Commit | Line | Data |
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76181c13 | 1 | /* Basic authentication token and access key management |
1da177e4 | 2 | * |
69664cf1 | 3 | * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
4 | * 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> | |
a7807a32 | 14 | #include <linux/poison.h> |
1da177e4 LT |
15 | #include <linux/sched.h> |
16 | #include <linux/slab.h> | |
29db9190 | 17 | #include <linux/security.h> |
1da177e4 | 18 | #include <linux/workqueue.h> |
e51f6d34 | 19 | #include <linux/random.h> |
1da177e4 LT |
20 | #include <linux/err.h> |
21 | #include "internal.h" | |
22 | ||
8bc16dea | 23 | struct kmem_cache *key_jar; |
1da177e4 LT |
24 | struct rb_root key_serial_tree; /* tree of keys indexed by serial */ |
25 | DEFINE_SPINLOCK(key_serial_lock); | |
26 | ||
27 | struct rb_root key_user_tree; /* tree of quota records indexed by UID */ | |
28 | DEFINE_SPINLOCK(key_user_lock); | |
29 | ||
738c5d19 SD |
30 | unsigned int key_quota_root_maxkeys = 1000000; /* root's key count quota */ |
31 | unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */ | |
0b77f5bf DH |
32 | unsigned int key_quota_maxkeys = 200; /* general key count quota */ |
33 | unsigned int key_quota_maxbytes = 20000; /* general key space quota */ | |
34 | ||
1da177e4 LT |
35 | static LIST_HEAD(key_types_list); |
36 | static DECLARE_RWSEM(key_types_sem); | |
37 | ||
973c9f4f | 38 | /* We serialise key instantiation and link */ |
76181c13 | 39 | DEFINE_MUTEX(key_construction_mutex); |
1da177e4 | 40 | |
1da177e4 LT |
41 | #ifdef KEY_DEBUGGING |
42 | void __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 | ||
1da177e4 | 50 | /* |
973c9f4f DH |
51 | * Get the key quota record for a user, allocating a new record if one doesn't |
52 | * already exist. | |
1da177e4 | 53 | */ |
9a56c2db | 54 | struct key_user *key_user_lookup(kuid_t uid) |
1da177e4 LT |
55 | { |
56 | struct key_user *candidate = NULL, *user; | |
8f674565 | 57 | struct rb_node *parent, **p; |
1da177e4 | 58 | |
973c9f4f | 59 | try_again: |
8f674565 | 60 | parent = NULL; |
1da177e4 LT |
61 | 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 | ||
9a56c2db | 69 | if (uid_lt(uid, user->uid)) |
1da177e4 | 70 | p = &(*p)->rb_left; |
9a56c2db | 71 | else if (uid_gt(uid, user->uid)) |
1d1e9756 | 72 | p = &(*p)->rb_right; |
1da177e4 LT |
73 | 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 */ | |
ddb99e11 | 96 | refcount_set(&candidate->usage, 1); |
1da177e4 LT |
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); | |
76181c13 | 103 | mutex_init(&candidate->cons_lock); |
1da177e4 LT |
104 | |
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 */ | |
973c9f4f | 112 | found: |
ddb99e11 | 113 | refcount_inc(&user->usage); |
1da177e4 | 114 | spin_unlock(&key_user_lock); |
a7f988ba | 115 | kfree(candidate); |
973c9f4f | 116 | out: |
1da177e4 | 117 | return user; |
a8b17ed0 | 118 | } |
1da177e4 | 119 | |
1da177e4 | 120 | /* |
973c9f4f | 121 | * Dispose of a user structure |
1da177e4 LT |
122 | */ |
123 | void key_user_put(struct key_user *user) | |
124 | { | |
ddb99e11 | 125 | if (refcount_dec_and_lock(&user->usage, &key_user_lock)) { |
1da177e4 LT |
126 | rb_erase(&user->node, &key_user_tree); |
127 | spin_unlock(&key_user_lock); | |
128 | ||
129 | kfree(user); | |
130 | } | |
a8b17ed0 | 131 | } |
1da177e4 | 132 | |
1da177e4 | 133 | /* |
973c9f4f DH |
134 | * Allocate a serial number for a key. These are assigned randomly to avoid |
135 | * security issues through covert channel problems. | |
1da177e4 LT |
136 | */ |
137 | static inline void key_alloc_serial(struct key *key) | |
138 | { | |
139 | struct rb_node *parent, **p; | |
140 | struct key *xkey; | |
141 | ||
e51f6d34 | 142 | /* propose a random serial number and look for a hole for it in the |
1da177e4 | 143 | * serial number tree */ |
e51f6d34 ML |
144 | 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); | |
1da177e4 | 151 | |
9ad0830f | 152 | attempt_insertion: |
1da177e4 LT |
153 | 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 | } | |
9ad0830f DH |
167 | |
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; | |
1da177e4 LT |
174 | |
175 | /* we found a key with the proposed serial number - walk the tree from | |
176 | * that point looking for the next unused serial number */ | |
e51f6d34 | 177 | serial_exists: |
1da177e4 | 178 | for (;;) { |
e51f6d34 | 179 | key->serial++; |
9ad0830f DH |
180 | if (key->serial < 3) { |
181 | key->serial = 3; | |
182 | goto attempt_insertion; | |
183 | } | |
1da177e4 LT |
184 | |
185 | parent = rb_next(parent); | |
186 | if (!parent) | |
9ad0830f | 187 | goto attempt_insertion; |
1da177e4 LT |
188 | |
189 | xkey = rb_entry(parent, struct key, serial_node); | |
190 | if (key->serial < xkey->serial) | |
9ad0830f | 191 | goto attempt_insertion; |
1da177e4 | 192 | } |
a8b17ed0 | 193 | } |
1da177e4 | 194 | |
973c9f4f DH |
195 | /** |
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. | |
2b6aa412 | 204 | * @restrict_link: Optional link restriction for new keyrings. |
973c9f4f DH |
205 | * |
206 | * Allocate a key of the specified type with the attributes given. The key is | |
207 | * returned in an uninstantiated state and the caller needs to instantiate the | |
208 | * key before returning. | |
209 | * | |
2b6aa412 MM |
210 | * The restrict_link structure (if not NULL) will be freed when the |
211 | * keyring is destroyed, so it must be dynamically allocated. | |
212 | * | |
973c9f4f DH |
213 | * The user's key count quota is updated to reflect the creation of the key and |
214 | * the user's key data quota has the default for the key type reserved. The | |
215 | * instantiation function should amend this as necessary. If insufficient | |
216 | * quota is available, -EDQUOT will be returned. | |
217 | * | |
218 | * The LSM security modules can prevent a key being created, in which case | |
219 | * -EACCES will be returned. | |
220 | * | |
221 | * Returns a pointer to the new key if successful and an error code otherwise. | |
222 | * | |
223 | * Note that the caller needs to ensure the key type isn't uninstantiated. | |
224 | * Internally this can be done by locking key_types_sem. Externally, this can | |
225 | * be done by either never unregistering the key type, or making sure | |
226 | * key_alloc() calls don't race with module unloading. | |
1da177e4 LT |
227 | */ |
228 | struct key *key_alloc(struct key_type *type, const char *desc, | |
9a56c2db | 229 | kuid_t uid, kgid_t gid, const struct cred *cred, |
5ac7eace | 230 | key_perm_t perm, unsigned long flags, |
2b6aa412 | 231 | struct key_restriction *restrict_link) |
1da177e4 LT |
232 | { |
233 | struct key_user *user = NULL; | |
234 | struct key *key; | |
235 | size_t desclen, quotalen; | |
29db9190 | 236 | int ret; |
1da177e4 LT |
237 | |
238 | key = ERR_PTR(-EINVAL); | |
239 | if (!desc || !*desc) | |
240 | goto error; | |
241 | ||
b9fffa38 DH |
242 | if (type->vet_description) { |
243 | ret = type->vet_description(desc); | |
244 | if (ret < 0) { | |
245 | key = ERR_PTR(ret); | |
246 | goto error; | |
247 | } | |
248 | } | |
249 | ||
16feef43 DH |
250 | desclen = strlen(desc); |
251 | quotalen = desclen + 1 + type->def_datalen; | |
1da177e4 LT |
252 | |
253 | /* get hold of the key tracking for this user */ | |
9a56c2db | 254 | user = key_user_lookup(uid); |
1da177e4 LT |
255 | if (!user) |
256 | goto no_memory_1; | |
257 | ||
258 | /* check that the user's quota permits allocation of another key and | |
259 | * its description */ | |
7e047ef5 | 260 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
9a56c2db | 261 | unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf | 262 | key_quota_root_maxkeys : key_quota_maxkeys; |
9a56c2db | 263 | unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
264 | key_quota_root_maxbytes : key_quota_maxbytes; |
265 | ||
1da177e4 | 266 | spin_lock(&user->lock); |
7e047ef5 | 267 | if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { |
fe303ba7 EB |
268 | if (user->qnkeys + 1 > maxkeys || |
269 | user->qnbytes + quotalen > maxbytes || | |
0b77f5bf | 270 | user->qnbytes + quotalen < user->qnbytes) |
7e047ef5 DH |
271 | goto no_quota; |
272 | } | |
1da177e4 LT |
273 | |
274 | user->qnkeys++; | |
275 | user->qnbytes += quotalen; | |
276 | spin_unlock(&user->lock); | |
277 | } | |
278 | ||
279 | /* allocate and initialise the key and its description */ | |
2480f57f | 280 | key = kmem_cache_zalloc(key_jar, GFP_KERNEL); |
1da177e4 LT |
281 | if (!key) |
282 | goto no_memory_2; | |
283 | ||
5057975a DC |
284 | key->index_key.desc_len = desclen; |
285 | key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); | |
27720e75 | 286 | if (!key->index_key.description) |
5057975a | 287 | goto no_memory_3; |
1da177e4 | 288 | |
fff29291 | 289 | refcount_set(&key->usage, 1); |
1da177e4 | 290 | init_rwsem(&key->sem); |
7845bc39 | 291 | lockdep_set_class(&key->sem, &type->lock_class); |
16feef43 | 292 | key->index_key.type = type; |
1da177e4 LT |
293 | key->user = user; |
294 | key->quotalen = quotalen; | |
295 | key->datalen = type->def_datalen; | |
296 | key->uid = uid; | |
297 | key->gid = gid; | |
298 | key->perm = perm; | |
5ac7eace | 299 | key->restrict_link = restrict_link; |
1da177e4 | 300 | |
7e047ef5 | 301 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
76d8aeab | 302 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
5d2787cf DH |
303 | if (flags & KEY_ALLOC_BUILT_IN) |
304 | key->flags |= 1 << KEY_FLAG_BUILTIN; | |
237bbd29 EB |
305 | if (flags & KEY_ALLOC_UID_KEYRING) |
306 | key->flags |= 1 << KEY_FLAG_UID_KEYRING; | |
1da177e4 | 307 | |
1da177e4 LT |
308 | #ifdef KEY_DEBUGGING |
309 | key->magic = KEY_DEBUG_MAGIC; | |
310 | #endif | |
311 | ||
29db9190 | 312 | /* let the security module know about the key */ |
d84f4f99 | 313 | ret = security_key_alloc(key, cred, flags); |
29db9190 DH |
314 | if (ret < 0) |
315 | goto security_error; | |
316 | ||
1da177e4 LT |
317 | /* publish the key by giving it a serial number */ |
318 | atomic_inc(&user->nkeys); | |
319 | key_alloc_serial(key); | |
320 | ||
29db9190 | 321 | error: |
1da177e4 LT |
322 | return key; |
323 | ||
29db9190 DH |
324 | security_error: |
325 | kfree(key->description); | |
1da177e4 | 326 | kmem_cache_free(key_jar, key); |
7e047ef5 | 327 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
1da177e4 LT |
328 | spin_lock(&user->lock); |
329 | user->qnkeys--; | |
330 | user->qnbytes -= quotalen; | |
331 | spin_unlock(&user->lock); | |
332 | } | |
333 | key_user_put(user); | |
29db9190 DH |
334 | key = ERR_PTR(ret); |
335 | goto error; | |
336 | ||
337 | no_memory_3: | |
338 | kmem_cache_free(key_jar, key); | |
339 | no_memory_2: | |
7e047ef5 | 340 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
29db9190 DH |
341 | spin_lock(&user->lock); |
342 | user->qnkeys--; | |
343 | user->qnbytes -= quotalen; | |
344 | spin_unlock(&user->lock); | |
345 | } | |
346 | key_user_put(user); | |
347 | no_memory_1: | |
1da177e4 LT |
348 | key = ERR_PTR(-ENOMEM); |
349 | goto error; | |
350 | ||
29db9190 | 351 | no_quota: |
1da177e4 LT |
352 | spin_unlock(&user->lock); |
353 | key_user_put(user); | |
354 | key = ERR_PTR(-EDQUOT); | |
355 | goto error; | |
a8b17ed0 | 356 | } |
1da177e4 LT |
357 | EXPORT_SYMBOL(key_alloc); |
358 | ||
973c9f4f DH |
359 | /** |
360 | * key_payload_reserve - Adjust data quota reservation for the key's payload | |
361 | * @key: The key to make the reservation for. | |
362 | * @datalen: The amount of data payload the caller now wants. | |
363 | * | |
364 | * Adjust the amount of the owning user's key data quota that a key reserves. | |
365 | * If the amount is increased, then -EDQUOT may be returned if there isn't | |
366 | * enough free quota available. | |
367 | * | |
368 | * If successful, 0 is returned. | |
1da177e4 LT |
369 | */ |
370 | int key_payload_reserve(struct key *key, size_t datalen) | |
371 | { | |
c5b60b5e | 372 | int delta = (int)datalen - key->datalen; |
1da177e4 LT |
373 | int ret = 0; |
374 | ||
375 | key_check(key); | |
376 | ||
377 | /* contemplate the quota adjustment */ | |
76d8aeab | 378 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
9a56c2db | 379 | unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
380 | key_quota_root_maxbytes : key_quota_maxbytes; |
381 | ||
1da177e4 LT |
382 | spin_lock(&key->user->lock); |
383 | ||
384 | if (delta > 0 && | |
0b77f5bf DH |
385 | (key->user->qnbytes + delta >= maxbytes || |
386 | key->user->qnbytes + delta < key->user->qnbytes)) { | |
1da177e4 LT |
387 | ret = -EDQUOT; |
388 | } | |
389 | else { | |
390 | key->user->qnbytes += delta; | |
391 | key->quotalen += delta; | |
392 | } | |
393 | spin_unlock(&key->user->lock); | |
394 | } | |
395 | ||
396 | /* change the recorded data length if that didn't generate an error */ | |
397 | if (ret == 0) | |
398 | key->datalen = datalen; | |
399 | ||
400 | return ret; | |
a8b17ed0 | 401 | } |
1da177e4 LT |
402 | EXPORT_SYMBOL(key_payload_reserve); |
403 | ||
363b02da DH |
404 | /* |
405 | * Change the key state to being instantiated. | |
406 | */ | |
407 | static void mark_key_instantiated(struct key *key, int reject_error) | |
408 | { | |
409 | /* Commit the payload before setting the state; barrier versus | |
410 | * key_read_state(). | |
411 | */ | |
412 | smp_store_release(&key->state, | |
413 | (reject_error < 0) ? reject_error : KEY_IS_POSITIVE); | |
414 | } | |
415 | ||
1da177e4 | 416 | /* |
973c9f4f DH |
417 | * Instantiate a key and link it into the target keyring atomically. Must be |
418 | * called with the target keyring's semaphore writelocked. The target key's | |
419 | * semaphore need not be locked as instantiation is serialised by | |
420 | * key_construction_mutex. | |
1da177e4 LT |
421 | */ |
422 | static int __key_instantiate_and_link(struct key *key, | |
cf7f601c | 423 | struct key_preparsed_payload *prep, |
3e30148c | 424 | struct key *keyring, |
f70e2e06 | 425 | struct key *authkey, |
b2a4df20 | 426 | struct assoc_array_edit **_edit) |
1da177e4 LT |
427 | { |
428 | int ret, awaken; | |
429 | ||
430 | key_check(key); | |
431 | key_check(keyring); | |
432 | ||
433 | awaken = 0; | |
434 | ret = -EBUSY; | |
435 | ||
76181c13 | 436 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
437 | |
438 | /* can't instantiate twice */ | |
363b02da | 439 | if (key->state == KEY_IS_UNINSTANTIATED) { |
1da177e4 | 440 | /* instantiate the key */ |
cf7f601c | 441 | ret = key->type->instantiate(key, prep); |
1da177e4 LT |
442 | |
443 | if (ret == 0) { | |
444 | /* mark the key as being instantiated */ | |
1da177e4 | 445 | atomic_inc(&key->user->nikeys); |
363b02da | 446 | mark_key_instantiated(key, 0); |
1da177e4 | 447 | |
76d8aeab | 448 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 449 | awaken = 1; |
1da177e4 LT |
450 | |
451 | /* and link it into the destination keyring */ | |
d3600bcf | 452 | if (keyring) { |
eee04502 DH |
453 | if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) |
454 | set_bit(KEY_FLAG_KEEP, &key->flags); | |
d3600bcf | 455 | |
b2a4df20 | 456 | __key_link(key, _edit); |
d3600bcf | 457 | } |
3e30148c DH |
458 | |
459 | /* disable the authorisation key */ | |
d84f4f99 DH |
460 | if (authkey) |
461 | key_revoke(authkey); | |
7dfa0ca6 DH |
462 | |
463 | if (prep->expiry != TIME_T_MAX) { | |
464 | key->expiry = prep->expiry; | |
465 | key_schedule_gc(prep->expiry + key_gc_delay); | |
466 | } | |
1da177e4 LT |
467 | } |
468 | } | |
469 | ||
76181c13 | 470 | mutex_unlock(&key_construction_mutex); |
1da177e4 LT |
471 | |
472 | /* wake up anyone waiting for a key to be constructed */ | |
473 | if (awaken) | |
76181c13 | 474 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 LT |
475 | |
476 | return ret; | |
a8b17ed0 | 477 | } |
1da177e4 | 478 | |
973c9f4f DH |
479 | /** |
480 | * key_instantiate_and_link - Instantiate a key and link it into the keyring. | |
481 | * @key: The key to instantiate. | |
482 | * @data: The data to use to instantiate the keyring. | |
483 | * @datalen: The length of @data. | |
484 | * @keyring: Keyring to create a link in on success (or NULL). | |
485 | * @authkey: The authorisation token permitting instantiation. | |
486 | * | |
487 | * Instantiate a key that's in the uninstantiated state using the provided data | |
488 | * and, if successful, link it in to the destination keyring if one is | |
489 | * supplied. | |
490 | * | |
491 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
492 | * waiting for the key is woken up. If the key was already instantiated, | |
493 | * -EBUSY will be returned. | |
1da177e4 LT |
494 | */ |
495 | int key_instantiate_and_link(struct key *key, | |
496 | const void *data, | |
497 | size_t datalen, | |
3e30148c | 498 | struct key *keyring, |
d84f4f99 | 499 | struct key *authkey) |
1da177e4 | 500 | { |
cf7f601c | 501 | struct key_preparsed_payload prep; |
b2a4df20 | 502 | struct assoc_array_edit *edit; |
1da177e4 LT |
503 | int ret; |
504 | ||
cf7f601c DH |
505 | memset(&prep, 0, sizeof(prep)); |
506 | prep.data = data; | |
507 | prep.datalen = datalen; | |
508 | prep.quotalen = key->type->def_datalen; | |
7dfa0ca6 | 509 | prep.expiry = TIME_T_MAX; |
cf7f601c DH |
510 | if (key->type->preparse) { |
511 | ret = key->type->preparse(&prep); | |
512 | if (ret < 0) | |
513 | goto error; | |
514 | } | |
515 | ||
f70e2e06 | 516 | if (keyring) { |
4a420896 MM |
517 | ret = __key_link_begin(keyring, &key->index_key, &edit); |
518 | if (ret < 0) | |
519 | goto error; | |
520 | ||
2b6aa412 MM |
521 | if (keyring->restrict_link && keyring->restrict_link->check) { |
522 | struct key_restriction *keyres = keyring->restrict_link; | |
523 | ||
524 | ret = keyres->check(keyring, key->type, &prep.payload, | |
525 | keyres->key); | |
5ac7eace | 526 | if (ret < 0) |
4a420896 | 527 | goto error_link_end; |
5ac7eace | 528 | } |
f70e2e06 | 529 | } |
1da177e4 | 530 | |
b2a4df20 | 531 | ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit); |
1da177e4 | 532 | |
4a420896 | 533 | error_link_end: |
1da177e4 | 534 | if (keyring) |
b2a4df20 | 535 | __key_link_end(keyring, &key->index_key, edit); |
1da177e4 | 536 | |
4d8c0250 | 537 | error: |
cf7f601c DH |
538 | if (key->type->preparse) |
539 | key->type->free_preparse(&prep); | |
1da177e4 | 540 | return ret; |
a8b17ed0 | 541 | } |
1da177e4 LT |
542 | |
543 | EXPORT_SYMBOL(key_instantiate_and_link); | |
544 | ||
973c9f4f | 545 | /** |
fdd1b945 | 546 | * key_reject_and_link - Negatively instantiate a key and link it into the keyring. |
973c9f4f DH |
547 | * @key: The key to instantiate. |
548 | * @timeout: The timeout on the negative key. | |
fdd1b945 | 549 | * @error: The error to return when the key is hit. |
973c9f4f DH |
550 | * @keyring: Keyring to create a link in on success (or NULL). |
551 | * @authkey: The authorisation token permitting instantiation. | |
552 | * | |
553 | * Negatively instantiate a key that's in the uninstantiated state and, if | |
fdd1b945 DH |
554 | * successful, set its timeout and stored error and link it in to the |
555 | * destination keyring if one is supplied. The key and any links to the key | |
556 | * will be automatically garbage collected after the timeout expires. | |
973c9f4f DH |
557 | * |
558 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
fdd1b945 DH |
559 | * them to return the stored error code (typically ENOKEY) until the negative |
560 | * key expires. | |
973c9f4f DH |
561 | * |
562 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
563 | * waiting for the key is woken up. If the key was already instantiated, | |
564 | * -EBUSY will be returned. | |
1da177e4 | 565 | */ |
fdd1b945 | 566 | int key_reject_and_link(struct key *key, |
1da177e4 | 567 | unsigned timeout, |
fdd1b945 | 568 | unsigned error, |
3e30148c | 569 | struct key *keyring, |
d84f4f99 | 570 | struct key *authkey) |
1da177e4 | 571 | { |
b2a4df20 | 572 | struct assoc_array_edit *edit; |
1da177e4 | 573 | struct timespec now; |
f70e2e06 | 574 | int ret, awaken, link_ret = 0; |
1da177e4 LT |
575 | |
576 | key_check(key); | |
577 | key_check(keyring); | |
578 | ||
579 | awaken = 0; | |
580 | ret = -EBUSY; | |
581 | ||
5ac7eace DH |
582 | if (keyring) { |
583 | if (keyring->restrict_link) | |
584 | return -EPERM; | |
585 | ||
b2a4df20 | 586 | link_ret = __key_link_begin(keyring, &key->index_key, &edit); |
5ac7eace | 587 | } |
1da177e4 | 588 | |
76181c13 | 589 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
590 | |
591 | /* can't instantiate twice */ | |
363b02da | 592 | if (key->state == KEY_IS_UNINSTANTIATED) { |
1da177e4 | 593 | /* mark the key as being negatively instantiated */ |
1da177e4 | 594 | atomic_inc(&key->user->nikeys); |
363b02da | 595 | mark_key_instantiated(key, -error); |
1da177e4 LT |
596 | now = current_kernel_time(); |
597 | key->expiry = now.tv_sec + timeout; | |
c08ef808 | 598 | key_schedule_gc(key->expiry + key_gc_delay); |
1da177e4 | 599 | |
76d8aeab | 600 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 601 | awaken = 1; |
1da177e4 | 602 | |
1da177e4 LT |
603 | ret = 0; |
604 | ||
605 | /* and link it into the destination keyring */ | |
f70e2e06 | 606 | if (keyring && link_ret == 0) |
b2a4df20 | 607 | __key_link(key, &edit); |
3e30148c DH |
608 | |
609 | /* disable the authorisation key */ | |
d84f4f99 DH |
610 | if (authkey) |
611 | key_revoke(authkey); | |
1da177e4 LT |
612 | } |
613 | ||
76181c13 | 614 | mutex_unlock(&key_construction_mutex); |
1da177e4 | 615 | |
38327424 | 616 | if (keyring && link_ret == 0) |
b2a4df20 | 617 | __key_link_end(keyring, &key->index_key, edit); |
1da177e4 LT |
618 | |
619 | /* wake up anyone waiting for a key to be constructed */ | |
620 | if (awaken) | |
76181c13 | 621 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 | 622 | |
f70e2e06 | 623 | return ret == 0 ? link_ret : ret; |
a8b17ed0 | 624 | } |
fdd1b945 | 625 | EXPORT_SYMBOL(key_reject_and_link); |
1da177e4 | 626 | |
973c9f4f DH |
627 | /** |
628 | * key_put - Discard a reference to a key. | |
629 | * @key: The key to discard a reference from. | |
630 | * | |
631 | * Discard a reference to a key, and when all the references are gone, we | |
632 | * schedule the cleanup task to come and pull it out of the tree in process | |
633 | * context at some later time. | |
1da177e4 LT |
634 | */ |
635 | void key_put(struct key *key) | |
636 | { | |
637 | if (key) { | |
638 | key_check(key); | |
639 | ||
fff29291 | 640 | if (refcount_dec_and_test(&key->usage)) |
3b07e9ca | 641 | schedule_work(&key_gc_work); |
1da177e4 | 642 | } |
a8b17ed0 | 643 | } |
1da177e4 LT |
644 | EXPORT_SYMBOL(key_put); |
645 | ||
1da177e4 | 646 | /* |
973c9f4f | 647 | * Find a key by its serial number. |
1da177e4 LT |
648 | */ |
649 | struct key *key_lookup(key_serial_t id) | |
650 | { | |
651 | struct rb_node *n; | |
652 | struct key *key; | |
653 | ||
654 | spin_lock(&key_serial_lock); | |
655 | ||
656 | /* search the tree for the specified key */ | |
657 | n = key_serial_tree.rb_node; | |
658 | while (n) { | |
659 | key = rb_entry(n, struct key, serial_node); | |
660 | ||
661 | if (id < key->serial) | |
662 | n = n->rb_left; | |
663 | else if (id > key->serial) | |
664 | n = n->rb_right; | |
665 | else | |
666 | goto found; | |
667 | } | |
668 | ||
973c9f4f | 669 | not_found: |
1da177e4 LT |
670 | key = ERR_PTR(-ENOKEY); |
671 | goto error; | |
672 | ||
973c9f4f | 673 | found: |
92347cfd MR |
674 | /* A key is allowed to be looked up only if someone still owns a |
675 | * reference to it - otherwise it's awaiting the gc. | |
1da177e4 | 676 | */ |
92347cfd MR |
677 | if (!refcount_inc_not_zero(&key->usage)) |
678 | goto not_found; | |
1da177e4 | 679 | |
973c9f4f | 680 | error: |
1da177e4 LT |
681 | spin_unlock(&key_serial_lock); |
682 | return key; | |
a8b17ed0 | 683 | } |
1da177e4 | 684 | |
1da177e4 | 685 | /* |
973c9f4f DH |
686 | * Find and lock the specified key type against removal. |
687 | * | |
688 | * We return with the sem read-locked if successful. If the type wasn't | |
689 | * available -ENOKEY is returned instead. | |
1da177e4 LT |
690 | */ |
691 | struct key_type *key_type_lookup(const char *type) | |
692 | { | |
693 | struct key_type *ktype; | |
694 | ||
695 | down_read(&key_types_sem); | |
696 | ||
697 | /* look up the key type to see if it's one of the registered kernel | |
698 | * types */ | |
699 | list_for_each_entry(ktype, &key_types_list, link) { | |
700 | if (strcmp(ktype->name, type) == 0) | |
701 | goto found_kernel_type; | |
702 | } | |
703 | ||
704 | up_read(&key_types_sem); | |
705 | ktype = ERR_PTR(-ENOKEY); | |
706 | ||
973c9f4f | 707 | found_kernel_type: |
1da177e4 | 708 | return ktype; |
a8b17ed0 | 709 | } |
1da177e4 | 710 | |
59e6b9c1 BS |
711 | void key_set_timeout(struct key *key, unsigned timeout) |
712 | { | |
713 | struct timespec now; | |
714 | time_t expiry = 0; | |
715 | ||
716 | /* make the changes with the locks held to prevent races */ | |
717 | down_write(&key->sem); | |
718 | ||
719 | if (timeout > 0) { | |
720 | now = current_kernel_time(); | |
721 | expiry = now.tv_sec + timeout; | |
722 | } | |
723 | ||
724 | key->expiry = expiry; | |
725 | key_schedule_gc(key->expiry + key_gc_delay); | |
726 | ||
727 | up_write(&key->sem); | |
728 | } | |
729 | EXPORT_SYMBOL_GPL(key_set_timeout); | |
730 | ||
1da177e4 | 731 | /* |
973c9f4f | 732 | * Unlock a key type locked by key_type_lookup(). |
1da177e4 LT |
733 | */ |
734 | void key_type_put(struct key_type *ktype) | |
735 | { | |
736 | up_read(&key_types_sem); | |
a8b17ed0 | 737 | } |
1da177e4 | 738 | |
1da177e4 | 739 | /* |
973c9f4f DH |
740 | * Attempt to update an existing key. |
741 | * | |
742 | * The key is given to us with an incremented refcount that we need to discard | |
743 | * if we get an error. | |
1da177e4 | 744 | */ |
664cceb0 | 745 | static inline key_ref_t __key_update(key_ref_t key_ref, |
cf7f601c | 746 | struct key_preparsed_payload *prep) |
1da177e4 | 747 | { |
664cceb0 | 748 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
749 | int ret; |
750 | ||
751 | /* need write permission on the key to update it */ | |
f5895943 | 752 | ret = key_permission(key_ref, KEY_NEED_WRITE); |
29db9190 | 753 | if (ret < 0) |
1da177e4 LT |
754 | goto error; |
755 | ||
756 | ret = -EEXIST; | |
757 | if (!key->type->update) | |
758 | goto error; | |
759 | ||
760 | down_write(&key->sem); | |
761 | ||
cf7f601c | 762 | ret = key->type->update(key, prep); |
76d8aeab | 763 | if (ret == 0) |
363b02da DH |
764 | /* Updating a negative key positively instantiates it */ |
765 | mark_key_instantiated(key, 0); | |
1da177e4 LT |
766 | |
767 | up_write(&key->sem); | |
768 | ||
769 | if (ret < 0) | |
770 | goto error; | |
664cceb0 DH |
771 | out: |
772 | return key_ref; | |
1da177e4 | 773 | |
664cceb0 | 774 | error: |
1da177e4 | 775 | key_put(key); |
664cceb0 | 776 | key_ref = ERR_PTR(ret); |
1da177e4 | 777 | goto out; |
a8b17ed0 | 778 | } |
1da177e4 | 779 | |
973c9f4f DH |
780 | /** |
781 | * key_create_or_update - Update or create and instantiate a key. | |
782 | * @keyring_ref: A pointer to the destination keyring with possession flag. | |
783 | * @type: The type of key. | |
784 | * @description: The searchable description for the key. | |
785 | * @payload: The data to use to instantiate or update the key. | |
786 | * @plen: The length of @payload. | |
787 | * @perm: The permissions mask for a new key. | |
788 | * @flags: The quota flags for a new key. | |
789 | * | |
790 | * Search the destination keyring for a key of the same description and if one | |
791 | * is found, update it, otherwise create and instantiate a new one and create a | |
792 | * link to it from that keyring. | |
793 | * | |
794 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be | |
795 | * concocted. | |
796 | * | |
797 | * Returns a pointer to the new key if successful, -ENODEV if the key type | |
798 | * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the | |
799 | * caller isn't permitted to modify the keyring or the LSM did not permit | |
800 | * creation of the key. | |
801 | * | |
802 | * On success, the possession flag from the keyring ref will be tacked on to | |
803 | * the key ref before it is returned. | |
1da177e4 | 804 | */ |
664cceb0 DH |
805 | key_ref_t key_create_or_update(key_ref_t keyring_ref, |
806 | const char *type, | |
807 | const char *description, | |
808 | const void *payload, | |
809 | size_t plen, | |
6b79ccb5 | 810 | key_perm_t perm, |
7e047ef5 | 811 | unsigned long flags) |
1da177e4 | 812 | { |
16feef43 DH |
813 | struct keyring_index_key index_key = { |
814 | .description = description, | |
815 | }; | |
cf7f601c | 816 | struct key_preparsed_payload prep; |
b2a4df20 | 817 | struct assoc_array_edit *edit; |
d84f4f99 | 818 | const struct cred *cred = current_cred(); |
664cceb0 | 819 | struct key *keyring, *key = NULL; |
664cceb0 | 820 | key_ref_t key_ref; |
1da177e4 | 821 | int ret; |
2b6aa412 | 822 | struct key_restriction *restrict_link = NULL; |
1da177e4 | 823 | |
1da177e4 LT |
824 | /* look up the key type to see if it's one of the registered kernel |
825 | * types */ | |
16feef43 DH |
826 | index_key.type = key_type_lookup(type); |
827 | if (IS_ERR(index_key.type)) { | |
664cceb0 | 828 | key_ref = ERR_PTR(-ENODEV); |
1da177e4 LT |
829 | goto error; |
830 | } | |
831 | ||
664cceb0 | 832 | key_ref = ERR_PTR(-EINVAL); |
c06cfb08 | 833 | if (!index_key.type->instantiate || |
16feef43 | 834 | (!index_key.description && !index_key.type->preparse)) |
cf7f601c | 835 | goto error_put_type; |
1da177e4 | 836 | |
664cceb0 DH |
837 | keyring = key_ref_to_ptr(keyring_ref); |
838 | ||
839 | key_check(keyring); | |
840 | ||
5ac7eace DH |
841 | key_ref = ERR_PTR(-EPERM); |
842 | if (!(flags & KEY_ALLOC_BYPASS_RESTRICTION)) | |
843 | restrict_link = keyring->restrict_link; | |
844 | ||
c3a9d654 DH |
845 | key_ref = ERR_PTR(-ENOTDIR); |
846 | if (keyring->type != &key_type_keyring) | |
cf7f601c DH |
847 | goto error_put_type; |
848 | ||
849 | memset(&prep, 0, sizeof(prep)); | |
850 | prep.data = payload; | |
851 | prep.datalen = plen; | |
16feef43 | 852 | prep.quotalen = index_key.type->def_datalen; |
7dfa0ca6 | 853 | prep.expiry = TIME_T_MAX; |
16feef43 DH |
854 | if (index_key.type->preparse) { |
855 | ret = index_key.type->preparse(&prep); | |
cf7f601c DH |
856 | if (ret < 0) { |
857 | key_ref = ERR_PTR(ret); | |
4d8c0250 | 858 | goto error_free_prep; |
cf7f601c | 859 | } |
16feef43 DH |
860 | if (!index_key.description) |
861 | index_key.description = prep.description; | |
cf7f601c | 862 | key_ref = ERR_PTR(-EINVAL); |
16feef43 | 863 | if (!index_key.description) |
cf7f601c DH |
864 | goto error_free_prep; |
865 | } | |
16feef43 | 866 | index_key.desc_len = strlen(index_key.description); |
c3a9d654 | 867 | |
4a420896 MM |
868 | ret = __key_link_begin(keyring, &index_key, &edit); |
869 | if (ret < 0) { | |
870 | key_ref = ERR_PTR(ret); | |
871 | goto error_free_prep; | |
872 | } | |
873 | ||
2b6aa412 MM |
874 | if (restrict_link && restrict_link->check) { |
875 | ret = restrict_link->check(keyring, index_key.type, | |
876 | &prep.payload, restrict_link->key); | |
5ac7eace DH |
877 | if (ret < 0) { |
878 | key_ref = ERR_PTR(ret); | |
4a420896 | 879 | goto error_link_end; |
5ac7eace DH |
880 | } |
881 | } | |
008643b8 | 882 | |
664cceb0 DH |
883 | /* if we're going to allocate a new key, we're going to have |
884 | * to modify the keyring */ | |
f5895943 | 885 | ret = key_permission(keyring_ref, KEY_NEED_WRITE); |
29db9190 DH |
886 | if (ret < 0) { |
887 | key_ref = ERR_PTR(ret); | |
cf7f601c | 888 | goto error_link_end; |
29db9190 | 889 | } |
664cceb0 | 890 | |
1d9b7d97 DH |
891 | /* if it's possible to update this type of key, search for an existing |
892 | * key of the same type and description in the destination keyring and | |
893 | * update that instead if possible | |
1da177e4 | 894 | */ |
16feef43 | 895 | if (index_key.type->update) { |
b2a4df20 DH |
896 | key_ref = find_key_to_update(keyring_ref, &index_key); |
897 | if (key_ref) | |
1d9b7d97 DH |
898 | goto found_matching_key; |
899 | } | |
1da177e4 | 900 | |
6b79ccb5 AR |
901 | /* if the client doesn't provide, decide on the permissions we want */ |
902 | if (perm == KEY_PERM_UNDEF) { | |
903 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; | |
96b5c8fe | 904 | perm |= KEY_USR_VIEW; |
1da177e4 | 905 | |
16feef43 | 906 | if (index_key.type->read) |
96b5c8fe | 907 | perm |= KEY_POS_READ; |
1da177e4 | 908 | |
16feef43 DH |
909 | if (index_key.type == &key_type_keyring || |
910 | index_key.type->update) | |
96b5c8fe | 911 | perm |= KEY_POS_WRITE; |
6b79ccb5 | 912 | } |
1da177e4 LT |
913 | |
914 | /* allocate a new key */ | |
16feef43 | 915 | key = key_alloc(index_key.type, index_key.description, |
5ac7eace | 916 | cred->fsuid, cred->fsgid, cred, perm, flags, NULL); |
1da177e4 | 917 | if (IS_ERR(key)) { |
e231c2ee | 918 | key_ref = ERR_CAST(key); |
cf7f601c | 919 | goto error_link_end; |
1da177e4 LT |
920 | } |
921 | ||
922 | /* instantiate it and link it into the target keyring */ | |
b2a4df20 | 923 | ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit); |
1da177e4 LT |
924 | if (ret < 0) { |
925 | key_put(key); | |
664cceb0 | 926 | key_ref = ERR_PTR(ret); |
cf7f601c | 927 | goto error_link_end; |
1da177e4 LT |
928 | } |
929 | ||
664cceb0 DH |
930 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
931 | ||
cf7f601c | 932 | error_link_end: |
b2a4df20 | 933 | __key_link_end(keyring, &index_key, edit); |
cf7f601c | 934 | error_free_prep: |
16feef43 DH |
935 | if (index_key.type->preparse) |
936 | index_key.type->free_preparse(&prep); | |
cf7f601c | 937 | error_put_type: |
16feef43 | 938 | key_type_put(index_key.type); |
cf7f601c | 939 | error: |
664cceb0 | 940 | return key_ref; |
1da177e4 LT |
941 | |
942 | found_matching_key: | |
943 | /* we found a matching key, so we're going to try to update it | |
944 | * - we can drop the locks first as we have the key pinned | |
945 | */ | |
b2a4df20 | 946 | __key_link_end(keyring, &index_key, edit); |
1da177e4 | 947 | |
60ff5b2f DH |
948 | key = key_ref_to_ptr(key_ref); |
949 | if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) { | |
950 | ret = wait_for_key_construction(key, true); | |
951 | if (ret < 0) { | |
952 | key_ref_put(key_ref); | |
953 | key_ref = ERR_PTR(ret); | |
954 | goto error_free_prep; | |
955 | } | |
956 | } | |
957 | ||
cf7f601c DH |
958 | key_ref = __key_update(key_ref, &prep); |
959 | goto error_free_prep; | |
a8b17ed0 | 960 | } |
1da177e4 LT |
961 | EXPORT_SYMBOL(key_create_or_update); |
962 | ||
973c9f4f DH |
963 | /** |
964 | * key_update - Update a key's contents. | |
965 | * @key_ref: The pointer (plus possession flag) to the key. | |
966 | * @payload: The data to be used to update the key. | |
967 | * @plen: The length of @payload. | |
968 | * | |
969 | * Attempt to update the contents of a key with the given payload data. The | |
970 | * caller must be granted Write permission on the key. Negative keys can be | |
971 | * instantiated by this method. | |
972 | * | |
973 | * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key | |
974 | * type does not support updating. The key type may return other errors. | |
1da177e4 | 975 | */ |
664cceb0 | 976 | int key_update(key_ref_t key_ref, const void *payload, size_t plen) |
1da177e4 | 977 | { |
cf7f601c | 978 | struct key_preparsed_payload prep; |
664cceb0 | 979 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
980 | int ret; |
981 | ||
982 | key_check(key); | |
983 | ||
984 | /* the key must be writable */ | |
f5895943 | 985 | ret = key_permission(key_ref, KEY_NEED_WRITE); |
29db9190 | 986 | if (ret < 0) |
63a0b050 | 987 | return ret; |
1da177e4 LT |
988 | |
989 | /* attempt to update it if supported */ | |
cf7f601c | 990 | if (!key->type->update) |
63a0b050 | 991 | return -EOPNOTSUPP; |
1da177e4 | 992 | |
cf7f601c DH |
993 | memset(&prep, 0, sizeof(prep)); |
994 | prep.data = payload; | |
995 | prep.datalen = plen; | |
996 | prep.quotalen = key->type->def_datalen; | |
7dfa0ca6 | 997 | prep.expiry = TIME_T_MAX; |
cf7f601c DH |
998 | if (key->type->preparse) { |
999 | ret = key->type->preparse(&prep); | |
1000 | if (ret < 0) | |
1001 | goto error; | |
1da177e4 LT |
1002 | } |
1003 | ||
cf7f601c DH |
1004 | down_write(&key->sem); |
1005 | ||
1006 | ret = key->type->update(key, &prep); | |
1007 | if (ret == 0) | |
363b02da DH |
1008 | /* Updating a negative key positively instantiates it */ |
1009 | mark_key_instantiated(key, 0); | |
cf7f601c DH |
1010 | |
1011 | up_write(&key->sem); | |
1012 | ||
4d8c0250 | 1013 | error: |
cf7f601c DH |
1014 | if (key->type->preparse) |
1015 | key->type->free_preparse(&prep); | |
1da177e4 | 1016 | return ret; |
a8b17ed0 | 1017 | } |
1da177e4 LT |
1018 | EXPORT_SYMBOL(key_update); |
1019 | ||
973c9f4f DH |
1020 | /** |
1021 | * key_revoke - Revoke a key. | |
1022 | * @key: The key to be revoked. | |
1023 | * | |
1024 | * Mark a key as being revoked and ask the type to free up its resources. The | |
1025 | * revocation timeout is set and the key and all its links will be | |
1026 | * automatically garbage collected after key_gc_delay amount of time if they | |
1027 | * are not manually dealt with first. | |
1da177e4 LT |
1028 | */ |
1029 | void key_revoke(struct key *key) | |
1030 | { | |
5d135440 DH |
1031 | struct timespec now; |
1032 | time_t time; | |
1033 | ||
1da177e4 LT |
1034 | key_check(key); |
1035 | ||
76181c13 DH |
1036 | /* make sure no one's trying to change or use the key when we mark it |
1037 | * - we tell lockdep that we might nest because we might be revoking an | |
1038 | * authorisation key whilst holding the sem on a key we've just | |
1039 | * instantiated | |
1040 | */ | |
1041 | down_write_nested(&key->sem, 1); | |
1042 | if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags) && | |
1043 | key->type->revoke) | |
04c567d9 DH |
1044 | key->type->revoke(key); |
1045 | ||
5d135440 DH |
1046 | /* set the death time to no more than the expiry time */ |
1047 | now = current_kernel_time(); | |
1048 | time = now.tv_sec; | |
1049 | if (key->revoked_at == 0 || key->revoked_at > time) { | |
1050 | key->revoked_at = time; | |
c08ef808 | 1051 | key_schedule_gc(key->revoked_at + key_gc_delay); |
5d135440 DH |
1052 | } |
1053 | ||
1da177e4 | 1054 | up_write(&key->sem); |
a8b17ed0 | 1055 | } |
1da177e4 LT |
1056 | EXPORT_SYMBOL(key_revoke); |
1057 | ||
fd75815f DH |
1058 | /** |
1059 | * key_invalidate - Invalidate a key. | |
1060 | * @key: The key to be invalidated. | |
1061 | * | |
1062 | * Mark a key as being invalidated and have it cleaned up immediately. The key | |
1063 | * is ignored by all searches and other operations from this point. | |
1064 | */ | |
1065 | void key_invalidate(struct key *key) | |
1066 | { | |
1067 | kenter("%d", key_serial(key)); | |
1068 | ||
1069 | key_check(key); | |
1070 | ||
1071 | if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { | |
1072 | down_write_nested(&key->sem, 1); | |
1073 | if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) | |
1074 | key_schedule_gc_links(); | |
1075 | up_write(&key->sem); | |
1076 | } | |
1077 | } | |
1078 | EXPORT_SYMBOL(key_invalidate); | |
1079 | ||
6a09d17b DH |
1080 | /** |
1081 | * generic_key_instantiate - Simple instantiation of a key from preparsed data | |
1082 | * @key: The key to be instantiated | |
1083 | * @prep: The preparsed data to load. | |
1084 | * | |
1085 | * Instantiate a key from preparsed data. We assume we can just copy the data | |
1086 | * in directly and clear the old pointers. | |
1087 | * | |
1088 | * This can be pointed to directly by the key type instantiate op pointer. | |
1089 | */ | |
1090 | int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep) | |
1091 | { | |
1092 | int ret; | |
1093 | ||
1094 | pr_devel("==>%s()\n", __func__); | |
1095 | ||
1096 | ret = key_payload_reserve(key, prep->quotalen); | |
1097 | if (ret == 0) { | |
146aa8b1 DH |
1098 | rcu_assign_keypointer(key, prep->payload.data[0]); |
1099 | key->payload.data[1] = prep->payload.data[1]; | |
1100 | key->payload.data[2] = prep->payload.data[2]; | |
1101 | key->payload.data[3] = prep->payload.data[3]; | |
1102 | prep->payload.data[0] = NULL; | |
1103 | prep->payload.data[1] = NULL; | |
1104 | prep->payload.data[2] = NULL; | |
1105 | prep->payload.data[3] = NULL; | |
6a09d17b DH |
1106 | } |
1107 | pr_devel("<==%s() = %d\n", __func__, ret); | |
1108 | return ret; | |
1109 | } | |
1110 | EXPORT_SYMBOL(generic_key_instantiate); | |
1111 | ||
973c9f4f DH |
1112 | /** |
1113 | * register_key_type - Register a type of key. | |
1114 | * @ktype: The new key type. | |
1115 | * | |
1116 | * Register a new key type. | |
1117 | * | |
1118 | * Returns 0 on success or -EEXIST if a type of this name already exists. | |
1da177e4 LT |
1119 | */ |
1120 | int register_key_type(struct key_type *ktype) | |
1121 | { | |
1122 | struct key_type *p; | |
1123 | int ret; | |
1124 | ||
7845bc39 DH |
1125 | memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); |
1126 | ||
1da177e4 LT |
1127 | ret = -EEXIST; |
1128 | down_write(&key_types_sem); | |
1129 | ||
1130 | /* disallow key types with the same name */ | |
1131 | list_for_each_entry(p, &key_types_list, link) { | |
1132 | if (strcmp(p->name, ktype->name) == 0) | |
1133 | goto out; | |
1134 | } | |
1135 | ||
1136 | /* store the type */ | |
1137 | list_add(&ktype->link, &key_types_list); | |
1eb1bcf5 DH |
1138 | |
1139 | pr_notice("Key type %s registered\n", ktype->name); | |
1da177e4 LT |
1140 | ret = 0; |
1141 | ||
973c9f4f | 1142 | out: |
1da177e4 LT |
1143 | up_write(&key_types_sem); |
1144 | return ret; | |
a8b17ed0 | 1145 | } |
1da177e4 LT |
1146 | EXPORT_SYMBOL(register_key_type); |
1147 | ||
973c9f4f DH |
1148 | /** |
1149 | * unregister_key_type - Unregister a type of key. | |
1150 | * @ktype: The key type. | |
1151 | * | |
1152 | * Unregister a key type and mark all the extant keys of this type as dead. | |
1153 | * Those keys of this type are then destroyed to get rid of their payloads and | |
1154 | * they and their links will be garbage collected as soon as possible. | |
1da177e4 LT |
1155 | */ |
1156 | void unregister_key_type(struct key_type *ktype) | |
1157 | { | |
1da177e4 | 1158 | down_write(&key_types_sem); |
1da177e4 | 1159 | list_del_init(&ktype->link); |
0c061b57 DH |
1160 | downgrade_write(&key_types_sem); |
1161 | key_gc_keytype(ktype); | |
1eb1bcf5 | 1162 | pr_notice("Key type %s unregistered\n", ktype->name); |
0c061b57 | 1163 | up_read(&key_types_sem); |
a8b17ed0 | 1164 | } |
1da177e4 LT |
1165 | EXPORT_SYMBOL(unregister_key_type); |
1166 | ||
1da177e4 | 1167 | /* |
973c9f4f | 1168 | * Initialise the key management state. |
1da177e4 LT |
1169 | */ |
1170 | void __init key_init(void) | |
1171 | { | |
1172 | /* allocate a slab in which we can store keys */ | |
1173 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), | |
20c2df83 | 1174 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1175 | |
1176 | /* add the special key types */ | |
1177 | list_add_tail(&key_type_keyring.link, &key_types_list); | |
1178 | list_add_tail(&key_type_dead.link, &key_types_list); | |
1179 | list_add_tail(&key_type_user.link, &key_types_list); | |
9f6ed2ca | 1180 | list_add_tail(&key_type_logon.link, &key_types_list); |
1da177e4 LT |
1181 | |
1182 | /* record the root user tracking */ | |
1183 | rb_link_node(&root_key_user.node, | |
1184 | NULL, | |
1185 | &key_user_tree.rb_node); | |
1186 | ||
1187 | rb_insert_color(&root_key_user.node, | |
1188 | &key_user_tree); | |
a8b17ed0 | 1189 | } |