
712 * The key is given to us with an incremented refcount that we need to discard
713 * if we get an error.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700714 */
David Howells664cceb2005-09-28 17:03:15 +0100715static inline key_ref_t __key_update(key_ref_t key_ref,
David Howellscf7f6012012-09-13 13:06:29 +0100716 struct key_preparsed_payload *prep)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700717{
David Howells664cceb2005-09-28 17:03:15 +0100718 struct key *key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700719 int ret;
720
721 /* need write permission on the key to update it */
David Howellsf5895942014-03-14 17:44:49 +0000722 ret = key_permission(key_ref, KEY_NEED_WRITE);
David Howells29db9192005-10-30 15:02:44 -0800723 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700724 goto error;
725
726 ret = -EEXIST;
727 if (!key->type->update)
728 goto error;
729
730 down_write(&key->sem);
731
David Howellscf7f6012012-09-13 13:06:29 +0100732 ret = key->type->update(key, prep);
David Howells76d8aea2005-06-23 22:00:49 -0700733 if (ret == 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700734 /* updating a negative key instantiates it */
David Howells76d8aea2005-06-23 22:00:49 -0700735 clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700736
737 up_write(&key->sem);
738
739 if (ret < 0)
740 goto error;
David Howells664cceb2005-09-28 17:03:15 +0100741out:
742 return key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700743
David Howells664cceb2005-09-28 17:03:15 +0100744error:
Linus Torvalds1da177e2005-04-16 15:20:36 -0700745 key_put(key);
David Howells664cceb2005-09-28 17:03:15 +0100746 key_ref = ERR_PTR(ret);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700747 goto out;
David Howellsa8b17ed2011-01-20 16:38:27 +0000748}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700749
David Howells973c9f42011-01-20 16:38:33 +0000750/**
751 * key_create_or_update - Update or create and instantiate a key.
752 * @keyring_ref: A pointer to the destination keyring with possession flag.
753 * @type: The type of key.
754 * @description: The searchable description for the key.
755 * @payload: The data to use to instantiate or update the key.
756 * @plen: The length of @payload.
757 * @perm: The permissions mask for a new key.
758 * @flags: The quota flags for a new key.
759 *
760 * Search the destination keyring for a key of the same description and if one
761 * is found, update it, otherwise create and instantiate a new one and create a
762 * link to it from that keyring.
763 *
764 * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be
765 * concocted.
766 *
767 * Returns a pointer to the new key if successful, -ENODEV if the key type
768 * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the
769 * caller isn't permitted to modify the keyring or the LSM did not permit
770 * creation of the key.
771 *
772 * On success, the possession flag from the keyring ref will be tacked on to
773 * the key ref before it is returned.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700774 */
David Howells664cceb2005-09-28 17:03:15 +0100775key_ref_t key_create_or_update(key_ref_t keyring_ref,
776 const char *type,
777 const char *description,
778 const void *payload,
779 size_t plen,
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700780 key_perm_t perm,
David Howells7e047ef2006-06-26 00:24:50 -0700781 unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700782{
David Howells16feef42013-09-24 10:35:15 +0100783 struct keyring_index_key index_key = {
784 .description = description,
785 };
David Howellscf7f6012012-09-13 13:06:29 +0100786 struct key_preparsed_payload prep;
David Howellsb2a4df22013-09-24 10:35:18 +0100787 struct assoc_array_edit *edit;
David Howellsd84f4f92008-11-14 10:39:23 +1100788 const struct cred *cred = current_cred();
David Howells664cceb2005-09-28 17:03:15 +0100789 struct key *keyring, *key = NULL;
David Howells664cceb2005-09-28 17:03:15 +0100790 key_ref_t key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700791 int ret;
792
Linus Torvalds1da177e2005-04-16 15:20:36 -0700793 /* look up the key type to see if it's one of the registered kernel
794 * types */
David Howells16feef42013-09-24 10:35:15 +0100795 index_key.type = key_type_lookup(type);
796 if (IS_ERR(index_key.type)) {
David Howells664cceb2005-09-28 17:03:15 +0100797 key_ref = ERR_PTR(-ENODEV);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700798 goto error;
799 }
800
David Howells664cceb2005-09-28 17:03:15 +0100801 key_ref = ERR_PTR(-EINVAL);
David Howellsc06cfb02014-09-16 17:36:06 +0100802 if (!index_key.type->instantiate ||
David Howells16feef42013-09-24 10:35:15 +0100803 (!index_key.description && !index_key.type->preparse))
David Howellscf7f6012012-09-13 13:06:29 +0100804 goto error_put_type;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700805
David Howells664cceb2005-09-28 17:03:15 +0100806 keyring = key_ref_to_ptr(keyring_ref);
807
808 key_check(keyring);
809
David Howellsc3a9d652006-04-10 15:15:21 +0100810 key_ref = ERR_PTR(-ENOTDIR);
811 if (keyring->type != &key_type_keyring)
David Howellscf7f6012012-09-13 13:06:29 +0100812 goto error_put_type;
813
814 memset(&prep, 0, sizeof(prep));
815 prep.data = payload;
816 prep.datalen = plen;
David Howells16feef42013-09-24 10:35:15 +0100817 prep.quotalen = index_key.type->def_datalen;
David Howells008643b2013-08-30 16:07:37 +0100818 prep.trusted = flags & KEY_ALLOC_TRUSTED;
David Howells7dfa0ca2014-07-18 18:56:34 +0100819 prep.expiry = TIME_T_MAX;
David Howells16feef42013-09-24 10:35:15 +0100820 if (index_key.type->preparse) {
821 ret = index_key.type->preparse(&prep);
David Howellscf7f6012012-09-13 13:06:29 +0100822 if (ret < 0) {
823 key_ref = ERR_PTR(ret);
David Howells4d8c0252014-07-18 18:56:34 +0100824 goto error_free_prep;
David Howellscf7f6012012-09-13 13:06:29 +0100825 }
David Howells16feef42013-09-24 10:35:15 +0100826 if (!index_key.description)
827 index_key.description = prep.description;
David Howellscf7f6012012-09-13 13:06:29 +0100828 key_ref = ERR_PTR(-EINVAL);
David Howells16feef42013-09-24 10:35:15 +0100829 if (!index_key.description)
David Howellscf7f6012012-09-13 13:06:29 +0100830 goto error_free_prep;
831 }
David Howells16feef42013-09-24 10:35:15 +0100832 index_key.desc_len = strlen(index_key.description);
David Howellsc3a9d652006-04-10 15:15:21 +0100833
David Howells008643b2013-08-30 16:07:37 +0100834 key_ref = ERR_PTR(-EPERM);
835 if (!prep.trusted && test_bit(KEY_FLAG_TRUSTED_ONLY, &keyring->flags))
836 goto error_free_prep;
837 flags |= prep.trusted ? KEY_ALLOC_TRUSTED : 0;
838
David Howellsb2a4df22013-09-24 10:35:18 +0100839 ret = __key_link_begin(keyring, &index_key, &edit);
David Howellscf7f6012012-09-13 13:06:29 +0100840 if (ret < 0) {
841 key_ref = ERR_PTR(ret);
842 goto error_free_prep;
843 }
David Howells664cceb2005-09-28 17:03:15 +0100844
845 /* if we're going to allocate a new key, we're going to have
846 * to modify the keyring */
David Howellsf5895942014-03-14 17:44:49 +0000847 ret = key_permission(keyring_ref, KEY_NEED_WRITE);
David Howells29db9192005-10-30 15:02:44 -0800848 if (ret < 0) {
849 key_ref = ERR_PTR(ret);
David Howellscf7f6012012-09-13 13:06:29 +0100850 goto error_link_end;
David Howells29db9192005-10-30 15:02:44 -0800851 }
David Howells664cceb2005-09-28 17:03:15 +0100852
David Howells1d9b7d92006-03-25 03:06:52 -0800853 /* if it's possible to update this type of key, search for an existing
854 * key of the same type and description in the destination keyring and
855 * update that instead if possible
Linus Torvalds1da177e2005-04-16 15:20:36 -0700856 */
David Howells16feef42013-09-24 10:35:15 +0100857 if (index_key.type->update) {
David Howellsb2a4df22013-09-24 10:35:18 +0100858 key_ref = find_key_to_update(keyring_ref, &index_key);
859 if (key_ref)
David Howells1d9b7d92006-03-25 03:06:52 -0800860 goto found_matching_key;
861 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700862
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700863 /* if the client doesn't provide, decide on the permissions we want */
864 if (perm == KEY_PERM_UNDEF) {
865 perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR;
David Howells96b5c8f2012-10-02 19:24:56 +0100866 perm |= KEY_USR_VIEW;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700867
David Howells16feef42013-09-24 10:35:15 +0100868 if (index_key.type->read)
David Howells96b5c8f2012-10-02 19:24:56 +0100869 perm |= KEY_POS_READ;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700870
David Howells16feef42013-09-24 10:35:15 +0100871 if (index_key.type == &key_type_keyring ||
872 index_key.type->update)
David Howells96b5c8f2012-10-02 19:24:56 +0100873 perm |= KEY_POS_WRITE;
Arun Raghavan6b79ccb2008-04-29 01:01:28 -0700874 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700875
876 /* allocate a new key */
David Howells16feef42013-09-24 10:35:15 +0100877 key = key_alloc(index_key.type, index_key.description,
878 cred->fsuid, cred->fsgid, cred, perm, flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700879 if (IS_ERR(key)) {
David Howellse231c2e2008-02-07 00:15:26 -0800880 key_ref = ERR_CAST(key);
David Howellscf7f6012012-09-13 13:06:29 +0100881 goto error_link_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700882 }
883
884 /* instantiate it and link it into the target keyring */
David Howellsb2a4df22013-09-24 10:35:18 +0100885 ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700886 if (ret < 0) {
887 key_put(key);
David Howells664cceb2005-09-28 17:03:15 +0100888 key_ref = ERR_PTR(ret);
David Howellscf7f6012012-09-13 13:06:29 +0100889 goto error_link_end;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700890 }
891
David Howells664cceb2005-09-28 17:03:15 +0100892 key_ref = make_key_ref(key, is_key_possessed(keyring_ref));
893
David Howellscf7f6012012-09-13 13:06:29 +0100894error_link_end:
David Howellsb2a4df22013-09-24 10:35:18 +0100895 __key_link_end(keyring, &index_key, edit);
David Howellscf7f6012012-09-13 13:06:29 +0100896error_free_prep:
David Howells16feef42013-09-24 10:35:15 +0100897 if (index_key.type->preparse)
898 index_key.type->free_preparse(&prep);
David Howellscf7f6012012-09-13 13:06:29 +0100899error_put_type:
David Howells16feef42013-09-24 10:35:15 +0100900 key_type_put(index_key.type);
David Howellscf7f6012012-09-13 13:06:29 +0100901error:
David Howells664cceb2005-09-28 17:03:15 +0100902 return key_ref;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700903
904 found_matching_key:
905 /* we found a matching key, so we're going to try to update it
906 * - we can drop the locks first as we have the key pinned
907 */
David Howellsb2a4df22013-09-24 10:35:18 +0100908 __key_link_end(keyring, &index_key, edit);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700909
David Howellscf7f6012012-09-13 13:06:29 +0100910 key_ref = __key_update(key_ref, &prep);
911 goto error_free_prep;
David Howellsa8b17ed2011-01-20 16:38:27 +0000912}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700913EXPORT_SYMBOL(key_create_or_update);
914
David Howells973c9f42011-01-20 16:38:33 +0000915/**
916 * key_update - Update a key's contents.
917 * @key_ref: The pointer (plus possession flag) to the key.
918 * @payload: The data to be used to update the key.
919 * @plen: The length of @payload.
920 *
921 * Attempt to update the contents of a key with the given payload data. The
922 * caller must be granted Write permission on the key. Negative keys can be
923 * instantiated by this method.
924 *
925 * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key
926 * type does not support updating. The key type may return other errors.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700927 */
David Howells664cceb2005-09-28 17:03:15 +0100928int key_update(key_ref_t key_ref, const void *payload, size_t plen)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700929{
David Howellscf7f6012012-09-13 13:06:29 +0100930 struct key_preparsed_payload prep;
David Howells664cceb2005-09-28 17:03:15 +0100931 struct key *key = key_ref_to_ptr(key_ref);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700932 int ret;
933
934 key_check(key);
935
936 /* the key must be writable */
David Howellsf5895942014-03-14 17:44:49 +0000937 ret = key_permission(key_ref, KEY_NEED_WRITE);
David Howells29db9192005-10-30 15:02:44 -0800938 if (ret < 0)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700939 goto error;
940
941 /* attempt to update it if supported */
942 ret = -EOPNOTSUPP;
David Howellscf7f6012012-09-13 13:06:29 +0100943 if (!key->type->update)
944 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700945
David Howellscf7f6012012-09-13 13:06:29 +0100946 memset(&prep, 0, sizeof(prep));
947 prep.data = payload;
948 prep.datalen = plen;
949 prep.quotalen = key->type->def_datalen;
David Howells7dfa0ca2014-07-18 18:56:34 +0100950 prep.expiry = TIME_T_MAX;
David Howellscf7f6012012-09-13 13:06:29 +0100951 if (key->type->preparse) {
952 ret = key->type->preparse(&prep);
953 if (ret < 0)
954 goto error;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700955 }
956
David Howellscf7f6012012-09-13 13:06:29 +0100957 down_write(&key->sem);
958
959 ret = key->type->update(key, &prep);
960 if (ret == 0)
961 /* updating a negative key instantiates it */
962 clear_bit(KEY_FLAG_NEGATIVE, &key->flags);
963
964 up_write(&key->sem);
965
David Howells4d8c0252014-07-18 18:56:34 +0100966error:
David Howellscf7f6012012-09-13 13:06:29 +0100967 if (key->type->preparse)
968 key->type->free_preparse(&prep);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700969 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +0000970}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700971EXPORT_SYMBOL(key_update);
972
David Howells973c9f42011-01-20 16:38:33 +0000973/**
974 * key_revoke - Revoke a key.
975 * @key: The key to be revoked.
976 *
977 * Mark a key as being revoked and ask the type to free up its resources. The
978 * revocation timeout is set and the key and all its links will be
979 * automatically garbage collected after key_gc_delay amount of time if they
980 * are not manually dealt with first.
Linus Torvalds1da177e2005-04-16 15:20:36 -0700981 */
982void key_revoke(struct key *key)
983{
David Howells5d135442009-09-02 09:14:00 +0100984 struct timespec now;
985 time_t time;
986
Linus Torvalds1da177e2005-04-16 15:20:36 -0700987 key_check(key);
988
David Howells76181c12007-10-16 23:29:46 -0700989 /* make sure no one's trying to change or use the key when we mark it
990 * - we tell lockdep that we might nest because we might be revoking an
991 * authorisation key whilst holding the sem on a key we've just
992 * instantiated
993 */
994 down_write_nested(&key->sem, 1);
995 if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) &&
996 key->type->revoke)
David Howells04c567d2006-06-22 14:47:18 -0700997 key->type->revoke(key);
998
David Howells5d135442009-09-02 09:14:00 +0100999 /* set the death time to no more than the expiry time */
1000 now = current_kernel_time();
1001 time = now.tv_sec;
1002 if (key->revoked_at == 0 || key->revoked_at > time) {
1003 key->revoked_at = time;
David Howellsc08ef802009-09-14 17:26:13 +01001004 key_schedule_gc(key->revoked_at + key_gc_delay);
David Howells5d135442009-09-02 09:14:00 +01001005 }
1006
Linus Torvalds1da177e2005-04-16 15:20:36 -07001007 up_write(&key->sem);
David Howellsa8b17ed2011-01-20 16:38:27 +00001008}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001009EXPORT_SYMBOL(key_revoke);
1010
David Howells973c9f42011-01-20 16:38:33 +00001011/**
David Howellsfd758152012-05-11 10:56:56 +01001012 * key_invalidate - Invalidate a key.
1013 * @key: The key to be invalidated.
1014 *
1015 * Mark a key as being invalidated and have it cleaned up immediately. The key
1016 * is ignored by all searches and other operations from this point.
1017 */
1018void key_invalidate(struct key *key)
1019{
1020 kenter("%d", key_serial(key));
1021
1022 key_check(key);
1023
1024 if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) {
1025 down_write_nested(&key->sem, 1);
1026 if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags))
1027 key_schedule_gc_links();
1028 up_write(&key->sem);
1029 }
1030}
1031EXPORT_SYMBOL(key_invalidate);
1032
1033/**
David Howells6a09d172014-07-18 18:56:34 +01001034 * generic_key_instantiate - Simple instantiation of a key from preparsed data
1035 * @key: The key to be instantiated
1036 * @prep: The preparsed data to load.
1037 *
1038 * Instantiate a key from preparsed data. We assume we can just copy the data
1039 * in directly and clear the old pointers.
1040 *
1041 * This can be pointed to directly by the key type instantiate op pointer.
1042 */
1043int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
1044{
1045 int ret;
1046
1047 pr_devel("==>%s()\n", __func__);
1048
1049 ret = key_payload_reserve(key, prep->quotalen);
1050 if (ret == 0) {
1051 key->type_data.p[0] = prep->type_data[0];
1052 key->type_data.p[1] = prep->type_data[1];
David Howellsfc7c70e2014-07-18 18:56:34 +01001053 rcu_assign_keypointer(key, prep->payload[0]);
1054 key->payload.data2[1] = prep->payload[1];
David Howells6a09d172014-07-18 18:56:34 +01001055 prep->type_data[0] = NULL;
1056 prep->type_data[1] = NULL;
David Howellsfc7c70e2014-07-18 18:56:34 +01001057 prep->payload[0] = NULL;
1058 prep->payload[1] = NULL;
David Howells6a09d172014-07-18 18:56:34 +01001059 }
1060 pr_devel("<==%s() = %d\n", __func__, ret);
1061 return ret;
1062}
1063EXPORT_SYMBOL(generic_key_instantiate);
1064
1065/**
David Howells973c9f42011-01-20 16:38:33 +00001066 * register_key_type - Register a type of key.
1067 * @ktype: The new key type.
1068 *
1069 * Register a new key type.
1070 *
1071 * Returns 0 on success or -EEXIST if a type of this name already exists.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001072 */
1073int register_key_type(struct key_type *ktype)
1074{
1075 struct key_type *p;
1076 int ret;
1077
David Howells7845bc392011-11-16 11:15:54 +00001078 memset(&ktype->lock_class, 0, sizeof(ktype->lock_class));
1079
Linus Torvalds1da177e2005-04-16 15:20:36 -07001080 ret = -EEXIST;
1081 down_write(&key_types_sem);
1082
1083 /* disallow key types with the same name */
1084 list_for_each_entry(p, &key_types_list, link) {
1085 if (strcmp(p->name, ktype->name) == 0)
1086 goto out;
1087 }
1088
1089 /* store the type */
1090 list_add(&ktype->link, &key_types_list);
David Howells1eb1bcf2012-05-11 10:56:56 +01001091
1092 pr_notice("Key type %s registered\n", ktype->name);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001093 ret = 0;
1094
David Howells973c9f42011-01-20 16:38:33 +00001095out:
Linus Torvalds1da177e2005-04-16 15:20:36 -07001096 up_write(&key_types_sem);
1097 return ret;
David Howellsa8b17ed2011-01-20 16:38:27 +00001098}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001099EXPORT_SYMBOL(register_key_type);
1100
David Howells973c9f42011-01-20 16:38:33 +00001101/**
1102 * unregister_key_type - Unregister a type of key.
1103 * @ktype: The key type.
1104 *
1105 * Unregister a key type and mark all the extant keys of this type as dead.
1106 * Those keys of this type are then destroyed to get rid of their payloads and
1107 * they and their links will be garbage collected as soon as possible.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001108 */
1109void unregister_key_type(struct key_type *ktype)
1110{
Linus Torvalds1da177e2005-04-16 15:20:36 -07001111 down_write(&key_types_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001112 list_del_init(&ktype->link);
David Howells0c061b52011-08-22 14:09:36 +01001113 downgrade_write(&key_types_sem);
1114 key_gc_keytype(ktype);
David Howells1eb1bcf2012-05-11 10:56:56 +01001115 pr_notice("Key type %s unregistered\n", ktype->name);
David Howells0c061b52011-08-22 14:09:36 +01001116 up_read(&key_types_sem);
David Howellsa8b17ed2011-01-20 16:38:27 +00001117}
Linus Torvalds1da177e2005-04-16 15:20:36 -07001118EXPORT_SYMBOL(unregister_key_type);
1119
Linus Torvalds1da177e2005-04-16 15:20:36 -07001120/*
David Howells973c9f42011-01-20 16:38:33 +00001121 * Initialise the key management state.
Linus Torvalds1da177e2005-04-16 15:20:36 -07001122 */
1123void __init key_init(void)
1124{
1125 /* allocate a slab in which we can store keys */
1126 key_jar = kmem_cache_create("key_jar", sizeof(struct key),
Paul Mundt20c2df82007-07-20 10:11:58 +09001127 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001128
1129 /* add the special key types */
1130 list_add_tail(&key_type_keyring.link, &key_types_list);
1131 list_add_tail(&key_type_dead.link, &key_types_list);
1132 list_add_tail(&key_type_user.link, &key_types_list);
Jeff Layton9f6ed2c2012-01-17 16:09:11 -05001133 list_add_tail(&key_type_logon.link, &key_types_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -07001134
1135 /* record the root user tracking */
1136 rb_link_node(&root_key_user.node,
1137 NULL,
1138 &key_user_tree.rb_node);
1139
1140 rb_insert_color(&root_key_user.node,
1141 &key_user_tree);
David Howellsa8b17ed2011-01-20 16:38:27 +00001142}