1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3 * Scatterlist Cryptographic API.
4 *
5 * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
6 * Copyright (c) 2002 David S. Miller (davem@redhat.com)
7 * Copyright (c) 2005 Herbert Xu <herbert@gondor.apana.org.au>
8 *
9 * Portions derived from Cryptoapi, by Alexander Kjeldaas <astor@fast.no>
10 * and Nettle, by Niels Möller.
11 */
12
13 #include <linux/err.h>
14 #include <linux/errno.h>
15 #include <linux/kernel.h>
16 #include <linux/kmod.h>
17 #include <linux/module.h>
18 #include <linux/param.h>
19 #include <linux/sched/signal.h>
20 #include <linux/slab.h>
21 #include <linux/string.h>
22 #include <linux/completion.h>
23 #include "internal.h"
24
25 LIST_HEAD(crypto_alg_list);
26 EXPORT_SYMBOL_GPL(crypto_alg_list);
27 DECLARE_RWSEM(crypto_alg_sem);
28 EXPORT_SYMBOL_GPL(crypto_alg_sem);
29
30 BLOCKING_NOTIFIER_HEAD(crypto_chain);
31 EXPORT_SYMBOL_GPL(crypto_chain);
32
33 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
34
crypto_mod_get(struct crypto_alg * alg)35 struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
36 {
37 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
38 }
39 EXPORT_SYMBOL_GPL(crypto_mod_get);
40
crypto_mod_put(struct crypto_alg * alg)41 void crypto_mod_put(struct crypto_alg *alg)
42 {
43 struct module *module = alg->cra_module;
44
45 crypto_alg_put(alg);
46 module_put(module);
47 }
48 EXPORT_SYMBOL_GPL(crypto_mod_put);
49
crypto_is_test_larval(struct crypto_larval * larval)50 static inline int crypto_is_test_larval(struct crypto_larval *larval)
51 {
52 return larval->alg.cra_driver_name[0];
53 }
54
__crypto_alg_lookup(const char * name,u32 type,u32 mask)55 static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
56 u32 mask)
57 {
58 struct crypto_alg *q, *alg = NULL;
59 int best = -2;
60
61 list_for_each_entry(q, &crypto_alg_list, cra_list) {
62 int exact, fuzzy;
63
64 if (crypto_is_moribund(q))
65 continue;
66
67 if ((q->cra_flags ^ type) & mask)
68 continue;
69
70 if (crypto_is_larval(q) &&
71 !crypto_is_test_larval((struct crypto_larval *)q) &&
72 ((struct crypto_larval *)q)->mask != mask)
73 continue;
74
75 exact = !strcmp(q->cra_driver_name, name);
76 fuzzy = !strcmp(q->cra_name, name);
77 if (!exact && !(fuzzy && q->cra_priority > best))
78 continue;
79
80 if (unlikely(!crypto_mod_get(q)))
81 continue;
82
83 best = q->cra_priority;
84 if (alg)
85 crypto_mod_put(alg);
86 alg = q;
87
88 if (exact)
89 break;
90 }
91
92 return alg;
93 }
94
crypto_larval_destroy(struct crypto_alg * alg)95 static void crypto_larval_destroy(struct crypto_alg *alg)
96 {
97 struct crypto_larval *larval = (void *)alg;
98
99 BUG_ON(!crypto_is_larval(alg));
100 if (!IS_ERR_OR_NULL(larval->adult))
101 crypto_mod_put(larval->adult);
102 kfree(larval);
103 }
104
crypto_larval_alloc(const char * name,u32 type,u32 mask)105 struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
106 {
107 struct crypto_larval *larval;
108
109 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
110 if (!larval)
111 return ERR_PTR(-ENOMEM);
112
113 larval->mask = mask;
114 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
115 larval->alg.cra_priority = -1;
116 larval->alg.cra_destroy = crypto_larval_destroy;
117
118 strlcpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
119 init_completion(&larval->completion);
120
121 return larval;
122 }
123 EXPORT_SYMBOL_GPL(crypto_larval_alloc);
124
crypto_larval_add(const char * name,u32 type,u32 mask)125 static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
126 u32 mask)
127 {
128 struct crypto_alg *alg;
129 struct crypto_larval *larval;
130
131 larval = crypto_larval_alloc(name, type, mask);
132 if (IS_ERR(larval))
133 return ERR_CAST(larval);
134
135 refcount_set(&larval->alg.cra_refcnt, 2);
136
137 down_write(&crypto_alg_sem);
138 alg = __crypto_alg_lookup(name, type, mask);
139 if (!alg) {
140 alg = &larval->alg;
141 list_add(&alg->cra_list, &crypto_alg_list);
142 }
143 up_write(&crypto_alg_sem);
144
145 if (alg != &larval->alg) {
146 kfree(larval);
147 if (crypto_is_larval(alg))
148 alg = crypto_larval_wait(alg);
149 }
150
151 return alg;
152 }
153
crypto_larval_kill(struct crypto_alg * alg)154 void crypto_larval_kill(struct crypto_alg *alg)
155 {
156 struct crypto_larval *larval = (void *)alg;
157
158 down_write(&crypto_alg_sem);
159 list_del(&alg->cra_list);
160 up_write(&crypto_alg_sem);
161 complete_all(&larval->completion);
162 crypto_alg_put(alg);
163 }
164 EXPORT_SYMBOL_GPL(crypto_larval_kill);
165
crypto_larval_wait(struct crypto_alg * alg)166 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
167 {
168 struct crypto_larval *larval = (void *)alg;
169 long timeout;
170
171 timeout = wait_for_completion_killable_timeout(
172 &larval->completion, 60 * HZ);
173
174 alg = larval->adult;
175 if (timeout < 0)
176 alg = ERR_PTR(-EINTR);
177 else if (!timeout)
178 alg = ERR_PTR(-ETIMEDOUT);
179 else if (!alg)
180 alg = ERR_PTR(-ENOENT);
181 else if (IS_ERR(alg))
182 ;
183 else if (crypto_is_test_larval(larval) &&
184 !(alg->cra_flags & CRYPTO_ALG_TESTED))
185 alg = ERR_PTR(-EAGAIN);
186 else if (!crypto_mod_get(alg))
187 alg = ERR_PTR(-EAGAIN);
188 crypto_mod_put(&larval->alg);
189
190 return alg;
191 }
192
crypto_alg_lookup(const char * name,u32 type,u32 mask)193 static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
194 u32 mask)
195 {
196 struct crypto_alg *alg;
197 u32 test = 0;
198
199 if (!((type | mask) & CRYPTO_ALG_TESTED))
200 test |= CRYPTO_ALG_TESTED;
201
202 down_read(&crypto_alg_sem);
203 alg = __crypto_alg_lookup(name, type | test, mask | test);
204 if (!alg && test) {
205 alg = __crypto_alg_lookup(name, type, mask);
206 if (alg && !crypto_is_larval(alg)) {
207 /* Test failed */
208 crypto_mod_put(alg);
209 alg = ERR_PTR(-ELIBBAD);
210 }
211 }
212 up_read(&crypto_alg_sem);
213
214 return alg;
215 }
216
crypto_larval_lookup(const char * name,u32 type,u32 mask)217 static struct crypto_alg *crypto_larval_lookup(const char *name, u32 type,
218 u32 mask)
219 {
220 struct crypto_alg *alg;
221
222 if (!name)
223 return ERR_PTR(-ENOENT);
224
225 type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
226 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
227
228 alg = crypto_alg_lookup(name, type, mask);
229 if (!alg && !(mask & CRYPTO_NOLOAD)) {
230 request_module("crypto-%s", name);
231
232 if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
233 CRYPTO_ALG_NEED_FALLBACK))
234 request_module("crypto-%s-all", name);
235
236 alg = crypto_alg_lookup(name, type, mask);
237 }
238
239 if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg))
240 alg = crypto_larval_wait(alg);
241 else if (!alg)
242 alg = crypto_larval_add(name, type, mask);
243
244 return alg;
245 }
246
crypto_probing_notify(unsigned long val,void * v)247 int crypto_probing_notify(unsigned long val, void *v)
248 {
249 int ok;
250
251 ok = blocking_notifier_call_chain(&crypto_chain, val, v);
252 if (ok == NOTIFY_DONE) {
253 request_module("cryptomgr");
254 ok = blocking_notifier_call_chain(&crypto_chain, val, v);
255 }
256
257 return ok;
258 }
259 EXPORT_SYMBOL_GPL(crypto_probing_notify);
260
crypto_alg_mod_lookup(const char * name,u32 type,u32 mask)261 struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
262 {
263 struct crypto_alg *alg;
264 struct crypto_alg *larval;
265 int ok;
266
267 /*
268 * If the internal flag is set for a cipher, require a caller to
269 * to invoke the cipher with the internal flag to use that cipher.
270 * Also, if a caller wants to allocate a cipher that may or may
271 * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and
272 * !(mask & CRYPTO_ALG_INTERNAL).
273 */
274 if (!((type | mask) & CRYPTO_ALG_INTERNAL))
275 mask |= CRYPTO_ALG_INTERNAL;
276
277 larval = crypto_larval_lookup(name, type, mask);
278 if (IS_ERR(larval) || !crypto_is_larval(larval))
279 return larval;
280
281 ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
282
283 if (ok == NOTIFY_STOP)
284 alg = crypto_larval_wait(larval);
285 else {
286 crypto_mod_put(larval);
287 alg = ERR_PTR(-ENOENT);
288 }
289 crypto_larval_kill(larval);
290 return alg;
291 }
292 EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
293
crypto_init_ops(struct crypto_tfm * tfm,u32 type,u32 mask)294 static int crypto_init_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
295 {
296 const struct crypto_type *type_obj = tfm->__crt_alg->cra_type;
297
298 if (type_obj)
299 return type_obj->init(tfm, type, mask);
300 return 0;
301 }
302
crypto_exit_ops(struct crypto_tfm * tfm)303 static void crypto_exit_ops(struct crypto_tfm *tfm)
304 {
305 const struct crypto_type *type = tfm->__crt_alg->cra_type;
306
307 if (type && tfm->exit)
308 tfm->exit(tfm);
309 }
310
crypto_ctxsize(struct crypto_alg * alg,u32 type,u32 mask)311 static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
312 {
313 const struct crypto_type *type_obj = alg->cra_type;
314 unsigned int len;
315
316 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
317 if (type_obj)
318 return len + type_obj->ctxsize(alg, type, mask);
319
320 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
321 default:
322 BUG();
323
324 case CRYPTO_ALG_TYPE_CIPHER:
325 len += crypto_cipher_ctxsize(alg);
326 break;
327
328 case CRYPTO_ALG_TYPE_COMPRESS:
329 len += crypto_compress_ctxsize(alg);
330 break;
331 }
332
333 return len;
334 }
335
crypto_shoot_alg(struct crypto_alg * alg)336 void crypto_shoot_alg(struct crypto_alg *alg)
337 {
338 down_write(&crypto_alg_sem);
339 alg->cra_flags |= CRYPTO_ALG_DYING;
340 up_write(&crypto_alg_sem);
341 }
342 EXPORT_SYMBOL_GPL(crypto_shoot_alg);
343
__crypto_alloc_tfm(struct crypto_alg * alg,u32 type,u32 mask)344 struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
345 u32 mask)
346 {
347 struct crypto_tfm *tfm = NULL;
348 unsigned int tfm_size;
349 int err = -ENOMEM;
350
351 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
352 tfm = kzalloc(tfm_size, GFP_KERNEL);
353 if (tfm == NULL)
354 goto out_err;
355
356 tfm->__crt_alg = alg;
357
358 err = crypto_init_ops(tfm, type, mask);
359 if (err)
360 goto out_free_tfm;
361
362 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
363 goto cra_init_failed;
364
365 goto out;
366
367 cra_init_failed:
368 crypto_exit_ops(tfm);
369 out_free_tfm:
370 if (err == -EAGAIN)
371 crypto_shoot_alg(alg);
372 kfree(tfm);
373 out_err:
374 tfm = ERR_PTR(err);
375 out:
376 return tfm;
377 }
378 EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
379
380 /*
381 * crypto_alloc_base - Locate algorithm and allocate transform
382 * @alg_name: Name of algorithm
383 * @type: Type of algorithm
384 * @mask: Mask for type comparison
385 *
386 * This function should not be used by new algorithm types.
387 * Please use crypto_alloc_tfm instead.
388 *
389 * crypto_alloc_base() will first attempt to locate an already loaded
390 * algorithm. If that fails and the kernel supports dynamically loadable
391 * modules, it will then attempt to load a module of the same name or
392 * alias. If that fails it will send a query to any loaded crypto manager
393 * to construct an algorithm on the fly. A refcount is grabbed on the
394 * algorithm which is then associated with the new transform.
395 *
396 * The returned transform is of a non-determinate type. Most people
397 * should use one of the more specific allocation functions such as
398 * crypto_alloc_skcipher().
399 *
400 * In case of error the return value is an error pointer.
401 */
crypto_alloc_base(const char * alg_name,u32 type,u32 mask)402 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
403 {
404 struct crypto_tfm *tfm;
405 int err;
406
407 for (;;) {
408 struct crypto_alg *alg;
409
410 alg = crypto_alg_mod_lookup(alg_name, type, mask);
411 if (IS_ERR(alg)) {
412 err = PTR_ERR(alg);
413 goto err;
414 }
415
416 tfm = __crypto_alloc_tfm(alg, type, mask);
417 if (!IS_ERR(tfm))
418 return tfm;
419
420 crypto_mod_put(alg);
421 err = PTR_ERR(tfm);
422
423 err:
424 if (err != -EAGAIN)
425 break;
426 if (fatal_signal_pending(current)) {
427 err = -EINTR;
428 break;
429 }
430 }
431
432 return ERR_PTR(err);
433 }
434 EXPORT_SYMBOL_GPL(crypto_alloc_base);
435
crypto_create_tfm_node(struct crypto_alg * alg,const struct crypto_type * frontend,int node)436 void *crypto_create_tfm_node(struct crypto_alg *alg,
437 const struct crypto_type *frontend,
438 int node)
439 {
440 char *mem;
441 struct crypto_tfm *tfm = NULL;
442 unsigned int tfmsize;
443 unsigned int total;
444 int err = -ENOMEM;
445
446 tfmsize = frontend->tfmsize;
447 total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
448
449 mem = kzalloc_node(total, GFP_KERNEL, node);
450 if (mem == NULL)
451 goto out_err;
452
453 tfm = (struct crypto_tfm *)(mem + tfmsize);
454 tfm->__crt_alg = alg;
455 tfm->node = node;
456
457 err = frontend->init_tfm(tfm);
458 if (err)
459 goto out_free_tfm;
460
461 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
462 goto cra_init_failed;
463
464 goto out;
465
466 cra_init_failed:
467 crypto_exit_ops(tfm);
468 out_free_tfm:
469 if (err == -EAGAIN)
470 crypto_shoot_alg(alg);
471 kfree(mem);
472 out_err:
473 mem = ERR_PTR(err);
474 out:
475 return mem;
476 }
477 EXPORT_SYMBOL_GPL(crypto_create_tfm_node);
478
crypto_find_alg(const char * alg_name,const struct crypto_type * frontend,u32 type,u32 mask)479 struct crypto_alg *crypto_find_alg(const char *alg_name,
480 const struct crypto_type *frontend,
481 u32 type, u32 mask)
482 {
483 if (frontend) {
484 type &= frontend->maskclear;
485 mask &= frontend->maskclear;
486 type |= frontend->type;
487 mask |= frontend->maskset;
488 }
489
490 return crypto_alg_mod_lookup(alg_name, type, mask);
491 }
492 EXPORT_SYMBOL_GPL(crypto_find_alg);
493
494 /*
495 * crypto_alloc_tfm_node - Locate algorithm and allocate transform
496 * @alg_name: Name of algorithm
497 * @frontend: Frontend algorithm type
498 * @type: Type of algorithm
499 * @mask: Mask for type comparison
500 * @node: NUMA node in which users desire to put requests, if node is
501 * NUMA_NO_NODE, it means users have no special requirement.
502 *
503 * crypto_alloc_tfm() will first attempt to locate an already loaded
504 * algorithm. If that fails and the kernel supports dynamically loadable
505 * modules, it will then attempt to load a module of the same name or
506 * alias. If that fails it will send a query to any loaded crypto manager
507 * to construct an algorithm on the fly. A refcount is grabbed on the
508 * algorithm which is then associated with the new transform.
509 *
510 * The returned transform is of a non-determinate type. Most people
511 * should use one of the more specific allocation functions such as
512 * crypto_alloc_skcipher().
513 *
514 * In case of error the return value is an error pointer.
515 */
516
crypto_alloc_tfm_node(const char * alg_name,const struct crypto_type * frontend,u32 type,u32 mask,int node)517 void *crypto_alloc_tfm_node(const char *alg_name,
518 const struct crypto_type *frontend, u32 type, u32 mask,
519 int node)
520 {
521 void *tfm;
522 int err;
523
524 for (;;) {
525 struct crypto_alg *alg;
526
527 alg = crypto_find_alg(alg_name, frontend, type, mask);
528 if (IS_ERR(alg)) {
529 err = PTR_ERR(alg);
530 goto err;
531 }
532
533 tfm = crypto_create_tfm_node(alg, frontend, node);
534 if (!IS_ERR(tfm))
535 return tfm;
536
537 crypto_mod_put(alg);
538 err = PTR_ERR(tfm);
539
540 err:
541 if (err != -EAGAIN)
542 break;
543 if (fatal_signal_pending(current)) {
544 err = -EINTR;
545 break;
546 }
547 }
548
549 return ERR_PTR(err);
550 }
551 EXPORT_SYMBOL_GPL(crypto_alloc_tfm_node);
552
553 /*
554 * crypto_destroy_tfm - Free crypto transform
555 * @mem: Start of tfm slab
556 * @tfm: Transform to free
557 *
558 * This function frees up the transform and any associated resources,
559 * then drops the refcount on the associated algorithm.
560 */
crypto_destroy_tfm(void * mem,struct crypto_tfm * tfm)561 void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
562 {
563 struct crypto_alg *alg;
564
565 if (IS_ERR_OR_NULL(mem))
566 return;
567
568 alg = tfm->__crt_alg;
569
570 if (!tfm->exit && alg->cra_exit)
571 alg->cra_exit(tfm);
572 crypto_exit_ops(tfm);
573 crypto_mod_put(alg);
574 kfree_sensitive(mem);
575 }
576 EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
577
crypto_has_alg(const char * name,u32 type,u32 mask)578 int crypto_has_alg(const char *name, u32 type, u32 mask)
579 {
580 int ret = 0;
581 struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
582
583 if (!IS_ERR(alg)) {
584 crypto_mod_put(alg);
585 ret = 1;
586 }
587
588 return ret;
589 }
590 EXPORT_SYMBOL_GPL(crypto_has_alg);
591
crypto_req_done(struct crypto_async_request * req,int err)592 void crypto_req_done(struct crypto_async_request *req, int err)
593 {
594 struct crypto_wait *wait = req->data;
595
596 if (err == -EINPROGRESS)
597 return;
598
599 wait->err = err;
600 complete(&wait->completion);
601 }
602 EXPORT_SYMBOL_GPL(crypto_req_done);
603
604 MODULE_DESCRIPTION("Cryptographic core API");
605 MODULE_LICENSE("GPL");
606 MODULE_SOFTDEP("pre: cryptomgr");
607
