blob: efe77df6863f4378f4f0da414591f940870b76ea [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
2 * Scatterlist Cryptographic API.
3 *
4 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
5 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
Herbert Xu5cb14542005-11-05 16:58:14 +11006 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
Linus Torvalds1da177e2005-04-16 15:20:36 -07007 *
8 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
John Anthony Kazos Jr991d1742007-10-19 23:06:17 +02009 * and Nettle, by Niels Möller.
Linus Torvalds1da177e2005-04-16 15:20:36 -070010 *
11 * This program is free software; you can redistribute it and/or modify it
12 * under the terms of the GNU General Public License as published by the Free
13 * Software Foundation; either version 2 of the License, or (at your option)
14 * any later version.
15 *
16 */
Jesper Juhla61cc442005-07-06 13:54:31 -070017
Herbert Xu6bfd4802006-09-21 11:39:29 +100018#include <linux/err.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070019#include <linux/errno.h>
Herbert Xu5cb14542005-11-05 16:58:14 +110020#include <linux/kernel.h>
Adrian Bunk176c3652005-07-06 13:53:09 -070021#include <linux/kmod.h>
Herbert Xu2b8c19d2006-09-21 11:31:44 +100022#include <linux/module.h>
Herbert Xu28259822006-08-06 21:23:26 +100023#include <linux/param.h>
Herbert Xu6bfd4802006-09-21 11:39:29 +100024#include <linux/sched.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070025#include <linux/slab.h>
Herbert Xu5cb14542005-11-05 16:58:14 +110026#include <linux/string.h>
Linus Torvalds1da177e2005-04-16 15:20:36 -070027#include "internal.h"
28
29LIST_HEAD(crypto_alg_list);
Herbert Xucce9e062006-08-21 21:08:13 +100030EXPORT_SYMBOL_GPL(crypto_alg_list);
Linus Torvalds1da177e2005-04-16 15:20:36 -070031DECLARE_RWSEM(crypto_alg_sem);
Herbert Xucce9e062006-08-21 21:08:13 +100032EXPORT_SYMBOL_GPL(crypto_alg_sem);
Linus Torvalds1da177e2005-04-16 15:20:36 -070033
Herbert Xu28259822006-08-06 21:23:26 +100034BLOCKING_NOTIFIER_HEAD(crypto_chain);
35EXPORT_SYMBOL_GPL(crypto_chain);
36
Herbert Xu6521f302006-08-06 20:28:44 +100037static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
Linus Torvalds1da177e2005-04-16 15:20:36 -070038{
Herbert Xu6521f302006-08-06 20:28:44 +100039 atomic_inc(&alg->cra_refcnt);
40 return alg;
Linus Torvalds1da177e2005-04-16 15:20:36 -070041}
42
Herbert Xu28259822006-08-06 21:23:26 +100043struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
Herbert Xu6521f302006-08-06 20:28:44 +100044{
45 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
46}
Herbert Xu28259822006-08-06 21:23:26 +100047EXPORT_SYMBOL_GPL(crypto_mod_get);
Herbert Xu6521f302006-08-06 20:28:44 +100048
Herbert Xu28259822006-08-06 21:23:26 +100049void crypto_mod_put(struct crypto_alg *alg)
Herbert Xu6521f302006-08-06 20:28:44 +100050{
Herbert Xuda7cd592007-05-19 14:51:00 +100051 struct module *module = alg->cra_module;
52
Herbert Xu6521f302006-08-06 20:28:44 +100053 crypto_alg_put(alg);
Herbert Xuda7cd592007-05-19 14:51:00 +100054 module_put(module);
Linus Torvalds1da177e2005-04-16 15:20:36 -070055}
Herbert Xu28259822006-08-06 21:23:26 +100056EXPORT_SYMBOL_GPL(crypto_mod_put);
Linus Torvalds1da177e2005-04-16 15:20:36 -070057
Herbert Xu73d38642008-08-03 21:15:23 +080058static inline int crypto_is_test_larval(struct crypto_larval *larval)
59{
60 return larval->alg.cra_driver_name[0];
61}
62
Herbert Xuc51b6c82008-08-04 11:44:59 +080063static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
64 u32 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -070065{
66 struct crypto_alg *q, *alg = NULL;
Herbert Xu28259822006-08-06 21:23:26 +100067 int best = -2;
Linus Torvalds1da177e2005-04-16 15:20:36 -070068
Linus Torvalds1da177e2005-04-16 15:20:36 -070069 list_for_each_entry(q, &crypto_alg_list, cra_list) {
Herbert Xu5cb14542005-11-05 16:58:14 +110070 int exact, fuzzy;
71
Herbert Xu6bfd4802006-09-21 11:39:29 +100072 if (crypto_is_moribund(q))
73 continue;
74
Herbert Xu492e2b62006-09-21 11:35:17 +100075 if ((q->cra_flags ^ type) & mask)
76 continue;
77
78 if (crypto_is_larval(q) &&
Herbert Xu73d38642008-08-03 21:15:23 +080079 !crypto_is_test_larval((struct crypto_larval *)q) &&
Herbert Xu492e2b62006-09-21 11:35:17 +100080 ((struct crypto_larval *)q)->mask != mask)
81 continue;
82
Herbert Xu5cb14542005-11-05 16:58:14 +110083 exact = !strcmp(q->cra_driver_name, name);
84 fuzzy = !strcmp(q->cra_name, name);
85 if (!exact && !(fuzzy && q->cra_priority > best))
86 continue;
87
Herbert Xu72fa4912006-05-28 09:05:24 +100088 if (unlikely(!crypto_mod_get(q)))
Herbert Xu5cb14542005-11-05 16:58:14 +110089 continue;
90
91 best = q->cra_priority;
92 if (alg)
Herbert Xu72fa4912006-05-28 09:05:24 +100093 crypto_mod_put(alg);
Herbert Xu5cb14542005-11-05 16:58:14 +110094 alg = q;
95
96 if (exact)
Linus Torvalds1da177e2005-04-16 15:20:36 -070097 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -070098 }
Herbert Xu28259822006-08-06 21:23:26 +100099
100 return alg;
101}
Herbert Xu28259822006-08-06 21:23:26 +1000102
103static void crypto_larval_destroy(struct crypto_alg *alg)
104{
105 struct crypto_larval *larval = (void *)alg;
106
107 BUG_ON(!crypto_is_larval(alg));
108 if (larval->adult)
109 crypto_mod_put(larval->adult);
110 kfree(larval);
111}
112
Herbert Xu73d38642008-08-03 21:15:23 +0800113struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
Herbert Xu28259822006-08-06 21:23:26 +1000114{
Herbert Xu28259822006-08-06 21:23:26 +1000115 struct crypto_larval *larval;
116
117 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
118 if (!larval)
Herbert Xu6bfd4802006-09-21 11:39:29 +1000119 return ERR_PTR(-ENOMEM);
Herbert Xu28259822006-08-06 21:23:26 +1000120
Herbert Xu492e2b62006-09-21 11:35:17 +1000121 larval->mask = mask;
122 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
Herbert Xu28259822006-08-06 21:23:26 +1000123 larval->alg.cra_priority = -1;
124 larval->alg.cra_destroy = crypto_larval_destroy;
125
Herbert Xu28259822006-08-06 21:23:26 +1000126 strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
127 init_completion(&larval->completion);
128
Herbert Xu73d38642008-08-03 21:15:23 +0800129 return larval;
130}
131EXPORT_SYMBOL_GPL(crypto_larval_alloc);
132
133static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
134 u32 mask)
135{
136 struct crypto_alg *alg;
137 struct crypto_larval *larval;
138
139 larval = crypto_larval_alloc(name, type, mask);
140 if (IS_ERR(larval))
141 return ERR_CAST(larval);
142
143 atomic_set(&larval->alg.cra_refcnt, 2);
144
Herbert Xu28259822006-08-06 21:23:26 +1000145 down_write(&crypto_alg_sem);
Herbert Xu492e2b62006-09-21 11:35:17 +1000146 alg = __crypto_alg_lookup(name, type, mask);
Herbert Xu28259822006-08-06 21:23:26 +1000147 if (!alg) {
148 alg = &larval->alg;
149 list_add(&alg->cra_list, &crypto_alg_list);
150 }
151 up_write(&crypto_alg_sem);
152
153 if (alg != &larval->alg)
154 kfree(larval);
155
156 return alg;
157}
158
Herbert Xub9c55aa2007-12-04 12:46:48 +1100159void crypto_larval_kill(struct crypto_alg *alg)
Herbert Xu28259822006-08-06 21:23:26 +1000160{
161 struct crypto_larval *larval = (void *)alg;
162
163 down_write(&crypto_alg_sem);
164 list_del(&alg->cra_list);
165 up_write(&crypto_alg_sem);
Herbert Xufe3c5202007-05-19 17:51:40 +1000166 complete_all(&larval->completion);
Herbert Xu28259822006-08-06 21:23:26 +1000167 crypto_alg_put(alg);
168}
Herbert Xub9c55aa2007-12-04 12:46:48 +1100169EXPORT_SYMBOL_GPL(crypto_larval_kill);
Herbert Xu28259822006-08-06 21:23:26 +1000170
171static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
172{
173 struct crypto_larval *larval = (void *)alg;
Herbert Xu73d38642008-08-03 21:15:23 +0800174 long timeout;
Herbert Xu28259822006-08-06 21:23:26 +1000175
Herbert Xu73d38642008-08-03 21:15:23 +0800176 timeout = wait_for_completion_interruptible_timeout(
177 &larval->completion, 60 * HZ);
178
Herbert Xu28259822006-08-06 21:23:26 +1000179 alg = larval->adult;
Herbert Xu73d38642008-08-03 21:15:23 +0800180 if (timeout < 0)
181 alg = ERR_PTR(-EINTR);
182 else if (!timeout)
183 alg = ERR_PTR(-ETIMEDOUT);
184 else if (!alg)
Herbert Xu6bfd4802006-09-21 11:39:29 +1000185 alg = ERR_PTR(-ENOENT);
Herbert Xu73d38642008-08-03 21:15:23 +0800186 else if (crypto_is_test_larval(larval) &&
187 !(alg->cra_flags & CRYPTO_ALG_TESTED))
188 alg = ERR_PTR(-EAGAIN);
189 else if (!crypto_mod_get(alg))
190 alg = ERR_PTR(-EAGAIN);
Herbert Xu28259822006-08-06 21:23:26 +1000191 crypto_mod_put(&larval->alg);
192
193 return alg;
194}
195
Herbert Xuc51b6c82008-08-04 11:44:59 +0800196struct crypto_alg *crypto_alg_lookup(const char *name, u32 type, u32 mask)
Herbert Xu28259822006-08-06 21:23:26 +1000197{
198 struct crypto_alg *alg;
199
Herbert Xu28259822006-08-06 21:23:26 +1000200 down_read(&crypto_alg_sem);
Herbert Xu492e2b62006-09-21 11:35:17 +1000201 alg = __crypto_alg_lookup(name, type, mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700202 up_read(&crypto_alg_sem);
Herbert Xu28259822006-08-06 21:23:26 +1000203
Linus Torvalds1da177e2005-04-16 15:20:36 -0700204 return alg;
205}
Herbert Xuc51b6c82008-08-04 11:44:59 +0800206EXPORT_SYMBOL_GPL(crypto_alg_lookup);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700207
Herbert Xub9c55aa2007-12-04 12:46:48 +1100208struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
Adrian Bunk176c3652005-07-06 13:53:09 -0700209{
Herbert Xu28259822006-08-06 21:23:26 +1000210 struct crypto_alg *alg;
Herbert Xu28259822006-08-06 21:23:26 +1000211
Herbert Xu6bfd4802006-09-21 11:39:29 +1000212 if (!name)
213 return ERR_PTR(-ENOENT);
214
215 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
Herbert Xu492e2b62006-09-21 11:35:17 +1000216 type &= mask;
217
218 alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
219 name);
Herbert Xu28259822006-08-06 21:23:26 +1000220 if (alg)
221 return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
222
Herbert Xu73d38642008-08-03 21:15:23 +0800223 return crypto_larval_add(name, type, mask);
Herbert Xub9c55aa2007-12-04 12:46:48 +1100224}
225EXPORT_SYMBOL_GPL(crypto_larval_lookup);
226
Herbert Xu73d38642008-08-03 21:15:23 +0800227int crypto_probing_notify(unsigned long val, void *v)
228{
229 int ok;
230
231 ok = blocking_notifier_call_chain(&crypto_chain, val, v);
232 if (ok == NOTIFY_DONE) {
233 request_module("cryptomgr");
234 ok = blocking_notifier_call_chain(&crypto_chain, val, v);
235 }
236
237 return ok;
238}
239EXPORT_SYMBOL_GPL(crypto_probing_notify);
240
Herbert Xub9c55aa2007-12-04 12:46:48 +1100241struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
242{
243 struct crypto_alg *alg;
244 struct crypto_alg *larval;
245 int ok;
246
Herbert Xu73d38642008-08-03 21:15:23 +0800247 if (!(mask & CRYPTO_ALG_TESTED)) {
248 type |= CRYPTO_ALG_TESTED;
249 mask |= CRYPTO_ALG_TESTED;
250 }
251
Herbert Xub9c55aa2007-12-04 12:46:48 +1100252 larval = crypto_larval_lookup(name, type, mask);
Herbert Xu6bfd4802006-09-21 11:39:29 +1000253 if (IS_ERR(larval) || !crypto_is_larval(larval))
Herbert Xu28259822006-08-06 21:23:26 +1000254 return larval;
255
Herbert Xu73d38642008-08-03 21:15:23 +0800256 ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
Herbert Xu2b8c19d2006-09-21 11:31:44 +1000257
258 if (ok == NOTIFY_STOP)
Herbert Xu28259822006-08-06 21:23:26 +1000259 alg = crypto_larval_wait(larval);
260 else {
261 crypto_mod_put(larval);
Herbert Xu6bfd4802006-09-21 11:39:29 +1000262 alg = ERR_PTR(-ENOENT);
Herbert Xu28259822006-08-06 21:23:26 +1000263 }
264 crypto_larval_kill(larval);
265 return alg;
Adrian Bunk176c3652005-07-06 13:53:09 -0700266}
Herbert Xu492e2b62006-09-21 11:35:17 +1000267EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
Adrian Bunk176c3652005-07-06 13:53:09 -0700268
Herbert Xu27d2a332007-01-24 20:50:26 +1100269static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700270{
Herbert Xu27d2a332007-01-24 20:50:26 +1100271 const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
Herbert Xue853c3c2006-08-22 00:06:54 +1000272
Herbert Xu27d2a332007-01-24 20:50:26 +1100273 if (type_obj)
274 return type_obj->init(tfm, type, mask);
Herbert Xue853c3c2006-08-22 00:06:54 +1000275
Linus Torvalds1da177e2005-04-16 15:20:36 -0700276 switch (crypto_tfm_alg_type(tfm)) {
277 case CRYPTO_ALG_TYPE_CIPHER:
278 return crypto_init_cipher_ops(tfm);
279
280 case CRYPTO_ALG_TYPE_DIGEST:
Loc Ho004a4032008-05-14 20:41:47 +0800281 if ((mask & CRYPTO_ALG_TYPE_HASH_MASK) !=
282 CRYPTO_ALG_TYPE_HASH_MASK)
283 return crypto_init_digest_ops_async(tfm);
284 else
285 return crypto_init_digest_ops(tfm);
286
Linus Torvalds1da177e2005-04-16 15:20:36 -0700287 case CRYPTO_ALG_TYPE_COMPRESS:
288 return crypto_init_compress_ops(tfm);
289
290 default:
291 break;
292 }
293
294 BUG();
295 return -EINVAL;
296}
297
298static void crypto_exit_ops(struct crypto_tfm *tfm)
299{
Herbert Xue853c3c2006-08-22 00:06:54 +1000300 const struct crypto_type *type = tfm->__crt_alg->cra_type;
301
302 if (type) {
Herbert Xu4a779482008-09-13 18:19:03 -0700303 if (tfm->exit)
304 tfm->exit(tfm);
Herbert Xue853c3c2006-08-22 00:06:54 +1000305 return;
306 }
307
Linus Torvalds1da177e2005-04-16 15:20:36 -0700308 switch (crypto_tfm_alg_type(tfm)) {
309 case CRYPTO_ALG_TYPE_CIPHER:
310 crypto_exit_cipher_ops(tfm);
311 break;
312
313 case CRYPTO_ALG_TYPE_DIGEST:
314 crypto_exit_digest_ops(tfm);
315 break;
316
317 case CRYPTO_ALG_TYPE_COMPRESS:
318 crypto_exit_compress_ops(tfm);
319 break;
320
321 default:
322 BUG();
323
324 }
325}
326
Herbert Xu27d2a332007-01-24 20:50:26 +1100327static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
Herbert Xufbdae9f2005-07-06 13:53:29 -0700328{
Herbert Xu27d2a332007-01-24 20:50:26 +1100329 const struct crypto_type *type_obj = alg->cra_type;
Herbert Xufbdae9f2005-07-06 13:53:29 -0700330 unsigned int len;
331
Herbert Xue853c3c2006-08-22 00:06:54 +1000332 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
Herbert Xu27d2a332007-01-24 20:50:26 +1100333 if (type_obj)
334 return len + type_obj->ctxsize(alg, type, mask);
Herbert Xue853c3c2006-08-22 00:06:54 +1000335
Herbert Xufbdae9f2005-07-06 13:53:29 -0700336 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
337 default:
338 BUG();
339
340 case CRYPTO_ALG_TYPE_CIPHER:
Herbert Xuf1ddcaf2007-01-27 10:05:15 +1100341 len += crypto_cipher_ctxsize(alg);
Herbert Xufbdae9f2005-07-06 13:53:29 -0700342 break;
343
344 case CRYPTO_ALG_TYPE_DIGEST:
Herbert Xuf1ddcaf2007-01-27 10:05:15 +1100345 len += crypto_digest_ctxsize(alg);
Herbert Xufbdae9f2005-07-06 13:53:29 -0700346 break;
347
348 case CRYPTO_ALG_TYPE_COMPRESS:
Herbert Xuf1ddcaf2007-01-27 10:05:15 +1100349 len += crypto_compress_ctxsize(alg);
Herbert Xufbdae9f2005-07-06 13:53:29 -0700350 break;
351 }
352
Herbert Xue853c3c2006-08-22 00:06:54 +1000353 return len;
Herbert Xufbdae9f2005-07-06 13:53:29 -0700354}
355
Herbert Xu6bfd4802006-09-21 11:39:29 +1000356void crypto_shoot_alg(struct crypto_alg *alg)
357{
358 down_write(&crypto_alg_sem);
359 alg->cra_flags |= CRYPTO_ALG_DYING;
360 up_write(&crypto_alg_sem);
361}
362EXPORT_SYMBOL_GPL(crypto_shoot_alg);
363
Herbert Xu27d2a332007-01-24 20:50:26 +1100364struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
365 u32 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700366{
367 struct crypto_tfm *tfm = NULL;
Herbert Xufbdae9f2005-07-06 13:53:29 -0700368 unsigned int tfm_size;
Herbert Xu6bfd4802006-09-21 11:39:29 +1000369 int err = -ENOMEM;
Herbert Xufbdae9f2005-07-06 13:53:29 -0700370
Herbert Xu27d2a332007-01-24 20:50:26 +1100371 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
Eric Sesterhennbbeb5632006-03-06 21:42:07 +1100372 tfm = kzalloc(tfm_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700373 if (tfm == NULL)
Akinobu Mita9765d262006-10-11 22:29:51 +1000374 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700375
Linus Torvalds1da177e2005-04-16 15:20:36 -0700376 tfm->__crt_alg = alg;
Herbert Xu6bfd4802006-09-21 11:39:29 +1000377
Herbert Xu27d2a332007-01-24 20:50:26 +1100378 err = crypto_init_ops(tfm, type, mask);
Herbert Xu6bfd4802006-09-21 11:39:29 +1000379 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700380 goto out_free_tfm;
Herbert Xuc7fc0592006-05-24 13:02:26 +1000381
Herbert Xu4a779482008-09-13 18:19:03 -0700382 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
Herbert Xuc7fc0592006-05-24 13:02:26 +1000383 goto cra_init_failed;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700384
385 goto out;
386
Herbert Xuc7fc0592006-05-24 13:02:26 +1000387cra_init_failed:
388 crypto_exit_ops(tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700389out_free_tfm:
Herbert Xu4a779482008-09-13 18:19:03 -0700390 if (err == -EAGAIN)
391 crypto_shoot_alg(alg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700392 kfree(tfm);
Akinobu Mita9765d262006-10-11 22:29:51 +1000393out_err:
Herbert Xu6bfd4802006-09-21 11:39:29 +1000394 tfm = ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700395out:
396 return tfm;
397}
Herbert Xu6bfd4802006-09-21 11:39:29 +1000398EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
399
Herbert Xu6d7d6842006-07-30 11:53:01 +1000400/*
401 * crypto_alloc_base - Locate algorithm and allocate transform
402 * @alg_name: Name of algorithm
403 * @type: Type of algorithm
404 * @mask: Mask for type comparison
405 *
Herbert Xu7b0bac62008-09-21 06:52:53 +0900406 * This function should not be used by new algorithm types.
407 * Plesae use crypto_alloc_tfm instead.
408 *
Herbert Xu6d7d6842006-07-30 11:53:01 +1000409 * crypto_alloc_base() will first attempt to locate an already loaded
410 * algorithm. If that fails and the kernel supports dynamically loadable
411 * modules, it will then attempt to load a module of the same name or
412 * alias. If that fails it will send a query to any loaded crypto manager
413 * to construct an algorithm on the fly. A refcount is grabbed on the
414 * algorithm which is then associated with the new transform.
415 *
416 * The returned transform is of a non-determinate type. Most people
417 * should use one of the more specific allocation functions such as
418 * crypto_alloc_blkcipher.
419 *
420 * In case of error the return value is an error pointer.
421 */
422struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
423{
424 struct crypto_tfm *tfm;
425 int err;
426
427 for (;;) {
428 struct crypto_alg *alg;
429
430 alg = crypto_alg_mod_lookup(alg_name, type, mask);
Akinobu Mita9765d262006-10-11 22:29:51 +1000431 if (IS_ERR(alg)) {
432 err = PTR_ERR(alg);
Herbert Xu6d7d6842006-07-30 11:53:01 +1000433 goto err;
Akinobu Mita9765d262006-10-11 22:29:51 +1000434 }
Herbert Xu6d7d6842006-07-30 11:53:01 +1000435
Herbert Xu27d2a332007-01-24 20:50:26 +1100436 tfm = __crypto_alloc_tfm(alg, type, mask);
Herbert Xu6d7d6842006-07-30 11:53:01 +1000437 if (!IS_ERR(tfm))
Akinobu Mita9765d262006-10-11 22:29:51 +1000438 return tfm;
Herbert Xu6d7d6842006-07-30 11:53:01 +1000439
440 crypto_mod_put(alg);
441 err = PTR_ERR(tfm);
442
443err:
444 if (err != -EAGAIN)
445 break;
446 if (signal_pending(current)) {
447 err = -EINTR;
448 break;
449 }
Akinobu Mita9765d262006-10-11 22:29:51 +1000450 }
Herbert Xu6d7d6842006-07-30 11:53:01 +1000451
Akinobu Mita9765d262006-10-11 22:29:51 +1000452 return ERR_PTR(err);
Herbert Xu6d7d6842006-07-30 11:53:01 +1000453}
454EXPORT_SYMBOL_GPL(crypto_alloc_base);
Herbert Xu7b0bac62008-09-21 06:52:53 +0900455
456struct crypto_tfm *crypto_create_tfm(struct crypto_alg *alg,
457 const struct crypto_type *frontend)
458{
459 char *mem;
460 struct crypto_tfm *tfm = NULL;
461 unsigned int tfmsize;
462 unsigned int total;
463 int err = -ENOMEM;
464
465 tfmsize = frontend->tfmsize;
466 total = tfmsize + sizeof(*tfm) + frontend->extsize(alg, frontend);
467
468 mem = kzalloc(total, GFP_KERNEL);
469 if (mem == NULL)
470 goto out_err;
471
472 tfm = (struct crypto_tfm *)(mem + tfmsize);
473 tfm->__crt_alg = alg;
474
475 err = frontend->init_tfm(tfm, frontend);
476 if (err)
477 goto out_free_tfm;
478
479 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
480 goto cra_init_failed;
481
482 goto out;
483
484cra_init_failed:
485 crypto_exit_ops(tfm);
486out_free_tfm:
487 if (err == -EAGAIN)
488 crypto_shoot_alg(alg);
489 kfree(mem);
490out_err:
491 tfm = ERR_PTR(err);
492out:
493 return tfm;
494}
495EXPORT_SYMBOL_GPL(crypto_create_tfm);
496
497/*
498 * crypto_alloc_tfm - Locate algorithm and allocate transform
499 * @alg_name: Name of algorithm
500 * @frontend: Frontend algorithm type
501 * @type: Type of algorithm
502 * @mask: Mask for type comparison
503 *
504 * crypto_alloc_tfm() will first attempt to locate an already loaded
505 * algorithm. If that fails and the kernel supports dynamically loadable
506 * modules, it will then attempt to load a module of the same name or
507 * alias. If that fails it will send a query to any loaded crypto manager
508 * to construct an algorithm on the fly. A refcount is grabbed on the
509 * algorithm which is then associated with the new transform.
510 *
511 * The returned transform is of a non-determinate type. Most people
512 * should use one of the more specific allocation functions such as
513 * crypto_alloc_blkcipher.
514 *
515 * In case of error the return value is an error pointer.
516 */
517struct crypto_tfm *crypto_alloc_tfm(const char *alg_name,
518 const struct crypto_type *frontend,
519 u32 type, u32 mask)
520{
521 struct crypto_alg *(*lookup)(const char *name, u32 type, u32 mask);
522 struct crypto_tfm *tfm;
523 int err;
524
525 type &= frontend->maskclear;
526 mask &= frontend->maskclear;
527 type |= frontend->type;
528 mask |= frontend->maskset;
529
530 lookup = frontend->lookup ?: crypto_alg_mod_lookup;
531
532 for (;;) {
533 struct crypto_alg *alg;
534
535 alg = lookup(alg_name, type, mask);
536 if (IS_ERR(alg)) {
537 err = PTR_ERR(alg);
538 goto err;
539 }
540
541 tfm = crypto_create_tfm(alg, frontend);
542 if (!IS_ERR(tfm))
543 return tfm;
544
545 crypto_mod_put(alg);
546 err = PTR_ERR(tfm);
547
548err:
549 if (err != -EAGAIN)
550 break;
551 if (signal_pending(current)) {
552 err = -EINTR;
553 break;
554 }
555 }
556
557 return ERR_PTR(err);
558}
559EXPORT_SYMBOL_GPL(crypto_alloc_tfm);
Herbert Xu7b2cd922009-02-05 16:48:24 +1100560
Herbert Xu6d7d6842006-07-30 11:53:01 +1000561/*
Herbert Xu7b2cd922009-02-05 16:48:24 +1100562 * crypto_destroy_tfm - Free crypto transform
563 * @mem: Start of tfm slab
Herbert Xu6d7d6842006-07-30 11:53:01 +1000564 * @tfm: Transform to free
565 *
Herbert Xu7b2cd922009-02-05 16:48:24 +1100566 * This function frees up the transform and any associated resources,
Herbert Xu6d7d6842006-07-30 11:53:01 +1000567 * then drops the refcount on the associated algorithm.
568 */
Herbert Xu7b2cd922009-02-05 16:48:24 +1100569void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700570{
Jesper Juhla61cc442005-07-06 13:54:31 -0700571 struct crypto_alg *alg;
572 int size;
573
Herbert Xu7b2cd922009-02-05 16:48:24 +1100574 if (unlikely(!mem))
Jesper Juhla61cc442005-07-06 13:54:31 -0700575 return;
576
577 alg = tfm->__crt_alg;
Herbert Xu7b2cd922009-02-05 16:48:24 +1100578 size = ksize(mem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700579
Herbert Xu4a779482008-09-13 18:19:03 -0700580 if (!tfm->exit && alg->cra_exit)
Herbert Xuc7fc0592006-05-24 13:02:26 +1000581 alg->cra_exit(tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700582 crypto_exit_ops(tfm);
Herbert Xu72fa4912006-05-28 09:05:24 +1000583 crypto_mod_put(alg);
Herbert Xu7b2cd922009-02-05 16:48:24 +1100584 memset(mem, 0, size);
585 kfree(mem);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700586}
Herbert Xu7b2cd922009-02-05 16:48:24 +1100587EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
Herbert Xufce32d72006-08-26 17:35:45 +1000588
589int crypto_has_alg(const char *name, u32 type, u32 mask)
590{
591 int ret = 0;
592 struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
593
594 if (!IS_ERR(alg)) {
595 crypto_mod_put(alg);
596 ret = 1;
597 }
598
599 return ret;
600}
601EXPORT_SYMBOL_GPL(crypto_has_alg);
Sebastian Siewiorc3715cb92008-03-30 16:36:09 +0800602
603MODULE_DESCRIPTION("Cryptographic core API");
604MODULE_LICENSE("GPL");