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Merge tag 'kvm-x86-misc-6.8' of https://github.com/kvm-x86/linux into HEAD
[thirdparty/kernel/stable.git] / crypto / api.c
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/jump_label.h>
16 #include <linux/kernel.h>
17 #include <linux/kmod.h>
18 #include <linux/module.h>
19 #include <linux/param.h>
20 #include <linux/sched/signal.h>
21 #include <linux/slab.h>
22 #include <linux/string.h>
23 #include <linux/completion.h>
24 #include "internal.h"
25
26 LIST_HEAD(crypto_alg_list);
27 EXPORT_SYMBOL_GPL(crypto_alg_list);
28 DECLARE_RWSEM(crypto_alg_sem);
29 EXPORT_SYMBOL_GPL(crypto_alg_sem);
30
31 BLOCKING_NOTIFIER_HEAD(crypto_chain);
32 EXPORT_SYMBOL_GPL(crypto_chain);
33
34 #ifndef CONFIG_CRYPTO_MANAGER_DISABLE_TESTS
35 DEFINE_STATIC_KEY_FALSE(__crypto_boot_test_finished);
36 EXPORT_SYMBOL_GPL(__crypto_boot_test_finished);
37 #endif
38
39 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
40
41 struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
42 {
43 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
44 }
45 EXPORT_SYMBOL_GPL(crypto_mod_get);
46
47 void crypto_mod_put(struct crypto_alg *alg)
48 {
49 struct module *module = alg->cra_module;
50
51 crypto_alg_put(alg);
52 module_put(module);
53 }
54 EXPORT_SYMBOL_GPL(crypto_mod_put);
55
56 static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
57 u32 mask)
58 {
59 struct crypto_alg *q, *alg = NULL;
60 int best = -2;
61
62 list_for_each_entry(q, &crypto_alg_list, cra_list) {
63 int exact, fuzzy;
64
65 if (crypto_is_moribund(q))
66 continue;
67
68 if ((q->cra_flags ^ type) & mask)
69 continue;
70
71 if (crypto_is_larval(q) &&
72 !crypto_is_test_larval((struct crypto_larval *)q) &&
73 ((struct crypto_larval *)q)->mask != mask)
74 continue;
75
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
81 if (unlikely(!crypto_mod_get(q)))
82 continue;
83
84 best = q->cra_priority;
85 if (alg)
86 crypto_mod_put(alg);
87 alg = q;
88
89 if (exact)
90 break;
91 }
92
93 return alg;
94 }
95
96 static void crypto_larval_destroy(struct crypto_alg *alg)
97 {
98 struct crypto_larval *larval = (void *)alg;
99
100 BUG_ON(!crypto_is_larval(alg));
101 if (!IS_ERR_OR_NULL(larval->adult))
102 crypto_mod_put(larval->adult);
103 kfree(larval);
104 }
105
106 struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
107 {
108 struct crypto_larval *larval;
109
110 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
111 if (!larval)
112 return ERR_PTR(-ENOMEM);
113
114 larval->mask = mask;
115 larval->alg.cra_flags = CRYPTO_ALG_LARVAL | type;
116 larval->alg.cra_priority = -1;
117 larval->alg.cra_destroy = crypto_larval_destroy;
118
119 strscpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
120 init_completion(&larval->completion);
121
122 return larval;
123 }
124 EXPORT_SYMBOL_GPL(crypto_larval_alloc);
125
126 static struct crypto_alg *crypto_larval_add(const char *name, u32 type,
127 u32 mask)
128 {
129 struct crypto_alg *alg;
130 struct crypto_larval *larval;
131
132 larval = crypto_larval_alloc(name, type, mask);
133 if (IS_ERR(larval))
134 return ERR_CAST(larval);
135
136 refcount_set(&larval->alg.cra_refcnt, 2);
137
138 down_write(&crypto_alg_sem);
139 alg = __crypto_alg_lookup(name, type, mask);
140 if (!alg) {
141 alg = &larval->alg;
142 list_add(&alg->cra_list, &crypto_alg_list);
143 }
144 up_write(&crypto_alg_sem);
145
146 if (alg != &larval->alg) {
147 kfree(larval);
148 if (crypto_is_larval(alg))
149 alg = crypto_larval_wait(alg);
150 }
151
152 return alg;
153 }
154
155 void crypto_larval_kill(struct crypto_alg *alg)
156 {
157 struct crypto_larval *larval = (void *)alg;
158
159 down_write(&crypto_alg_sem);
160 list_del(&alg->cra_list);
161 up_write(&crypto_alg_sem);
162 complete_all(&larval->completion);
163 crypto_alg_put(alg);
164 }
165 EXPORT_SYMBOL_GPL(crypto_larval_kill);
166
167 void crypto_wait_for_test(struct crypto_larval *larval)
168 {
169 int err;
170
171 err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
172 if (WARN_ON_ONCE(err != NOTIFY_STOP))
173 goto out;
174
175 err = wait_for_completion_killable(&larval->completion);
176 WARN_ON(err);
177 out:
178 crypto_larval_kill(&larval->alg);
179 }
180 EXPORT_SYMBOL_GPL(crypto_wait_for_test);
181
182 static void crypto_start_test(struct crypto_larval *larval)
183 {
184 if (!crypto_is_test_larval(larval))
185 return;
186
187 if (larval->test_started)
188 return;
189
190 down_write(&crypto_alg_sem);
191 if (larval->test_started) {
192 up_write(&crypto_alg_sem);
193 return;
194 }
195
196 larval->test_started = true;
197 up_write(&crypto_alg_sem);
198
199 crypto_wait_for_test(larval);
200 }
201
202 static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
203 {
204 struct crypto_larval *larval = (void *)alg;
205 long timeout;
206
207 if (!crypto_boot_test_finished())
208 crypto_start_test(larval);
209
210 timeout = wait_for_completion_killable_timeout(
211 &larval->completion, 60 * HZ);
212
213 alg = larval->adult;
214 if (timeout < 0)
215 alg = ERR_PTR(-EINTR);
216 else if (!timeout)
217 alg = ERR_PTR(-ETIMEDOUT);
218 else if (!alg)
219 alg = ERR_PTR(-ENOENT);
220 else if (IS_ERR(alg))
221 ;
222 else if (crypto_is_test_larval(larval) &&
223 !(alg->cra_flags & CRYPTO_ALG_TESTED))
224 alg = ERR_PTR(-EAGAIN);
225 else if (alg->cra_flags & CRYPTO_ALG_FIPS_INTERNAL)
226 alg = ERR_PTR(-EAGAIN);
227 else if (!crypto_mod_get(alg))
228 alg = ERR_PTR(-EAGAIN);
229 crypto_mod_put(&larval->alg);
230
231 return alg;
232 }
233
234 static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
235 u32 mask)
236 {
237 const u32 fips = CRYPTO_ALG_FIPS_INTERNAL;
238 struct crypto_alg *alg;
239 u32 test = 0;
240
241 if (!((type | mask) & CRYPTO_ALG_TESTED))
242 test |= CRYPTO_ALG_TESTED;
243
244 down_read(&crypto_alg_sem);
245 alg = __crypto_alg_lookup(name, (type | test) & ~fips,
246 (mask | test) & ~fips);
247 if (alg) {
248 if (((type | mask) ^ fips) & fips)
249 mask |= fips;
250 mask &= fips;
251
252 if (!crypto_is_larval(alg) &&
253 ((type ^ alg->cra_flags) & mask)) {
254 /* Algorithm is disallowed in FIPS mode. */
255 crypto_mod_put(alg);
256 alg = ERR_PTR(-ENOENT);
257 }
258 } else if (test) {
259 alg = __crypto_alg_lookup(name, type, mask);
260 if (alg && !crypto_is_larval(alg)) {
261 /* Test failed */
262 crypto_mod_put(alg);
263 alg = ERR_PTR(-ELIBBAD);
264 }
265 }
266 up_read(&crypto_alg_sem);
267
268 return alg;
269 }
270
271 static struct crypto_alg *crypto_larval_lookup(const char *name, u32 type,
272 u32 mask)
273 {
274 struct crypto_alg *alg;
275
276 if (!name)
277 return ERR_PTR(-ENOENT);
278
279 type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
280 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
281
282 alg = crypto_alg_lookup(name, type, mask);
283 if (!alg && !(mask & CRYPTO_NOLOAD)) {
284 request_module("crypto-%s", name);
285
286 if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
287 CRYPTO_ALG_NEED_FALLBACK))
288 request_module("crypto-%s-all", name);
289
290 alg = crypto_alg_lookup(name, type, mask);
291 }
292
293 if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg))
294 alg = crypto_larval_wait(alg);
295 else if (!alg)
296 alg = crypto_larval_add(name, type, mask);
297
298 return alg;
299 }
300
301 int crypto_probing_notify(unsigned long val, void *v)
302 {
303 int ok;
304
305 ok = blocking_notifier_call_chain(&crypto_chain, val, v);
306 if (ok == NOTIFY_DONE) {
307 request_module("cryptomgr");
308 ok = blocking_notifier_call_chain(&crypto_chain, val, v);
309 }
310
311 return ok;
312 }
313 EXPORT_SYMBOL_GPL(crypto_probing_notify);
314
315 struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
316 {
317 struct crypto_alg *alg;
318 struct crypto_alg *larval;
319 int ok;
320
321 /*
322 * If the internal flag is set for a cipher, require a caller to
323 * invoke the cipher with the internal flag to use that cipher.
324 * Also, if a caller wants to allocate a cipher that may or may
325 * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and
326 * !(mask & CRYPTO_ALG_INTERNAL).
327 */
328 if (!((type | mask) & CRYPTO_ALG_INTERNAL))
329 mask |= CRYPTO_ALG_INTERNAL;
330
331 larval = crypto_larval_lookup(name, type, mask);
332 if (IS_ERR(larval) || !crypto_is_larval(larval))
333 return larval;
334
335 ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
336
337 if (ok == NOTIFY_STOP)
338 alg = crypto_larval_wait(larval);
339 else {
340 crypto_mod_put(larval);
341 alg = ERR_PTR(-ENOENT);
342 }
343 crypto_larval_kill(larval);
344 return alg;
345 }
346 EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
347
348 static void crypto_exit_ops(struct crypto_tfm *tfm)
349 {
350 const struct crypto_type *type = tfm->__crt_alg->cra_type;
351
352 if (type && tfm->exit)
353 tfm->exit(tfm);
354 }
355
356 static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
357 {
358 const struct crypto_type *type_obj = alg->cra_type;
359 unsigned int len;
360
361 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
362 if (type_obj)
363 return len + type_obj->ctxsize(alg, type, mask);
364
365 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
366 default:
367 BUG();
368
369 case CRYPTO_ALG_TYPE_CIPHER:
370 len += crypto_cipher_ctxsize(alg);
371 break;
372
373 case CRYPTO_ALG_TYPE_COMPRESS:
374 len += crypto_compress_ctxsize(alg);
375 break;
376 }
377
378 return len;
379 }
380
381 void crypto_shoot_alg(struct crypto_alg *alg)
382 {
383 down_write(&crypto_alg_sem);
384 alg->cra_flags |= CRYPTO_ALG_DYING;
385 up_write(&crypto_alg_sem);
386 }
387 EXPORT_SYMBOL_GPL(crypto_shoot_alg);
388
389 struct crypto_tfm *__crypto_alloc_tfmgfp(struct crypto_alg *alg, u32 type,
390 u32 mask, gfp_t gfp)
391 {
392 struct crypto_tfm *tfm;
393 unsigned int tfm_size;
394 int err = -ENOMEM;
395
396 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
397 tfm = kzalloc(tfm_size, gfp);
398 if (tfm == NULL)
399 goto out_err;
400
401 tfm->__crt_alg = alg;
402 refcount_set(&tfm->refcnt, 1);
403
404 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
405 goto cra_init_failed;
406
407 goto out;
408
409 cra_init_failed:
410 crypto_exit_ops(tfm);
411 if (err == -EAGAIN)
412 crypto_shoot_alg(alg);
413 kfree(tfm);
414 out_err:
415 tfm = ERR_PTR(err);
416 out:
417 return tfm;
418 }
419 EXPORT_SYMBOL_GPL(__crypto_alloc_tfmgfp);
420
421 struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
422 u32 mask)
423 {
424 return __crypto_alloc_tfmgfp(alg, type, mask, GFP_KERNEL);
425 }
426 EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
427
428 /*
429 * crypto_alloc_base - Locate algorithm and allocate transform
430 * @alg_name: Name of algorithm
431 * @type: Type of algorithm
432 * @mask: Mask for type comparison
433 *
434 * This function should not be used by new algorithm types.
435 * Please use crypto_alloc_tfm instead.
436 *
437 * crypto_alloc_base() will first attempt to locate an already loaded
438 * algorithm. If that fails and the kernel supports dynamically loadable
439 * modules, it will then attempt to load a module of the same name or
440 * alias. If that fails it will send a query to any loaded crypto manager
441 * to construct an algorithm on the fly. A refcount is grabbed on the
442 * algorithm which is then associated with the new transform.
443 *
444 * The returned transform is of a non-determinate type. Most people
445 * should use one of the more specific allocation functions such as
446 * crypto_alloc_skcipher().
447 *
448 * In case of error the return value is an error pointer.
449 */
450 struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
451 {
452 struct crypto_tfm *tfm;
453 int err;
454
455 for (;;) {
456 struct crypto_alg *alg;
457
458 alg = crypto_alg_mod_lookup(alg_name, type, mask);
459 if (IS_ERR(alg)) {
460 err = PTR_ERR(alg);
461 goto err;
462 }
463
464 tfm = __crypto_alloc_tfm(alg, type, mask);
465 if (!IS_ERR(tfm))
466 return tfm;
467
468 crypto_mod_put(alg);
469 err = PTR_ERR(tfm);
470
471 err:
472 if (err != -EAGAIN)
473 break;
474 if (fatal_signal_pending(current)) {
475 err = -EINTR;
476 break;
477 }
478 }
479
480 return ERR_PTR(err);
481 }
482 EXPORT_SYMBOL_GPL(crypto_alloc_base);
483
484 static void *crypto_alloc_tfmmem(struct crypto_alg *alg,
485 const struct crypto_type *frontend, int node,
486 gfp_t gfp)
487 {
488 struct crypto_tfm *tfm;
489 unsigned int tfmsize;
490 unsigned int total;
491 char *mem;
492
493 tfmsize = frontend->tfmsize;
494 total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
495
496 mem = kzalloc_node(total, gfp, node);
497 if (mem == NULL)
498 return ERR_PTR(-ENOMEM);
499
500 tfm = (struct crypto_tfm *)(mem + tfmsize);
501 tfm->__crt_alg = alg;
502 tfm->node = node;
503 refcount_set(&tfm->refcnt, 1);
504
505 return mem;
506 }
507
508 void *crypto_create_tfm_node(struct crypto_alg *alg,
509 const struct crypto_type *frontend,
510 int node)
511 {
512 struct crypto_tfm *tfm;
513 char *mem;
514 int err;
515
516 mem = crypto_alloc_tfmmem(alg, frontend, node, GFP_KERNEL);
517 if (IS_ERR(mem))
518 goto out;
519
520 tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
521
522 err = frontend->init_tfm(tfm);
523 if (err)
524 goto out_free_tfm;
525
526 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
527 goto cra_init_failed;
528
529 goto out;
530
531 cra_init_failed:
532 crypto_exit_ops(tfm);
533 out_free_tfm:
534 if (err == -EAGAIN)
535 crypto_shoot_alg(alg);
536 kfree(mem);
537 mem = ERR_PTR(err);
538 out:
539 return mem;
540 }
541 EXPORT_SYMBOL_GPL(crypto_create_tfm_node);
542
543 void *crypto_clone_tfm(const struct crypto_type *frontend,
544 struct crypto_tfm *otfm)
545 {
546 struct crypto_alg *alg = otfm->__crt_alg;
547 struct crypto_tfm *tfm;
548 char *mem;
549
550 mem = ERR_PTR(-ESTALE);
551 if (unlikely(!crypto_mod_get(alg)))
552 goto out;
553
554 mem = crypto_alloc_tfmmem(alg, frontend, otfm->node, GFP_ATOMIC);
555 if (IS_ERR(mem)) {
556 crypto_mod_put(alg);
557 goto out;
558 }
559
560 tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
561 tfm->crt_flags = otfm->crt_flags;
562 tfm->exit = otfm->exit;
563
564 out:
565 return mem;
566 }
567 EXPORT_SYMBOL_GPL(crypto_clone_tfm);
568
569 struct crypto_alg *crypto_find_alg(const char *alg_name,
570 const struct crypto_type *frontend,
571 u32 type, u32 mask)
572 {
573 if (frontend) {
574 type &= frontend->maskclear;
575 mask &= frontend->maskclear;
576 type |= frontend->type;
577 mask |= frontend->maskset;
578 }
579
580 return crypto_alg_mod_lookup(alg_name, type, mask);
581 }
582 EXPORT_SYMBOL_GPL(crypto_find_alg);
583
584 /*
585 * crypto_alloc_tfm_node - Locate algorithm and allocate transform
586 * @alg_name: Name of algorithm
587 * @frontend: Frontend algorithm type
588 * @type: Type of algorithm
589 * @mask: Mask for type comparison
590 * @node: NUMA node in which users desire to put requests, if node is
591 * NUMA_NO_NODE, it means users have no special requirement.
592 *
593 * crypto_alloc_tfm() will first attempt to locate an already loaded
594 * algorithm. If that fails and the kernel supports dynamically loadable
595 * modules, it will then attempt to load a module of the same name or
596 * alias. If that fails it will send a query to any loaded crypto manager
597 * to construct an algorithm on the fly. A refcount is grabbed on the
598 * algorithm which is then associated with the new transform.
599 *
600 * The returned transform is of a non-determinate type. Most people
601 * should use one of the more specific allocation functions such as
602 * crypto_alloc_skcipher().
603 *
604 * In case of error the return value is an error pointer.
605 */
606
607 void *crypto_alloc_tfm_node(const char *alg_name,
608 const struct crypto_type *frontend, u32 type, u32 mask,
609 int node)
610 {
611 void *tfm;
612 int err;
613
614 for (;;) {
615 struct crypto_alg *alg;
616
617 alg = crypto_find_alg(alg_name, frontend, type, mask);
618 if (IS_ERR(alg)) {
619 err = PTR_ERR(alg);
620 goto err;
621 }
622
623 tfm = crypto_create_tfm_node(alg, frontend, node);
624 if (!IS_ERR(tfm))
625 return tfm;
626
627 crypto_mod_put(alg);
628 err = PTR_ERR(tfm);
629
630 err:
631 if (err != -EAGAIN)
632 break;
633 if (fatal_signal_pending(current)) {
634 err = -EINTR;
635 break;
636 }
637 }
638
639 return ERR_PTR(err);
640 }
641 EXPORT_SYMBOL_GPL(crypto_alloc_tfm_node);
642
643 /*
644 * crypto_destroy_tfm - Free crypto transform
645 * @mem: Start of tfm slab
646 * @tfm: Transform to free
647 *
648 * This function frees up the transform and any associated resources,
649 * then drops the refcount on the associated algorithm.
650 */
651 void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
652 {
653 struct crypto_alg *alg;
654
655 if (IS_ERR_OR_NULL(mem))
656 return;
657
658 if (!refcount_dec_and_test(&tfm->refcnt))
659 return;
660 alg = tfm->__crt_alg;
661
662 if (!tfm->exit && alg->cra_exit)
663 alg->cra_exit(tfm);
664 crypto_exit_ops(tfm);
665 crypto_mod_put(alg);
666 kfree_sensitive(mem);
667 }
668 EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
669
670 int crypto_has_alg(const char *name, u32 type, u32 mask)
671 {
672 int ret = 0;
673 struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
674
675 if (!IS_ERR(alg)) {
676 crypto_mod_put(alg);
677 ret = 1;
678 }
679
680 return ret;
681 }
682 EXPORT_SYMBOL_GPL(crypto_has_alg);
683
684 void crypto_req_done(void *data, int err)
685 {
686 struct crypto_wait *wait = data;
687
688 if (err == -EINPROGRESS)
689 return;
690
691 wait->err = err;
692 complete(&wait->completion);
693 }
694 EXPORT_SYMBOL_GPL(crypto_req_done);
695
696 MODULE_DESCRIPTION("Cryptographic core API");
697 MODULE_LICENSE("GPL");
Mirror https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git