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Commit | Line | Data |
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2874c5fd | 1 | // SPDX-License-Identifier: GPL-2.0-or-later |
76181c13 | 2 | /* Request a key from userspace |
1da177e4 | 3 | * |
76181c13 | 4 | * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved. |
1da177e4 LT |
5 | * Written by David Howells (dhowells@redhat.com) |
6 | * | |
3db38ed7 | 7 | * See Documentation/security/keys/request-key.rst |
1da177e4 LT |
8 | */ |
9 | ||
876979c9 | 10 | #include <linux/export.h> |
1da177e4 LT |
11 | #include <linux/sched.h> |
12 | #include <linux/kmod.h> | |
13 | #include <linux/err.h> | |
3e30148c | 14 | #include <linux/keyctl.h> |
fdb89bce | 15 | #include <linux/slab.h> |
1da177e4 | 16 | #include "internal.h" |
822ad64d | 17 | #include <keys/request_key_auth-type.h> |
1da177e4 | 18 | |
e9e349b0 DH |
19 | #define key_negative_timeout 60 /* default timeout on a negative key's existence */ |
20 | ||
973c9f4f DH |
21 | /** |
22 | * complete_request_key - Complete the construction of a key. | |
822ad64d | 23 | * @auth_key: The authorisation key. |
973c9f4f DH |
24 | * @error: The success or failute of the construction. |
25 | * | |
26 | * Complete the attempt to construct a key. The key will be negated | |
27 | * if an error is indicated. The authorisation key will be revoked | |
28 | * unconditionally. | |
76181c13 | 29 | */ |
822ad64d | 30 | void complete_request_key(struct key *authkey, int error) |
76181c13 | 31 | { |
822ad64d DH |
32 | struct request_key_auth *rka = get_request_key_auth(authkey); |
33 | struct key *key = rka->target_key; | |
34 | ||
35 | kenter("%d{%d},%d", authkey->serial, key->serial, error); | |
1da177e4 | 36 | |
76181c13 | 37 | if (error < 0) |
822ad64d | 38 | key_negate_and_link(key, key_negative_timeout, NULL, authkey); |
76181c13 | 39 | else |
822ad64d | 40 | key_revoke(authkey); |
76181c13 DH |
41 | } |
42 | EXPORT_SYMBOL(complete_request_key); | |
1da177e4 | 43 | |
973c9f4f DH |
44 | /* |
45 | * Initialise a usermode helper that is going to have a specific session | |
46 | * keyring. | |
47 | * | |
48 | * This is called in context of freshly forked kthread before kernel_execve(), | |
49 | * so we can simply install the desired session_keyring at this point. | |
50 | */ | |
87966996 | 51 | static int umh_keys_init(struct subprocess_info *info, struct cred *cred) |
685bfd2c | 52 | { |
685bfd2c | 53 | struct key *keyring = info->data; |
973c9f4f | 54 | |
685bfd2c ON |
55 | return install_session_keyring_to_cred(cred, keyring); |
56 | } | |
57 | ||
973c9f4f DH |
58 | /* |
59 | * Clean up a usermode helper with session keyring. | |
60 | */ | |
685bfd2c ON |
61 | static void umh_keys_cleanup(struct subprocess_info *info) |
62 | { | |
63 | struct key *keyring = info->data; | |
64 | key_put(keyring); | |
65 | } | |
66 | ||
973c9f4f DH |
67 | /* |
68 | * Call a usermode helper with a specific session keyring. | |
69 | */ | |
377e7a27 | 70 | static int call_usermodehelper_keys(const char *path, char **argv, char **envp, |
9d944ef3 | 71 | struct key *session_keyring, int wait) |
685bfd2c | 72 | { |
93997f6d LDM |
73 | struct subprocess_info *info; |
74 | ||
75 | info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL, | |
76 | umh_keys_init, umh_keys_cleanup, | |
77 | session_keyring); | |
78 | if (!info) | |
79 | return -ENOMEM; | |
80 | ||
81 | key_get(session_keyring); | |
82 | return call_usermodehelper_exec(info, wait); | |
685bfd2c ON |
83 | } |
84 | ||
1da177e4 | 85 | /* |
973c9f4f | 86 | * Request userspace finish the construction of a key |
b5f545c8 | 87 | * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>" |
1da177e4 | 88 | */ |
822ad64d | 89 | static int call_sbin_request_key(struct key *authkey, void *aux) |
1da177e4 | 90 | { |
377e7a27 | 91 | static char const request_key[] = "/sbin/request-key"; |
822ad64d | 92 | struct request_key_auth *rka = get_request_key_auth(authkey); |
86a264ab | 93 | const struct cred *cred = current_cred(); |
1da177e4 | 94 | key_serial_t prkey, sskey; |
822ad64d | 95 | struct key *key = rka->target_key, *keyring, *session; |
b5f545c8 | 96 | char *argv[9], *envp[3], uid_str[12], gid_str[12]; |
1da177e4 | 97 | char key_str[12], keyring_str[3][12]; |
b5f545c8 | 98 | char desc[20]; |
3e30148c DH |
99 | int ret, i; |
100 | ||
822ad64d | 101 | kenter("{%d},{%d},%s", key->serial, authkey->serial, rka->op); |
3e30148c | 102 | |
8bbf4976 DH |
103 | ret = install_user_keyrings(); |
104 | if (ret < 0) | |
105 | goto error_alloc; | |
106 | ||
b5f545c8 DH |
107 | /* allocate a new session keyring */ |
108 | sprintf(desc, "_req.%u", key->serial); | |
109 | ||
d84f4f99 DH |
110 | cred = get_current_cred(); |
111 | keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, | |
96b5c8fe | 112 | KEY_POS_ALL | KEY_USR_VIEW | KEY_USR_READ, |
5ac7eace | 113 | KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL); |
d84f4f99 | 114 | put_cred(cred); |
b5f545c8 DH |
115 | if (IS_ERR(keyring)) { |
116 | ret = PTR_ERR(keyring); | |
117 | goto error_alloc; | |
3e30148c | 118 | } |
1da177e4 | 119 | |
b5f545c8 | 120 | /* attach the auth key to the session keyring */ |
896903c2 | 121 | ret = key_link(keyring, authkey); |
b5f545c8 DH |
122 | if (ret < 0) |
123 | goto error_link; | |
124 | ||
1da177e4 | 125 | /* record the UID and GID */ |
9a56c2db EB |
126 | sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); |
127 | sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); | |
1da177e4 LT |
128 | |
129 | /* we say which key is under construction */ | |
130 | sprintf(key_str, "%d", key->serial); | |
131 | ||
132 | /* we specify the process's default keyrings */ | |
133 | sprintf(keyring_str[0], "%d", | |
d84f4f99 | 134 | cred->thread_keyring ? cred->thread_keyring->serial : 0); |
1da177e4 LT |
135 | |
136 | prkey = 0; | |
3a50597d DH |
137 | if (cred->process_keyring) |
138 | prkey = cred->process_keyring->serial; | |
5ad18a0d | 139 | sprintf(keyring_str[1], "%d", prkey); |
1da177e4 | 140 | |
5c7e372c | 141 | session = cred->session_keyring; |
93b4a44f DH |
142 | if (!session) |
143 | session = cred->user->session_keyring; | |
144 | sskey = session->serial; | |
1da177e4 | 145 | |
1da177e4 LT |
146 | sprintf(keyring_str[2], "%d", sskey); |
147 | ||
148 | /* set up a minimal environment */ | |
149 | i = 0; | |
150 | envp[i++] = "HOME=/"; | |
151 | envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; | |
152 | envp[i] = NULL; | |
153 | ||
154 | /* set up the argument list */ | |
155 | i = 0; | |
377e7a27 | 156 | argv[i++] = (char *)request_key; |
822ad64d | 157 | argv[i++] = (char *)rka->op; |
1da177e4 LT |
158 | argv[i++] = key_str; |
159 | argv[i++] = uid_str; | |
160 | argv[i++] = gid_str; | |
161 | argv[i++] = keyring_str[0]; | |
162 | argv[i++] = keyring_str[1]; | |
163 | argv[i++] = keyring_str[2]; | |
1da177e4 LT |
164 | argv[i] = NULL; |
165 | ||
166 | /* do it */ | |
377e7a27 | 167 | ret = call_usermodehelper_keys(request_key, argv, envp, keyring, |
86313c48 | 168 | UMH_WAIT_PROC); |
76181c13 DH |
169 | kdebug("usermode -> 0x%x", ret); |
170 | if (ret >= 0) { | |
171 | /* ret is the exit/wait code */ | |
172 | if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) || | |
173 | key_validate(key) < 0) | |
174 | ret = -ENOKEY; | |
175 | else | |
176 | /* ignore any errors from userspace if the key was | |
177 | * instantiated */ | |
178 | ret = 0; | |
179 | } | |
3e30148c | 180 | |
b5f545c8 DH |
181 | error_link: |
182 | key_put(keyring); | |
3e30148c | 183 | |
b5f545c8 | 184 | error_alloc: |
822ad64d | 185 | complete_request_key(authkey, ret); |
d84f4f99 | 186 | kleave(" = %d", ret); |
3e30148c | 187 | return ret; |
76181c13 | 188 | } |
1da177e4 | 189 | |
1da177e4 | 190 | /* |
973c9f4f DH |
191 | * Call out to userspace for key construction. |
192 | * | |
193 | * Program failure is ignored in favour of key status. | |
1da177e4 | 194 | */ |
4a38e122 | 195 | static int construct_key(struct key *key, const void *callout_info, |
8bbf4976 DH |
196 | size_t callout_len, void *aux, |
197 | struct key *dest_keyring) | |
1da177e4 | 198 | { |
b5f545c8 | 199 | request_key_actor_t actor; |
76181c13 DH |
200 | struct key *authkey; |
201 | int ret; | |
1da177e4 | 202 | |
4a38e122 | 203 | kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux); |
3e30148c | 204 | |
b5f545c8 | 205 | /* allocate an authorisation key */ |
822ad64d | 206 | authkey = request_key_auth_new(key, "create", callout_info, callout_len, |
8bbf4976 | 207 | dest_keyring); |
822ad64d DH |
208 | if (IS_ERR(authkey)) |
209 | return PTR_ERR(authkey); | |
76181c13 | 210 | |
822ad64d DH |
211 | /* Make the call */ |
212 | actor = call_sbin_request_key; | |
213 | if (key->type->request_key) | |
214 | actor = key->type->request_key; | |
76181c13 | 215 | |
822ad64d | 216 | ret = actor(authkey, aux); |
76181c13 | 217 | |
822ad64d DH |
218 | /* check that the actor called complete_request_key() prior to |
219 | * returning an error */ | |
220 | WARN_ON(ret < 0 && | |
221 | !test_bit(KEY_FLAG_REVOKED, &authkey->flags)); | |
1da177e4 | 222 | |
822ad64d | 223 | key_put(authkey); |
76181c13 DH |
224 | kleave(" = %d", ret); |
225 | return ret; | |
226 | } | |
1da177e4 | 227 | |
3e30148c | 228 | /* |
973c9f4f DH |
229 | * Get the appropriate destination keyring for the request. |
230 | * | |
231 | * The keyring selected is returned with an extra reference upon it which the | |
232 | * caller must release. | |
3e30148c | 233 | */ |
4dca6ea1 | 234 | static int construct_get_dest_keyring(struct key **_dest_keyring) |
3e30148c | 235 | { |
8bbf4976 | 236 | struct request_key_auth *rka; |
bb952bb9 | 237 | const struct cred *cred = current_cred(); |
8bbf4976 | 238 | struct key *dest_keyring = *_dest_keyring, *authkey; |
4dca6ea1 | 239 | int ret; |
3e30148c | 240 | |
8bbf4976 | 241 | kenter("%p", dest_keyring); |
3e30148c DH |
242 | |
243 | /* find the appropriate keyring */ | |
8bbf4976 DH |
244 | if (dest_keyring) { |
245 | /* the caller supplied one */ | |
246 | key_get(dest_keyring); | |
247 | } else { | |
4dca6ea1 EB |
248 | bool do_perm_check = true; |
249 | ||
8bbf4976 DH |
250 | /* use a default keyring; falling through the cases until we |
251 | * find one that we actually have */ | |
bb952bb9 | 252 | switch (cred->jit_keyring) { |
3e30148c | 253 | case KEY_REQKEY_DEFL_DEFAULT: |
8bbf4976 | 254 | case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: |
bb952bb9 DH |
255 | if (cred->request_key_auth) { |
256 | authkey = cred->request_key_auth; | |
8bbf4976 | 257 | down_read(&authkey->sem); |
822ad64d | 258 | rka = get_request_key_auth(authkey); |
8bbf4976 DH |
259 | if (!test_bit(KEY_FLAG_REVOKED, |
260 | &authkey->flags)) | |
261 | dest_keyring = | |
262 | key_get(rka->dest_keyring); | |
263 | up_read(&authkey->sem); | |
4dca6ea1 EB |
264 | if (dest_keyring) { |
265 | do_perm_check = false; | |
8bbf4976 | 266 | break; |
4dca6ea1 | 267 | } |
8bbf4976 DH |
268 | } |
269 | ||
23711df7 | 270 | /* fall through */ |
3e30148c | 271 | case KEY_REQKEY_DEFL_THREAD_KEYRING: |
bb952bb9 | 272 | dest_keyring = key_get(cred->thread_keyring); |
3e30148c DH |
273 | if (dest_keyring) |
274 | break; | |
275 | ||
23711df7 | 276 | /* fall through */ |
3e30148c | 277 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: |
3a50597d | 278 | dest_keyring = key_get(cred->process_keyring); |
3e30148c DH |
279 | if (dest_keyring) |
280 | break; | |
281 | ||
23711df7 | 282 | /* fall through */ |
3e30148c | 283 | case KEY_REQKEY_DEFL_SESSION_KEYRING: |
5c7e372c | 284 | dest_keyring = key_get(cred->session_keyring); |
3e30148c DH |
285 | |
286 | if (dest_keyring) | |
287 | break; | |
288 | ||
23711df7 | 289 | /* fall through */ |
3e30148c | 290 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: |
b6dff3ec | 291 | dest_keyring = |
0b9dc6c9 | 292 | key_get(READ_ONCE(cred->user->session_keyring)); |
3e30148c DH |
293 | break; |
294 | ||
295 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
0b9dc6c9 JH |
296 | dest_keyring = |
297 | key_get(READ_ONCE(cred->user->uid_keyring)); | |
3e30148c DH |
298 | break; |
299 | ||
300 | case KEY_REQKEY_DEFL_GROUP_KEYRING: | |
301 | default: | |
302 | BUG(); | |
303 | } | |
4dca6ea1 EB |
304 | |
305 | /* | |
306 | * Require Write permission on the keyring. This is essential | |
307 | * because the default keyring may be the session keyring, and | |
308 | * joining a keyring only requires Search permission. | |
309 | * | |
310 | * However, this check is skipped for the "requestor keyring" so | |
311 | * that /sbin/request-key can itself use request_key() to add | |
312 | * keys to the original requestor's destination keyring. | |
313 | */ | |
314 | if (dest_keyring && do_perm_check) { | |
315 | ret = key_permission(make_key_ref(dest_keyring, 1), | |
316 | KEY_NEED_WRITE); | |
317 | if (ret) { | |
318 | key_put(dest_keyring); | |
319 | return ret; | |
320 | } | |
321 | } | |
3e30148c DH |
322 | } |
323 | ||
8bbf4976 DH |
324 | *_dest_keyring = dest_keyring; |
325 | kleave(" [dk %d]", key_serial(dest_keyring)); | |
4dca6ea1 | 326 | return 0; |
76181c13 | 327 | } |
3e30148c | 328 | |
76181c13 | 329 | /* |
973c9f4f DH |
330 | * Allocate a new key in under-construction state and attempt to link it in to |
331 | * the requested keyring. | |
332 | * | |
333 | * May return a key that's already under construction instead if there was a | |
334 | * race between two thread calling request_key(). | |
76181c13 | 335 | */ |
4bdf0bc3 | 336 | static int construct_alloc_key(struct keyring_search_context *ctx, |
76181c13 DH |
337 | struct key *dest_keyring, |
338 | unsigned long flags, | |
339 | struct key_user *user, | |
340 | struct key **_key) | |
341 | { | |
b2a4df20 | 342 | struct assoc_array_edit *edit; |
76181c13 | 343 | struct key *key; |
96b5c8fe | 344 | key_perm_t perm; |
76181c13 | 345 | key_ref_t key_ref; |
2b9e4688 | 346 | int ret; |
76181c13 | 347 | |
4bdf0bc3 DH |
348 | kenter("%s,%s,,,", |
349 | ctx->index_key.type->name, ctx->index_key.description); | |
76181c13 | 350 | |
f70e2e06 | 351 | *_key = NULL; |
76181c13 DH |
352 | mutex_lock(&user->cons_lock); |
353 | ||
96b5c8fe DH |
354 | perm = KEY_POS_VIEW | KEY_POS_SEARCH | KEY_POS_LINK | KEY_POS_SETATTR; |
355 | perm |= KEY_USR_VIEW; | |
4bdf0bc3 | 356 | if (ctx->index_key.type->read) |
96b5c8fe | 357 | perm |= KEY_POS_READ; |
4bdf0bc3 DH |
358 | if (ctx->index_key.type == &key_type_keyring || |
359 | ctx->index_key.type->update) | |
96b5c8fe DH |
360 | perm |= KEY_POS_WRITE; |
361 | ||
4bdf0bc3 DH |
362 | key = key_alloc(ctx->index_key.type, ctx->index_key.description, |
363 | ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred, | |
5ac7eace | 364 | perm, flags, NULL); |
76181c13 DH |
365 | if (IS_ERR(key)) |
366 | goto alloc_failed; | |
367 | ||
368 | set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); | |
369 | ||
f70e2e06 | 370 | if (dest_keyring) { |
b2a4df20 | 371 | ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit); |
f70e2e06 DH |
372 | if (ret < 0) |
373 | goto link_prealloc_failed; | |
374 | } | |
76181c13 DH |
375 | |
376 | /* attach the key to the destination keyring under lock, but we do need | |
377 | * to do another check just in case someone beat us to it whilst we | |
378 | * waited for locks */ | |
379 | mutex_lock(&key_construction_mutex); | |
380 | ||
4bdf0bc3 | 381 | key_ref = search_process_keyrings(ctx); |
76181c13 DH |
382 | if (!IS_ERR(key_ref)) |
383 | goto key_already_present; | |
384 | ||
34574dd1 | 385 | if (dest_keyring) |
b2a4df20 | 386 | __key_link(key, &edit); |
76181c13 DH |
387 | |
388 | mutex_unlock(&key_construction_mutex); | |
34574dd1 | 389 | if (dest_keyring) |
b2a4df20 | 390 | __key_link_end(dest_keyring, &ctx->index_key, edit); |
76181c13 DH |
391 | mutex_unlock(&user->cons_lock); |
392 | *_key = key; | |
393 | kleave(" = 0 [%d]", key_serial(key)); | |
394 | return 0; | |
395 | ||
2b9e4688 DH |
396 | /* the key is now present - we tell the caller that we found it by |
397 | * returning -EINPROGRESS */ | |
76181c13 | 398 | key_already_present: |
f70e2e06 | 399 | key_put(key); |
76181c13 | 400 | mutex_unlock(&key_construction_mutex); |
f70e2e06 | 401 | key = key_ref_to_ptr(key_ref); |
03449cd9 | 402 | if (dest_keyring) { |
f70e2e06 DH |
403 | ret = __key_link_check_live_key(dest_keyring, key); |
404 | if (ret == 0) | |
b2a4df20 DH |
405 | __key_link(key, &edit); |
406 | __key_link_end(dest_keyring, &ctx->index_key, edit); | |
f70e2e06 DH |
407 | if (ret < 0) |
408 | goto link_check_failed; | |
03449cd9 | 409 | } |
76181c13 | 410 | mutex_unlock(&user->cons_lock); |
f70e2e06 | 411 | *_key = key; |
76181c13 DH |
412 | kleave(" = -EINPROGRESS [%d]", key_serial(key)); |
413 | return -EINPROGRESS; | |
414 | ||
f70e2e06 DH |
415 | link_check_failed: |
416 | mutex_unlock(&user->cons_lock); | |
417 | key_put(key); | |
418 | kleave(" = %d [linkcheck]", ret); | |
419 | return ret; | |
420 | ||
421 | link_prealloc_failed: | |
f70e2e06 | 422 | mutex_unlock(&user->cons_lock); |
d0709f1e | 423 | key_put(key); |
f70e2e06 DH |
424 | kleave(" = %d [prelink]", ret); |
425 | return ret; | |
426 | ||
76181c13 DH |
427 | alloc_failed: |
428 | mutex_unlock(&user->cons_lock); | |
76181c13 DH |
429 | kleave(" = %ld", PTR_ERR(key)); |
430 | return PTR_ERR(key); | |
431 | } | |
432 | ||
433 | /* | |
973c9f4f | 434 | * Commence key construction. |
76181c13 | 435 | */ |
4bdf0bc3 | 436 | static struct key *construct_key_and_link(struct keyring_search_context *ctx, |
76181c13 | 437 | const char *callout_info, |
4a38e122 | 438 | size_t callout_len, |
76181c13 DH |
439 | void *aux, |
440 | struct key *dest_keyring, | |
441 | unsigned long flags) | |
442 | { | |
443 | struct key_user *user; | |
444 | struct key *key; | |
445 | int ret; | |
446 | ||
d84f4f99 DH |
447 | kenter(""); |
448 | ||
911b79cd DH |
449 | if (ctx->index_key.type == &key_type_keyring) |
450 | return ERR_PTR(-EPERM); | |
965475ac | 451 | |
4dca6ea1 EB |
452 | ret = construct_get_dest_keyring(&dest_keyring); |
453 | if (ret) | |
454 | goto error; | |
76181c13 | 455 | |
4dca6ea1 EB |
456 | user = key_user_lookup(current_fsuid()); |
457 | if (!user) { | |
458 | ret = -ENOMEM; | |
459 | goto error_put_dest_keyring; | |
460 | } | |
8bbf4976 | 461 | |
4bdf0bc3 | 462 | ret = construct_alloc_key(ctx, dest_keyring, flags, user, &key); |
76181c13 DH |
463 | key_user_put(user); |
464 | ||
465 | if (ret == 0) { | |
8bbf4976 DH |
466 | ret = construct_key(key, callout_info, callout_len, aux, |
467 | dest_keyring); | |
d84f4f99 DH |
468 | if (ret < 0) { |
469 | kdebug("cons failed"); | |
76181c13 | 470 | goto construction_failed; |
d84f4f99 | 471 | } |
2b9e4688 DH |
472 | } else if (ret == -EINPROGRESS) { |
473 | ret = 0; | |
474 | } else { | |
4dca6ea1 | 475 | goto error_put_dest_keyring; |
76181c13 DH |
476 | } |
477 | ||
8bbf4976 | 478 | key_put(dest_keyring); |
d84f4f99 | 479 | kleave(" = key %d", key_serial(key)); |
76181c13 DH |
480 | return key; |
481 | ||
482 | construction_failed: | |
483 | key_negate_and_link(key, key_negative_timeout, NULL, NULL); | |
484 | key_put(key); | |
4dca6ea1 | 485 | error_put_dest_keyring: |
8bbf4976 | 486 | key_put(dest_keyring); |
4dca6ea1 | 487 | error: |
d84f4f99 | 488 | kleave(" = %d", ret); |
76181c13 DH |
489 | return ERR_PTR(ret); |
490 | } | |
3e30148c | 491 | |
973c9f4f DH |
492 | /** |
493 | * request_key_and_link - Request a key and cache it in a keyring. | |
494 | * @type: The type of key we want. | |
495 | * @description: The searchable description of the key. | |
496 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
497 | * @callout_len: The length of callout_info. | |
498 | * @aux: Auxiliary data for the upcall. | |
499 | * @dest_keyring: Where to cache the key. | |
500 | * @flags: Flags to key_alloc(). | |
501 | * | |
502 | * A key matching the specified criteria is searched for in the process's | |
503 | * keyrings and returned with its usage count incremented if found. Otherwise, | |
504 | * if callout_info is not NULL, a key will be allocated and some service | |
505 | * (probably in userspace) will be asked to instantiate it. | |
506 | * | |
507 | * If successfully found or created, the key will be linked to the destination | |
508 | * keyring if one is provided. | |
509 | * | |
510 | * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED | |
511 | * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was | |
512 | * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT | |
513 | * if insufficient key quota was available to create a new key; or -ENOMEM if | |
514 | * insufficient memory was available. | |
515 | * | |
516 | * If the returned key was created, then it may still be under construction, | |
517 | * and wait_for_key_construction() should be used to wait for that to complete. | |
1da177e4 | 518 | */ |
3e30148c DH |
519 | struct key *request_key_and_link(struct key_type *type, |
520 | const char *description, | |
4a38e122 DH |
521 | const void *callout_info, |
522 | size_t callout_len, | |
4e54f085 | 523 | void *aux, |
7e047ef5 DH |
524 | struct key *dest_keyring, |
525 | unsigned long flags) | |
1da177e4 | 526 | { |
4bdf0bc3 DH |
527 | struct keyring_search_context ctx = { |
528 | .index_key.type = type, | |
529 | .index_key.description = description, | |
ede0fa98 | 530 | .index_key.desc_len = strlen(description), |
4bdf0bc3 | 531 | .cred = current_cred(), |
c06cfb08 | 532 | .match_data.cmp = key_default_cmp, |
46291959 DH |
533 | .match_data.raw_data = description, |
534 | .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, | |
0b0a8415 DH |
535 | .flags = (KEYRING_SEARCH_DO_STATE_CHECK | |
536 | KEYRING_SEARCH_SKIP_EXPIRED), | |
4bdf0bc3 | 537 | }; |
1da177e4 | 538 | struct key *key; |
664cceb0 | 539 | key_ref_t key_ref; |
2b9e4688 | 540 | int ret; |
1da177e4 | 541 | |
4a38e122 | 542 | kenter("%s,%s,%p,%zu,%p,%p,%lx", |
4bdf0bc3 DH |
543 | ctx.index_key.type->name, ctx.index_key.description, |
544 | callout_info, callout_len, aux, dest_keyring, flags); | |
3e30148c | 545 | |
46291959 DH |
546 | if (type->match_preparse) { |
547 | ret = type->match_preparse(&ctx.match_data); | |
548 | if (ret < 0) { | |
549 | key = ERR_PTR(ret); | |
550 | goto error; | |
551 | } | |
552 | } | |
553 | ||
1da177e4 | 554 | /* search all the process keyrings for a key */ |
4bdf0bc3 | 555 | key_ref = search_process_keyrings(&ctx); |
1da177e4 | 556 | |
664cceb0 DH |
557 | if (!IS_ERR(key_ref)) { |
558 | key = key_ref_to_ptr(key_ref); | |
03449cd9 | 559 | if (dest_keyring) { |
2b9e4688 | 560 | ret = key_link(dest_keyring, key); |
2b9e4688 DH |
561 | if (ret < 0) { |
562 | key_put(key); | |
563 | key = ERR_PTR(ret); | |
46291959 | 564 | goto error_free; |
2b9e4688 | 565 | } |
03449cd9 | 566 | } |
76181c13 | 567 | } else if (PTR_ERR(key_ref) != -EAGAIN) { |
e231c2ee | 568 | key = ERR_CAST(key_ref); |
76181c13 | 569 | } else { |
1da177e4 LT |
570 | /* the search failed, but the keyrings were searchable, so we |
571 | * should consult userspace if we can */ | |
572 | key = ERR_PTR(-ENOKEY); | |
573 | if (!callout_info) | |
46291959 | 574 | goto error_free; |
1da177e4 | 575 | |
4bdf0bc3 DH |
576 | key = construct_key_and_link(&ctx, callout_info, callout_len, |
577 | aux, dest_keyring, flags); | |
1da177e4 LT |
578 | } |
579 | ||
46291959 DH |
580 | error_free: |
581 | if (type->match_free) | |
582 | type->match_free(&ctx.match_data); | |
3e30148c DH |
583 | error: |
584 | kleave(" = %p", key); | |
1da177e4 | 585 | return key; |
76181c13 | 586 | } |
1da177e4 | 587 | |
973c9f4f DH |
588 | /** |
589 | * wait_for_key_construction - Wait for construction of a key to complete | |
590 | * @key: The key being waited for. | |
591 | * @intr: Whether to wait interruptibly. | |
592 | * | |
593 | * Wait for a key to finish being constructed. | |
594 | * | |
595 | * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY | |
596 | * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was | |
597 | * revoked or expired. | |
76181c13 DH |
598 | */ |
599 | int wait_for_key_construction(struct key *key, bool intr) | |
600 | { | |
601 | int ret; | |
3e30148c | 602 | |
76181c13 | 603 | ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT, |
76181c13 | 604 | intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE); |
74316201 N |
605 | if (ret) |
606 | return -ERESTARTSYS; | |
363b02da DH |
607 | ret = key_read_state(key); |
608 | if (ret < 0) | |
609 | return ret; | |
76181c13 DH |
610 | return key_validate(key); |
611 | } | |
612 | EXPORT_SYMBOL(wait_for_key_construction); | |
3e30148c | 613 | |
973c9f4f DH |
614 | /** |
615 | * request_key - Request a key and wait for construction | |
616 | * @type: Type of key. | |
617 | * @description: The searchable description of the key. | |
618 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
619 | * | |
620 | * As for request_key_and_link() except that it does not add the returned key | |
621 | * to a keyring if found, new keys are always allocated in the user's quota, | |
622 | * the callout_info must be a NUL-terminated string and no auxiliary data can | |
623 | * be passed. | |
624 | * | |
625 | * Furthermore, it then works as wait_for_key_construction() to wait for the | |
626 | * completion of keys undergoing construction with a non-interruptible wait. | |
3e30148c DH |
627 | */ |
628 | struct key *request_key(struct key_type *type, | |
629 | const char *description, | |
630 | const char *callout_info) | |
631 | { | |
76181c13 | 632 | struct key *key; |
4a38e122 | 633 | size_t callout_len = 0; |
76181c13 DH |
634 | int ret; |
635 | ||
4a38e122 DH |
636 | if (callout_info) |
637 | callout_len = strlen(callout_info); | |
638 | key = request_key_and_link(type, description, callout_info, callout_len, | |
639 | NULL, NULL, KEY_ALLOC_IN_QUOTA); | |
76181c13 DH |
640 | if (!IS_ERR(key)) { |
641 | ret = wait_for_key_construction(key, false); | |
642 | if (ret < 0) { | |
643 | key_put(key); | |
644 | return ERR_PTR(ret); | |
645 | } | |
646 | } | |
647 | return key; | |
648 | } | |
1da177e4 | 649 | EXPORT_SYMBOL(request_key); |
4e54f085 | 650 | |
973c9f4f DH |
651 | /** |
652 | * request_key_with_auxdata - Request a key with auxiliary data for the upcaller | |
653 | * @type: The type of key we want. | |
654 | * @description: The searchable description of the key. | |
655 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
656 | * @callout_len: The length of callout_info. | |
657 | * @aux: Auxiliary data for the upcall. | |
658 | * | |
659 | * As for request_key_and_link() except that it does not add the returned key | |
660 | * to a keyring if found and new keys are always allocated in the user's quota. | |
661 | * | |
662 | * Furthermore, it then works as wait_for_key_construction() to wait for the | |
663 | * completion of keys undergoing construction with a non-interruptible wait. | |
4e54f085 DH |
664 | */ |
665 | struct key *request_key_with_auxdata(struct key_type *type, | |
666 | const char *description, | |
4a38e122 DH |
667 | const void *callout_info, |
668 | size_t callout_len, | |
4e54f085 DH |
669 | void *aux) |
670 | { | |
76181c13 DH |
671 | struct key *key; |
672 | int ret; | |
673 | ||
4a38e122 DH |
674 | key = request_key_and_link(type, description, callout_info, callout_len, |
675 | aux, NULL, KEY_ALLOC_IN_QUOTA); | |
76181c13 DH |
676 | if (!IS_ERR(key)) { |
677 | ret = wait_for_key_construction(key, false); | |
678 | if (ret < 0) { | |
679 | key_put(key); | |
680 | return ERR_PTR(ret); | |
681 | } | |
682 | } | |
683 | return key; | |
684 | } | |
685 | EXPORT_SYMBOL(request_key_with_auxdata); | |
4e54f085 | 686 | |
76181c13 | 687 | /* |
973c9f4f DH |
688 | * request_key_async - Request a key (allow async construction) |
689 | * @type: Type of key. | |
690 | * @description: The searchable description of the key. | |
691 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
692 | * @callout_len: The length of callout_info. | |
693 | * | |
694 | * As for request_key_and_link() except that it does not add the returned key | |
695 | * to a keyring if found, new keys are always allocated in the user's quota and | |
696 | * no auxiliary data can be passed. | |
697 | * | |
698 | * The caller should call wait_for_key_construction() to wait for the | |
699 | * completion of the returned key if it is still undergoing construction. | |
76181c13 DH |
700 | */ |
701 | struct key *request_key_async(struct key_type *type, | |
702 | const char *description, | |
4a38e122 DH |
703 | const void *callout_info, |
704 | size_t callout_len) | |
76181c13 | 705 | { |
4a38e122 DH |
706 | return request_key_and_link(type, description, callout_info, |
707 | callout_len, NULL, NULL, | |
708 | KEY_ALLOC_IN_QUOTA); | |
76181c13 DH |
709 | } |
710 | EXPORT_SYMBOL(request_key_async); | |
4e54f085 | 711 | |
76181c13 DH |
712 | /* |
713 | * request a key with auxiliary data for the upcaller (allow async construction) | |
973c9f4f DH |
714 | * @type: Type of key. |
715 | * @description: The searchable description of the key. | |
716 | * @callout_info: The data to pass to the instantiation upcall (or NULL). | |
717 | * @callout_len: The length of callout_info. | |
718 | * @aux: Auxiliary data for the upcall. | |
719 | * | |
720 | * As for request_key_and_link() except that it does not add the returned key | |
721 | * to a keyring if found and new keys are always allocated in the user's quota. | |
722 | * | |
723 | * The caller should call wait_for_key_construction() to wait for the | |
724 | * completion of the returned key if it is still undergoing construction. | |
76181c13 DH |
725 | */ |
726 | struct key *request_key_async_with_auxdata(struct key_type *type, | |
727 | const char *description, | |
4a38e122 DH |
728 | const void *callout_info, |
729 | size_t callout_len, | |
76181c13 DH |
730 | void *aux) |
731 | { | |
4a38e122 DH |
732 | return request_key_and_link(type, description, callout_info, |
733 | callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA); | |
76181c13 DH |
734 | } |
735 | EXPORT_SYMBOL(request_key_async_with_auxdata); |