Commit | Line | Data |
---|---|---|
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 | ||
876979c9 | 14 | #include <linux/export.h> |
1da177e4 LT |
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> |
a58946c1 | 20 | #include <net/net_namespace.h> |
1da177e4 | 21 | #include "internal.h" |
822ad64d | 22 | #include <keys/request_key_auth-type.h> |
1da177e4 | 23 | |
e9e349b0 DH |
24 | #define key_negative_timeout 60 /* default timeout on a negative key's existence */ |
25 | ||
7743c48e DH |
26 | static struct key *check_cached_key(struct keyring_search_context *ctx) |
27 | { | |
28 | #ifdef CONFIG_KEYS_REQUEST_CACHE | |
29 | struct key *key = current->cached_requested_key; | |
30 | ||
31 | if (key && | |
32 | ctx->match_data.cmp(key, &ctx->match_data) && | |
33 | !(key->flags & ((1 << KEY_FLAG_INVALIDATED) | | |
34 | (1 << KEY_FLAG_REVOKED)))) | |
35 | return key_get(key); | |
36 | #endif | |
37 | return NULL; | |
38 | } | |
39 | ||
40 | static void cache_requested_key(struct key *key) | |
41 | { | |
42 | #ifdef CONFIG_KEYS_REQUEST_CACHE | |
43 | struct task_struct *t = current; | |
44 | ||
45 | key_put(t->cached_requested_key); | |
46 | t->cached_requested_key = key_get(key); | |
47 | set_tsk_thread_flag(t, TIF_NOTIFY_RESUME); | |
48 | #endif | |
49 | } | |
50 | ||
973c9f4f DH |
51 | /** |
52 | * complete_request_key - Complete the construction of a key. | |
9fd16537 | 53 | * @authkey: The authorisation key. |
973c9f4f DH |
54 | * @error: The success or failute of the construction. |
55 | * | |
56 | * Complete the attempt to construct a key. The key will be negated | |
57 | * if an error is indicated. The authorisation key will be revoked | |
58 | * unconditionally. | |
76181c13 | 59 | */ |
822ad64d | 60 | void complete_request_key(struct key *authkey, int error) |
76181c13 | 61 | { |
822ad64d DH |
62 | struct request_key_auth *rka = get_request_key_auth(authkey); |
63 | struct key *key = rka->target_key; | |
64 | ||
65 | kenter("%d{%d},%d", authkey->serial, key->serial, error); | |
1da177e4 | 66 | |
76181c13 | 67 | if (error < 0) |
822ad64d | 68 | key_negate_and_link(key, key_negative_timeout, NULL, authkey); |
76181c13 | 69 | else |
822ad64d | 70 | key_revoke(authkey); |
76181c13 DH |
71 | } |
72 | EXPORT_SYMBOL(complete_request_key); | |
1da177e4 | 73 | |
973c9f4f DH |
74 | /* |
75 | * Initialise a usermode helper that is going to have a specific session | |
76 | * keyring. | |
77 | * | |
78 | * This is called in context of freshly forked kthread before kernel_execve(), | |
79 | * so we can simply install the desired session_keyring at this point. | |
80 | */ | |
87966996 | 81 | static int umh_keys_init(struct subprocess_info *info, struct cred *cred) |
685bfd2c | 82 | { |
685bfd2c | 83 | struct key *keyring = info->data; |
973c9f4f | 84 | |
685bfd2c ON |
85 | return install_session_keyring_to_cred(cred, keyring); |
86 | } | |
87 | ||
973c9f4f DH |
88 | /* |
89 | * Clean up a usermode helper with session keyring. | |
90 | */ | |
685bfd2c ON |
91 | static void umh_keys_cleanup(struct subprocess_info *info) |
92 | { | |
93 | struct key *keyring = info->data; | |
94 | key_put(keyring); | |
95 | } | |
96 | ||
973c9f4f DH |
97 | /* |
98 | * Call a usermode helper with a specific session keyring. | |
99 | */ | |
377e7a27 | 100 | static int call_usermodehelper_keys(const char *path, char **argv, char **envp, |
9d944ef3 | 101 | struct key *session_keyring, int wait) |
685bfd2c | 102 | { |
93997f6d LDM |
103 | struct subprocess_info *info; |
104 | ||
105 | info = call_usermodehelper_setup(path, argv, envp, GFP_KERNEL, | |
106 | umh_keys_init, umh_keys_cleanup, | |
107 | session_keyring); | |
108 | if (!info) | |
109 | return -ENOMEM; | |
110 | ||
111 | key_get(session_keyring); | |
112 | return call_usermodehelper_exec(info, wait); | |
685bfd2c ON |
113 | } |
114 | ||
1da177e4 | 115 | /* |
973c9f4f | 116 | * Request userspace finish the construction of a key |
b5f545c8 | 117 | * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>" |
1da177e4 | 118 | */ |
822ad64d | 119 | static int call_sbin_request_key(struct key *authkey, void *aux) |
1da177e4 | 120 | { |
377e7a27 | 121 | static char const request_key[] = "/sbin/request-key"; |
822ad64d | 122 | struct request_key_auth *rka = get_request_key_auth(authkey); |
86a264ab | 123 | const struct cred *cred = current_cred(); |
1da177e4 | 124 | key_serial_t prkey, sskey; |
0f44e4d9 | 125 | struct key *key = rka->target_key, *keyring, *session, *user_session; |
b5f545c8 | 126 | char *argv[9], *envp[3], uid_str[12], gid_str[12]; |
1da177e4 | 127 | char key_str[12], keyring_str[3][12]; |
b5f545c8 | 128 | char desc[20]; |
3e30148c DH |
129 | int ret, i; |
130 | ||
822ad64d | 131 | kenter("{%d},{%d},%s", key->serial, authkey->serial, rka->op); |
3e30148c | 132 | |
0f44e4d9 | 133 | ret = look_up_user_keyrings(NULL, &user_session); |
8bbf4976 | 134 | if (ret < 0) |
0f44e4d9 | 135 | goto error_us; |
8bbf4976 | 136 | |
b5f545c8 DH |
137 | /* allocate a new session keyring */ |
138 | sprintf(desc, "_req.%u", key->serial); | |
139 | ||
d84f4f99 DH |
140 | cred = get_current_cred(); |
141 | keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred, | |
2e12256b | 142 | NULL, KEY_ALLOC_QUOTA_OVERRUN, NULL, NULL); |
d84f4f99 | 143 | put_cred(cred); |
b5f545c8 DH |
144 | if (IS_ERR(keyring)) { |
145 | ret = PTR_ERR(keyring); | |
146 | goto error_alloc; | |
3e30148c | 147 | } |
1da177e4 | 148 | |
b5f545c8 | 149 | /* attach the auth key to the session keyring */ |
896903c2 | 150 | ret = key_link(keyring, authkey); |
b5f545c8 DH |
151 | if (ret < 0) |
152 | goto error_link; | |
153 | ||
1da177e4 | 154 | /* record the UID and GID */ |
9a56c2db EB |
155 | sprintf(uid_str, "%d", from_kuid(&init_user_ns, cred->fsuid)); |
156 | sprintf(gid_str, "%d", from_kgid(&init_user_ns, cred->fsgid)); | |
1da177e4 LT |
157 | |
158 | /* we say which key is under construction */ | |
159 | sprintf(key_str, "%d", key->serial); | |
160 | ||
161 | /* we specify the process's default keyrings */ | |
162 | sprintf(keyring_str[0], "%d", | |
d84f4f99 | 163 | cred->thread_keyring ? cred->thread_keyring->serial : 0); |
1da177e4 LT |
164 | |
165 | prkey = 0; | |
3a50597d DH |
166 | if (cred->process_keyring) |
167 | prkey = cred->process_keyring->serial; | |
5ad18a0d | 168 | sprintf(keyring_str[1], "%d", prkey); |
1da177e4 | 169 | |
5c7e372c | 170 | session = cred->session_keyring; |
93b4a44f | 171 | if (!session) |
0f44e4d9 | 172 | session = user_session; |
93b4a44f | 173 | sskey = session->serial; |
1da177e4 | 174 | |
1da177e4 LT |
175 | sprintf(keyring_str[2], "%d", sskey); |
176 | ||
177 | /* set up a minimal environment */ | |
178 | i = 0; | |
179 | envp[i++] = "HOME=/"; | |
180 | envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin"; | |
181 | envp[i] = NULL; | |
182 | ||
183 | /* set up the argument list */ | |
184 | i = 0; | |
377e7a27 | 185 | argv[i++] = (char *)request_key; |
822ad64d | 186 | argv[i++] = (char *)rka->op; |
1da177e4 LT |
187 | argv[i++] = key_str; |
188 | argv[i++] = uid_str; | |
189 | argv[i++] = gid_str; | |
190 | argv[i++] = keyring_str[0]; | |
191 | argv[i++] = keyring_str[1]; | |
192 | argv[i++] = keyring_str[2]; | |
1da177e4 LT |
193 | argv[i] = NULL; |
194 | ||
195 | /* do it */ | |
377e7a27 | 196 | ret = call_usermodehelper_keys(request_key, argv, envp, keyring, |
86313c48 | 197 | UMH_WAIT_PROC); |
76181c13 DH |
198 | kdebug("usermode -> 0x%x", ret); |
199 | if (ret >= 0) { | |
200 | /* ret is the exit/wait code */ | |
201 | if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) || | |
202 | key_validate(key) < 0) | |
203 | ret = -ENOKEY; | |
204 | else | |
205 | /* ignore any errors from userspace if the key was | |
206 | * instantiated */ | |
207 | ret = 0; | |
208 | } | |
3e30148c | 209 | |
b5f545c8 DH |
210 | error_link: |
211 | key_put(keyring); | |
3e30148c | 212 | |
b5f545c8 | 213 | error_alloc: |
0f44e4d9 DH |
214 | key_put(user_session); |
215 | error_us: | |
822ad64d | 216 | complete_request_key(authkey, ret); |
d84f4f99 | 217 | kleave(" = %d", ret); |
3e30148c | 218 | return ret; |
76181c13 | 219 | } |
1da177e4 | 220 | |
1da177e4 | 221 | /* |
973c9f4f DH |
222 | * Call out to userspace for key construction. |
223 | * | |
224 | * Program failure is ignored in favour of key status. | |
1da177e4 | 225 | */ |
4a38e122 | 226 | static int construct_key(struct key *key, const void *callout_info, |
8bbf4976 DH |
227 | size_t callout_len, void *aux, |
228 | struct key *dest_keyring) | |
1da177e4 | 229 | { |
b5f545c8 | 230 | request_key_actor_t actor; |
76181c13 DH |
231 | struct key *authkey; |
232 | int ret; | |
1da177e4 | 233 | |
4a38e122 | 234 | kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux); |
3e30148c | 235 | |
b5f545c8 | 236 | /* allocate an authorisation key */ |
822ad64d | 237 | authkey = request_key_auth_new(key, "create", callout_info, callout_len, |
8bbf4976 | 238 | dest_keyring); |
822ad64d DH |
239 | if (IS_ERR(authkey)) |
240 | return PTR_ERR(authkey); | |
76181c13 | 241 | |
822ad64d DH |
242 | /* Make the call */ |
243 | actor = call_sbin_request_key; | |
244 | if (key->type->request_key) | |
245 | actor = key->type->request_key; | |
76181c13 | 246 | |
822ad64d | 247 | ret = actor(authkey, aux); |
76181c13 | 248 | |
822ad64d DH |
249 | /* check that the actor called complete_request_key() prior to |
250 | * returning an error */ | |
251 | WARN_ON(ret < 0 && | |
a09003b5 | 252 | !test_bit(KEY_FLAG_INVALIDATED, &authkey->flags)); |
1da177e4 | 253 | |
822ad64d | 254 | key_put(authkey); |
76181c13 DH |
255 | kleave(" = %d", ret); |
256 | return ret; | |
257 | } | |
1da177e4 | 258 | |
3e30148c | 259 | /* |
973c9f4f DH |
260 | * Get the appropriate destination keyring for the request. |
261 | * | |
262 | * The keyring selected is returned with an extra reference upon it which the | |
263 | * caller must release. | |
3e30148c | 264 | */ |
4dca6ea1 | 265 | static int construct_get_dest_keyring(struct key **_dest_keyring) |
3e30148c | 266 | { |
8bbf4976 | 267 | struct request_key_auth *rka; |
bb952bb9 | 268 | const struct cred *cred = current_cred(); |
8bbf4976 | 269 | struct key *dest_keyring = *_dest_keyring, *authkey; |
4dca6ea1 | 270 | int ret; |
3e30148c | 271 | |
8bbf4976 | 272 | kenter("%p", dest_keyring); |
3e30148c DH |
273 | |
274 | /* find the appropriate keyring */ | |
8bbf4976 DH |
275 | if (dest_keyring) { |
276 | /* the caller supplied one */ | |
277 | key_get(dest_keyring); | |
278 | } else { | |
4dca6ea1 EB |
279 | bool do_perm_check = true; |
280 | ||
8bbf4976 DH |
281 | /* use a default keyring; falling through the cases until we |
282 | * find one that we actually have */ | |
bb952bb9 | 283 | switch (cred->jit_keyring) { |
3e30148c | 284 | case KEY_REQKEY_DEFL_DEFAULT: |
8bbf4976 | 285 | case KEY_REQKEY_DEFL_REQUESTOR_KEYRING: |
bb952bb9 DH |
286 | if (cred->request_key_auth) { |
287 | authkey = cred->request_key_auth; | |
8bbf4976 | 288 | down_read(&authkey->sem); |
822ad64d | 289 | rka = get_request_key_auth(authkey); |
8bbf4976 DH |
290 | if (!test_bit(KEY_FLAG_REVOKED, |
291 | &authkey->flags)) | |
292 | dest_keyring = | |
293 | key_get(rka->dest_keyring); | |
294 | up_read(&authkey->sem); | |
4dca6ea1 EB |
295 | if (dest_keyring) { |
296 | do_perm_check = false; | |
8bbf4976 | 297 | break; |
4dca6ea1 | 298 | } |
8bbf4976 DH |
299 | } |
300 | ||
23711df7 | 301 | /* fall through */ |
3e30148c | 302 | case KEY_REQKEY_DEFL_THREAD_KEYRING: |
bb952bb9 | 303 | dest_keyring = key_get(cred->thread_keyring); |
3e30148c DH |
304 | if (dest_keyring) |
305 | break; | |
306 | ||
23711df7 | 307 | /* fall through */ |
3e30148c | 308 | case KEY_REQKEY_DEFL_PROCESS_KEYRING: |
3a50597d | 309 | dest_keyring = key_get(cred->process_keyring); |
3e30148c DH |
310 | if (dest_keyring) |
311 | break; | |
312 | ||
23711df7 | 313 | /* fall through */ |
3e30148c | 314 | case KEY_REQKEY_DEFL_SESSION_KEYRING: |
5c7e372c | 315 | dest_keyring = key_get(cred->session_keyring); |
3e30148c DH |
316 | |
317 | if (dest_keyring) | |
318 | break; | |
319 | ||
23711df7 | 320 | /* fall through */ |
3e30148c | 321 | case KEY_REQKEY_DEFL_USER_SESSION_KEYRING: |
0f44e4d9 DH |
322 | ret = look_up_user_keyrings(NULL, &dest_keyring); |
323 | if (ret < 0) | |
324 | return ret; | |
3e30148c DH |
325 | break; |
326 | ||
327 | case KEY_REQKEY_DEFL_USER_KEYRING: | |
0f44e4d9 DH |
328 | ret = look_up_user_keyrings(&dest_keyring, NULL); |
329 | if (ret < 0) | |
330 | return ret; | |
3e30148c DH |
331 | break; |
332 | ||
333 | case KEY_REQKEY_DEFL_GROUP_KEYRING: | |
334 | default: | |
335 | BUG(); | |
336 | } | |
4dca6ea1 EB |
337 | |
338 | /* | |
339 | * Require Write permission on the keyring. This is essential | |
340 | * because the default keyring may be the session keyring, and | |
341 | * joining a keyring only requires Search permission. | |
342 | * | |
343 | * However, this check is skipped for the "requestor keyring" so | |
344 | * that /sbin/request-key can itself use request_key() to add | |
345 | * keys to the original requestor's destination keyring. | |
346 | */ | |
347 | if (dest_keyring && do_perm_check) { | |
348 | ret = key_permission(make_key_ref(dest_keyring, 1), | |
349 | KEY_NEED_WRITE); | |
350 | if (ret) { | |
351 | key_put(dest_keyring); | |
352 | return ret; | |
353 | } | |
354 | } | |
3e30148c DH |
355 | } |
356 | ||
8bbf4976 DH |
357 | *_dest_keyring = dest_keyring; |
358 | kleave(" [dk %d]", key_serial(dest_keyring)); | |
4dca6ea1 | 359 | return 0; |
76181c13 | 360 | } |
3e30148c | 361 | |
76181c13 | 362 | /* |
973c9f4f DH |
363 | * Allocate a new key in under-construction state and attempt to link it in to |
364 | * the requested keyring. | |
365 | * | |
366 | * May return a key that's already under construction instead if there was a | |
367 | * race between two thread calling request_key(). | |
76181c13 | 368 | */ |
4bdf0bc3 | 369 | static int construct_alloc_key(struct keyring_search_context *ctx, |
76181c13 DH |
370 | struct key *dest_keyring, |
371 | unsigned long flags, | |
372 | struct key_user *user, | |
2e12256b | 373 | struct key_acl *acl, |
76181c13 DH |
374 | struct key **_key) |
375 | { | |
df593ee2 | 376 | struct assoc_array_edit *edit = NULL; |
76181c13 DH |
377 | struct key *key; |
378 | key_ref_t key_ref; | |
2b9e4688 | 379 | int ret; |
76181c13 | 380 | |
4bdf0bc3 DH |
381 | kenter("%s,%s,,,", |
382 | ctx->index_key.type->name, ctx->index_key.description); | |
76181c13 | 383 | |
f70e2e06 | 384 | *_key = NULL; |
76181c13 DH |
385 | mutex_lock(&user->cons_lock); |
386 | ||
4bdf0bc3 DH |
387 | key = key_alloc(ctx->index_key.type, ctx->index_key.description, |
388 | ctx->cred->fsuid, ctx->cred->fsgid, ctx->cred, | |
2e12256b | 389 | acl, flags, NULL); |
76181c13 DH |
390 | if (IS_ERR(key)) |
391 | goto alloc_failed; | |
392 | ||
393 | set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags); | |
394 | ||
f70e2e06 | 395 | if (dest_keyring) { |
df593ee2 DH |
396 | ret = __key_link_lock(dest_keyring, &ctx->index_key); |
397 | if (ret < 0) | |
398 | goto link_lock_failed; | |
b2a4df20 | 399 | ret = __key_link_begin(dest_keyring, &ctx->index_key, &edit); |
f70e2e06 DH |
400 | if (ret < 0) |
401 | goto link_prealloc_failed; | |
402 | } | |
76181c13 DH |
403 | |
404 | /* attach the key to the destination keyring under lock, but we do need | |
405 | * to do another check just in case someone beat us to it whilst we | |
406 | * waited for locks */ | |
407 | mutex_lock(&key_construction_mutex); | |
408 | ||
e59428f7 DH |
409 | rcu_read_lock(); |
410 | key_ref = search_process_keyrings_rcu(ctx); | |
411 | rcu_read_unlock(); | |
76181c13 DH |
412 | if (!IS_ERR(key_ref)) |
413 | goto key_already_present; | |
414 | ||
34574dd1 | 415 | if (dest_keyring) |
b2a4df20 | 416 | __key_link(key, &edit); |
76181c13 DH |
417 | |
418 | mutex_unlock(&key_construction_mutex); | |
34574dd1 | 419 | if (dest_keyring) |
b2a4df20 | 420 | __key_link_end(dest_keyring, &ctx->index_key, edit); |
76181c13 DH |
421 | mutex_unlock(&user->cons_lock); |
422 | *_key = key; | |
423 | kleave(" = 0 [%d]", key_serial(key)); | |
424 | return 0; | |
425 | ||
2b9e4688 DH |
426 | /* the key is now present - we tell the caller that we found it by |
427 | * returning -EINPROGRESS */ | |
76181c13 | 428 | key_already_present: |
f70e2e06 | 429 | key_put(key); |
76181c13 | 430 | mutex_unlock(&key_construction_mutex); |
f70e2e06 | 431 | key = key_ref_to_ptr(key_ref); |
03449cd9 | 432 | if (dest_keyring) { |
f70e2e06 DH |
433 | ret = __key_link_check_live_key(dest_keyring, key); |
434 | if (ret == 0) | |
b2a4df20 DH |
435 | __key_link(key, &edit); |
436 | __key_link_end(dest_keyring, &ctx->index_key, edit); | |
f70e2e06 DH |
437 | if (ret < 0) |
438 | goto link_check_failed; | |
03449cd9 | 439 | } |
76181c13 | 440 | mutex_unlock(&user->cons_lock); |
f70e2e06 | 441 | *_key = key; |
76181c13 DH |
442 | kleave(" = -EINPROGRESS [%d]", key_serial(key)); |
443 | return -EINPROGRESS; | |
444 | ||
f70e2e06 DH |
445 | link_check_failed: |
446 | mutex_unlock(&user->cons_lock); | |
447 | key_put(key); | |
448 | kleave(" = %d [linkcheck]", ret); | |
449 | return ret; | |
450 | ||
451 | link_prealloc_failed: | |
df593ee2 DH |
452 | __key_link_end(dest_keyring, &ctx->index_key, edit); |
453 | link_lock_failed: | |
f70e2e06 | 454 | mutex_unlock(&user->cons_lock); |
d0709f1e | 455 | key_put(key); |
f70e2e06 DH |
456 | kleave(" = %d [prelink]", ret); |
457 | return ret; | |
458 | ||
76181c13 DH |
459 | alloc_failed: |
460 | mutex_unlock(&user->cons_lock); | |
76181c13 DH |
461 | kleave(" = %ld", PTR_ERR(key)); |
462 | return PTR_ERR(key); | |
463 | } | |
464 | ||
465 | /* | |
973c9f4f | 466 | * Commence key construction. |
76181c13 | 467 | */ |
4bdf0bc3 | 468 | static struct key *construct_key_and_link(struct keyring_search_context *ctx, |
76181c13 | 469 | const char *callout_info, |
4a38e122 | 470 | size_t callout_len, |
76181c13 | 471 | void *aux, |
2e12256b | 472 | struct key_acl *acl, |
76181c13 DH |
473 | struct key *dest_keyring, |
474 | unsigned long flags) | |
475 | { | |
476 | struct key_user *user; | |
477 | struct key *key; | |
478 | int ret; | |
479 | ||
d84f4f99 DH |
480 | kenter(""); |
481 | ||
911b79cd DH |
482 | if (ctx->index_key.type == &key_type_keyring) |
483 | return ERR_PTR(-EPERM); | |
965475ac | 484 | |
4dca6ea1 EB |
485 | ret = construct_get_dest_keyring(&dest_keyring); |
486 | if (ret) | |
487 | goto error; | |
76181c13 | 488 | |
4dca6ea1 EB |
489 | user = key_user_lookup(current_fsuid()); |
490 | if (!user) { | |
491 | ret = -ENOMEM; | |
492 | goto error_put_dest_keyring; | |
493 | } | |
8bbf4976 | 494 | |
2e12256b | 495 | ret = construct_alloc_key(ctx, dest_keyring, flags, user, acl, &key); |
76181c13 DH |
496 | key_user_put(user); |
497 | ||
498 | if (ret == 0) { | |
8bbf4976 DH |
499 | ret = construct_key(key, callout_info, callout_len, aux, |
500 | dest_keyring); | |
d84f4f99 DH |
501 | if (ret < 0) { |
502 | kdebug("cons failed"); | |
76181c13 | 503 | goto construction_failed; |
d84f4f99 | 504 | } |
2b9e4688 DH |
505 | } else if (ret == -EINPROGRESS) { |
506 | ret = 0; | |
507 | } else { | |
4dca6ea1 | 508 | goto error_put_dest_keyring; |
76181c13 DH |
509 | } |
510 | ||
8bbf4976 | 511 | key_put(dest_keyring); |
d84f4f99 | 512 | kleave(" = key %d", key_serial(key)); |
76181c13 DH |
513 | return key; |
514 | ||
515 | construction_failed: | |
516 | key_negate_and_link(key, key_negative_timeout, NULL, NULL); | |
517 | key_put(key); | |
4dca6ea1 | 518 | error_put_dest_keyring: |
8bbf4976 | 519 | key_put(dest_keyring); |
4dca6ea1 | 520 | error: |
d84f4f99 | 521 | kleave(" = %d", ret); |
76181c13 DH |
522 | return ERR_PTR(ret); |
523 | } | |
3e30148c | 524 | |
973c9f4f DH |
525 | /** |
526 | * request_key_and_link - Request a key and cache it in a keyring. | |
527 | * @type: The type of key we want. | |
528 | * @description: The searchable description of the key. | |
a58946c1 | 529 | * @domain_tag: The domain in which the key operates. |
973c9f4f DH |
530 | * @callout_info: The data to pass to the instantiation upcall (or NULL). |
531 | * @callout_len: The length of callout_info. | |
532 | * @aux: Auxiliary data for the upcall. | |
2e12256b | 533 | * @acl: The ACL to attach if a new key is created. |
973c9f4f DH |
534 | * @dest_keyring: Where to cache the key. |
535 | * @flags: Flags to key_alloc(). | |
536 | * | |
a58946c1 DH |
537 | * A key matching the specified criteria (type, description, domain_tag) is |
538 | * searched for in the process's keyrings and returned with its usage count | |
539 | * incremented if found. Otherwise, if callout_info is not NULL, a key will be | |
540 | * allocated and some service (probably in userspace) will be asked to | |
541 | * instantiate it. | |
973c9f4f DH |
542 | * |
543 | * If successfully found or created, the key will be linked to the destination | |
544 | * keyring if one is provided. | |
545 | * | |
546 | * Returns a pointer to the key if successful; -EACCES, -ENOKEY, -EKEYREVOKED | |
547 | * or -EKEYEXPIRED if an inaccessible, negative, revoked or expired key was | |
548 | * found; -ENOKEY if no key was found and no @callout_info was given; -EDQUOT | |
549 | * if insufficient key quota was available to create a new key; or -ENOMEM if | |
550 | * insufficient memory was available. | |
551 | * | |
552 | * If the returned key was created, then it may still be under construction, | |
553 | * and wait_for_key_construction() should be used to wait for that to complete. | |
1da177e4 | 554 | */ |
3e30148c DH |
555 | struct key *request_key_and_link(struct key_type *type, |
556 | const char *description, | |
a58946c1 | 557 | struct key_tag *domain_tag, |
4a38e122 DH |
558 | const void *callout_info, |
559 | size_t callout_len, | |
4e54f085 | 560 | void *aux, |
2e12256b | 561 | struct key_acl *acl, |
7e047ef5 DH |
562 | struct key *dest_keyring, |
563 | unsigned long flags) | |
1da177e4 | 564 | { |
4bdf0bc3 DH |
565 | struct keyring_search_context ctx = { |
566 | .index_key.type = type, | |
a58946c1 | 567 | .index_key.domain_tag = domain_tag, |
4bdf0bc3 | 568 | .index_key.description = description, |
ede0fa98 | 569 | .index_key.desc_len = strlen(description), |
4bdf0bc3 | 570 | .cred = current_cred(), |
c06cfb08 | 571 | .match_data.cmp = key_default_cmp, |
46291959 DH |
572 | .match_data.raw_data = description, |
573 | .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, | |
0b0a8415 | 574 | .flags = (KEYRING_SEARCH_DO_STATE_CHECK | |
dcf49dbc DH |
575 | KEYRING_SEARCH_SKIP_EXPIRED | |
576 | KEYRING_SEARCH_RECURSE), | |
4bdf0bc3 | 577 | }; |
1da177e4 | 578 | struct key *key; |
664cceb0 | 579 | key_ref_t key_ref; |
2b9e4688 | 580 | int ret; |
1da177e4 | 581 | |
4a38e122 | 582 | kenter("%s,%s,%p,%zu,%p,%p,%lx", |
4bdf0bc3 DH |
583 | ctx.index_key.type->name, ctx.index_key.description, |
584 | callout_info, callout_len, aux, dest_keyring, flags); | |
3e30148c | 585 | |
46291959 DH |
586 | if (type->match_preparse) { |
587 | ret = type->match_preparse(&ctx.match_data); | |
588 | if (ret < 0) { | |
589 | key = ERR_PTR(ret); | |
590 | goto error; | |
591 | } | |
592 | } | |
593 | ||
7743c48e DH |
594 | key = check_cached_key(&ctx); |
595 | if (key) | |
596 | return key; | |
597 | ||
1da177e4 | 598 | /* search all the process keyrings for a key */ |
e59428f7 DH |
599 | rcu_read_lock(); |
600 | key_ref = search_process_keyrings_rcu(&ctx); | |
601 | rcu_read_unlock(); | |
1da177e4 | 602 | |
664cceb0 | 603 | if (!IS_ERR(key_ref)) { |
504b69eb DH |
604 | if (dest_keyring) { |
605 | ret = key_task_permission(key_ref, current_cred(), | |
606 | KEY_NEED_LINK); | |
607 | if (ret < 0) { | |
608 | key_ref_put(key_ref); | |
609 | key = ERR_PTR(ret); | |
610 | goto error_free; | |
611 | } | |
612 | } | |
613 | ||
664cceb0 | 614 | key = key_ref_to_ptr(key_ref); |
03449cd9 | 615 | if (dest_keyring) { |
2b9e4688 | 616 | ret = key_link(dest_keyring, key); |
2b9e4688 DH |
617 | if (ret < 0) { |
618 | key_put(key); | |
619 | key = ERR_PTR(ret); | |
46291959 | 620 | goto error_free; |
2b9e4688 | 621 | } |
03449cd9 | 622 | } |
7743c48e DH |
623 | |
624 | /* Only cache the key on immediate success */ | |
625 | cache_requested_key(key); | |
76181c13 | 626 | } else if (PTR_ERR(key_ref) != -EAGAIN) { |
e231c2ee | 627 | key = ERR_CAST(key_ref); |
76181c13 | 628 | } else { |
1da177e4 LT |
629 | /* the search failed, but the keyrings were searchable, so we |
630 | * should consult userspace if we can */ | |
631 | key = ERR_PTR(-ENOKEY); | |
632 | if (!callout_info) | |
46291959 | 633 | goto error_free; |
1da177e4 | 634 | |
4bdf0bc3 | 635 | key = construct_key_and_link(&ctx, callout_info, callout_len, |
2e12256b | 636 | aux, acl, dest_keyring, flags); |
1da177e4 LT |
637 | } |
638 | ||
46291959 DH |
639 | error_free: |
640 | if (type->match_free) | |
641 | type->match_free(&ctx.match_data); | |
3e30148c DH |
642 | error: |
643 | kleave(" = %p", key); | |
1da177e4 | 644 | return key; |
76181c13 | 645 | } |
1da177e4 | 646 | |
973c9f4f DH |
647 | /** |
648 | * wait_for_key_construction - Wait for construction of a key to complete | |
649 | * @key: The key being waited for. | |
650 | * @intr: Whether to wait interruptibly. | |
651 | * | |
652 | * Wait for a key to finish being constructed. | |
653 | * | |
654 | * Returns 0 if successful; -ERESTARTSYS if the wait was interrupted; -ENOKEY | |
655 | * if the key was negated; or -EKEYREVOKED or -EKEYEXPIRED if the key was | |
656 | * revoked or expired. | |
76181c13 DH |
657 | */ |
658 | int wait_for_key_construction(struct key *key, bool intr) | |
659 | { | |
660 | int ret; | |
3e30148c | 661 | |
76181c13 | 662 | ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT, |
76181c13 | 663 | intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE); |
74316201 N |
664 | if (ret) |
665 | return -ERESTARTSYS; | |
363b02da DH |
666 | ret = key_read_state(key); |
667 | if (ret < 0) | |
668 | return ret; | |
76181c13 DH |
669 | return key_validate(key); |
670 | } | |
671 | EXPORT_SYMBOL(wait_for_key_construction); | |
3e30148c | 672 | |
973c9f4f | 673 | /** |
a58946c1 | 674 | * request_key_tag - Request a key and wait for construction |
973c9f4f DH |
675 | * @type: Type of key. |
676 | * @description: The searchable description of the key. | |
a58946c1 | 677 | * @domain_tag: The domain in which the key operates. |
973c9f4f | 678 | * @callout_info: The data to pass to the instantiation upcall (or NULL). |
2e12256b | 679 | * @acl: The ACL to attach if a new key is created. |
973c9f4f DH |
680 | * |
681 | * As for request_key_and_link() except that it does not add the returned key | |
682 | * to a keyring if found, new keys are always allocated in the user's quota, | |
683 | * the callout_info must be a NUL-terminated string and no auxiliary data can | |
684 | * be passed. | |
685 | * | |
686 | * Furthermore, it then works as wait_for_key_construction() to wait for the | |
687 | * completion of keys undergoing construction with a non-interruptible wait. | |
3e30148c | 688 | */ |
a58946c1 DH |
689 | struct key *request_key_tag(struct key_type *type, |
690 | const char *description, | |
691 | struct key_tag *domain_tag, | |
2e12256b DH |
692 | const char *callout_info, |
693 | struct key_acl *acl) | |
3e30148c | 694 | { |
76181c13 | 695 | struct key *key; |
4a38e122 | 696 | size_t callout_len = 0; |
76181c13 DH |
697 | int ret; |
698 | ||
4a38e122 DH |
699 | if (callout_info) |
700 | callout_len = strlen(callout_info); | |
a58946c1 DH |
701 | key = request_key_and_link(type, description, domain_tag, |
702 | callout_info, callout_len, | |
2e12256b | 703 | NULL, acl, NULL, KEY_ALLOC_IN_QUOTA); |
76181c13 DH |
704 | if (!IS_ERR(key)) { |
705 | ret = wait_for_key_construction(key, false); | |
706 | if (ret < 0) { | |
707 | key_put(key); | |
708 | return ERR_PTR(ret); | |
709 | } | |
710 | } | |
711 | return key; | |
712 | } | |
a58946c1 | 713 | EXPORT_SYMBOL(request_key_tag); |
4e54f085 | 714 | |
973c9f4f DH |
715 | /** |
716 | * request_key_with_auxdata - Request a key with auxiliary data for the upcaller | |
717 | * @type: The type of key we want. | |
718 | * @description: The searchable description of the key. | |
a58946c1 | 719 | * @domain_tag: The domain in which the key operates. |
973c9f4f DH |
720 | * @callout_info: The data to pass to the instantiation upcall (or NULL). |
721 | * @callout_len: The length of callout_info. | |
722 | * @aux: Auxiliary data for the upcall. | |
2e12256b | 723 | * @acl: The ACL to attach if a new key is created. |
973c9f4f DH |
724 | * |
725 | * As for request_key_and_link() except that it does not add the returned key | |
726 | * to a keyring if found and new keys are always allocated in the user's quota. | |
727 | * | |
728 | * Furthermore, it then works as wait_for_key_construction() to wait for the | |
729 | * completion of keys undergoing construction with a non-interruptible wait. | |
4e54f085 DH |
730 | */ |
731 | struct key *request_key_with_auxdata(struct key_type *type, | |
732 | const char *description, | |
a58946c1 | 733 | struct key_tag *domain_tag, |
4a38e122 DH |
734 | const void *callout_info, |
735 | size_t callout_len, | |
2e12256b DH |
736 | void *aux, |
737 | struct key_acl *acl) | |
4e54f085 | 738 | { |
76181c13 DH |
739 | struct key *key; |
740 | int ret; | |
741 | ||
a58946c1 DH |
742 | key = request_key_and_link(type, description, domain_tag, |
743 | callout_info, callout_len, | |
2e12256b | 744 | aux, acl, NULL, KEY_ALLOC_IN_QUOTA); |
76181c13 DH |
745 | if (!IS_ERR(key)) { |
746 | ret = wait_for_key_construction(key, false); | |
747 | if (ret < 0) { | |
748 | key_put(key); | |
749 | return ERR_PTR(ret); | |
750 | } | |
751 | } | |
752 | return key; | |
753 | } | |
754 | EXPORT_SYMBOL(request_key_with_auxdata); | |
4e54f085 | 755 | |
896f1950 DH |
756 | /** |
757 | * request_key_rcu - Request key from RCU-read-locked context | |
758 | * @type: The type of key we want. | |
759 | * @description: The name of the key we want. | |
a58946c1 | 760 | * @domain_tag: The domain in which the key operates. |
896f1950 DH |
761 | * |
762 | * Request a key from a context that we may not sleep in (such as RCU-mode | |
763 | * pathwalk). Keys under construction are ignored. | |
764 | * | |
765 | * Return a pointer to the found key if successful, -ENOKEY if we couldn't find | |
766 | * a key or some other error if the key found was unsuitable or inaccessible. | |
767 | */ | |
a58946c1 DH |
768 | struct key *request_key_rcu(struct key_type *type, |
769 | const char *description, | |
770 | struct key_tag *domain_tag) | |
896f1950 DH |
771 | { |
772 | struct keyring_search_context ctx = { | |
773 | .index_key.type = type, | |
a58946c1 | 774 | .index_key.domain_tag = domain_tag, |
896f1950 DH |
775 | .index_key.description = description, |
776 | .index_key.desc_len = strlen(description), | |
777 | .cred = current_cred(), | |
778 | .match_data.cmp = key_default_cmp, | |
779 | .match_data.raw_data = description, | |
780 | .match_data.lookup_type = KEYRING_SEARCH_LOOKUP_DIRECT, | |
781 | .flags = (KEYRING_SEARCH_DO_STATE_CHECK | | |
782 | KEYRING_SEARCH_SKIP_EXPIRED), | |
783 | }; | |
784 | struct key *key; | |
785 | key_ref_t key_ref; | |
786 | ||
787 | kenter("%s,%s", type->name, description); | |
788 | ||
7743c48e DH |
789 | key = check_cached_key(&ctx); |
790 | if (key) | |
791 | return key; | |
792 | ||
896f1950 DH |
793 | /* search all the process keyrings for a key */ |
794 | key_ref = search_process_keyrings_rcu(&ctx); | |
795 | if (IS_ERR(key_ref)) { | |
796 | key = ERR_CAST(key_ref); | |
797 | if (PTR_ERR(key_ref) == -EAGAIN) | |
798 | key = ERR_PTR(-ENOKEY); | |
799 | } else { | |
800 | key = key_ref_to_ptr(key_ref); | |
7743c48e | 801 | cache_requested_key(key); |
896f1950 DH |
802 | } |
803 | ||
804 | kleave(" = %p", key); | |
805 | return key; | |
806 | } | |
807 | EXPORT_SYMBOL(request_key_rcu); |