blob: 0088dd8bf68a77b29637527733ff0b8985b8ecb7 [file] [log] [blame]
David Howells76181c12007-10-16 23:29:46 -07001/* Request a key from userspace
Linus Torvalds1da177e2005-04-16 15:20:36 -07002 *
David Howells76181c12007-10-16 23:29:46 -07003 * Copyright (C) 2004-2007 Red Hat, Inc. All Rights Reserved.
Linus Torvalds1da177e2005-04-16 15:20:36 -07004 * 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.
David Howellsf1a9bad2005-10-07 15:04:52 +010010 *
11 * See Documentation/keys-request-key.txt
Linus Torvalds1da177e2005-04-16 15:20:36 -070012 */
13
14#include <linux/module.h>
15#include <linux/sched.h>
16#include <linux/kmod.h>
17#include <linux/err.h>
David Howells3e301482005-06-23 22:00:56 -070018#include <linux/keyctl.h>
Robert P. J. Dayfdb89bc2008-04-29 01:01:32 -070019#include <linux/slab.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070020#include "internal.h"
21
David Howellse9e349b2008-11-14 10:39:13 +110022#define key_negative_timeout 60 /* default timeout on a negative key's existence */
23
David Howells76181c12007-10-16 23:29:46 -070024/*
25 * wait_on_bit() sleep function for uninterruptible waiting
26 */
27static int key_wait_bit(void *flags)
28{
29 schedule();
30 return 0;
31}
Linus Torvalds1da177e2005-04-16 15:20:36 -070032
David Howells76181c12007-10-16 23:29:46 -070033/*
34 * wait_on_bit() sleep function for interruptible waiting
35 */
36static int key_wait_bit_intr(void *flags)
37{
38 schedule();
39 return signal_pending(current) ? -ERESTARTSYS : 0;
40}
Linus Torvalds1da177e2005-04-16 15:20:36 -070041
David Howells76181c12007-10-16 23:29:46 -070042/*
43 * call to complete the construction of a key
44 */
45void complete_request_key(struct key_construction *cons, int error)
46{
47 kenter("{%d,%d},%d", cons->key->serial, cons->authkey->serial, error);
48
49 if (error < 0)
50 key_negate_and_link(cons->key, key_negative_timeout, NULL,
51 cons->authkey);
52 else
53 key_revoke(cons->authkey);
54
55 key_put(cons->key);
56 key_put(cons->authkey);
57 kfree(cons);
58}
59EXPORT_SYMBOL(complete_request_key);
60
Oleg Nesterov685bfd22010-05-26 14:43:00 -070061static int umh_keys_init(struct subprocess_info *info)
62{
63 struct cred *cred = (struct cred*)current_cred();
64 struct key *keyring = info->data;
65 /*
66 * This is called in context of freshly forked kthread before
67 * kernel_execve(), we can just change our ->session_keyring.
68 */
69 return install_session_keyring_to_cred(cred, keyring);
70}
71
72static void umh_keys_cleanup(struct subprocess_info *info)
73{
74 struct key *keyring = info->data;
75 key_put(keyring);
76}
77
78static int call_usermodehelper_keys(char *path, char **argv, char **envp,
79 struct key *session_keyring, enum umh_wait wait)
80{
81 gfp_t gfp_mask = (wait == UMH_NO_WAIT) ? GFP_ATOMIC : GFP_KERNEL;
82 struct subprocess_info *info =
83 call_usermodehelper_setup(path, argv, envp, gfp_mask);
84
85 if (!info)
86 return -ENOMEM;
87
88 call_usermodehelper_setfns(info, umh_keys_init, umh_keys_cleanup,
89 key_get(session_keyring));
90 return call_usermodehelper_exec(info, wait);
91}
92
Linus Torvalds1da177e2005-04-16 15:20:36 -070093/*
94 * request userspace finish the construction of a key
David Howellsb5f545c2006-01-08 01:02:47 -080095 * - execute "/sbin/request-key <op> <key> <uid> <gid> <keyring> <keyring> <keyring>"
Linus Torvalds1da177e2005-04-16 15:20:36 -070096 */
David Howells76181c12007-10-16 23:29:46 -070097static int call_sbin_request_key(struct key_construction *cons,
David Howells4e54f082006-06-29 02:24:28 -070098 const char *op,
99 void *aux)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700100{
David Howells86a264a2008-11-14 10:39:18 +1100101 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700102 key_serial_t prkey, sskey;
David Howells93b4a442010-04-23 13:18:00 -0400103 struct key *key = cons->key, *authkey = cons->authkey, *keyring,
104 *session;
David Howellsb5f545c2006-01-08 01:02:47 -0800105 char *argv[9], *envp[3], uid_str[12], gid_str[12];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700106 char key_str[12], keyring_str[3][12];
David Howellsb5f545c2006-01-08 01:02:47 -0800107 char desc[20];
David Howells3e301482005-06-23 22:00:56 -0700108 int ret, i;
109
David Howellsb5f545c2006-01-08 01:02:47 -0800110 kenter("{%d},{%d},%s", key->serial, authkey->serial, op);
David Howells3e301482005-06-23 22:00:56 -0700111
David Howells8bbf49762008-11-14 10:39:14 +1100112 ret = install_user_keyrings();
113 if (ret < 0)
114 goto error_alloc;
115
David Howellsb5f545c2006-01-08 01:02:47 -0800116 /* allocate a new session keyring */
117 sprintf(desc, "_req.%u", key->serial);
118
David Howellsd84f4f92008-11-14 10:39:23 +1100119 cred = get_current_cred();
120 keyring = keyring_alloc(desc, cred->fsuid, cred->fsgid, cred,
David Howells7e047ef2006-06-26 00:24:50 -0700121 KEY_ALLOC_QUOTA_OVERRUN, NULL);
David Howellsd84f4f92008-11-14 10:39:23 +1100122 put_cred(cred);
David Howellsb5f545c2006-01-08 01:02:47 -0800123 if (IS_ERR(keyring)) {
124 ret = PTR_ERR(keyring);
125 goto error_alloc;
David Howells3e301482005-06-23 22:00:56 -0700126 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700127
David Howellsb5f545c2006-01-08 01:02:47 -0800128 /* attach the auth key to the session keyring */
David Howells896903c2010-04-30 14:32:23 +0100129 ret = key_link(keyring, authkey);
David Howellsb5f545c2006-01-08 01:02:47 -0800130 if (ret < 0)
131 goto error_link;
132
Linus Torvalds1da177e2005-04-16 15:20:36 -0700133 /* record the UID and GID */
David Howells86a264a2008-11-14 10:39:18 +1100134 sprintf(uid_str, "%d", cred->fsuid);
135 sprintf(gid_str, "%d", cred->fsgid);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700136
137 /* we say which key is under construction */
138 sprintf(key_str, "%d", key->serial);
139
140 /* we specify the process's default keyrings */
141 sprintf(keyring_str[0], "%d",
David Howellsd84f4f92008-11-14 10:39:23 +1100142 cred->thread_keyring ? cred->thread_keyring->serial : 0);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700143
144 prkey = 0;
David Howellsbb952bb2008-11-14 10:39:20 +1100145 if (cred->tgcred->process_keyring)
146 prkey = cred->tgcred->process_keyring->serial;
Justin P. Mattock5ad18a02010-06-30 10:39:11 +0100147 sprintf(keyring_str[1], "%d", prkey);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700148
David Howells93b4a442010-04-23 13:18:00 -0400149 rcu_read_lock();
150 session = rcu_dereference(cred->tgcred->session_keyring);
151 if (!session)
152 session = cred->user->session_keyring;
153 sskey = session->serial;
154 rcu_read_unlock();
David Howells3e301482005-06-23 22:00:56 -0700155
Linus Torvalds1da177e2005-04-16 15:20:36 -0700156 sprintf(keyring_str[2], "%d", sskey);
157
158 /* set up a minimal environment */
159 i = 0;
160 envp[i++] = "HOME=/";
161 envp[i++] = "PATH=/sbin:/bin:/usr/sbin:/usr/bin";
162 envp[i] = NULL;
163
164 /* set up the argument list */
165 i = 0;
166 argv[i++] = "/sbin/request-key";
167 argv[i++] = (char *) op;
168 argv[i++] = key_str;
169 argv[i++] = uid_str;
170 argv[i++] = gid_str;
171 argv[i++] = keyring_str[0];
172 argv[i++] = keyring_str[1];
173 argv[i++] = keyring_str[2];
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 argv[i] = NULL;
175
176 /* do it */
Jeremy Fitzhardinge86313c42007-07-17 18:37:03 -0700177 ret = call_usermodehelper_keys(argv[0], argv, envp, keyring,
178 UMH_WAIT_PROC);
David Howells76181c12007-10-16 23:29:46 -0700179 kdebug("usermode -> 0x%x", ret);
180 if (ret >= 0) {
181 /* ret is the exit/wait code */
182 if (test_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags) ||
183 key_validate(key) < 0)
184 ret = -ENOKEY;
185 else
186 /* ignore any errors from userspace if the key was
187 * instantiated */
188 ret = 0;
189 }
David Howells3e301482005-06-23 22:00:56 -0700190
David Howellsb5f545c2006-01-08 01:02:47 -0800191error_link:
192 key_put(keyring);
David Howells3e301482005-06-23 22:00:56 -0700193
David Howellsb5f545c2006-01-08 01:02:47 -0800194error_alloc:
David Howells76181c12007-10-16 23:29:46 -0700195 complete_request_key(cons, ret);
David Howellsd84f4f92008-11-14 10:39:23 +1100196 kleave(" = %d", ret);
David Howells3e301482005-06-23 22:00:56 -0700197 return ret;
David Howells76181c12007-10-16 23:29:46 -0700198}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700199
Linus Torvalds1da177e2005-04-16 15:20:36 -0700200/*
David Howells76181c12007-10-16 23:29:46 -0700201 * call out to userspace for key construction
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 * - we ignore program failure and go on key status instead
203 */
David Howells4a38e122008-04-29 01:01:24 -0700204static int construct_key(struct key *key, const void *callout_info,
David Howells8bbf49762008-11-14 10:39:14 +1100205 size_t callout_len, void *aux,
206 struct key *dest_keyring)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207{
David Howells76181c12007-10-16 23:29:46 -0700208 struct key_construction *cons;
David Howellsb5f545c2006-01-08 01:02:47 -0800209 request_key_actor_t actor;
David Howells76181c12007-10-16 23:29:46 -0700210 struct key *authkey;
211 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700212
David Howells4a38e122008-04-29 01:01:24 -0700213 kenter("%d,%p,%zu,%p", key->serial, callout_info, callout_len, aux);
David Howells3e301482005-06-23 22:00:56 -0700214
David Howells76181c12007-10-16 23:29:46 -0700215 cons = kmalloc(sizeof(*cons), GFP_KERNEL);
216 if (!cons)
217 return -ENOMEM;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218
David Howellsb5f545c2006-01-08 01:02:47 -0800219 /* allocate an authorisation key */
David Howells8bbf49762008-11-14 10:39:14 +1100220 authkey = request_key_auth_new(key, callout_info, callout_len,
221 dest_keyring);
David Howellsb5f545c2006-01-08 01:02:47 -0800222 if (IS_ERR(authkey)) {
David Howells76181c12007-10-16 23:29:46 -0700223 kfree(cons);
David Howellsb5f545c2006-01-08 01:02:47 -0800224 ret = PTR_ERR(authkey);
225 authkey = NULL;
David Howells76181c12007-10-16 23:29:46 -0700226 } 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);
David Howellsb5f545c2006-01-08 01:02:47 -0800242 }
243
David Howells76181c12007-10-16 23:29:46 -0700244 kleave(" = %d", ret);
245 return ret;
246}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700247
Linus Torvalds1da177e2005-04-16 15:20:36 -0700248/*
David Howells8bbf49762008-11-14 10:39:14 +1100249 * get the appropriate destination keyring for the request
250 * - we return whatever keyring we select with an extra reference upon it which
251 * the caller must release
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 */
David Howells8bbf49762008-11-14 10:39:14 +1100253static void construct_get_dest_keyring(struct key **_dest_keyring)
David Howells3e301482005-06-23 22:00:56 -0700254{
David Howells8bbf49762008-11-14 10:39:14 +1100255 struct request_key_auth *rka;
David Howellsbb952bb2008-11-14 10:39:20 +1100256 const struct cred *cred = current_cred();
David Howells8bbf49762008-11-14 10:39:14 +1100257 struct key *dest_keyring = *_dest_keyring, *authkey;
David Howells3e301482005-06-23 22:00:56 -0700258
David Howells8bbf49762008-11-14 10:39:14 +1100259 kenter("%p", dest_keyring);
David Howells3e301482005-06-23 22:00:56 -0700260
261 /* find the appropriate keyring */
David Howells8bbf49762008-11-14 10:39:14 +1100262 if (dest_keyring) {
263 /* the caller supplied one */
264 key_get(dest_keyring);
265 } else {
266 /* use a default keyring; falling through the cases until we
267 * find one that we actually have */
David Howellsbb952bb2008-11-14 10:39:20 +1100268 switch (cred->jit_keyring) {
David Howells3e301482005-06-23 22:00:56 -0700269 case KEY_REQKEY_DEFL_DEFAULT:
David Howells8bbf49762008-11-14 10:39:14 +1100270 case KEY_REQKEY_DEFL_REQUESTOR_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100271 if (cred->request_key_auth) {
272 authkey = cred->request_key_auth;
David Howells8bbf49762008-11-14 10:39:14 +1100273 down_read(&authkey->sem);
274 rka = authkey->payload.data;
275 if (!test_bit(KEY_FLAG_REVOKED,
276 &authkey->flags))
277 dest_keyring =
278 key_get(rka->dest_keyring);
279 up_read(&authkey->sem);
280 if (dest_keyring)
281 break;
282 }
283
David Howells3e301482005-06-23 22:00:56 -0700284 case KEY_REQKEY_DEFL_THREAD_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100285 dest_keyring = key_get(cred->thread_keyring);
David Howells3e301482005-06-23 22:00:56 -0700286 if (dest_keyring)
287 break;
288
289 case KEY_REQKEY_DEFL_PROCESS_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100290 dest_keyring = key_get(cred->tgcred->process_keyring);
David Howells3e301482005-06-23 22:00:56 -0700291 if (dest_keyring)
292 break;
293
294 case KEY_REQKEY_DEFL_SESSION_KEYRING:
295 rcu_read_lock();
296 dest_keyring = key_get(
David Howellsbb952bb2008-11-14 10:39:20 +1100297 rcu_dereference(cred->tgcred->session_keyring));
David Howells3e301482005-06-23 22:00:56 -0700298 rcu_read_unlock();
David Howells3e301482005-06-23 22:00:56 -0700299
300 if (dest_keyring)
301 break;
302
303 case KEY_REQKEY_DEFL_USER_SESSION_KEYRING:
David Howellsb6dff3e2008-11-14 10:39:16 +1100304 dest_keyring =
David Howellsbb952bb2008-11-14 10:39:20 +1100305 key_get(cred->user->session_keyring);
David Howells3e301482005-06-23 22:00:56 -0700306 break;
307
308 case KEY_REQKEY_DEFL_USER_KEYRING:
David Howellsbb952bb2008-11-14 10:39:20 +1100309 dest_keyring = key_get(cred->user->uid_keyring);
David Howells3e301482005-06-23 22:00:56 -0700310 break;
311
312 case KEY_REQKEY_DEFL_GROUP_KEYRING:
313 default:
314 BUG();
315 }
316 }
317
David Howells8bbf49762008-11-14 10:39:14 +1100318 *_dest_keyring = dest_keyring;
319 kleave(" [dk %d]", key_serial(dest_keyring));
320 return;
David Howells76181c12007-10-16 23:29:46 -0700321}
David Howells3e301482005-06-23 22:00:56 -0700322
David Howells76181c12007-10-16 23:29:46 -0700323/*
324 * allocate a new key in under-construction state and attempt to link it in to
325 * the requested place
326 * - may return a key that's already under construction instead
327 */
328static int construct_alloc_key(struct key_type *type,
329 const char *description,
330 struct key *dest_keyring,
331 unsigned long flags,
332 struct key_user *user,
333 struct key **_key)
334{
David Howellsf70e2e02010-04-30 14:32:39 +0100335 struct keyring_list *prealloc;
David Howellsd84f4f92008-11-14 10:39:23 +1100336 const struct cred *cred = current_cred();
David Howells76181c12007-10-16 23:29:46 -0700337 struct key *key;
338 key_ref_t key_ref;
David Howells2b9e4682010-04-30 14:32:34 +0100339 int ret;
David Howells3e301482005-06-23 22:00:56 -0700340
David Howells76181c12007-10-16 23:29:46 -0700341 kenter("%s,%s,,,", type->name, description);
342
David Howellsf70e2e02010-04-30 14:32:39 +0100343 *_key = NULL;
David Howells76181c12007-10-16 23:29:46 -0700344 mutex_lock(&user->cons_lock);
345
David Howellsd84f4f92008-11-14 10:39:23 +1100346 key = key_alloc(type, description, cred->fsuid, cred->fsgid, cred,
347 KEY_POS_ALL, flags);
David Howells76181c12007-10-16 23:29:46 -0700348 if (IS_ERR(key))
349 goto alloc_failed;
350
351 set_bit(KEY_FLAG_USER_CONSTRUCT, &key->flags);
352
David Howellsf70e2e02010-04-30 14:32:39 +0100353 if (dest_keyring) {
354 ret = __key_link_begin(dest_keyring, type, description,
355 &prealloc);
356 if (ret < 0)
357 goto link_prealloc_failed;
358 }
David Howells76181c12007-10-16 23:29:46 -0700359
360 /* attach the key to the destination keyring under lock, but we do need
361 * to do another check just in case someone beat us to it whilst we
362 * waited for locks */
363 mutex_lock(&key_construction_mutex);
364
David Howellsd84f4f92008-11-14 10:39:23 +1100365 key_ref = search_process_keyrings(type, description, type->match, cred);
David Howells76181c12007-10-16 23:29:46 -0700366 if (!IS_ERR(key_ref))
367 goto key_already_present;
368
David Howells34574dd2009-04-09 17:14:05 +0100369 if (dest_keyring)
David Howellsf70e2e02010-04-30 14:32:39 +0100370 __key_link(dest_keyring, key, &prealloc);
David Howells76181c12007-10-16 23:29:46 -0700371
372 mutex_unlock(&key_construction_mutex);
David Howells34574dd2009-04-09 17:14:05 +0100373 if (dest_keyring)
David Howellsf70e2e02010-04-30 14:32:39 +0100374 __key_link_end(dest_keyring, type, prealloc);
David Howells76181c12007-10-16 23:29:46 -0700375 mutex_unlock(&user->cons_lock);
376 *_key = key;
377 kleave(" = 0 [%d]", key_serial(key));
378 return 0;
379
David Howells2b9e4682010-04-30 14:32:34 +0100380 /* the key is now present - we tell the caller that we found it by
381 * returning -EINPROGRESS */
David Howells76181c12007-10-16 23:29:46 -0700382key_already_present:
David Howellsf70e2e02010-04-30 14:32:39 +0100383 key_put(key);
David Howells76181c12007-10-16 23:29:46 -0700384 mutex_unlock(&key_construction_mutex);
David Howellsf70e2e02010-04-30 14:32:39 +0100385 key = key_ref_to_ptr(key_ref);
David Howells03449cd2010-04-27 13:13:08 -0700386 if (dest_keyring) {
David Howellsf70e2e02010-04-30 14:32:39 +0100387 ret = __key_link_check_live_key(dest_keyring, key);
388 if (ret == 0)
389 __key_link(dest_keyring, key, &prealloc);
390 __key_link_end(dest_keyring, type, prealloc);
391 if (ret < 0)
392 goto link_check_failed;
David Howells03449cd2010-04-27 13:13:08 -0700393 }
David Howells76181c12007-10-16 23:29:46 -0700394 mutex_unlock(&user->cons_lock);
David Howellsf70e2e02010-04-30 14:32:39 +0100395 *_key = key;
David Howells76181c12007-10-16 23:29:46 -0700396 kleave(" = -EINPROGRESS [%d]", key_serial(key));
397 return -EINPROGRESS;
398
David Howellsf70e2e02010-04-30 14:32:39 +0100399link_check_failed:
400 mutex_unlock(&user->cons_lock);
401 key_put(key);
402 kleave(" = %d [linkcheck]", ret);
403 return ret;
404
405link_prealloc_failed:
406 up_write(&dest_keyring->sem);
407 mutex_unlock(&user->cons_lock);
408 kleave(" = %d [prelink]", ret);
409 return ret;
410
David Howells76181c12007-10-16 23:29:46 -0700411alloc_failed:
412 mutex_unlock(&user->cons_lock);
David Howells76181c12007-10-16 23:29:46 -0700413 kleave(" = %ld", PTR_ERR(key));
414 return PTR_ERR(key);
415}
416
417/*
418 * commence key construction
419 */
420static struct key *construct_key_and_link(struct key_type *type,
421 const char *description,
422 const char *callout_info,
David Howells4a38e122008-04-29 01:01:24 -0700423 size_t callout_len,
David Howells76181c12007-10-16 23:29:46 -0700424 void *aux,
425 struct key *dest_keyring,
426 unsigned long flags)
427{
428 struct key_user *user;
429 struct key *key;
430 int ret;
431
David Howellsd84f4f92008-11-14 10:39:23 +1100432 kenter("");
433
Serge E. Hallyn1d1e9752009-02-26 18:27:38 -0600434 user = key_user_lookup(current_fsuid(), current_user_ns());
David Howells76181c12007-10-16 23:29:46 -0700435 if (!user)
436 return ERR_PTR(-ENOMEM);
437
David Howells8bbf49762008-11-14 10:39:14 +1100438 construct_get_dest_keyring(&dest_keyring);
439
David Howells76181c12007-10-16 23:29:46 -0700440 ret = construct_alloc_key(type, description, dest_keyring, flags, user,
441 &key);
442 key_user_put(user);
443
444 if (ret == 0) {
David Howells8bbf49762008-11-14 10:39:14 +1100445 ret = construct_key(key, callout_info, callout_len, aux,
446 dest_keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100447 if (ret < 0) {
448 kdebug("cons failed");
David Howells76181c12007-10-16 23:29:46 -0700449 goto construction_failed;
David Howellsd84f4f92008-11-14 10:39:23 +1100450 }
David Howells2b9e4682010-04-30 14:32:34 +0100451 } else if (ret == -EINPROGRESS) {
452 ret = 0;
453 } else {
454 key = ERR_PTR(ret);
David Howells76181c12007-10-16 23:29:46 -0700455 }
456
David Howells8bbf49762008-11-14 10:39:14 +1100457 key_put(dest_keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100458 kleave(" = key %d", key_serial(key));
David Howells76181c12007-10-16 23:29:46 -0700459 return key;
460
461construction_failed:
462 key_negate_and_link(key, key_negative_timeout, NULL, NULL);
463 key_put(key);
David Howells8bbf49762008-11-14 10:39:14 +1100464 key_put(dest_keyring);
David Howellsd84f4f92008-11-14 10:39:23 +1100465 kleave(" = %d", ret);
David Howells76181c12007-10-16 23:29:46 -0700466 return ERR_PTR(ret);
467}
468
David Howells3e301482005-06-23 22:00:56 -0700469/*
Linus Torvalds1da177e2005-04-16 15:20:36 -0700470 * request a key
471 * - search the process's keyrings
472 * - check the list of keys being created or updated
David Howells3e301482005-06-23 22:00:56 -0700473 * - call out to userspace for a key if supplementary info was provided
474 * - cache the key in an appropriate keyring
Linus Torvalds1da177e2005-04-16 15:20:36 -0700475 */
David Howells3e301482005-06-23 22:00:56 -0700476struct key *request_key_and_link(struct key_type *type,
477 const char *description,
David Howells4a38e122008-04-29 01:01:24 -0700478 const void *callout_info,
479 size_t callout_len,
David Howells4e54f082006-06-29 02:24:28 -0700480 void *aux,
David Howells7e047ef2006-06-26 00:24:50 -0700481 struct key *dest_keyring,
482 unsigned long flags)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700483{
David Howellsd84f4f92008-11-14 10:39:23 +1100484 const struct cred *cred = current_cred();
Linus Torvalds1da177e2005-04-16 15:20:36 -0700485 struct key *key;
David Howells664cceb2005-09-28 17:03:15 +0100486 key_ref_t key_ref;
David Howells2b9e4682010-04-30 14:32:34 +0100487 int ret;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700488
David Howells4a38e122008-04-29 01:01:24 -0700489 kenter("%s,%s,%p,%zu,%p,%p,%lx",
490 type->name, description, callout_info, callout_len, aux,
David Howells4e54f082006-06-29 02:24:28 -0700491 dest_keyring, flags);
David Howells3e301482005-06-23 22:00:56 -0700492
Linus Torvalds1da177e2005-04-16 15:20:36 -0700493 /* search all the process keyrings for a key */
David Howells664cceb2005-09-28 17:03:15 +0100494 key_ref = search_process_keyrings(type, description, type->match,
David Howellsd84f4f92008-11-14 10:39:23 +1100495 cred);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700496
David Howells664cceb2005-09-28 17:03:15 +0100497 if (!IS_ERR(key_ref)) {
498 key = key_ref_to_ptr(key_ref);
David Howells03449cd2010-04-27 13:13:08 -0700499 if (dest_keyring) {
500 construct_get_dest_keyring(&dest_keyring);
David Howells2b9e4682010-04-30 14:32:34 +0100501 ret = key_link(dest_keyring, key);
David Howells03449cd2010-04-27 13:13:08 -0700502 key_put(dest_keyring);
David Howells2b9e4682010-04-30 14:32:34 +0100503 if (ret < 0) {
504 key_put(key);
505 key = ERR_PTR(ret);
506 goto error;
507 }
David Howells03449cd2010-04-27 13:13:08 -0700508 }
David Howells76181c12007-10-16 23:29:46 -0700509 } else if (PTR_ERR(key_ref) != -EAGAIN) {
David Howellse231c2e2008-02-07 00:15:26 -0800510 key = ERR_CAST(key_ref);
David Howells76181c12007-10-16 23:29:46 -0700511 } else {
Linus Torvalds1da177e2005-04-16 15:20:36 -0700512 /* the search failed, but the keyrings were searchable, so we
513 * should consult userspace if we can */
514 key = ERR_PTR(-ENOKEY);
515 if (!callout_info)
516 goto error;
517
David Howells76181c12007-10-16 23:29:46 -0700518 key = construct_key_and_link(type, description, callout_info,
David Howells4a38e122008-04-29 01:01:24 -0700519 callout_len, aux, dest_keyring,
520 flags);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700521 }
522
David Howells3e301482005-06-23 22:00:56 -0700523error:
524 kleave(" = %p", key);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700525 return key;
David Howells76181c12007-10-16 23:29:46 -0700526}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700527
David Howells76181c12007-10-16 23:29:46 -0700528/*
529 * wait for construction of a key to complete
530 */
531int wait_for_key_construction(struct key *key, bool intr)
532{
533 int ret;
David Howells3e301482005-06-23 22:00:56 -0700534
David Howells76181c12007-10-16 23:29:46 -0700535 ret = wait_on_bit(&key->flags, KEY_FLAG_USER_CONSTRUCT,
536 intr ? key_wait_bit_intr : key_wait_bit,
537 intr ? TASK_INTERRUPTIBLE : TASK_UNINTERRUPTIBLE);
538 if (ret < 0)
539 return ret;
David Howells1e456a12010-08-06 16:08:27 +0100540 if (test_bit(KEY_FLAG_NEGATIVE, &key->flags))
541 return -ENOKEY;
David Howells76181c12007-10-16 23:29:46 -0700542 return key_validate(key);
543}
544EXPORT_SYMBOL(wait_for_key_construction);
David Howells3e301482005-06-23 22:00:56 -0700545
David Howells3e301482005-06-23 22:00:56 -0700546/*
547 * request a key
548 * - search the process's keyrings
549 * - check the list of keys being created or updated
550 * - call out to userspace for a key if supplementary info was provided
David Howells76181c12007-10-16 23:29:46 -0700551 * - waits uninterruptible for creation to complete
David Howells3e301482005-06-23 22:00:56 -0700552 */
553struct key *request_key(struct key_type *type,
554 const char *description,
555 const char *callout_info)
556{
David Howells76181c12007-10-16 23:29:46 -0700557 struct key *key;
David Howells4a38e122008-04-29 01:01:24 -0700558 size_t callout_len = 0;
David Howells76181c12007-10-16 23:29:46 -0700559 int ret;
David Howells3e301482005-06-23 22:00:56 -0700560
David Howells4a38e122008-04-29 01:01:24 -0700561 if (callout_info)
562 callout_len = strlen(callout_info);
563 key = request_key_and_link(type, description, callout_info, callout_len,
564 NULL, NULL, KEY_ALLOC_IN_QUOTA);
David Howells76181c12007-10-16 23:29:46 -0700565 if (!IS_ERR(key)) {
566 ret = wait_for_key_construction(key, false);
567 if (ret < 0) {
568 key_put(key);
569 return ERR_PTR(ret);
570 }
571 }
572 return key;
573}
Linus Torvalds1da177e2005-04-16 15:20:36 -0700574EXPORT_SYMBOL(request_key);
David Howells4e54f082006-06-29 02:24:28 -0700575
David Howells4e54f082006-06-29 02:24:28 -0700576/*
577 * request a key with auxiliary data for the upcaller
578 * - search the process's keyrings
579 * - check the list of keys being created or updated
580 * - call out to userspace for a key if supplementary info was provided
David Howells76181c12007-10-16 23:29:46 -0700581 * - waits uninterruptible for creation to complete
David Howells4e54f082006-06-29 02:24:28 -0700582 */
583struct key *request_key_with_auxdata(struct key_type *type,
584 const char *description,
David Howells4a38e122008-04-29 01:01:24 -0700585 const void *callout_info,
586 size_t callout_len,
David Howells4e54f082006-06-29 02:24:28 -0700587 void *aux)
588{
David Howells76181c12007-10-16 23:29:46 -0700589 struct key *key;
590 int ret;
591
David Howells4a38e122008-04-29 01:01:24 -0700592 key = request_key_and_link(type, description, callout_info, callout_len,
593 aux, NULL, KEY_ALLOC_IN_QUOTA);
David Howells76181c12007-10-16 23:29:46 -0700594 if (!IS_ERR(key)) {
595 ret = wait_for_key_construction(key, false);
596 if (ret < 0) {
597 key_put(key);
598 return ERR_PTR(ret);
599 }
600 }
601 return key;
602}
603EXPORT_SYMBOL(request_key_with_auxdata);
604
605/*
606 * request a key (allow async construction)
607 * - search the process's keyrings
608 * - check the list of keys being created or updated
609 * - call out to userspace for a key if supplementary info was provided
610 */
611struct key *request_key_async(struct key_type *type,
612 const char *description,
David Howells4a38e122008-04-29 01:01:24 -0700613 const void *callout_info,
614 size_t callout_len)
David Howells76181c12007-10-16 23:29:46 -0700615{
David Howells4a38e122008-04-29 01:01:24 -0700616 return request_key_and_link(type, description, callout_info,
617 callout_len, NULL, NULL,
618 KEY_ALLOC_IN_QUOTA);
David Howells76181c12007-10-16 23:29:46 -0700619}
620EXPORT_SYMBOL(request_key_async);
621
622/*
623 * request a key with auxiliary data for the upcaller (allow async construction)
624 * - search the process's keyrings
625 * - check the list of keys being created or updated
626 * - call out to userspace for a key if supplementary info was provided
627 */
628struct key *request_key_async_with_auxdata(struct key_type *type,
629 const char *description,
David Howells4a38e122008-04-29 01:01:24 -0700630 const void *callout_info,
631 size_t callout_len,
David Howells76181c12007-10-16 23:29:46 -0700632 void *aux)
633{
David Howells4a38e122008-04-29 01:01:24 -0700634 return request_key_and_link(type, description, callout_info,
635 callout_len, aux, NULL, KEY_ALLOC_IN_QUOTA);
David Howells76181c12007-10-16 23:29:46 -0700636}
637EXPORT_SYMBOL(request_key_async_with_auxdata);