Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
76181c13 | 2 | /* Basic authentication token and access key management |
1da177e4 | 3 | * |
69664cf1 | 4 | * Copyright (C) 2004-2008 Red Hat, Inc. All Rights Reserved. |
1da177e4 | 5 | * Written by David Howells (dhowells@redhat.com) |
1da177e4 LT |
6 | */ |
7 | ||
876979c9 | 8 | #include <linux/export.h> |
1da177e4 | 9 | #include <linux/init.h> |
a7807a32 | 10 | #include <linux/poison.h> |
1da177e4 LT |
11 | #include <linux/sched.h> |
12 | #include <linux/slab.h> | |
29db9190 | 13 | #include <linux/security.h> |
1da177e4 | 14 | #include <linux/workqueue.h> |
e51f6d34 | 15 | #include <linux/random.h> |
cb1aa382 | 16 | #include <linux/ima.h> |
1da177e4 LT |
17 | #include <linux/err.h> |
18 | #include "internal.h" | |
19 | ||
8bc16dea | 20 | struct kmem_cache *key_jar; |
1da177e4 LT |
21 | struct rb_root key_serial_tree; /* tree of keys indexed by serial */ |
22 | DEFINE_SPINLOCK(key_serial_lock); | |
23 | ||
24 | struct rb_root key_user_tree; /* tree of quota records indexed by UID */ | |
25 | DEFINE_SPINLOCK(key_user_lock); | |
26 | ||
738c5d19 SD |
27 | unsigned int key_quota_root_maxkeys = 1000000; /* root's key count quota */ |
28 | unsigned int key_quota_root_maxbytes = 25000000; /* root's key space quota */ | |
0b77f5bf DH |
29 | unsigned int key_quota_maxkeys = 200; /* general key count quota */ |
30 | unsigned int key_quota_maxbytes = 20000; /* general key space quota */ | |
31 | ||
1da177e4 LT |
32 | static LIST_HEAD(key_types_list); |
33 | static DECLARE_RWSEM(key_types_sem); | |
34 | ||
973c9f4f | 35 | /* We serialise key instantiation and link */ |
76181c13 | 36 | DEFINE_MUTEX(key_construction_mutex); |
1da177e4 | 37 | |
1da177e4 LT |
38 | #ifdef KEY_DEBUGGING |
39 | void __key_check(const struct key *key) | |
40 | { | |
41 | printk("__key_check: key %p {%08x} should be {%08x}\n", | |
42 | key, key->magic, KEY_DEBUG_MAGIC); | |
43 | BUG(); | |
44 | } | |
45 | #endif | |
46 | ||
1da177e4 | 47 | /* |
973c9f4f DH |
48 | * Get the key quota record for a user, allocating a new record if one doesn't |
49 | * already exist. | |
1da177e4 | 50 | */ |
9a56c2db | 51 | struct key_user *key_user_lookup(kuid_t uid) |
1da177e4 LT |
52 | { |
53 | struct key_user *candidate = NULL, *user; | |
8f674565 | 54 | struct rb_node *parent, **p; |
1da177e4 | 55 | |
973c9f4f | 56 | try_again: |
8f674565 | 57 | parent = NULL; |
1da177e4 LT |
58 | p = &key_user_tree.rb_node; |
59 | spin_lock(&key_user_lock); | |
60 | ||
61 | /* search the tree for a user record with a matching UID */ | |
62 | while (*p) { | |
63 | parent = *p; | |
64 | user = rb_entry(parent, struct key_user, node); | |
65 | ||
9a56c2db | 66 | if (uid_lt(uid, user->uid)) |
1da177e4 | 67 | p = &(*p)->rb_left; |
9a56c2db | 68 | else if (uid_gt(uid, user->uid)) |
1d1e9756 | 69 | p = &(*p)->rb_right; |
1da177e4 LT |
70 | else |
71 | goto found; | |
72 | } | |
73 | ||
74 | /* if we get here, we failed to find a match in the tree */ | |
75 | if (!candidate) { | |
76 | /* allocate a candidate user record if we don't already have | |
77 | * one */ | |
78 | spin_unlock(&key_user_lock); | |
79 | ||
80 | user = NULL; | |
81 | candidate = kmalloc(sizeof(struct key_user), GFP_KERNEL); | |
82 | if (unlikely(!candidate)) | |
83 | goto out; | |
84 | ||
85 | /* the allocation may have scheduled, so we need to repeat the | |
86 | * search lest someone else added the record whilst we were | |
87 | * asleep */ | |
88 | goto try_again; | |
89 | } | |
90 | ||
91 | /* if we get here, then the user record still hadn't appeared on the | |
92 | * second pass - so we use the candidate record */ | |
ddb99e11 | 93 | refcount_set(&candidate->usage, 1); |
1da177e4 LT |
94 | atomic_set(&candidate->nkeys, 0); |
95 | atomic_set(&candidate->nikeys, 0); | |
96 | candidate->uid = uid; | |
97 | candidate->qnkeys = 0; | |
98 | candidate->qnbytes = 0; | |
99 | spin_lock_init(&candidate->lock); | |
76181c13 | 100 | mutex_init(&candidate->cons_lock); |
1da177e4 LT |
101 | |
102 | rb_link_node(&candidate->node, parent, p); | |
103 | rb_insert_color(&candidate->node, &key_user_tree); | |
104 | spin_unlock(&key_user_lock); | |
105 | user = candidate; | |
106 | goto out; | |
107 | ||
108 | /* okay - we found a user record for this UID */ | |
973c9f4f | 109 | found: |
ddb99e11 | 110 | refcount_inc(&user->usage); |
1da177e4 | 111 | spin_unlock(&key_user_lock); |
a7f988ba | 112 | kfree(candidate); |
973c9f4f | 113 | out: |
1da177e4 | 114 | return user; |
a8b17ed0 | 115 | } |
1da177e4 | 116 | |
1da177e4 | 117 | /* |
973c9f4f | 118 | * Dispose of a user structure |
1da177e4 LT |
119 | */ |
120 | void key_user_put(struct key_user *user) | |
121 | { | |
ddb99e11 | 122 | if (refcount_dec_and_lock(&user->usage, &key_user_lock)) { |
1da177e4 LT |
123 | rb_erase(&user->node, &key_user_tree); |
124 | spin_unlock(&key_user_lock); | |
125 | ||
126 | kfree(user); | |
127 | } | |
a8b17ed0 | 128 | } |
1da177e4 | 129 | |
1da177e4 | 130 | /* |
973c9f4f DH |
131 | * Allocate a serial number for a key. These are assigned randomly to avoid |
132 | * security issues through covert channel problems. | |
1da177e4 LT |
133 | */ |
134 | static inline void key_alloc_serial(struct key *key) | |
135 | { | |
136 | struct rb_node *parent, **p; | |
137 | struct key *xkey; | |
138 | ||
e51f6d34 | 139 | /* propose a random serial number and look for a hole for it in the |
1da177e4 | 140 | * serial number tree */ |
e51f6d34 ML |
141 | do { |
142 | get_random_bytes(&key->serial, sizeof(key->serial)); | |
143 | ||
144 | key->serial >>= 1; /* negative numbers are not permitted */ | |
145 | } while (key->serial < 3); | |
146 | ||
147 | spin_lock(&key_serial_lock); | |
1da177e4 | 148 | |
9ad0830f | 149 | attempt_insertion: |
1da177e4 LT |
150 | parent = NULL; |
151 | p = &key_serial_tree.rb_node; | |
152 | ||
153 | while (*p) { | |
154 | parent = *p; | |
155 | xkey = rb_entry(parent, struct key, serial_node); | |
156 | ||
157 | if (key->serial < xkey->serial) | |
158 | p = &(*p)->rb_left; | |
159 | else if (key->serial > xkey->serial) | |
160 | p = &(*p)->rb_right; | |
161 | else | |
162 | goto serial_exists; | |
163 | } | |
9ad0830f DH |
164 | |
165 | /* we've found a suitable hole - arrange for this key to occupy it */ | |
166 | rb_link_node(&key->serial_node, parent, p); | |
167 | rb_insert_color(&key->serial_node, &key_serial_tree); | |
168 | ||
169 | spin_unlock(&key_serial_lock); | |
170 | return; | |
1da177e4 LT |
171 | |
172 | /* we found a key with the proposed serial number - walk the tree from | |
173 | * that point looking for the next unused serial number */ | |
e51f6d34 | 174 | serial_exists: |
1da177e4 | 175 | for (;;) { |
e51f6d34 | 176 | key->serial++; |
9ad0830f DH |
177 | if (key->serial < 3) { |
178 | key->serial = 3; | |
179 | goto attempt_insertion; | |
180 | } | |
1da177e4 LT |
181 | |
182 | parent = rb_next(parent); | |
183 | if (!parent) | |
9ad0830f | 184 | goto attempt_insertion; |
1da177e4 LT |
185 | |
186 | xkey = rb_entry(parent, struct key, serial_node); | |
187 | if (key->serial < xkey->serial) | |
9ad0830f | 188 | goto attempt_insertion; |
1da177e4 | 189 | } |
a8b17ed0 | 190 | } |
1da177e4 | 191 | |
973c9f4f DH |
192 | /** |
193 | * key_alloc - Allocate a key of the specified type. | |
194 | * @type: The type of key to allocate. | |
195 | * @desc: The key description to allow the key to be searched out. | |
196 | * @uid: The owner of the new key. | |
197 | * @gid: The group ID for the new key's group permissions. | |
198 | * @cred: The credentials specifying UID namespace. | |
028db3e2 | 199 | * @perm: The permissions mask of the new key. |
973c9f4f | 200 | * @flags: Flags specifying quota properties. |
2b6aa412 | 201 | * @restrict_link: Optional link restriction for new keyrings. |
973c9f4f DH |
202 | * |
203 | * Allocate a key of the specified type with the attributes given. The key is | |
204 | * returned in an uninstantiated state and the caller needs to instantiate the | |
205 | * key before returning. | |
206 | * | |
2b6aa412 MM |
207 | * The restrict_link structure (if not NULL) will be freed when the |
208 | * keyring is destroyed, so it must be dynamically allocated. | |
209 | * | |
973c9f4f DH |
210 | * The user's key count quota is updated to reflect the creation of the key and |
211 | * the user's key data quota has the default for the key type reserved. The | |
212 | * instantiation function should amend this as necessary. If insufficient | |
213 | * quota is available, -EDQUOT will be returned. | |
214 | * | |
215 | * The LSM security modules can prevent a key being created, in which case | |
216 | * -EACCES will be returned. | |
217 | * | |
218 | * Returns a pointer to the new key if successful and an error code otherwise. | |
219 | * | |
220 | * Note that the caller needs to ensure the key type isn't uninstantiated. | |
221 | * Internally this can be done by locking key_types_sem. Externally, this can | |
222 | * be done by either never unregistering the key type, or making sure | |
223 | * key_alloc() calls don't race with module unloading. | |
1da177e4 LT |
224 | */ |
225 | struct key *key_alloc(struct key_type *type, const char *desc, | |
9a56c2db | 226 | kuid_t uid, kgid_t gid, const struct cred *cred, |
028db3e2 | 227 | key_perm_t perm, unsigned long flags, |
2b6aa412 | 228 | struct key_restriction *restrict_link) |
1da177e4 LT |
229 | { |
230 | struct key_user *user = NULL; | |
231 | struct key *key; | |
232 | size_t desclen, quotalen; | |
29db9190 | 233 | int ret; |
1da177e4 LT |
234 | |
235 | key = ERR_PTR(-EINVAL); | |
236 | if (!desc || !*desc) | |
237 | goto error; | |
238 | ||
b9fffa38 DH |
239 | if (type->vet_description) { |
240 | ret = type->vet_description(desc); | |
241 | if (ret < 0) { | |
242 | key = ERR_PTR(ret); | |
243 | goto error; | |
244 | } | |
245 | } | |
246 | ||
16feef43 DH |
247 | desclen = strlen(desc); |
248 | quotalen = desclen + 1 + type->def_datalen; | |
1da177e4 LT |
249 | |
250 | /* get hold of the key tracking for this user */ | |
9a56c2db | 251 | user = key_user_lookup(uid); |
1da177e4 LT |
252 | if (!user) |
253 | goto no_memory_1; | |
254 | ||
255 | /* check that the user's quota permits allocation of another key and | |
256 | * its description */ | |
7e047ef5 | 257 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
9a56c2db | 258 | unsigned maxkeys = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf | 259 | key_quota_root_maxkeys : key_quota_maxkeys; |
9a56c2db | 260 | unsigned maxbytes = uid_eq(uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
261 | key_quota_root_maxbytes : key_quota_maxbytes; |
262 | ||
1da177e4 | 263 | spin_lock(&user->lock); |
7e047ef5 | 264 | if (!(flags & KEY_ALLOC_QUOTA_OVERRUN)) { |
a08bf91c EB |
265 | if (user->qnkeys + 1 > maxkeys || |
266 | user->qnbytes + quotalen > maxbytes || | |
0b77f5bf | 267 | user->qnbytes + quotalen < user->qnbytes) |
7e047ef5 DH |
268 | goto no_quota; |
269 | } | |
1da177e4 LT |
270 | |
271 | user->qnkeys++; | |
272 | user->qnbytes += quotalen; | |
273 | spin_unlock(&user->lock); | |
274 | } | |
275 | ||
276 | /* allocate and initialise the key and its description */ | |
2480f57f | 277 | key = kmem_cache_zalloc(key_jar, GFP_KERNEL); |
1da177e4 LT |
278 | if (!key) |
279 | goto no_memory_2; | |
280 | ||
5057975a DC |
281 | key->index_key.desc_len = desclen; |
282 | key->index_key.description = kmemdup(desc, desclen + 1, GFP_KERNEL); | |
27720e75 | 283 | if (!key->index_key.description) |
5057975a | 284 | goto no_memory_3; |
355ef8e1 | 285 | key->index_key.type = type; |
f771fde8 | 286 | key_set_index_key(&key->index_key); |
1da177e4 | 287 | |
fff29291 | 288 | refcount_set(&key->usage, 1); |
1da177e4 | 289 | init_rwsem(&key->sem); |
7845bc39 | 290 | lockdep_set_class(&key->sem, &type->lock_class); |
1da177e4 LT |
291 | key->user = user; |
292 | key->quotalen = quotalen; | |
293 | key->datalen = type->def_datalen; | |
294 | key->uid = uid; | |
295 | key->gid = gid; | |
028db3e2 | 296 | key->perm = perm; |
5ac7eace | 297 | key->restrict_link = restrict_link; |
7c1857bd | 298 | key->last_used_at = ktime_get_real_seconds(); |
1da177e4 | 299 | |
7e047ef5 | 300 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) |
76d8aeab | 301 | key->flags |= 1 << KEY_FLAG_IN_QUOTA; |
5d2787cf DH |
302 | if (flags & KEY_ALLOC_BUILT_IN) |
303 | key->flags |= 1 << KEY_FLAG_BUILTIN; | |
237bbd29 EB |
304 | if (flags & KEY_ALLOC_UID_KEYRING) |
305 | key->flags |= 1 << KEY_FLAG_UID_KEYRING; | |
4993e1f9 DH |
306 | if (flags & KEY_ALLOC_SET_KEEP) |
307 | key->flags |= 1 << KEY_FLAG_KEEP; | |
1da177e4 | 308 | |
1da177e4 LT |
309 | #ifdef KEY_DEBUGGING |
310 | key->magic = KEY_DEBUG_MAGIC; | |
311 | #endif | |
312 | ||
29db9190 | 313 | /* let the security module know about the key */ |
d84f4f99 | 314 | ret = security_key_alloc(key, cred, flags); |
29db9190 DH |
315 | if (ret < 0) |
316 | goto security_error; | |
317 | ||
1da177e4 | 318 | /* publish the key by giving it a serial number */ |
3b6e4de0 | 319 | refcount_inc(&key->domain_tag->usage); |
1da177e4 LT |
320 | atomic_inc(&user->nkeys); |
321 | key_alloc_serial(key); | |
322 | ||
29db9190 | 323 | error: |
1da177e4 LT |
324 | return key; |
325 | ||
29db9190 DH |
326 | security_error: |
327 | kfree(key->description); | |
1da177e4 | 328 | kmem_cache_free(key_jar, key); |
7e047ef5 | 329 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
1da177e4 LT |
330 | spin_lock(&user->lock); |
331 | user->qnkeys--; | |
332 | user->qnbytes -= quotalen; | |
333 | spin_unlock(&user->lock); | |
334 | } | |
335 | key_user_put(user); | |
29db9190 DH |
336 | key = ERR_PTR(ret); |
337 | goto error; | |
338 | ||
339 | no_memory_3: | |
340 | kmem_cache_free(key_jar, key); | |
341 | no_memory_2: | |
7e047ef5 | 342 | if (!(flags & KEY_ALLOC_NOT_IN_QUOTA)) { |
29db9190 DH |
343 | spin_lock(&user->lock); |
344 | user->qnkeys--; | |
345 | user->qnbytes -= quotalen; | |
346 | spin_unlock(&user->lock); | |
347 | } | |
348 | key_user_put(user); | |
349 | no_memory_1: | |
1da177e4 LT |
350 | key = ERR_PTR(-ENOMEM); |
351 | goto error; | |
352 | ||
29db9190 | 353 | no_quota: |
1da177e4 LT |
354 | spin_unlock(&user->lock); |
355 | key_user_put(user); | |
356 | key = ERR_PTR(-EDQUOT); | |
357 | goto error; | |
a8b17ed0 | 358 | } |
1da177e4 LT |
359 | EXPORT_SYMBOL(key_alloc); |
360 | ||
973c9f4f DH |
361 | /** |
362 | * key_payload_reserve - Adjust data quota reservation for the key's payload | |
363 | * @key: The key to make the reservation for. | |
364 | * @datalen: The amount of data payload the caller now wants. | |
365 | * | |
366 | * Adjust the amount of the owning user's key data quota that a key reserves. | |
367 | * If the amount is increased, then -EDQUOT may be returned if there isn't | |
368 | * enough free quota available. | |
369 | * | |
370 | * If successful, 0 is returned. | |
1da177e4 LT |
371 | */ |
372 | int key_payload_reserve(struct key *key, size_t datalen) | |
373 | { | |
c5b60b5e | 374 | int delta = (int)datalen - key->datalen; |
1da177e4 LT |
375 | int ret = 0; |
376 | ||
377 | key_check(key); | |
378 | ||
379 | /* contemplate the quota adjustment */ | |
76d8aeab | 380 | if (delta != 0 && test_bit(KEY_FLAG_IN_QUOTA, &key->flags)) { |
9a56c2db | 381 | unsigned maxbytes = uid_eq(key->user->uid, GLOBAL_ROOT_UID) ? |
0b77f5bf DH |
382 | key_quota_root_maxbytes : key_quota_maxbytes; |
383 | ||
1da177e4 LT |
384 | spin_lock(&key->user->lock); |
385 | ||
386 | if (delta > 0 && | |
2e356101 | 387 | (key->user->qnbytes + delta > maxbytes || |
0b77f5bf | 388 | key->user->qnbytes + delta < key->user->qnbytes)) { |
1da177e4 LT |
389 | ret = -EDQUOT; |
390 | } | |
391 | else { | |
392 | key->user->qnbytes += delta; | |
393 | key->quotalen += delta; | |
394 | } | |
395 | spin_unlock(&key->user->lock); | |
396 | } | |
397 | ||
398 | /* change the recorded data length if that didn't generate an error */ | |
399 | if (ret == 0) | |
400 | key->datalen = datalen; | |
401 | ||
402 | return ret; | |
a8b17ed0 | 403 | } |
1da177e4 LT |
404 | EXPORT_SYMBOL(key_payload_reserve); |
405 | ||
363b02da DH |
406 | /* |
407 | * Change the key state to being instantiated. | |
408 | */ | |
409 | static void mark_key_instantiated(struct key *key, int reject_error) | |
410 | { | |
411 | /* Commit the payload before setting the state; barrier versus | |
412 | * key_read_state(). | |
413 | */ | |
414 | smp_store_release(&key->state, | |
415 | (reject_error < 0) ? reject_error : KEY_IS_POSITIVE); | |
416 | } | |
417 | ||
1da177e4 | 418 | /* |
973c9f4f DH |
419 | * Instantiate a key and link it into the target keyring atomically. Must be |
420 | * called with the target keyring's semaphore writelocked. The target key's | |
421 | * semaphore need not be locked as instantiation is serialised by | |
422 | * key_construction_mutex. | |
1da177e4 LT |
423 | */ |
424 | static int __key_instantiate_and_link(struct key *key, | |
cf7f601c | 425 | struct key_preparsed_payload *prep, |
3e30148c | 426 | struct key *keyring, |
f70e2e06 | 427 | struct key *authkey, |
b2a4df20 | 428 | struct assoc_array_edit **_edit) |
1da177e4 LT |
429 | { |
430 | int ret, awaken; | |
431 | ||
432 | key_check(key); | |
433 | key_check(keyring); | |
434 | ||
435 | awaken = 0; | |
436 | ret = -EBUSY; | |
437 | ||
76181c13 | 438 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
439 | |
440 | /* can't instantiate twice */ | |
363b02da | 441 | if (key->state == KEY_IS_UNINSTANTIATED) { |
1da177e4 | 442 | /* instantiate the key */ |
cf7f601c | 443 | ret = key->type->instantiate(key, prep); |
1da177e4 LT |
444 | |
445 | if (ret == 0) { | |
446 | /* mark the key as being instantiated */ | |
1da177e4 | 447 | atomic_inc(&key->user->nikeys); |
363b02da | 448 | mark_key_instantiated(key, 0); |
f7e47677 | 449 | notify_key(key, NOTIFY_KEY_INSTANTIATED, 0); |
1da177e4 | 450 | |
76d8aeab | 451 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 452 | awaken = 1; |
1da177e4 LT |
453 | |
454 | /* and link it into the destination keyring */ | |
d3600bcf | 455 | if (keyring) { |
eee04502 DH |
456 | if (test_bit(KEY_FLAG_KEEP, &keyring->flags)) |
457 | set_bit(KEY_FLAG_KEEP, &key->flags); | |
d3600bcf | 458 | |
f7e47677 | 459 | __key_link(keyring, key, _edit); |
d3600bcf | 460 | } |
3e30148c DH |
461 | |
462 | /* disable the authorisation key */ | |
d84f4f99 | 463 | if (authkey) |
a09003b5 | 464 | key_invalidate(authkey); |
7dfa0ca6 | 465 | |
0a9dd0e0 | 466 | if (prep->expiry != TIME64_MAX) { |
7dfa0ca6 DH |
467 | key->expiry = prep->expiry; |
468 | key_schedule_gc(prep->expiry + key_gc_delay); | |
469 | } | |
1da177e4 LT |
470 | } |
471 | } | |
472 | ||
76181c13 | 473 | mutex_unlock(&key_construction_mutex); |
1da177e4 LT |
474 | |
475 | /* wake up anyone waiting for a key to be constructed */ | |
476 | if (awaken) | |
76181c13 | 477 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 LT |
478 | |
479 | return ret; | |
a8b17ed0 | 480 | } |
1da177e4 | 481 | |
973c9f4f DH |
482 | /** |
483 | * key_instantiate_and_link - Instantiate a key and link it into the keyring. | |
484 | * @key: The key to instantiate. | |
485 | * @data: The data to use to instantiate the keyring. | |
486 | * @datalen: The length of @data. | |
487 | * @keyring: Keyring to create a link in on success (or NULL). | |
488 | * @authkey: The authorisation token permitting instantiation. | |
489 | * | |
490 | * Instantiate a key that's in the uninstantiated state using the provided data | |
491 | * and, if successful, link it in to the destination keyring if one is | |
492 | * supplied. | |
493 | * | |
494 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
495 | * waiting for the key is woken up. If the key was already instantiated, | |
496 | * -EBUSY will be returned. | |
1da177e4 LT |
497 | */ |
498 | int key_instantiate_and_link(struct key *key, | |
499 | const void *data, | |
500 | size_t datalen, | |
3e30148c | 501 | struct key *keyring, |
d84f4f99 | 502 | struct key *authkey) |
1da177e4 | 503 | { |
cf7f601c | 504 | struct key_preparsed_payload prep; |
df593ee2 | 505 | struct assoc_array_edit *edit = NULL; |
1da177e4 LT |
506 | int ret; |
507 | ||
cf7f601c | 508 | memset(&prep, 0, sizeof(prep)); |
8eb62169 | 509 | prep.orig_description = key->description; |
cf7f601c DH |
510 | prep.data = data; |
511 | prep.datalen = datalen; | |
512 | prep.quotalen = key->type->def_datalen; | |
0a9dd0e0 | 513 | prep.expiry = TIME64_MAX; |
cf7f601c DH |
514 | if (key->type->preparse) { |
515 | ret = key->type->preparse(&prep); | |
516 | if (ret < 0) | |
517 | goto error; | |
518 | } | |
519 | ||
f70e2e06 | 520 | if (keyring) { |
df593ee2 | 521 | ret = __key_link_lock(keyring, &key->index_key); |
4a420896 MM |
522 | if (ret < 0) |
523 | goto error; | |
524 | ||
df593ee2 DH |
525 | ret = __key_link_begin(keyring, &key->index_key, &edit); |
526 | if (ret < 0) | |
527 | goto error_link_end; | |
528 | ||
2b6aa412 MM |
529 | if (keyring->restrict_link && keyring->restrict_link->check) { |
530 | struct key_restriction *keyres = keyring->restrict_link; | |
531 | ||
532 | ret = keyres->check(keyring, key->type, &prep.payload, | |
533 | keyres->key); | |
5ac7eace | 534 | if (ret < 0) |
4a420896 | 535 | goto error_link_end; |
5ac7eace | 536 | } |
f70e2e06 | 537 | } |
1da177e4 | 538 | |
b2a4df20 | 539 | ret = __key_instantiate_and_link(key, &prep, keyring, authkey, &edit); |
1da177e4 | 540 | |
4a420896 | 541 | error_link_end: |
1da177e4 | 542 | if (keyring) |
b2a4df20 | 543 | __key_link_end(keyring, &key->index_key, edit); |
1da177e4 | 544 | |
4d8c0250 | 545 | error: |
cf7f601c DH |
546 | if (key->type->preparse) |
547 | key->type->free_preparse(&prep); | |
1da177e4 | 548 | return ret; |
a8b17ed0 | 549 | } |
1da177e4 LT |
550 | |
551 | EXPORT_SYMBOL(key_instantiate_and_link); | |
552 | ||
973c9f4f | 553 | /** |
fdd1b945 | 554 | * key_reject_and_link - Negatively instantiate a key and link it into the keyring. |
973c9f4f DH |
555 | * @key: The key to instantiate. |
556 | * @timeout: The timeout on the negative key. | |
fdd1b945 | 557 | * @error: The error to return when the key is hit. |
973c9f4f DH |
558 | * @keyring: Keyring to create a link in on success (or NULL). |
559 | * @authkey: The authorisation token permitting instantiation. | |
560 | * | |
561 | * Negatively instantiate a key that's in the uninstantiated state and, if | |
fdd1b945 DH |
562 | * successful, set its timeout and stored error and link it in to the |
563 | * destination keyring if one is supplied. The key and any links to the key | |
564 | * will be automatically garbage collected after the timeout expires. | |
973c9f4f DH |
565 | * |
566 | * Negative keys are used to rate limit repeated request_key() calls by causing | |
fdd1b945 DH |
567 | * them to return the stored error code (typically ENOKEY) until the negative |
568 | * key expires. | |
973c9f4f DH |
569 | * |
570 | * If successful, 0 is returned, the authorisation token is revoked and anyone | |
571 | * waiting for the key is woken up. If the key was already instantiated, | |
572 | * -EBUSY will be returned. | |
1da177e4 | 573 | */ |
fdd1b945 | 574 | int key_reject_and_link(struct key *key, |
1da177e4 | 575 | unsigned timeout, |
fdd1b945 | 576 | unsigned error, |
3e30148c | 577 | struct key *keyring, |
d84f4f99 | 578 | struct key *authkey) |
1da177e4 | 579 | { |
df593ee2 | 580 | struct assoc_array_edit *edit = NULL; |
f70e2e06 | 581 | int ret, awaken, link_ret = 0; |
1da177e4 LT |
582 | |
583 | key_check(key); | |
584 | key_check(keyring); | |
585 | ||
586 | awaken = 0; | |
587 | ret = -EBUSY; | |
588 | ||
5ac7eace DH |
589 | if (keyring) { |
590 | if (keyring->restrict_link) | |
591 | return -EPERM; | |
592 | ||
df593ee2 DH |
593 | link_ret = __key_link_lock(keyring, &key->index_key); |
594 | if (link_ret == 0) { | |
595 | link_ret = __key_link_begin(keyring, &key->index_key, &edit); | |
596 | if (link_ret < 0) | |
597 | __key_link_end(keyring, &key->index_key, edit); | |
598 | } | |
5ac7eace | 599 | } |
1da177e4 | 600 | |
76181c13 | 601 | mutex_lock(&key_construction_mutex); |
1da177e4 LT |
602 | |
603 | /* can't instantiate twice */ | |
363b02da | 604 | if (key->state == KEY_IS_UNINSTANTIATED) { |
1da177e4 | 605 | /* mark the key as being negatively instantiated */ |
1da177e4 | 606 | atomic_inc(&key->user->nikeys); |
363b02da | 607 | mark_key_instantiated(key, -error); |
f7e47677 | 608 | notify_key(key, NOTIFY_KEY_INSTANTIATED, -error); |
074d5898 | 609 | key->expiry = ktime_get_real_seconds() + timeout; |
c08ef808 | 610 | key_schedule_gc(key->expiry + key_gc_delay); |
1da177e4 | 611 | |
76d8aeab | 612 | if (test_and_clear_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) |
1da177e4 | 613 | awaken = 1; |
1da177e4 | 614 | |
1da177e4 LT |
615 | ret = 0; |
616 | ||
617 | /* and link it into the destination keyring */ | |
f70e2e06 | 618 | if (keyring && link_ret == 0) |
f7e47677 | 619 | __key_link(keyring, key, &edit); |
3e30148c DH |
620 | |
621 | /* disable the authorisation key */ | |
d84f4f99 | 622 | if (authkey) |
a09003b5 | 623 | key_invalidate(authkey); |
1da177e4 LT |
624 | } |
625 | ||
76181c13 | 626 | mutex_unlock(&key_construction_mutex); |
1da177e4 | 627 | |
38327424 | 628 | if (keyring && link_ret == 0) |
b2a4df20 | 629 | __key_link_end(keyring, &key->index_key, edit); |
1da177e4 LT |
630 | |
631 | /* wake up anyone waiting for a key to be constructed */ | |
632 | if (awaken) | |
76181c13 | 633 | wake_up_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT); |
1da177e4 | 634 | |
f70e2e06 | 635 | return ret == 0 ? link_ret : ret; |
a8b17ed0 | 636 | } |
fdd1b945 | 637 | EXPORT_SYMBOL(key_reject_and_link); |
1da177e4 | 638 | |
973c9f4f DH |
639 | /** |
640 | * key_put - Discard a reference to a key. | |
641 | * @key: The key to discard a reference from. | |
642 | * | |
643 | * Discard a reference to a key, and when all the references are gone, we | |
644 | * schedule the cleanup task to come and pull it out of the tree in process | |
645 | * context at some later time. | |
1da177e4 LT |
646 | */ |
647 | void key_put(struct key *key) | |
648 | { | |
649 | if (key) { | |
650 | key_check(key); | |
651 | ||
fff29291 | 652 | if (refcount_dec_and_test(&key->usage)) |
3b07e9ca | 653 | schedule_work(&key_gc_work); |
1da177e4 | 654 | } |
a8b17ed0 | 655 | } |
1da177e4 LT |
656 | EXPORT_SYMBOL(key_put); |
657 | ||
1da177e4 | 658 | /* |
973c9f4f | 659 | * Find a key by its serial number. |
1da177e4 LT |
660 | */ |
661 | struct key *key_lookup(key_serial_t id) | |
662 | { | |
663 | struct rb_node *n; | |
664 | struct key *key; | |
665 | ||
666 | spin_lock(&key_serial_lock); | |
667 | ||
668 | /* search the tree for the specified key */ | |
669 | n = key_serial_tree.rb_node; | |
670 | while (n) { | |
671 | key = rb_entry(n, struct key, serial_node); | |
672 | ||
673 | if (id < key->serial) | |
674 | n = n->rb_left; | |
675 | else if (id > key->serial) | |
676 | n = n->rb_right; | |
677 | else | |
678 | goto found; | |
679 | } | |
680 | ||
973c9f4f | 681 | not_found: |
1da177e4 LT |
682 | key = ERR_PTR(-ENOKEY); |
683 | goto error; | |
684 | ||
973c9f4f | 685 | found: |
92347cfd MR |
686 | /* A key is allowed to be looked up only if someone still owns a |
687 | * reference to it - otherwise it's awaiting the gc. | |
1da177e4 | 688 | */ |
92347cfd MR |
689 | if (!refcount_inc_not_zero(&key->usage)) |
690 | goto not_found; | |
1da177e4 | 691 | |
973c9f4f | 692 | error: |
1da177e4 LT |
693 | spin_unlock(&key_serial_lock); |
694 | return key; | |
a8b17ed0 | 695 | } |
037c3431 | 696 | EXPORT_SYMBOL(key_lookup); |
1da177e4 | 697 | |
1da177e4 | 698 | /* |
973c9f4f DH |
699 | * Find and lock the specified key type against removal. |
700 | * | |
701 | * We return with the sem read-locked if successful. If the type wasn't | |
702 | * available -ENOKEY is returned instead. | |
1da177e4 LT |
703 | */ |
704 | struct key_type *key_type_lookup(const char *type) | |
705 | { | |
706 | struct key_type *ktype; | |
707 | ||
708 | down_read(&key_types_sem); | |
709 | ||
710 | /* look up the key type to see if it's one of the registered kernel | |
711 | * types */ | |
712 | list_for_each_entry(ktype, &key_types_list, link) { | |
713 | if (strcmp(ktype->name, type) == 0) | |
714 | goto found_kernel_type; | |
715 | } | |
716 | ||
717 | up_read(&key_types_sem); | |
718 | ktype = ERR_PTR(-ENOKEY); | |
719 | ||
973c9f4f | 720 | found_kernel_type: |
1da177e4 | 721 | return ktype; |
a8b17ed0 | 722 | } |
1da177e4 | 723 | |
59e6b9c1 BS |
724 | void key_set_timeout(struct key *key, unsigned timeout) |
725 | { | |
074d5898 | 726 | time64_t expiry = 0; |
59e6b9c1 BS |
727 | |
728 | /* make the changes with the locks held to prevent races */ | |
729 | down_write(&key->sem); | |
730 | ||
074d5898 BW |
731 | if (timeout > 0) |
732 | expiry = ktime_get_real_seconds() + timeout; | |
59e6b9c1 BS |
733 | |
734 | key->expiry = expiry; | |
735 | key_schedule_gc(key->expiry + key_gc_delay); | |
736 | ||
737 | up_write(&key->sem); | |
738 | } | |
739 | EXPORT_SYMBOL_GPL(key_set_timeout); | |
740 | ||
1da177e4 | 741 | /* |
973c9f4f | 742 | * Unlock a key type locked by key_type_lookup(). |
1da177e4 LT |
743 | */ |
744 | void key_type_put(struct key_type *ktype) | |
745 | { | |
746 | up_read(&key_types_sem); | |
a8b17ed0 | 747 | } |
1da177e4 | 748 | |
1da177e4 | 749 | /* |
973c9f4f DH |
750 | * Attempt to update an existing key. |
751 | * | |
752 | * The key is given to us with an incremented refcount that we need to discard | |
753 | * if we get an error. | |
1da177e4 | 754 | */ |
664cceb0 | 755 | static inline key_ref_t __key_update(key_ref_t key_ref, |
cf7f601c | 756 | struct key_preparsed_payload *prep) |
1da177e4 | 757 | { |
664cceb0 | 758 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
759 | int ret; |
760 | ||
761 | /* need write permission on the key to update it */ | |
f5895943 | 762 | ret = key_permission(key_ref, KEY_NEED_WRITE); |
29db9190 | 763 | if (ret < 0) |
1da177e4 LT |
764 | goto error; |
765 | ||
766 | ret = -EEXIST; | |
767 | if (!key->type->update) | |
768 | goto error; | |
769 | ||
770 | down_write(&key->sem); | |
771 | ||
cf7f601c | 772 | ret = key->type->update(key, prep); |
f7e47677 | 773 | if (ret == 0) { |
363b02da DH |
774 | /* Updating a negative key positively instantiates it */ |
775 | mark_key_instantiated(key, 0); | |
f7e47677 DH |
776 | notify_key(key, NOTIFY_KEY_UPDATED, 0); |
777 | } | |
1da177e4 LT |
778 | |
779 | up_write(&key->sem); | |
780 | ||
781 | if (ret < 0) | |
782 | goto error; | |
664cceb0 DH |
783 | out: |
784 | return key_ref; | |
1da177e4 | 785 | |
664cceb0 | 786 | error: |
1da177e4 | 787 | key_put(key); |
664cceb0 | 788 | key_ref = ERR_PTR(ret); |
1da177e4 | 789 | goto out; |
a8b17ed0 | 790 | } |
1da177e4 | 791 | |
6c1976ad TW |
792 | /* |
793 | * Create or potentially update a key. The combined logic behind | |
794 | * key_create_or_update() and key_create() | |
1da177e4 | 795 | */ |
6c1976ad TW |
796 | static key_ref_t __key_create_or_update(key_ref_t keyring_ref, |
797 | const char *type, | |
798 | const char *description, | |
799 | const void *payload, | |
800 | size_t plen, | |
801 | key_perm_t perm, | |
802 | unsigned long flags, | |
803 | bool allow_update) | |
1da177e4 | 804 | { |
16feef43 DH |
805 | struct keyring_index_key index_key = { |
806 | .description = description, | |
807 | }; | |
cf7f601c | 808 | struct key_preparsed_payload prep; |
df593ee2 | 809 | struct assoc_array_edit *edit = NULL; |
d84f4f99 | 810 | const struct cred *cred = current_cred(); |
664cceb0 | 811 | struct key *keyring, *key = NULL; |
664cceb0 | 812 | key_ref_t key_ref; |
1da177e4 | 813 | int ret; |
2b6aa412 | 814 | struct key_restriction *restrict_link = NULL; |
1da177e4 | 815 | |
1da177e4 LT |
816 | /* look up the key type to see if it's one of the registered kernel |
817 | * types */ | |
16feef43 DH |
818 | index_key.type = key_type_lookup(type); |
819 | if (IS_ERR(index_key.type)) { | |
664cceb0 | 820 | key_ref = ERR_PTR(-ENODEV); |
1da177e4 LT |
821 | goto error; |
822 | } | |
823 | ||
664cceb0 | 824 | key_ref = ERR_PTR(-EINVAL); |
c06cfb08 | 825 | if (!index_key.type->instantiate || |
16feef43 | 826 | (!index_key.description && !index_key.type->preparse)) |
cf7f601c | 827 | goto error_put_type; |
1da177e4 | 828 | |
664cceb0 DH |
829 | keyring = key_ref_to_ptr(keyring_ref); |
830 | ||
831 | key_check(keyring); | |
832 | ||
5ac7eace DH |
833 | if (!(flags & KEY_ALLOC_BYPASS_RESTRICTION)) |
834 | restrict_link = keyring->restrict_link; | |
835 | ||
c3a9d654 DH |
836 | key_ref = ERR_PTR(-ENOTDIR); |
837 | if (keyring->type != &key_type_keyring) | |
cf7f601c DH |
838 | goto error_put_type; |
839 | ||
840 | memset(&prep, 0, sizeof(prep)); | |
8eb62169 | 841 | prep.orig_description = description; |
cf7f601c DH |
842 | prep.data = payload; |
843 | prep.datalen = plen; | |
16feef43 | 844 | prep.quotalen = index_key.type->def_datalen; |
0a9dd0e0 | 845 | prep.expiry = TIME64_MAX; |
16feef43 DH |
846 | if (index_key.type->preparse) { |
847 | ret = index_key.type->preparse(&prep); | |
cf7f601c DH |
848 | if (ret < 0) { |
849 | key_ref = ERR_PTR(ret); | |
4d8c0250 | 850 | goto error_free_prep; |
cf7f601c | 851 | } |
16feef43 DH |
852 | if (!index_key.description) |
853 | index_key.description = prep.description; | |
cf7f601c | 854 | key_ref = ERR_PTR(-EINVAL); |
16feef43 | 855 | if (!index_key.description) |
cf7f601c DH |
856 | goto error_free_prep; |
857 | } | |
16feef43 | 858 | index_key.desc_len = strlen(index_key.description); |
f771fde8 | 859 | key_set_index_key(&index_key); |
c3a9d654 | 860 | |
df593ee2 | 861 | ret = __key_link_lock(keyring, &index_key); |
4a420896 MM |
862 | if (ret < 0) { |
863 | key_ref = ERR_PTR(ret); | |
864 | goto error_free_prep; | |
865 | } | |
866 | ||
df593ee2 DH |
867 | ret = __key_link_begin(keyring, &index_key, &edit); |
868 | if (ret < 0) { | |
869 | key_ref = ERR_PTR(ret); | |
870 | goto error_link_end; | |
871 | } | |
872 | ||
2b6aa412 MM |
873 | if (restrict_link && restrict_link->check) { |
874 | ret = restrict_link->check(keyring, index_key.type, | |
875 | &prep.payload, restrict_link->key); | |
5ac7eace DH |
876 | if (ret < 0) { |
877 | key_ref = ERR_PTR(ret); | |
4a420896 | 878 | goto error_link_end; |
5ac7eace DH |
879 | } |
880 | } | |
008643b8 | 881 | |
664cceb0 DH |
882 | /* if we're going to allocate a new key, we're going to have |
883 | * to modify the keyring */ | |
f5895943 | 884 | ret = key_permission(keyring_ref, KEY_NEED_WRITE); |
29db9190 DH |
885 | if (ret < 0) { |
886 | key_ref = ERR_PTR(ret); | |
cf7f601c | 887 | goto error_link_end; |
29db9190 | 888 | } |
664cceb0 | 889 | |
6c1976ad TW |
890 | /* if it's requested and possible to update this type of key, search |
891 | * for an existing key of the same type and description in the | |
892 | * destination keyring and update that instead if possible | |
1da177e4 | 893 | */ |
6c1976ad TW |
894 | if (allow_update) { |
895 | if (index_key.type->update) { | |
896 | key_ref = find_key_to_update(keyring_ref, &index_key); | |
897 | if (key_ref) | |
898 | goto found_matching_key; | |
899 | } | |
900 | } else { | |
b2a4df20 | 901 | key_ref = find_key_to_update(keyring_ref, &index_key); |
6c1976ad TW |
902 | if (key_ref) { |
903 | key_ref_put(key_ref); | |
904 | key_ref = ERR_PTR(-EEXIST); | |
905 | goto error_link_end; | |
906 | } | |
1d9b7d97 | 907 | } |
1da177e4 | 908 | |
028db3e2 LT |
909 | /* if the client doesn't provide, decide on the permissions we want */ |
910 | if (perm == KEY_PERM_UNDEF) { | |
911 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; | |
912 | perm |= KEY_USR_VIEW; | |
913 | ||
914 | if (index_key.type->read) | |
915 | perm |= KEY_POS_READ; | |
916 | ||
917 | if (index_key.type == &key_type_keyring || | |
918 | index_key.type->update) | |
919 | perm |= KEY_POS_WRITE; | |
920 | } | |
921 | ||
1da177e4 | 922 | /* allocate a new key */ |
16feef43 | 923 | key = key_alloc(index_key.type, index_key.description, |
028db3e2 | 924 | cred->fsuid, cred->fsgid, cred, perm, flags, NULL); |
1da177e4 | 925 | if (IS_ERR(key)) { |
e231c2ee | 926 | key_ref = ERR_CAST(key); |
cf7f601c | 927 | goto error_link_end; |
1da177e4 LT |
928 | } |
929 | ||
930 | /* instantiate it and link it into the target keyring */ | |
b2a4df20 | 931 | ret = __key_instantiate_and_link(key, &prep, keyring, NULL, &edit); |
1da177e4 LT |
932 | if (ret < 0) { |
933 | key_put(key); | |
664cceb0 | 934 | key_ref = ERR_PTR(ret); |
cf7f601c | 935 | goto error_link_end; |
1da177e4 LT |
936 | } |
937 | ||
cb1aa382 LR |
938 | ima_post_key_create_or_update(keyring, key, payload, plen, |
939 | flags, true); | |
940 | ||
664cceb0 DH |
941 | key_ref = make_key_ref(key, is_key_possessed(keyring_ref)); |
942 | ||
cf7f601c | 943 | error_link_end: |
b2a4df20 | 944 | __key_link_end(keyring, &index_key, edit); |
cf7f601c | 945 | error_free_prep: |
16feef43 DH |
946 | if (index_key.type->preparse) |
947 | index_key.type->free_preparse(&prep); | |
cf7f601c | 948 | error_put_type: |
16feef43 | 949 | key_type_put(index_key.type); |
cf7f601c | 950 | error: |
664cceb0 | 951 | return key_ref; |
1da177e4 LT |
952 | |
953 | found_matching_key: | |
954 | /* we found a matching key, so we're going to try to update it | |
955 | * - we can drop the locks first as we have the key pinned | |
956 | */ | |
b2a4df20 | 957 | __key_link_end(keyring, &index_key, edit); |
1da177e4 | 958 | |
60ff5b2f DH |
959 | key = key_ref_to_ptr(key_ref); |
960 | if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags)) { | |
961 | ret = wait_for_key_construction(key, true); | |
962 | if (ret < 0) { | |
963 | key_ref_put(key_ref); | |
964 | key_ref = ERR_PTR(ret); | |
965 | goto error_free_prep; | |
966 | } | |
967 | } | |
968 | ||
cf7f601c | 969 | key_ref = __key_update(key_ref, &prep); |
cb1aa382 LR |
970 | |
971 | if (!IS_ERR(key_ref)) | |
972 | ima_post_key_create_or_update(keyring, key, | |
973 | payload, plen, | |
974 | flags, false); | |
975 | ||
cf7f601c | 976 | goto error_free_prep; |
a8b17ed0 | 977 | } |
6c1976ad TW |
978 | |
979 | /** | |
980 | * key_create_or_update - Update or create and instantiate a key. | |
981 | * @keyring_ref: A pointer to the destination keyring with possession flag. | |
982 | * @type: The type of key. | |
983 | * @description: The searchable description for the key. | |
984 | * @payload: The data to use to instantiate or update the key. | |
985 | * @plen: The length of @payload. | |
986 | * @perm: The permissions mask for a new key. | |
987 | * @flags: The quota flags for a new key. | |
988 | * | |
989 | * Search the destination keyring for a key of the same description and if one | |
990 | * is found, update it, otherwise create and instantiate a new one and create a | |
991 | * link to it from that keyring. | |
992 | * | |
993 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be | |
994 | * concocted. | |
995 | * | |
996 | * Returns a pointer to the new key if successful, -ENODEV if the key type | |
997 | * wasn't available, -ENOTDIR if the keyring wasn't a keyring, -EACCES if the | |
998 | * caller isn't permitted to modify the keyring or the LSM did not permit | |
999 | * creation of the key. | |
1000 | * | |
1001 | * On success, the possession flag from the keyring ref will be tacked on to | |
1002 | * the key ref before it is returned. | |
1003 | */ | |
1004 | key_ref_t key_create_or_update(key_ref_t keyring_ref, | |
1005 | const char *type, | |
1006 | const char *description, | |
1007 | const void *payload, | |
1008 | size_t plen, | |
1009 | key_perm_t perm, | |
1010 | unsigned long flags) | |
1011 | { | |
1012 | return __key_create_or_update(keyring_ref, type, description, payload, | |
1013 | plen, perm, flags, true); | |
1014 | } | |
1da177e4 LT |
1015 | EXPORT_SYMBOL(key_create_or_update); |
1016 | ||
6c1976ad TW |
1017 | /** |
1018 | * key_create - Create and instantiate a key. | |
1019 | * @keyring_ref: A pointer to the destination keyring with possession flag. | |
1020 | * @type: The type of key. | |
1021 | * @description: The searchable description for the key. | |
1022 | * @payload: The data to use to instantiate or update the key. | |
1023 | * @plen: The length of @payload. | |
1024 | * @perm: The permissions mask for a new key. | |
1025 | * @flags: The quota flags for a new key. | |
1026 | * | |
1027 | * Create and instantiate a new key and link to it from the destination keyring. | |
1028 | * | |
1029 | * If perm is KEY_PERM_UNDEF then an appropriate key permissions mask will be | |
1030 | * concocted. | |
1031 | * | |
1032 | * Returns a pointer to the new key if successful, -EEXIST if a key with the | |
1033 | * same description already exists, -ENODEV if the key type wasn't available, | |
1034 | * -ENOTDIR if the keyring wasn't a keyring, -EACCES if the caller isn't | |
1035 | * permitted to modify the keyring or the LSM did not permit creation of the | |
1036 | * key. | |
1037 | * | |
1038 | * On success, the possession flag from the keyring ref will be tacked on to | |
1039 | * the key ref before it is returned. | |
1040 | */ | |
1041 | key_ref_t key_create(key_ref_t keyring_ref, | |
1042 | const char *type, | |
1043 | const char *description, | |
1044 | const void *payload, | |
1045 | size_t plen, | |
1046 | key_perm_t perm, | |
1047 | unsigned long flags) | |
1048 | { | |
1049 | return __key_create_or_update(keyring_ref, type, description, payload, | |
1050 | plen, perm, flags, false); | |
1051 | } | |
1052 | EXPORT_SYMBOL(key_create); | |
1053 | ||
973c9f4f DH |
1054 | /** |
1055 | * key_update - Update a key's contents. | |
1056 | * @key_ref: The pointer (plus possession flag) to the key. | |
1057 | * @payload: The data to be used to update the key. | |
1058 | * @plen: The length of @payload. | |
1059 | * | |
1060 | * Attempt to update the contents of a key with the given payload data. The | |
1061 | * caller must be granted Write permission on the key. Negative keys can be | |
1062 | * instantiated by this method. | |
1063 | * | |
1064 | * Returns 0 on success, -EACCES if not permitted and -EOPNOTSUPP if the key | |
1065 | * type does not support updating. The key type may return other errors. | |
1da177e4 | 1066 | */ |
664cceb0 | 1067 | int key_update(key_ref_t key_ref, const void *payload, size_t plen) |
1da177e4 | 1068 | { |
cf7f601c | 1069 | struct key_preparsed_payload prep; |
664cceb0 | 1070 | struct key *key = key_ref_to_ptr(key_ref); |
1da177e4 LT |
1071 | int ret; |
1072 | ||
1073 | key_check(key); | |
1074 | ||
1075 | /* the key must be writable */ | |
f5895943 | 1076 | ret = key_permission(key_ref, KEY_NEED_WRITE); |
29db9190 | 1077 | if (ret < 0) |
63a0b050 | 1078 | return ret; |
1da177e4 LT |
1079 | |
1080 | /* attempt to update it if supported */ | |
cf7f601c | 1081 | if (!key->type->update) |
63a0b050 | 1082 | return -EOPNOTSUPP; |
1da177e4 | 1083 | |
cf7f601c DH |
1084 | memset(&prep, 0, sizeof(prep)); |
1085 | prep.data = payload; | |
1086 | prep.datalen = plen; | |
1087 | prep.quotalen = key->type->def_datalen; | |
0a9dd0e0 | 1088 | prep.expiry = TIME64_MAX; |
cf7f601c DH |
1089 | if (key->type->preparse) { |
1090 | ret = key->type->preparse(&prep); | |
1091 | if (ret < 0) | |
1092 | goto error; | |
1da177e4 LT |
1093 | } |
1094 | ||
cf7f601c DH |
1095 | down_write(&key->sem); |
1096 | ||
1097 | ret = key->type->update(key, &prep); | |
f7e47677 | 1098 | if (ret == 0) { |
363b02da DH |
1099 | /* Updating a negative key positively instantiates it */ |
1100 | mark_key_instantiated(key, 0); | |
f7e47677 DH |
1101 | notify_key(key, NOTIFY_KEY_UPDATED, 0); |
1102 | } | |
cf7f601c DH |
1103 | |
1104 | up_write(&key->sem); | |
1105 | ||
4d8c0250 | 1106 | error: |
cf7f601c DH |
1107 | if (key->type->preparse) |
1108 | key->type->free_preparse(&prep); | |
1da177e4 | 1109 | return ret; |
a8b17ed0 | 1110 | } |
1da177e4 LT |
1111 | EXPORT_SYMBOL(key_update); |
1112 | ||
973c9f4f DH |
1113 | /** |
1114 | * key_revoke - Revoke a key. | |
1115 | * @key: The key to be revoked. | |
1116 | * | |
1117 | * Mark a key as being revoked and ask the type to free up its resources. The | |
1118 | * revocation timeout is set and the key and all its links will be | |
1119 | * automatically garbage collected after key_gc_delay amount of time if they | |
1120 | * are not manually dealt with first. | |
1da177e4 LT |
1121 | */ |
1122 | void key_revoke(struct key *key) | |
1123 | { | |
074d5898 | 1124 | time64_t time; |
5d135440 | 1125 | |
1da177e4 LT |
1126 | key_check(key); |
1127 | ||
76181c13 DH |
1128 | /* make sure no one's trying to change or use the key when we mark it |
1129 | * - we tell lockdep that we might nest because we might be revoking an | |
1130 | * authorisation key whilst holding the sem on a key we've just | |
1131 | * instantiated | |
1132 | */ | |
1133 | down_write_nested(&key->sem, 1); | |
f7e47677 DH |
1134 | if (!test_and_set_bit(KEY_FLAG_REVOKED, &key->flags)) { |
1135 | notify_key(key, NOTIFY_KEY_REVOKED, 0); | |
1136 | if (key->type->revoke) | |
1137 | key->type->revoke(key); | |
1138 | ||
1139 | /* set the death time to no more than the expiry time */ | |
1140 | time = ktime_get_real_seconds(); | |
1141 | if (key->revoked_at == 0 || key->revoked_at > time) { | |
1142 | key->revoked_at = time; | |
1143 | key_schedule_gc(key->revoked_at + key_gc_delay); | |
1144 | } | |
5d135440 DH |
1145 | } |
1146 | ||
1da177e4 | 1147 | up_write(&key->sem); |
a8b17ed0 | 1148 | } |
1da177e4 LT |
1149 | EXPORT_SYMBOL(key_revoke); |
1150 | ||
fd75815f DH |
1151 | /** |
1152 | * key_invalidate - Invalidate a key. | |
1153 | * @key: The key to be invalidated. | |
1154 | * | |
1155 | * Mark a key as being invalidated and have it cleaned up immediately. The key | |
1156 | * is ignored by all searches and other operations from this point. | |
1157 | */ | |
1158 | void key_invalidate(struct key *key) | |
1159 | { | |
1160 | kenter("%d", key_serial(key)); | |
1161 | ||
1162 | key_check(key); | |
1163 | ||
1164 | if (!test_bit(KEY_FLAG_INVALIDATED, &key->flags)) { | |
1165 | down_write_nested(&key->sem, 1); | |
f7e47677 DH |
1166 | if (!test_and_set_bit(KEY_FLAG_INVALIDATED, &key->flags)) { |
1167 | notify_key(key, NOTIFY_KEY_INVALIDATED, 0); | |
fd75815f | 1168 | key_schedule_gc_links(); |
f7e47677 | 1169 | } |
fd75815f DH |
1170 | up_write(&key->sem); |
1171 | } | |
1172 | } | |
1173 | EXPORT_SYMBOL(key_invalidate); | |
1174 | ||
6a09d17b DH |
1175 | /** |
1176 | * generic_key_instantiate - Simple instantiation of a key from preparsed data | |
1177 | * @key: The key to be instantiated | |
1178 | * @prep: The preparsed data to load. | |
1179 | * | |
1180 | * Instantiate a key from preparsed data. We assume we can just copy the data | |
1181 | * in directly and clear the old pointers. | |
1182 | * | |
1183 | * This can be pointed to directly by the key type instantiate op pointer. | |
1184 | */ | |
1185 | int generic_key_instantiate(struct key *key, struct key_preparsed_payload *prep) | |
1186 | { | |
1187 | int ret; | |
1188 | ||
1189 | pr_devel("==>%s()\n", __func__); | |
1190 | ||
1191 | ret = key_payload_reserve(key, prep->quotalen); | |
1192 | if (ret == 0) { | |
146aa8b1 DH |
1193 | rcu_assign_keypointer(key, prep->payload.data[0]); |
1194 | key->payload.data[1] = prep->payload.data[1]; | |
1195 | key->payload.data[2] = prep->payload.data[2]; | |
1196 | key->payload.data[3] = prep->payload.data[3]; | |
1197 | prep->payload.data[0] = NULL; | |
1198 | prep->payload.data[1] = NULL; | |
1199 | prep->payload.data[2] = NULL; | |
1200 | prep->payload.data[3] = NULL; | |
6a09d17b DH |
1201 | } |
1202 | pr_devel("<==%s() = %d\n", __func__, ret); | |
1203 | return ret; | |
1204 | } | |
1205 | EXPORT_SYMBOL(generic_key_instantiate); | |
1206 | ||
973c9f4f DH |
1207 | /** |
1208 | * register_key_type - Register a type of key. | |
1209 | * @ktype: The new key type. | |
1210 | * | |
1211 | * Register a new key type. | |
1212 | * | |
1213 | * Returns 0 on success or -EEXIST if a type of this name already exists. | |
1da177e4 LT |
1214 | */ |
1215 | int register_key_type(struct key_type *ktype) | |
1216 | { | |
1217 | struct key_type *p; | |
1218 | int ret; | |
1219 | ||
7845bc39 DH |
1220 | memset(&ktype->lock_class, 0, sizeof(ktype->lock_class)); |
1221 | ||
1da177e4 LT |
1222 | ret = -EEXIST; |
1223 | down_write(&key_types_sem); | |
1224 | ||
1225 | /* disallow key types with the same name */ | |
1226 | list_for_each_entry(p, &key_types_list, link) { | |
1227 | if (strcmp(p->name, ktype->name) == 0) | |
1228 | goto out; | |
1229 | } | |
1230 | ||
1231 | /* store the type */ | |
1232 | list_add(&ktype->link, &key_types_list); | |
1eb1bcf5 DH |
1233 | |
1234 | pr_notice("Key type %s registered\n", ktype->name); | |
1da177e4 LT |
1235 | ret = 0; |
1236 | ||
973c9f4f | 1237 | out: |
1da177e4 LT |
1238 | up_write(&key_types_sem); |
1239 | return ret; | |
a8b17ed0 | 1240 | } |
1da177e4 LT |
1241 | EXPORT_SYMBOL(register_key_type); |
1242 | ||
973c9f4f DH |
1243 | /** |
1244 | * unregister_key_type - Unregister a type of key. | |
1245 | * @ktype: The key type. | |
1246 | * | |
1247 | * Unregister a key type and mark all the extant keys of this type as dead. | |
1248 | * Those keys of this type are then destroyed to get rid of their payloads and | |
1249 | * they and their links will be garbage collected as soon as possible. | |
1da177e4 LT |
1250 | */ |
1251 | void unregister_key_type(struct key_type *ktype) | |
1252 | { | |
1da177e4 | 1253 | down_write(&key_types_sem); |
1da177e4 | 1254 | list_del_init(&ktype->link); |
0c061b57 DH |
1255 | downgrade_write(&key_types_sem); |
1256 | key_gc_keytype(ktype); | |
1eb1bcf5 | 1257 | pr_notice("Key type %s unregistered\n", ktype->name); |
0c061b57 | 1258 | up_read(&key_types_sem); |
a8b17ed0 | 1259 | } |
1da177e4 LT |
1260 | EXPORT_SYMBOL(unregister_key_type); |
1261 | ||
1da177e4 | 1262 | /* |
973c9f4f | 1263 | * Initialise the key management state. |
1da177e4 LT |
1264 | */ |
1265 | void __init key_init(void) | |
1266 | { | |
1267 | /* allocate a slab in which we can store keys */ | |
1268 | key_jar = kmem_cache_create("key_jar", sizeof(struct key), | |
20c2df83 | 1269 | 0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL); |
1da177e4 LT |
1270 | |
1271 | /* add the special key types */ | |
1272 | list_add_tail(&key_type_keyring.link, &key_types_list); | |
1273 | list_add_tail(&key_type_dead.link, &key_types_list); | |
1274 | list_add_tail(&key_type_user.link, &key_types_list); | |
9f6ed2ca | 1275 | list_add_tail(&key_type_logon.link, &key_types_list); |
1da177e4 LT |
1276 | |
1277 | /* record the root user tracking */ | |
1278 | rb_link_node(&root_key_user.node, | |
1279 | NULL, | |
1280 | &key_user_tree.rb_node); | |
1281 | ||
1282 | rb_insert_color(&root_key_user.node, | |
1283 | &key_user_tree); | |
a8b17ed0 | 1284 | } |