blob: 1f5c724773568acf31f7dde568972f4925f39407 [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 Xu492e2b62006-09-21 11:35:17 +100058struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type, u32 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -070059{
60 struct crypto_alg *q, *alg = NULL;
Herbert Xu28259822006-08-06 21:23:26 +100061 int best = -2;
Linus Torvalds1da177e2005-04-16 15:20:36 -070062
Linus Torvalds1da177e2005-04-16 15:20:36 -070063 list_for_each_entry(q, &crypto_alg_list, cra_list) {
Herbert Xu5cb14542005-11-05 16:58:14 +110064 int exact, fuzzy;
65
Herbert Xu6bfd4802006-09-21 11:39:29 +100066 if (crypto_is_moribund(q))
67 continue;
68
Herbert Xu492e2b62006-09-21 11:35:17 +100069 if ((q->cra_flags ^ type) & mask)
70 continue;
71
72 if (crypto_is_larval(q) &&
73 ((struct crypto_larval *)q)->mask != mask)
74 continue;
75
Herbert Xu5cb14542005-11-05 16:58:14 +110076 exact = !strcmp(q->cra_driver_name, name);
77 fuzzy = !strcmp(q->cra_name, name);
78 if (!exact && !(fuzzy && q->cra_priority > best))
79 continue;
80
Herbert Xu72fa4912006-05-28 09:05:24 +100081 if (unlikely(!crypto_mod_get(q)))
Herbert Xu5cb14542005-11-05 16:58:14 +110082 continue;
83
84 best = q->cra_priority;
85 if (alg)
Herbert Xu72fa4912006-05-28 09:05:24 +100086 crypto_mod_put(alg);
Herbert Xu5cb14542005-11-05 16:58:14 +110087 alg = q;
88
89 if (exact)
Linus Torvalds1da177e2005-04-16 15:20:36 -070090 break;
Linus Torvalds1da177e2005-04-16 15:20:36 -070091 }
Herbert Xu28259822006-08-06 21:23:26 +100092
93 return alg;
94}
95EXPORT_SYMBOL_GPL(__crypto_alg_lookup);
96
97static void crypto_larval_destroy(struct crypto_alg *alg)
98{
99 struct crypto_larval *larval = (void *)alg;
100
101 BUG_ON(!crypto_is_larval(alg));
102 if (larval->adult)
103 crypto_mod_put(larval->adult);
104 kfree(larval);
105}
106
Herbert Xu492e2b62006-09-21 11:35:17 +1000107static struct crypto_alg *crypto_larval_alloc(const char *name, u32 type,
108 u32 mask)
Herbert Xu28259822006-08-06 21:23:26 +1000109{
110 struct crypto_alg *alg;
111 struct crypto_larval *larval;
112
113 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
114 if (!larval)
Herbert Xu6bfd4802006-09-21 11:39:29 +1000115 return ERR_PTR(-ENOMEM);
Herbert Xu28259822006-08-06 21:23:26 +1000116
Herbert Xu492e2b62006-09-21 11:35:17 +1000117 larval->mask = mask;
118 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
Herbert Xu28259822006-08-06 21:23:26 +1000119 larval->alg.cra_priority = -1;
120 larval->alg.cra_destroy = crypto_larval_destroy;
121
122 atomic_set(&larval->alg.cra_refcnt, 2);
123 strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
124 init_completion(&larval->completion);
125
126 down_write(&crypto_alg_sem);
Herbert Xu492e2b62006-09-21 11:35:17 +1000127 alg = __crypto_alg_lookup(name, type, mask);
Herbert Xu28259822006-08-06 21:23:26 +1000128 if (!alg) {
129 alg = &larval->alg;
130 list_add(&alg->cra_list, &crypto_alg_list);
131 }
132 up_write(&crypto_alg_sem);
133
134 if (alg != &larval->alg)
135 kfree(larval);
136
137 return alg;
138}
139
140static void crypto_larval_kill(struct crypto_alg *alg)
141{
142 struct crypto_larval *larval = (void *)alg;
143
144 down_write(&crypto_alg_sem);
145 list_del(&alg->cra_list);
146 up_write(&crypto_alg_sem);
Herbert Xufe3c5202007-05-19 17:51:40 +1000147 complete_all(&larval->completion);
Herbert Xu28259822006-08-06 21:23:26 +1000148 crypto_alg_put(alg);
149}
150
151static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
152{
153 struct crypto_larval *larval = (void *)alg;
154
155 wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);
156 alg = larval->adult;
Herbert Xu6bfd4802006-09-21 11:39:29 +1000157 if (alg) {
158 if (!crypto_mod_get(alg))
159 alg = ERR_PTR(-EAGAIN);
160 } else
161 alg = ERR_PTR(-ENOENT);
Herbert Xu28259822006-08-06 21:23:26 +1000162 crypto_mod_put(&larval->alg);
163
164 return alg;
165}
166
Herbert Xu492e2b62006-09-21 11:35:17 +1000167static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
168 u32 mask)
Herbert Xu28259822006-08-06 21:23:26 +1000169{
170 struct crypto_alg *alg;
171
Herbert Xu28259822006-08-06 21:23:26 +1000172 down_read(&crypto_alg_sem);
Herbert Xu492e2b62006-09-21 11:35:17 +1000173 alg = __crypto_alg_lookup(name, type, mask);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700174 up_read(&crypto_alg_sem);
Herbert Xu28259822006-08-06 21:23:26 +1000175
Linus Torvalds1da177e2005-04-16 15:20:36 -0700176 return alg;
177}
178
Herbert Xu492e2b62006-09-21 11:35:17 +1000179struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
Adrian Bunk176c3652005-07-06 13:53:09 -0700180{
Herbert Xu28259822006-08-06 21:23:26 +1000181 struct crypto_alg *alg;
182 struct crypto_alg *larval;
Herbert Xu2b8c19d2006-09-21 11:31:44 +1000183 int ok;
Herbert Xu28259822006-08-06 21:23:26 +1000184
Herbert Xu6bfd4802006-09-21 11:39:29 +1000185 if (!name)
186 return ERR_PTR(-ENOENT);
187
188 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
Herbert Xu492e2b62006-09-21 11:35:17 +1000189 type &= mask;
190
191 alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
192 name);
Herbert Xu28259822006-08-06 21:23:26 +1000193 if (alg)
194 return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
195
Herbert Xu492e2b62006-09-21 11:35:17 +1000196 larval = crypto_larval_alloc(name, type, mask);
Herbert Xu6bfd4802006-09-21 11:39:29 +1000197 if (IS_ERR(larval) || !crypto_is_larval(larval))
Herbert Xu28259822006-08-06 21:23:26 +1000198 return larval;
199
Herbert Xu2b8c19d2006-09-21 11:31:44 +1000200 ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
201 if (ok == NOTIFY_DONE) {
202 request_module("cryptomgr");
203 ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
204 }
205
206 if (ok == NOTIFY_STOP)
Herbert Xu28259822006-08-06 21:23:26 +1000207 alg = crypto_larval_wait(larval);
208 else {
209 crypto_mod_put(larval);
Herbert Xu6bfd4802006-09-21 11:39:29 +1000210 alg = ERR_PTR(-ENOENT);
Herbert Xu28259822006-08-06 21:23:26 +1000211 }
212 crypto_larval_kill(larval);
213 return alg;
Adrian Bunk176c3652005-07-06 13:53:09 -0700214}
Herbert Xu492e2b62006-09-21 11:35:17 +1000215EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
Adrian Bunk176c3652005-07-06 13:53:09 -0700216
Herbert Xu27d2a332007-01-24 20:50:26 +1100217static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700218{
Herbert Xu27d2a332007-01-24 20:50:26 +1100219 const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
Herbert Xue853c3c2006-08-22 00:06:54 +1000220
Herbert Xu27d2a332007-01-24 20:50:26 +1100221 if (type_obj)
222 return type_obj->init(tfm, type, mask);
Herbert Xue853c3c2006-08-22 00:06:54 +1000223
Linus Torvalds1da177e2005-04-16 15:20:36 -0700224 switch (crypto_tfm_alg_type(tfm)) {
225 case CRYPTO_ALG_TYPE_CIPHER:
226 return crypto_init_cipher_ops(tfm);
227
228 case CRYPTO_ALG_TYPE_DIGEST:
229 return crypto_init_digest_ops(tfm);
230
231 case CRYPTO_ALG_TYPE_COMPRESS:
232 return crypto_init_compress_ops(tfm);
233
234 default:
235 break;
236 }
237
238 BUG();
239 return -EINVAL;
240}
241
242static void crypto_exit_ops(struct crypto_tfm *tfm)
243{
Herbert Xue853c3c2006-08-22 00:06:54 +1000244 const struct crypto_type *type = tfm->__crt_alg->cra_type;
245
246 if (type) {
247 if (type->exit)
248 type->exit(tfm);
249 return;
250 }
251
Linus Torvalds1da177e2005-04-16 15:20:36 -0700252 switch (crypto_tfm_alg_type(tfm)) {
253 case CRYPTO_ALG_TYPE_CIPHER:
254 crypto_exit_cipher_ops(tfm);
255 break;
256
257 case CRYPTO_ALG_TYPE_DIGEST:
258 crypto_exit_digest_ops(tfm);
259 break;
260
261 case CRYPTO_ALG_TYPE_COMPRESS:
262 crypto_exit_compress_ops(tfm);
263 break;
264
265 default:
266 BUG();
267
268 }
269}
270
Herbert Xu27d2a332007-01-24 20:50:26 +1100271static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
Herbert Xufbdae9f2005-07-06 13:53:29 -0700272{
Herbert Xu27d2a332007-01-24 20:50:26 +1100273 const struct crypto_type *type_obj = alg->cra_type;
Herbert Xufbdae9f2005-07-06 13:53:29 -0700274 unsigned int len;
275
Herbert Xue853c3c2006-08-22 00:06:54 +1000276 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
Herbert Xu27d2a332007-01-24 20:50:26 +1100277 if (type_obj)
278 return len + type_obj->ctxsize(alg, type, mask);
Herbert Xue853c3c2006-08-22 00:06:54 +1000279
Herbert Xufbdae9f2005-07-06 13:53:29 -0700280 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
281 default:
282 BUG();
283
284 case CRYPTO_ALG_TYPE_CIPHER:
Herbert Xuf1ddcaf2007-01-27 10:05:15 +1100285 len += crypto_cipher_ctxsize(alg);
Herbert Xufbdae9f2005-07-06 13:53:29 -0700286 break;
287
288 case CRYPTO_ALG_TYPE_DIGEST:
Herbert Xuf1ddcaf2007-01-27 10:05:15 +1100289 len += crypto_digest_ctxsize(alg);
Herbert Xufbdae9f2005-07-06 13:53:29 -0700290 break;
291
292 case CRYPTO_ALG_TYPE_COMPRESS:
Herbert Xuf1ddcaf2007-01-27 10:05:15 +1100293 len += crypto_compress_ctxsize(alg);
Herbert Xufbdae9f2005-07-06 13:53:29 -0700294 break;
295 }
296
Herbert Xue853c3c2006-08-22 00:06:54 +1000297 return len;
Herbert Xufbdae9f2005-07-06 13:53:29 -0700298}
299
Herbert Xu6bfd4802006-09-21 11:39:29 +1000300void crypto_shoot_alg(struct crypto_alg *alg)
301{
302 down_write(&crypto_alg_sem);
303 alg->cra_flags |= CRYPTO_ALG_DYING;
304 up_write(&crypto_alg_sem);
305}
306EXPORT_SYMBOL_GPL(crypto_shoot_alg);
307
Herbert Xu27d2a332007-01-24 20:50:26 +1100308struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
309 u32 mask)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700310{
311 struct crypto_tfm *tfm = NULL;
Herbert Xufbdae9f2005-07-06 13:53:29 -0700312 unsigned int tfm_size;
Herbert Xu6bfd4802006-09-21 11:39:29 +1000313 int err = -ENOMEM;
Herbert Xufbdae9f2005-07-06 13:53:29 -0700314
Herbert Xu27d2a332007-01-24 20:50:26 +1100315 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
Eric Sesterhennbbeb5632006-03-06 21:42:07 +1100316 tfm = kzalloc(tfm_size, GFP_KERNEL);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700317 if (tfm == NULL)
Akinobu Mita9765d262006-10-11 22:29:51 +1000318 goto out_err;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700319
Linus Torvalds1da177e2005-04-16 15:20:36 -0700320 tfm->__crt_alg = alg;
Herbert Xu6bfd4802006-09-21 11:39:29 +1000321
Herbert Xu27d2a332007-01-24 20:50:26 +1100322 err = crypto_init_ops(tfm, type, mask);
Herbert Xu6bfd4802006-09-21 11:39:29 +1000323 if (err)
Linus Torvalds1da177e2005-04-16 15:20:36 -0700324 goto out_free_tfm;
Herbert Xuc7fc0592006-05-24 13:02:26 +1000325
Herbert Xu6bfd4802006-09-21 11:39:29 +1000326 if (alg->cra_init && (err = alg->cra_init(tfm))) {
327 if (err == -EAGAIN)
328 crypto_shoot_alg(alg);
Herbert Xuc7fc0592006-05-24 13:02:26 +1000329 goto cra_init_failed;
Herbert Xu6bfd4802006-09-21 11:39:29 +1000330 }
Linus Torvalds1da177e2005-04-16 15:20:36 -0700331
332 goto out;
333
Herbert Xuc7fc0592006-05-24 13:02:26 +1000334cra_init_failed:
335 crypto_exit_ops(tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700336out_free_tfm:
337 kfree(tfm);
Akinobu Mita9765d262006-10-11 22:29:51 +1000338out_err:
Herbert Xu6bfd4802006-09-21 11:39:29 +1000339 tfm = ERR_PTR(err);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700340out:
341 return tfm;
342}
Herbert Xu6bfd4802006-09-21 11:39:29 +1000343EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
344
Herbert Xu6d7d6842006-07-30 11:53:01 +1000345/*
346 * crypto_alloc_base - Locate algorithm and allocate transform
347 * @alg_name: Name of algorithm
348 * @type: Type of algorithm
349 * @mask: Mask for type comparison
350 *
351 * crypto_alloc_base() will first attempt to locate an already loaded
352 * algorithm. If that fails and the kernel supports dynamically loadable
353 * modules, it will then attempt to load a module of the same name or
354 * alias. If that fails it will send a query to any loaded crypto manager
355 * to construct an algorithm on the fly. A refcount is grabbed on the
356 * algorithm which is then associated with the new transform.
357 *
358 * The returned transform is of a non-determinate type. Most people
359 * should use one of the more specific allocation functions such as
360 * crypto_alloc_blkcipher.
361 *
362 * In case of error the return value is an error pointer.
363 */
364struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
365{
366 struct crypto_tfm *tfm;
367 int err;
368
369 for (;;) {
370 struct crypto_alg *alg;
371
372 alg = crypto_alg_mod_lookup(alg_name, type, mask);
Akinobu Mita9765d262006-10-11 22:29:51 +1000373 if (IS_ERR(alg)) {
374 err = PTR_ERR(alg);
Herbert Xu6d7d6842006-07-30 11:53:01 +1000375 goto err;
Akinobu Mita9765d262006-10-11 22:29:51 +1000376 }
Herbert Xu6d7d6842006-07-30 11:53:01 +1000377
Herbert Xu27d2a332007-01-24 20:50:26 +1100378 tfm = __crypto_alloc_tfm(alg, type, mask);
Herbert Xu6d7d6842006-07-30 11:53:01 +1000379 if (!IS_ERR(tfm))
Akinobu Mita9765d262006-10-11 22:29:51 +1000380 return tfm;
Herbert Xu6d7d6842006-07-30 11:53:01 +1000381
382 crypto_mod_put(alg);
383 err = PTR_ERR(tfm);
384
385err:
386 if (err != -EAGAIN)
387 break;
388 if (signal_pending(current)) {
389 err = -EINTR;
390 break;
391 }
Akinobu Mita9765d262006-10-11 22:29:51 +1000392 }
Herbert Xu6d7d6842006-07-30 11:53:01 +1000393
Akinobu Mita9765d262006-10-11 22:29:51 +1000394 return ERR_PTR(err);
Herbert Xu6d7d6842006-07-30 11:53:01 +1000395}
396EXPORT_SYMBOL_GPL(crypto_alloc_base);
397
398/*
399 * crypto_free_tfm - Free crypto transform
400 * @tfm: Transform to free
401 *
402 * crypto_free_tfm() frees up the transform and any associated resources,
403 * then drops the refcount on the associated algorithm.
404 */
Linus Torvalds1da177e2005-04-16 15:20:36 -0700405void crypto_free_tfm(struct crypto_tfm *tfm)
406{
Jesper Juhla61cc442005-07-06 13:54:31 -0700407 struct crypto_alg *alg;
408 int size;
409
410 if (unlikely(!tfm))
411 return;
412
413 alg = tfm->__crt_alg;
414 size = sizeof(*tfm) + alg->cra_ctxsize;
Linus Torvalds1da177e2005-04-16 15:20:36 -0700415
Herbert Xuc7fc0592006-05-24 13:02:26 +1000416 if (alg->cra_exit)
417 alg->cra_exit(tfm);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700418 crypto_exit_ops(tfm);
Herbert Xu72fa4912006-05-28 09:05:24 +1000419 crypto_mod_put(alg);
Linus Torvalds1da177e2005-04-16 15:20:36 -0700420 memset(tfm, 0, size);
421 kfree(tfm);
422}
423
Linus Torvalds1da177e2005-04-16 15:20:36 -0700424EXPORT_SYMBOL_GPL(crypto_free_tfm);
Herbert Xufce32d72006-08-26 17:35:45 +1000425
426int crypto_has_alg(const char *name, u32 type, u32 mask)
427{
428 int ret = 0;
429 struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
430
431 if (!IS_ERR(alg)) {
432 crypto_mod_put(alg);
433 ret = 1;
434 }
435
436 return ret;
437}
438EXPORT_SYMBOL_GPL(crypto_has_alg);