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Commit | Line | Data |
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76181c13 | 1 | /* Request a key from userspace |
1da177e4 | 2 | * |
76181c13 | 3 | * Copyright (C) 2004-2007 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. | |
f1a9badc | 10 | * |
3db38ed7 | 11 | * See Documentation/security/keys/request-key.rst |
1da177e4 LT |
12 | */ |
13 | ||
14 | #include <linux/module.h> | |
15 | #include <linux/sched.h> | |
16 | #include <linux/kmod.h> | |
17 | #include <linux/err.h> | |
3e30148c | 18 | #include <linux/keyctl.h> |
fdb89bce | 19 | #include <linux/slab.h> |
1da177e4 LT |
20 | #include "internal.h" |
21 | ||
e9e349b0 DH |
22 | #define key_negative_timeout 60 /* default timeout on a negative key's existence */ |
23 | ||
973c9f4f DH |
24 | /** |
25 | * complete_request_key - Complete the construction of a key. | |
26 | * @cons: The key construction record. | |
27 | * @error: The success or failute of the construction. | |
28 | * | |
29 | * Complete the attempt to construct a key. The key will be negated | |
30 | * if an error is indicated. The authorisation key will be revoked | |
31 | * unconditionally. | |
76181c13 DH |
32 | */ |
33 | void complete_request_key(struct key_construction *cons, int error) | |
34 | { | |
35 | kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error); | |
1da177e4 | 36 | |
76181c13 DH |
37 | if (error < 0) |
38 | key_negate_and_link(cons->key, key_negative_timeout, NULL, | |
39 | cons->authkey); | |
40 | else | |
41 | key_revoke(cons->authkey); | |
42 | ||
43 | key_put(cons->key); | |
44 | key_put(cons->authkey); | |
45 | kfree(cons); | |
46 | } | |
47 | EXPORT_SYMBOL(complete_request_key); | |
1da177e4 | 48 | |
973c9f4f DH |
49 | /* |
50 | * Initialise a usermode helper that is going to have a specific session | |
51 | * keyring. | |
52 | * | |
53 | * This is called in context of freshly forked kthread before kernel_execve(), | |
54 | * so we can simply install the desired session_keyring at this point. | |
55 | */ | |
87966996 | 56 | static int umh_keys_init(struct subprocess_info *info, struct cred *cred) |
685bfd2c | 57 | { |
685bfd2c | 58 | struct key *keyring = info->data; |
973c9f4f | 59 | |
685bfd2c ON |
60 | return install_session_keyring_to_cred(cred, keyring); |
61 | } | |
62 | ||
973c9f4f DH |
63 | /* |
64 | * Clean up a usermode helper with session keyring. | |
65 | */ | |
685bfd2c ON |
66 | static void umh_keys_cleanup(struct subprocess_info *info) |
67 | { | |
68 | struct key *keyring = info->data; | |
69 | key_put(keyring); | |
70 | } | |
71 | ||
973c9f4f DH |
72 | /* |
73 | * Call a usermode helper with a specific session keyring. | |
74 | */ | |
377e7a27 | 75 | static int call_usermodehelper_keys(const char *path, char **argv, char **envp, |
9d944ef3 | 76 | struct key *session_keyring, int wait) |
685bfd2c | 77 | { |
93997f6d LDM |
78 | struct subprocess_info *info; |
79 | ||
80 | info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL, | |
81 | umh_keys_init, umh_keys_cleanup, | |
82 | session_keyring); | |
83 | if (!info) | |
84 | return -ENOMEM; | |
85 | ||
86 | key_get(session_keyring); | |
87 | return call_usermodehelper_exec(info, wait); | |
685bfd2c ON |
88 | } |
89 | ||
1da177e4 | 90 | /* |
973c9f4f | 91 | * Request userspace finish the construction of a key |
b5f545c8 | 92 | * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>" |
1da177e4 | 93 | */ |
76181c13 | 94 | static int call_sbin_request_key(struct key_construction *cons, |
4e54f085 DH |
95 | const char *op, |
96 | void *aux) | |
1da177e4 | 97 | { |
377e7a27 | 98 | static char const request_key[] = "/sbin/request-key"; |
86a264ab | 99 | const struct cred *cred = current_cred(); |
1da177e4 | 100 | key_serial_t prkey, sskey; |
93b4a44f DH |
101 | struct key *key = cons->key, *authkey = cons->authkey, *keyring, |
102 | *session; | |
b5f545c8 | 103 | char *argv[9], *envp[3], uid_str[12], gid_str[12]; |
1da177e4 | 104 | char key_str[12], keyring_str[3][12]; |
b5f545c8 | 105 | char desc[20]; |
3e30148c DH |
106 | int ret, i; |
107 | ||
b5f545c8 | 108 | kenter("{%d},{%d},%s", key->serial, authkey->serial, op); |
3e30148c | 109 | |
8bbf4976 DH |
110 | ret = install_user_keyrings(); |
111 | if (ret < 0) | |
112 | goto error_alloc; | |
113 | ||
b5f545c8 DH |
114 | /* allocate a new session keyring */ |
115 | sprintf(desc, "_req.%u", key->serial); | |
116 | ||
d84f4f99 DH |
117 | cred = get_current_cred(); |
118 | keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, | |
96b5c8fe | 119 | KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, |
5ac7eace | 120 | KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL); |
d84f4f99 | 121 | put_cred(cred); |
b5f545c8 DH |
122 | if (IS_ERR(keyring)) { |
123 | ret = PTR_ERR(keyring); | |
124 | goto error_alloc; | |
3e30148c | 125 | } |
1da177e4 | 126 | |
b5f545c8 | 127 | /* attach the auth key to the session keyring */ |
896903c2 | 128 | ret = key_link(keyring, authkey); |
b5f545c8 DH |
129 | if (ret < 0) |
130 | goto error_link; | |
131 | ||
1da177e4 | 132 | /* record the UID and GID */ |
9a56c2db EB |
133 | sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); |
134 | sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); | |
1da177e4 LT |
135 | |
136 | /* we say which key is under construction */ | |
137 | sprintf(key_str, "%d", key->serial); | |
138 | ||
139 | /* we specify the process's default keyrings */ | |
140 | sprintf(keyring_str[0], "%d", | |
d84f4f99 | 141 | cred->thread_keyring ? cred->thread_keyring->serial : 0); |
1da177e4 LT |
142 | |
143 | prkey = 0; | |
3a50597d DH |
144 | if (cred->process_keyring) |
145 | prkey = cred->process_keyring->serial; | |
5ad18a0d | 146 | sprintf(keyring_str[1], "%d", prkey); |
1da177e4 | 147 | |
93b4a44f | 148 | rcu_read_lock(); |
3a50597d | 149 | session = rcu_dereference(cred->session_keyring); |
93b4a44f DH |
150 | if (!session) |
151 | session = cred->user->session_keyring; | |
152 | sskey = session->serial; | |
153 | rcu_read_unlock(); | |
1da177e4 | 154 | |
1da177e4 LT |
155 | sprintf(keyring_str[2], "%d", sskey); |
156 | ||
157 | /* set up a minimal environment */ | |
158 | i = 0; | |
159 | envp[i++] = "HOME=/"; | |
160 | envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; | |
161 | envp[i] = NULL; | |
162 | ||
163 | /* set up the argument list */ | |
164 | i = 0; | |
377e7a27 | 165 | argv[i++] = (char *)request_key; |
1da177e4 LT |
166 | argv[i++] = (char *) op; |
167 | argv[i++] = key_str; | |
168 | argv[i++] = uid_str; | |
169 | argv[i++] = gid_str; | |
170 | argv[i++] = keyring_str[0]; | |
171 | argv[i++] = keyring_str[1]; | |
172 | argv[i++] = keyring_str[2]; | |
1da177e4 LT |
173 | argv[i] = NULL; |
174 | ||
175 | /* do it */ | |
377e7a27 | 176 | ret = call_usermodehelper_keys(request_key, argv, envp, keyring, |
86313c48 | 177 | UMH_WAIT_PROC); |
76181c13 DH |
178 | kdebug("usermode -> 0x%x", ret); |
179 | if (ret >= 0) { | |
180 | /* ret is the exit/wait code */ | |
181 | if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) || | |
182 | key_validate(key) < 0) | |
183 | ret = -ENOKEY; | |
184 | else | |
185 | /* ignore any errors from userspace if the key was | |
186 | * instantiated */ | |
187 | ret = 0; | |
188 | } | |
3e30148c | 189 | |
b5f545c8 DH |
190 | error_link: |
191 | key_put(keyring); | |
3e30148c | 192 | |
b5f545c8 | 193 | error_alloc: |
76181c13 | 194 | complete_request_key(cons, ret); |
d84f4f99 | 195 | kleave(" = %d", ret); |
3e30148c | 196 | return ret; |
76181c13 | 197 | } |
1da177e4 | 198 | |
1da177e4 | 199 | /* |
973c9f4f DH |
200 | * Call out to userspace for key construction. |
201 | * | |
202 | * Program failure is ignored in favour of key status. | |
1da177e4 | 203 | */ |
4a38e122 | 204 | static int construct_key(struct key *key, const void *callout_info, |
8bbf4976 DH |
205 | size_t callout_len, void *aux, |
206 | struct key *dest_keyring) | |
1da177e4 | 207 | { |
76181c13 | 208 | struct key_construction *cons; |
b5f545c8 | 209 | request_key_actor_t actor; |
76181c13 DH |
210 | struct key *authkey; |
211 | int ret; | |
1da177e4 | 212 | |
4a38e122 | 213 | kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux); |
3e30148c | 214 | |
76181c13 DH |
215 | cons = kmalloc(sizeof(*cons), GFP_KERNEL); |
216 | if (!cons) | |
217 | return -ENOMEM; | |
1da177e4 | 218 | |
b5f545c8 | 219 | /* allocate an authorisation key */ |
8bbf4976 DH |
220 | authkey = request_key_auth_new(key, callout_info, callout_len, |
221 | dest_keyring); | |
b5f545c8 | 222 | if (IS_ERR(authkey)) { |
76181c13 | 223 | kfree(cons); |
b5f545c8 DH |
224 | ret = PTR_ERR(authkey); |
225 | authkey = NULL; | |
76181c13 DH |
226 | } else { |
227 | cons->authkey = key_get(authkey); | |
228 | cons->key = key_get(key); | |
229 | ||
230 | /* make the call */ | |
231 | actor = call_sbin_request_key; | |
232 | if (key->type->request_key) | |
233 | actor = key->type->request_key; | |
234 | ||
235 | ret = actor(cons, "create", aux); | |
236 | ||
237 | /* check that the actor called complete_request_key() prior to | |
238 | * returning an error */ | |
239 | WARN_ON(ret < 0 && | |
240 | !test_bit(KEY_FLAG_REVOKED, &authkey->flags)); | |
241 | key_put(authkey); | |
1da177e4 LT |
242 | } |
243 | ||
76181c13 DH |
244 | kleave(" = %d", ret); |
245 | return ret; | |
246 | } | |
1da177e4 | 247 | |
3e30148c | 248 | /* |
973c9f4f DH |
249 | * Get the appropriate destination keyring for the request. |
250 | * | |
251 | * The keyring selected is returned with an extra reference upon it which the | |
252 | * caller must release. | |
3e30148c | 253 | */ |
4dca6ea1 | 254 | static int construct_get_dest_keyring(struct key **_dest_keyring) |
3e30148c | 255 | { |
8bbf4976 | 256 | struct request_key_auth *rka; |
bb952bb9 | 257 | const struct cred *cred = current_cred(); |
8bbf4976 | 258 | struct key *dest_keyring = *_dest_keyring, *authkey; |
4dca6ea1 | 259 | int ret; |
3e30148c | 260 | |
8bbf4976 | 261 | kenter("%p", dest_keyring); |
3e30148c DH |
262 | |
263 | /* find the appropriate keyring */ | |
8bbf4976 DH |
264 | if (dest_keyring) { |
265 | /* the caller supplied one */ | |
266 | key_get(dest_keyring); | |
267 | } else { | |
4dca6ea1 EB |
268 | bool do_perm_check = true; |
269 | ||
8bbf4976 DH |
270 | /* use a default keyring; falling through the cases until we |
271 | * find one that we actually have */ | |
bb952bb9 | 272 | switch (cred->jit_keyring) { |
3e30148c | 273 | case KEY_REQKEY_DEFL_DEFAULT: |
8bbf4976 | 274 | case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: |
bb952bb9 DH |
275 | if (cred->request_key_auth) { |
276 | authkey = cred->request_key_auth; | |
8bbf4976 | 277 | down_read(&authkey->sem); |
146aa8b1 | 278 | rka = authkey->payload.data[0]; |
8bbf4976 DH |
279 | if (!test_bit(KEY_FLAG_REVOKED, |
280 | &authkey->flags)) | |
281 | dest_keyring = | |
282 | key_get(rka->dest_keyring); | |
283 | up_read(&authkey->sem); | |
4dca6ea1 EB |
284 | if (dest_keyring) { |
285 | do_perm_check = false; | |
8bbf4976 | 286 | break; |
4dca6ea1 | 287 | } |
8bbf4976 DH |
288 | } |
289 | ||
3e30148c | 290 | case KEY_REQKEY_DEFL_THREAD_KEYRING: |
bb952bb9 | 291 | dest_keyring = key_get(cred->thread_keyring); |
3e30148c DH |
292 | if (dest_keyring) |
293 | break; | |
294 | ||
295 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: | |
3a50597d | 296 | dest_keyring = key_get(cred->process_keyring); |
3e30148c DH |
297 | if (dest_keyring) |
298 | break; | |
299 | ||
300 | case KEY_REQKEY_DEFL_SESSION_KEYRING: | |
301 | rcu_read_lock(); | |
302 | dest_keyring = key_get( | |
3a50597d | 303 | rcu_dereference(cred->session_keyring)); |
3e30148c | 304 | rcu_read_unlock(); |
3e30148c DH |
305 | |
306 | if (dest_keyring) | |
307 | break; | |
308 | ||
309 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: | |
b6dff3ec | 310 | dest_keyring = |
bb952bb9 | 311 | key_get(cred->user->session_keyring); |
3e30148c DH |
312 | break; |
313 | ||
314 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
bb952bb9 | 315 | dest_keyring = key_get(cred->user->uid_keyring); |
3e30148c DH |
316 | break; |
317 | ||
318 | case KEY_REQKEY_DEFL_GROUP_KEYRING: | |
319 | default: | |
320 | BUG(); | |
321 | } | |
4dca6ea1 EB |
322 | |
323 | /* | |
324 | * Require Write permission on the keyring. This is essential | |
325 | * because the default keyring may be the session keyring, and | |
326 | * joining a keyring only requires Search permission. | |
327 | * | |
328 | * However, this check is skipped for the "requestor keyring" so | |
329 | * that /sbin/request-key can itself use request_key() to add | |
330 | * keys to the original requestor's destination keyring. | |
331 | */ | |
332 | if (dest_keyring && do_perm_check) { | |
333 | ret = key_permission(make_key_ref(dest_keyring, 1), | |
334 | KEY_NEED_WRITE); | |
335 | if (ret) { | |
336 | key_put(dest_keyring); | |
337 | return ret; | |
338 | } | |
339 | } | |
3e30148c DH |
340 | } |
341 | ||
8bbf4976 DH |
342 | *_dest_keyring = dest_keyring; |
343 | kleave(" [dk %d]", key_serial(dest_keyring)); | |
4dca6ea1 | 344 | return 0; |
76181c13 | 345 | } |
3e30148c | 346 | |
76181c13 | 347 | /* |
973c9f4f DH |
348 | * Allocate a new key in under-construction state and attempt to link it in to |
349 | * the requested keyring. | |
350 | * | |
351 | * May return a key that's already under construction instead if there was a | |
352 | * race between two thread calling request_key(). | |
76181c13 | 353 | */ |
4bdf0bc3 | 354 | static int construct_alloc_key(struct keyring_search_context *ctx, |
76181c13 DH |
355 | struct key *dest_keyring, |
356 | unsigned long flags, | |
357 | struct key_user *user, | |
358 | struct key **_key) | |
359 | { | |
b2a4df20 | 360 | struct assoc_array_edit *edit; |
76181c13 | 361 | struct key *key; |
96b5c8fe | 362 | key_perm_t perm; |
76181c13 | 363 | key_ref_t key_ref; |
2b9e4688 | 364 | int ret; |
76181c13 | 365 | |
4bdf0bc3 DH |
366 | kenter("%s,%s,,,", |
367 | ctx->index_key.type->name, ctx->index_key.description); | |
76181c13 | 368 | |
f70e2e06 | 369 | *_key = NULL; |
76181c13 DH |
370 | mutex_lock(&user->cons_lock); |
371 | ||
96b5c8fe DH |
372 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; |
373 | perm |= KEY_USR_VIEW; | |
4bdf0bc3 | 374 | if (ctx->index_key.type->read) |
96b5c8fe | 375 | perm |= KEY_POS_READ; |
4bdf0bc3 DH |
376 | if (ctx->index_key.type == &key_type_keyring || |
377 | ctx->index_key.type->update) | |
96b5c8fe DH |
378 | perm |= KEY_POS_WRITE; |
379 | ||
4bdf0bc3 DH |
380 | key = key_alloc(ctx->index_key.type, ctx->index_key.description, |
381 | ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred, | |
5ac7eace | 382 | perm, flags, NULL); |
76181c13 DH |
383 | if (IS_ERR(key)) |
384 | goto alloc_failed; | |
385 | ||
386 | set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); | |
387 | ||
f70e2e06 | 388 | if (dest_keyring) { |
b2a4df20 | 389 | ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit); |
f70e2e06 DH |
390 | if (ret < 0) |
391 | goto link_prealloc_failed; | |
392 | } | |
76181c13 DH |
393 | |
394 | /* attach the key to the destination keyring under lock, but we do need | |
395 | * to do another check just in case someone beat us to it whilst we | |
396 | * waited for locks */ | |
397 | mutex_lock(&key_construction_mutex); | |
398 | ||
4bdf0bc3 | 399 | key_ref = search_process_keyrings(ctx); |
76181c13 DH |
400 | if (!IS_ERR(key_ref)) |
401 | goto key_already_present; | |
402 | ||
34574dd1 | 403 | if (dest_keyring) |
b2a4df20 | 404 | __key_link(key, &edit); |
76181c13 DH |
405 | |
406 | mutex_unlock(&key_construction_mutex); | |
34574dd1 | 407 | if (dest_keyring) |
b2a4df20 | 408 | __key_link_end(dest_keyring, &ctx->index_key, edit); |
76181c13 DH |
409 | mutex_unlock(&user->cons_lock); |
410 | *_key = key; | |
411 | kleave(" = 0 [%d]", key_serial(key)); | |
412 | return 0; | |
413 | ||
2b9e4688 DH |
414 | /* the key is now present - we tell the caller that we found it by |
415 | * returning -EINPROGRESS */ | |
76181c13 | 416 | key_already_present: |
f70e2e06 | 417 | key_put(key); |
76181c13 | 418 | mutex_unlock(&key_construction_mutex); |
f70e2e06 | 419 | key = key_ref_to_ptr(key_ref); |
03449cd9 | 420 | if (dest_keyring) { |
f70e2e06 DH |
421 | ret = __key_link_check_live_key(dest_keyring, key); |
422 | if (ret == 0) | |
b2a4df20 DH |
423 | __key_link(key, &edit); |
424 | __key_link_end(dest_keyring, &ctx->index_key, edit); | |
f70e2e06 DH |
425 | if (ret < 0) |
426 | goto link_check_failed; | |
03449cd9 | 427 | } |
76181c13 | 428 | mutex_unlock(&user->cons_lock); |
f70e2e06 | 429 | *_key = key; |
76181c13 DH |
430 | kleave(" = -EINPROGRESS [%d]", key_serial(key)); |
431 | return -EINPROGRESS; | |
432 | ||
f70e2e06 DH |
433 | link_check_failed: |
434 | mutex_unlock(&user->cons_lock); | |
435 | key_put(key); | |
436 | kleave(" = %d [linkcheck]", ret); | |
437 | return ret; | |
438 | ||
439 | link_prealloc_failed: | |
f70e2e06 | 440 | mutex_unlock(&user->cons_lock); |
d0709f1e | 441 | key_put(key); |
f70e2e06 DH |
442 | kleave(" = %d [prelink]", ret); |
443 | return ret; | |
444 | ||
76181c13 DH |
445 | alloc_failed: |
446 | mutex_unlock(&user->cons_lock); | |
76181c13 DH |
447 | kleave(" = %ld", PTR_ERR(key)); |
448 | return PTR_ERR(key); | |
449 | } | |
450 | ||
451 | /* | |
973c9f4f | 452 | * Commence key construction. |
76181c13 | 453 | */ |
4bdf0bc3 | 454 | static struct key *construct_key_and_link(struct keyring_search_context *ctx, |
76181c13 | 455 | const char *callout_info, |
4a38e122 | 456 | size_t callout_len, |
76181c13 DH |
457 | void *aux, |
458 | struct key *dest_keyring, | |
459 | unsigned long flags) | |
460 | { | |
461 | struct key_user *user; | |
462 | struct key *key; | |
463 | int ret; | |
464 | ||
d84f4f99 DH |
465 | kenter(""); |
466 | ||
911b79cd DH |
467 | if (ctx->index_key.type == &key_type_keyring) |
468 | return ERR_PTR(-EPERM); | |
965475ac | 469 | |
4dca6ea1 EB |
470 | ret = construct_get_dest_keyring(&dest_keyring); |
471 | if (ret) | |
472 | goto error; | |
76181c13 | 473 | |
4dca6ea1 EB |
474 | user = key_user_lookup(current_fsuid()); |
475 | if (!user) { | |
476 | ret = -ENOMEM; | |
477 | goto error_put_dest_keyring; | |
478 | } | |
8bbf4976 | 479 | |
4bdf0bc3 | 480 | ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key); |
76181c13 DH |
481 | key_user_put(user); |
482 | ||
483 | if (ret == 0) { | |
8bbf4976 DH |
484 | ret = construct_key(key, callout_info, callout_len, aux, |
485 | dest_keyring); | |
d84f4f99 DH |
486 | if (ret < 0) { |
487 | kdebug("cons failed"); | |
76181c13 | 488 | goto construction_failed; |
d84f4f99 | 489 | } |
2b9e4688 DH |
490 | } else if (ret == -EINPROGRESS) { |
491 | ret = 0; | |
492 | } else { | |
4dca6ea1 | 493 | goto error_put_dest_keyring; |
76181c13 DH |
494 | } |
495 | ||
8bbf4976 | 496 | key_put(dest_keyring); |
d84f4f99 | 497 | kleave(" = key %d", key_serial(key)); |
76181c13 DH |
498 | return key; |
499 | ||
500 | construction_failed: | |
501 | key_negate_and_link(key, key_negative_timeout, NULL, NULL); | |
502 | key_put(key); | |
4dca6ea1 | 503 | error_put_dest_keyring: |
8bbf4976 | 504 | key_put(dest_keyring); |
4dca6ea1 | 505 | error: |
d84f4f99 | 506 | kleave(" = %d", ret); |
76181c13 DH |
507 | return ERR_PTR(ret); |
508 | } | |
3e30148c | 509 | |
973c9f4f DH |
510 | /** |
511 | * request_key_and_link - Request a key and cache it in a keyring. | |
512 | * @type: The type of key we want. | |
513 | * @description: The searchable description of the key. | |
514 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
515 | * @callout_len: The length of callout_info. | |
516 | * @aux: Auxiliary data for the upcall. | |
517 | * @dest_keyring: Where to cache the key. | |
518 | * @flags: Flags to key_alloc(). | |
519 | * | |
520 | * A key matching the specified criteria is searched for in the process's | |
521 | * keyrings and returned with its usage count incremented if found. Otherwise, | |
522 | * if callout_info is not NULL, a key will be allocated and some service | |
523 | * (probably in userspace) will be asked to instantiate it. | |
524 | * | |
525 | * If successfully found or created, the key will be linked to the destination | |
526 | * keyring if one is provided. | |
527 | * | |
528 | * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED | |
529 | * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was | |
530 | * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT | |
531 | * if insufficient key quota was available to create a new key; or -ENOMEM if | |
532 | * insufficient memory was available. | |
533 | * | |
534 | * If the returned key was created, then it may still be under construction, | |
535 | * and wait_for_key_construction() should be used to wait for that to complete. | |
1da177e4 | 536 | */ |
3e30148c DH |
537 | struct key *request_key_and_link(struct key_type *type, |
538 | const char *description, | |
4a38e122 DH |
539 | const void *callout_info, |
540 | size_t callout_len, | |
4e54f085 | 541 | void *aux, |
7e047ef5 DH |
542 | struct key *dest_keyring, |
543 | unsigned long flags) | |
1da177e4 | 544 | { |
4bdf0bc3 DH |
545 | struct keyring_search_context ctx = { |
546 | .index_key.type = type, | |
547 | .index_key.description = description, | |
548 | .cred = current_cred(), | |
c06cfb08 | 549 | .match_data.cmp = key_default_cmp, |
46291959 DH |
550 | .match_data.raw_data = description, |
551 | .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, | |
0b0a8415 DH |
552 | .flags = (KEYRING_SEARCH_DO_STATE_CHECK | |
553 | KEYRING_SEARCH_SKIP_EXPIRED), | |
4bdf0bc3 | 554 | }; |
1da177e4 | 555 | struct key *key; |
664cceb0 | 556 | key_ref_t key_ref; |
2b9e4688 | 557 | int ret; |
1da177e4 | 558 | |
4a38e122 | 559 | kenter("%s,%s,%p,%zu,%p,%p,%lx", |
4bdf0bc3 DH |
560 | ctx.index_key.type->name, ctx.index_key.description, |
561 | callout_info, callout_len, aux, dest_keyring, flags); | |
3e30148c | 562 | |
46291959 DH |
563 | if (type->match_preparse) { |
564 | ret = type->match_preparse(&ctx.match_data); | |
565 | if (ret < 0) { | |
566 | key = ERR_PTR(ret); | |
567 | goto error; | |
568 | } | |
569 | } | |
570 | ||
1da177e4 | 571 | /* search all the process keyrings for a key */ |
4bdf0bc3 | 572 | key_ref = search_process_keyrings(&ctx); |
1da177e4 | 573 | |
664cceb0 DH |
574 | if (!IS_ERR(key_ref)) { |
575 | key = key_ref_to_ptr(key_ref); | |
03449cd9 | 576 | if (dest_keyring) { |
2b9e4688 | 577 | ret = key_link(dest_keyring, key); |
2b9e4688 DH |
578 | if (ret < 0) { |
579 | key_put(key); | |
580 | key = ERR_PTR(ret); | |
46291959 | 581 | goto error_free; |
2b9e4688 | 582 | } |
03449cd9 | 583 | } |
76181c13 | 584 | } else if (PTR_ERR(key_ref) != -EAGAIN) { |
e231c2ee | 585 | key = ERR_CAST(key_ref); |
76181c13 | 586 | } else { |
1da177e4 LT |
587 | /* the search failed, but the keyrings were searchable, so we |
588 | * should consult userspace if we can */ | |
589 | key = ERR_PTR(-ENOKEY); | |
590 | if (!callout_info) | |
46291959 | 591 | goto error_free; |
1da177e4 | 592 | |
4bdf0bc3 DH |
593 | key = construct_key_and_link(&ctx, callout_info, callout_len, |
594 | aux, dest_keyring, flags); | |
1da177e4 LT |
595 | } |
596 | ||
46291959 DH |
597 | error_free: |
598 | if (type->match_free) | |
599 | type->match_free(&ctx.match_data); | |
3e30148c DH |
600 | error: |
601 | kleave(" = %p", key); | |
1da177e4 | 602 | return key; |
76181c13 | 603 | } |
1da177e4 | 604 | |
973c9f4f DH |
605 | /** |
606 | * wait_for_key_construction - Wait for construction of a key to complete | |
607 | * @key: The key being waited for. | |
608 | * @intr: Whether to wait interruptibly. | |
609 | * | |
610 | * Wait for a key to finish being constructed. | |
611 | * | |
612 | * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY | |
613 | * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was | |
614 | * revoked or expired. | |
76181c13 DH |
615 | */ |
616 | int wait_for_key_construction(struct key *key, bool intr) | |
617 | { | |
618 | int ret; | |
3e30148c | 619 | |
76181c13 | 620 | ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT, |
76181c13 | 621 | intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE); |
74316201 N |
622 | if (ret) |
623 | return -ERESTARTSYS; | |
363b02da DH |
624 | ret = key_read_state(key); |
625 | if (ret < 0) | |
626 | return ret; | |
76181c13 DH |
627 | return key_validate(key); |
628 | } | |
629 | EXPORT_SYMBOL(wait_for_key_construction); | |
3e30148c | 630 | |
973c9f4f DH |
631 | /** |
632 | * request_key - Request a key and wait for construction | |
633 | * @type: Type of key. | |
634 | * @description: The searchable description of the key. | |
635 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
636 | * | |
637 | * As for request_key_and_link() except that it does not add the returned key | |
638 | * to a keyring if found, new keys are always allocated in the user's quota, | |
639 | * the callout_info must be a NUL-terminated string and no auxiliary data can | |
640 | * be passed. | |
641 | * | |
642 | * Furthermore, it then works as wait_for_key_construction() to wait for the | |
643 | * completion of keys undergoing construction with a non-interruptible wait. | |
3e30148c DH |
644 | */ |
645 | struct key *request_key(struct key_type *type, | |
646 | const char *description, | |
647 | const char *callout_info) | |
648 | { | |
76181c13 | 649 | struct key *key; |
4a38e122 | 650 | size_t callout_len = 0; |
76181c13 DH |
651 | int ret; |
652 | ||
4a38e122 DH |
653 | if (callout_info) |
654 | callout_len = strlen(callout_info); | |
655 | key = request_key_and_link(type, description, callout_info, callout_len, | |
656 | NULL, NULL, KEY_ALLOC_IN_QUOTA); | |
76181c13 DH |
657 | if (!IS_ERR(key)) { |
658 | ret = wait_for_key_construction(key, false); | |
659 | if (ret < 0) { | |
660 | key_put(key); | |
661 | return ERR_PTR(ret); | |
662 | } | |
663 | } | |
664 | return key; | |
665 | } | |
1da177e4 | 666 | EXPORT_SYMBOL(request_key); |
4e54f085 | 667 | |
973c9f4f DH |
668 | /** |
669 | * request_key_with_auxdata - Request a key with auxiliary data for the upcaller | |
670 | * @type: The type of key we want. | |
671 | * @description: The searchable description of the key. | |
672 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
673 | * @callout_len: The length of callout_info. | |
674 | * @aux: Auxiliary data for the upcall. | |
675 | * | |
676 | * As for request_key_and_link() except that it does not add the returned key | |
677 | * to a keyring if found and new keys are always allocated in the user's quota. | |
678 | * | |
679 | * Furthermore, it then works as wait_for_key_construction() to wait for the | |
680 | * completion of keys undergoing construction with a non-interruptible wait. | |
4e54f085 DH |
681 | */ |
682 | struct key *request_key_with_auxdata(struct key_type *type, | |
683 | const char *description, | |
4a38e122 DH |
684 | const void *callout_info, |
685 | size_t callout_len, | |
4e54f085 DH |
686 | void *aux) |
687 | { | |
76181c13 DH |
688 | struct key *key; |
689 | int ret; | |
690 | ||
4a38e122 DH |
691 | key = request_key_and_link(type, description, callout_info, callout_len, |
692 | aux, NULL, KEY_ALLOC_IN_QUOTA); | |
76181c13 DH |
693 | if (!IS_ERR(key)) { |
694 | ret = wait_for_key_construction(key, false); | |
695 | if (ret < 0) { | |
696 | key_put(key); | |
697 | return ERR_PTR(ret); | |
698 | } | |
699 | } | |
700 | return key; | |
701 | } | |
702 | EXPORT_SYMBOL(request_key_with_auxdata); | |
4e54f085 | 703 | |
76181c13 | 704 | /* |
973c9f4f DH |
705 | * request_key_async - Request a key (allow async construction) |
706 | * @type: Type of key. | |
707 | * @description: The searchable description of the key. | |
708 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
709 | * @callout_len: The length of callout_info. | |
710 | * | |
711 | * As for request_key_and_link() except that it does not add the returned key | |
712 | * to a keyring if found, new keys are always allocated in the user's quota and | |
713 | * no auxiliary data can be passed. | |
714 | * | |
715 | * The caller should call wait_for_key_construction() to wait for the | |
716 | * completion of the returned key if it is still undergoing construction. | |
76181c13 DH |
717 | */ |
718 | struct key *request_key_async(struct key_type *type, | |
719 | const char *description, | |
4a38e122 DH |
720 | const void *callout_info, |
721 | size_t callout_len) | |
76181c13 | 722 | { |
4a38e122 DH |
723 | return request_key_and_link(type, description, callout_info, |
724 | callout_len, NULL, NULL, | |
725 | KEY_ALLOC_IN_QUOTA); | |
76181c13 DH |
726 | } |
727 | EXPORT_SYMBOL(request_key_async); | |
4e54f085 | 728 | |
76181c13 DH |
729 | /* |
730 | * request a key with auxiliary data for the upcaller (allow async construction) | |
973c9f4f DH |
731 | * @type: Type of key. |
732 | * @description: The searchable description of the key. | |
733 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
734 | * @callout_len: The length of callout_info. | |
735 | * @aux: Auxiliary data for the upcall. | |
736 | * | |
737 | * As for request_key_and_link() except that it does not add the returned key | |
738 | * to a keyring if found and new keys are always allocated in the user's quota. | |
739 | * | |
740 | * The caller should call wait_for_key_construction() to wait for the | |
741 | * completion of the returned key if it is still undergoing construction. | |
76181c13 DH |
742 | */ |
743 | struct key *request_key_async_with_auxdata(struct key_type *type, | |
744 | const char *description, | |
4a38e122 DH |
745 | const void *callout_info, |
746 | size_t callout_len, | |
76181c13 DH |
747 | void *aux) |
748 | { | |
4a38e122 DH |
749 | return request_key_and_link(type, description, callout_info, |
750 | callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA); | |
76181c13 DH |
751 | } |
752 | EXPORT_SYMBOL(request_key_async_with_auxdata); |