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1da177e4
LT
1/*
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)
5cb1454b 6 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
1da177e4
LT
7 *
8 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
991d1740 9 * and Nettle, by Niels Möller.
1da177e4
LT
10 *
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 */
a61cc448 17
6bfd4809 18#include <linux/err.h>
1da177e4 19#include <linux/errno.h>
5cb1454b 20#include <linux/kernel.h>
176c3652 21#include <linux/kmod.h>
2b8c19db 22#include <linux/module.h>
2825982d 23#include <linux/param.h>
6bfd4809 24#include <linux/sched.h>
1da177e4 25#include <linux/slab.h>
5cb1454b 26#include <linux/string.h>
1da177e4
LT
27#include "internal.h"
28
29LIST_HEAD(crypto_alg_list);
cce9e06d 30EXPORT_SYMBOL_GPL(crypto_alg_list);
1da177e4 31DECLARE_RWSEM(crypto_alg_sem);
cce9e06d 32EXPORT_SYMBOL_GPL(crypto_alg_sem);
1da177e4 33
2825982d
HX
34BLOCKING_NOTIFIER_HEAD(crypto_chain);
35EXPORT_SYMBOL_GPL(crypto_chain);
36
6521f302 37static inline struct crypto_alg *crypto_alg_get(struct crypto_alg *alg)
1da177e4 38{
6521f302
HX
39 atomic_inc(&alg->cra_refcnt);
40 return alg;
41}
42
2825982d 43struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
6521f302
HX
44{
45 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
1da177e4 46}
2825982d 47EXPORT_SYMBOL_GPL(crypto_mod_get);
1da177e4 48
2825982d 49void crypto_mod_put(struct crypto_alg *alg)
1da177e4 50{
da7cd59a
HX
51 struct module *module = alg->cra_module;
52
6521f302 53 crypto_alg_put(alg);
da7cd59a 54 module_put(module);
1da177e4 55}
2825982d 56EXPORT_SYMBOL_GPL(crypto_mod_put);
1da177e4 57
492e2b63 58struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type, u32 mask)
1da177e4
LT
59{
60 struct crypto_alg *q, *alg = NULL;
2825982d 61 int best = -2;
1da177e4 62
1da177e4 63 list_for_each_entry(q, &crypto_alg_list, cra_list) {
5cb1454b
HX
64 int exact, fuzzy;
65
6bfd4809
HX
66 if (crypto_is_moribund(q))
67 continue;
68
492e2b63
HX
69 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
5cb1454b
HX
76 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
72fa4919 81 if (unlikely(!crypto_mod_get(q)))
5cb1454b
HX
82 continue;
83
84 best = q->cra_priority;
85 if (alg)
72fa4919 86 crypto_mod_put(alg);
5cb1454b
HX
87 alg = q;
88
89 if (exact)
1da177e4 90 break;
1da177e4 91 }
2825982d
HX
92
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
492e2b63
HX
107static struct crypto_alg *crypto_larval_alloc(const char *name, u32 type,
108 u32 mask)
2825982d
HX
109{
110 struct crypto_alg *alg;
111 struct crypto_larval *larval;
112
113 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
114 if (!larval)
6bfd4809 115 return ERR_PTR(-ENOMEM);
2825982d 116
492e2b63
HX
117 larval->mask = mask;
118 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
2825982d
HX
119 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);
492e2b63 127 alg = __crypto_alg_lookup(name, type, mask);
2825982d
HX
128 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
b9c55aa4 140void crypto_larval_kill(struct crypto_alg *alg)
2825982d
HX
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);
fe3c5206 147 complete_all(&larval->completion);
2825982d
HX
148 crypto_alg_put(alg);
149}
b9c55aa4 150EXPORT_SYMBOL_GPL(crypto_larval_kill);
2825982d
HX
151
152static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
153{
154 struct crypto_larval *larval = (void *)alg;
155
156 wait_for_completion_interruptible_timeout(&larval->completion, 60 * HZ);
157 alg = larval->adult;
6bfd4809
HX
158 if (alg) {
159 if (!crypto_mod_get(alg))
160 alg = ERR_PTR(-EAGAIN);
161 } else
162 alg = ERR_PTR(-ENOENT);
2825982d
HX
163 crypto_mod_put(&larval->alg);
164
165 return alg;
166}
167
492e2b63
HX
168static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
169 u32 mask)
2825982d
HX
170{
171 struct crypto_alg *alg;
172
2825982d 173 down_read(&crypto_alg_sem);
492e2b63 174 alg = __crypto_alg_lookup(name, type, mask);
1da177e4 175 up_read(&crypto_alg_sem);
2825982d 176
1da177e4
LT
177 return alg;
178}
179
b9c55aa4 180struct crypto_alg *crypto_larval_lookup(const char *name, u32 type, u32 mask)
176c3652 181{
2825982d 182 struct crypto_alg *alg;
2825982d 183
6bfd4809
HX
184 if (!name)
185 return ERR_PTR(-ENOENT);
186
187 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
492e2b63
HX
188 type &= mask;
189
190 alg = try_then_request_module(crypto_alg_lookup(name, type, mask),
191 name);
2825982d
HX
192 if (alg)
193 return crypto_is_larval(alg) ? crypto_larval_wait(alg) : alg;
194
b9c55aa4
HX
195 return crypto_larval_alloc(name, type, mask);
196}
197EXPORT_SYMBOL_GPL(crypto_larval_lookup);
198
199struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
200{
201 struct crypto_alg *alg;
202 struct crypto_alg *larval;
203 int ok;
204
205 larval = crypto_larval_lookup(name, type, mask);
6bfd4809 206 if (IS_ERR(larval) || !crypto_is_larval(larval))
2825982d
HX
207 return larval;
208
2b8c19db
HX
209 ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
210 if (ok == NOTIFY_DONE) {
211 request_module("cryptomgr");
212 ok = crypto_notify(CRYPTO_MSG_ALG_REQUEST, larval);
213 }
214
215 if (ok == NOTIFY_STOP)
2825982d
HX
216 alg = crypto_larval_wait(larval);
217 else {
218 crypto_mod_put(larval);
6bfd4809 219 alg = ERR_PTR(-ENOENT);
2825982d
HX
220 }
221 crypto_larval_kill(larval);
222 return alg;
176c3652 223}
492e2b63 224EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
176c3652 225
27d2a330 226static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
1da177e4 227{
27d2a330 228 const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
e853c3cf 229
27d2a330
HX
230 if (type_obj)
231 return type_obj->init(tfm, type, mask);
e853c3cf 232
1da177e4
LT
233 switch (crypto_tfm_alg_type(tfm)) {
234 case CRYPTO_ALG_TYPE_CIPHER:
235 return crypto_init_cipher_ops(tfm);
236
237 case CRYPTO_ALG_TYPE_DIGEST:
004a403c
LH
238 if ((mask & CRYPTO_ALG_TYPE_HASH_MASK) !=
239 CRYPTO_ALG_TYPE_HASH_MASK)
240 return crypto_init_digest_ops_async(tfm);
241 else
242 return crypto_init_digest_ops(tfm);
243
1da177e4
LT
244 case CRYPTO_ALG_TYPE_COMPRESS:
245 return crypto_init_compress_ops(tfm);
246
247 default:
248 break;
249 }
250
251 BUG();
252 return -EINVAL;
253}
254
255static void crypto_exit_ops(struct crypto_tfm *tfm)
256{
e853c3cf
HX
257 const struct crypto_type *type = tfm->__crt_alg->cra_type;
258
259 if (type) {
260 if (type->exit)
261 type->exit(tfm);
262 return;
263 }
264
1da177e4
LT
265 switch (crypto_tfm_alg_type(tfm)) {
266 case CRYPTO_ALG_TYPE_CIPHER:
267 crypto_exit_cipher_ops(tfm);
268 break;
269
270 case CRYPTO_ALG_TYPE_DIGEST:
271 crypto_exit_digest_ops(tfm);
272 break;
273
274 case CRYPTO_ALG_TYPE_COMPRESS:
275 crypto_exit_compress_ops(tfm);
276 break;
277
278 default:
279 BUG();
280
281 }
282}
283
27d2a330 284static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
fbdae9f3 285{
27d2a330 286 const struct crypto_type *type_obj = alg->cra_type;
fbdae9f3
HX
287 unsigned int len;
288
e853c3cf 289 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
27d2a330
HX
290 if (type_obj)
291 return len + type_obj->ctxsize(alg, type, mask);
e853c3cf 292
fbdae9f3
HX
293 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
294 default:
295 BUG();
296
297 case CRYPTO_ALG_TYPE_CIPHER:
f1ddcaf3 298 len += crypto_cipher_ctxsize(alg);
fbdae9f3
HX
299 break;
300
301 case CRYPTO_ALG_TYPE_DIGEST:
f1ddcaf3 302 len += crypto_digest_ctxsize(alg);
fbdae9f3
HX
303 break;
304
305 case CRYPTO_ALG_TYPE_COMPRESS:
f1ddcaf3 306 len += crypto_compress_ctxsize(alg);
fbdae9f3
HX
307 break;
308 }
309
e853c3cf 310 return len;
fbdae9f3
HX
311}
312
6bfd4809
HX
313void crypto_shoot_alg(struct crypto_alg *alg)
314{
315 down_write(&crypto_alg_sem);
316 alg->cra_flags |= CRYPTO_ALG_DYING;
317 up_write(&crypto_alg_sem);
318}
319EXPORT_SYMBOL_GPL(crypto_shoot_alg);
320
27d2a330
HX
321struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
322 u32 mask)
1da177e4
LT
323{
324 struct crypto_tfm *tfm = NULL;
fbdae9f3 325 unsigned int tfm_size;
6bfd4809 326 int err = -ENOMEM;
fbdae9f3 327
27d2a330 328 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
bbeb563f 329 tfm = kzalloc(tfm_size, GFP_KERNEL);
1da177e4 330 if (tfm == NULL)
9765d262 331 goto out_err;
1da177e4 332
1da177e4 333 tfm->__crt_alg = alg;
6bfd4809 334
27d2a330 335 err = crypto_init_ops(tfm, type, mask);
6bfd4809 336 if (err)
1da177e4 337 goto out_free_tfm;
c7fc0599 338
6bfd4809
HX
339 if (alg->cra_init && (err = alg->cra_init(tfm))) {
340 if (err == -EAGAIN)
341 crypto_shoot_alg(alg);
c7fc0599 342 goto cra_init_failed;
6bfd4809 343 }
1da177e4
LT
344
345 goto out;
346
c7fc0599
HX
347cra_init_failed:
348 crypto_exit_ops(tfm);
1da177e4
LT
349out_free_tfm:
350 kfree(tfm);
9765d262 351out_err:
6bfd4809 352 tfm = ERR_PTR(err);
1da177e4
LT
353out:
354 return tfm;
355}
6bfd4809
HX
356EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
357
6d7d684d
HX
358/*
359 * crypto_alloc_base - Locate algorithm and allocate transform
360 * @alg_name: Name of algorithm
361 * @type: Type of algorithm
362 * @mask: Mask for type comparison
363 *
364 * crypto_alloc_base() will first attempt to locate an already loaded
365 * algorithm. If that fails and the kernel supports dynamically loadable
366 * modules, it will then attempt to load a module of the same name or
367 * alias. If that fails it will send a query to any loaded crypto manager
368 * to construct an algorithm on the fly. A refcount is grabbed on the
369 * algorithm which is then associated with the new transform.
370 *
371 * The returned transform is of a non-determinate type. Most people
372 * should use one of the more specific allocation functions such as
373 * crypto_alloc_blkcipher.
374 *
375 * In case of error the return value is an error pointer.
376 */
377struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
378{
379 struct crypto_tfm *tfm;
380 int err;
381
382 for (;;) {
383 struct crypto_alg *alg;
384
385 alg = crypto_alg_mod_lookup(alg_name, type, mask);
9765d262
AM
386 if (IS_ERR(alg)) {
387 err = PTR_ERR(alg);
6d7d684d 388 goto err;
9765d262 389 }
6d7d684d 390
27d2a330 391 tfm = __crypto_alloc_tfm(alg, type, mask);
6d7d684d 392 if (!IS_ERR(tfm))
9765d262 393 return tfm;
6d7d684d
HX
394
395 crypto_mod_put(alg);
396 err = PTR_ERR(tfm);
397
398err:
399 if (err != -EAGAIN)
400 break;
401 if (signal_pending(current)) {
402 err = -EINTR;
403 break;
404 }
9765d262 405 }
6d7d684d 406
9765d262 407 return ERR_PTR(err);
6d7d684d
HX
408}
409EXPORT_SYMBOL_GPL(crypto_alloc_base);
410
411/*
412 * crypto_free_tfm - Free crypto transform
413 * @tfm: Transform to free
414 *
415 * crypto_free_tfm() frees up the transform and any associated resources,
416 * then drops the refcount on the associated algorithm.
417 */
1da177e4
LT
418void crypto_free_tfm(struct crypto_tfm *tfm)
419{
a61cc448
JJ
420 struct crypto_alg *alg;
421 int size;
422
423 if (unlikely(!tfm))
424 return;
425
426 alg = tfm->__crt_alg;
427 size = sizeof(*tfm) + alg->cra_ctxsize;
1da177e4 428
c7fc0599
HX
429 if (alg->cra_exit)
430 alg->cra_exit(tfm);
1da177e4 431 crypto_exit_ops(tfm);
72fa4919 432 crypto_mod_put(alg);
1da177e4
LT
433 memset(tfm, 0, size);
434 kfree(tfm);
435}
436
1da177e4 437EXPORT_SYMBOL_GPL(crypto_free_tfm);
fce32d70
HX
438
439int crypto_has_alg(const char *name, u32 type, u32 mask)
440{
441 int ret = 0;
442 struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
443
444 if (!IS_ERR(alg)) {
445 crypto_mod_put(alg);
446 ret = 1;
447 }
448
449 return ret;
450}
451EXPORT_SYMBOL_GPL(crypto_has_alg);
c3715cb9
SS
452
453MODULE_DESCRIPTION("Cryptographic core API");
454MODULE_LICENSE("GPL");