projects/linux·blob v6.13 · refs

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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Scatterlist Cryptographic API.
4 *
5 * Copyright (c) 2002 James Morris <[email protected]>
6 * Copyright (c) 2002 David S. Miller ([email protected])
7 * Copyright (c) 2005 Herbert Xu <[email protected]>
8 *
9 * Portions derived from Cryptoapi, by Alexander Kjeldaas <[email protected]>
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
26LIST_HEAD(crypto_alg_list);
27EXPORT_SYMBOL_GPL(crypto_alg_list);
28DECLARE_RWSEM(crypto_alg_sem);
29EXPORT_SYMBOL_GPL(crypto_alg_sem);
30
31BLOCKING_NOTIFIER_HEAD(crypto_chain);
32EXPORT_SYMBOL_GPL(crypto_chain);
33
34#if IS_BUILTIN(CONFIG_CRYPTO_ALGAPI) && \
35 !IS_ENABLED(CONFIG_CRYPTO_MANAGER_DISABLE_TESTS)
36DEFINE_STATIC_KEY_FALSE(__crypto_boot_test_finished);
37#endif
38
39static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg);
40static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
41 u32 mask);
42
43struct crypto_alg *crypto_mod_get(struct crypto_alg *alg)
44{
45 return try_module_get(alg->cra_module) ? crypto_alg_get(alg) : NULL;
46}
47EXPORT_SYMBOL_GPL(crypto_mod_get);
48
49void crypto_mod_put(struct crypto_alg *alg)
50{
51 struct module *module = alg->cra_module;
52
53 crypto_alg_put(alg);
54 module_put(module);
55}
56EXPORT_SYMBOL_GPL(crypto_mod_put);
57
58static struct crypto_alg *__crypto_alg_lookup(const char *name, u32 type,
59 u32 mask)
60{
61 struct crypto_alg *q, *alg = NULL;
62 int best = -2;
63
64 list_for_each_entry(q, &crypto_alg_list, cra_list) {
65 int exact, fuzzy;
66
67 if (crypto_is_moribund(q))
68 continue;
69
70 if ((q->cra_flags ^ type) & mask)
71 continue;
72
73 exact = !strcmp(q->cra_driver_name, name);
74 fuzzy = !strcmp(q->cra_name, name);
75 if (!exact && !(fuzzy && q->cra_priority > best))
76 continue;
77
78 if (unlikely(!crypto_mod_get(q)))
79 continue;
80
81 best = q->cra_priority;
82 if (alg)
83 crypto_mod_put(alg);
84 alg = q;
85
86 if (exact)
87 break;
88 }
89
90 return alg;
91}
92
93static void crypto_larval_destroy(struct crypto_alg *alg)
94{
95 struct crypto_larval *larval = (void *)alg;
96
97 BUG_ON(!crypto_is_larval(alg));
98 if (!IS_ERR_OR_NULL(larval->adult))
99 crypto_mod_put(larval->adult);
100 kfree(larval);
101}
102
103struct crypto_larval *crypto_larval_alloc(const char *name, u32 type, u32 mask)
104{
105 struct crypto_larval *larval;
106
107 larval = kzalloc(sizeof(*larval), GFP_KERNEL);
108 if (!larval)
109 return ERR_PTR(-ENOMEM);
110
111 type &= ~CRYPTO_ALG_TYPE_MASK | (mask ?: CRYPTO_ALG_TYPE_MASK);
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 strscpy(larval->alg.cra_name, name, CRYPTO_MAX_ALG_NAME);
119 init_completion(&larval->completion);
120
121 return larval;
122}
123EXPORT_SYMBOL_GPL(crypto_larval_alloc);
124
125static 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
154static void crypto_larval_kill(struct crypto_larval *larval)
155{
156 bool unlinked;
157
158 down_write(&crypto_alg_sem);
159 unlinked = list_empty(&larval->alg.cra_list);
160 if (!unlinked)
161 list_del_init(&larval->alg.cra_list);
162 up_write(&crypto_alg_sem);
163
164 if (unlinked)
165 return;
166
167 complete_all(&larval->completion);
168 crypto_alg_put(&larval->alg);
169}
170
171void crypto_schedule_test(struct crypto_larval *larval)
172{
173 int err;
174
175 err = crypto_probing_notify(CRYPTO_MSG_ALG_REGISTER, larval->adult);
176 WARN_ON_ONCE(err != NOTIFY_STOP);
177}
178EXPORT_SYMBOL_GPL(crypto_schedule_test);
179
180static void crypto_start_test(struct crypto_larval *larval)
181{
182 if (!crypto_is_test_larval(larval))
183 return;
184
185 if (larval->test_started)
186 return;
187
188 down_write(&crypto_alg_sem);
189 if (larval->test_started) {
190 up_write(&crypto_alg_sem);
191 return;
192 }
193
194 larval->test_started = true;
195 up_write(&crypto_alg_sem);
196
197 crypto_schedule_test(larval);
198}
199
200static struct crypto_alg *crypto_larval_wait(struct crypto_alg *alg)
201{
202 struct crypto_larval *larval;
203 long time_left;
204
205again:
206 larval = container_of(alg, struct crypto_larval, alg);
207
208 if (!crypto_boot_test_finished())
209 crypto_start_test(larval);
210
211 time_left = wait_for_completion_killable_timeout(
212 &larval->completion, 60 * HZ);
213
214 alg = larval->adult;
215 if (time_left < 0)
216 alg = ERR_PTR(-EINTR);
217 else if (!time_left) {
218 if (crypto_is_test_larval(larval))
219 crypto_larval_kill(larval);
220 alg = ERR_PTR(-ETIMEDOUT);
221 } else if (!alg) {
222 u32 type;
223 u32 mask;
224
225 alg = &larval->alg;
226 type = alg->cra_flags & ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
227 mask = larval->mask;
228 alg = crypto_alg_lookup(alg->cra_name, type, mask) ?:
229 ERR_PTR(-EAGAIN);
230 } else if (IS_ERR(alg))
231 ;
232 else if (crypto_is_test_larval(larval) &&
233 !(alg->cra_flags & CRYPTO_ALG_TESTED))
234 alg = ERR_PTR(-EAGAIN);
235 else if (alg->cra_flags & CRYPTO_ALG_FIPS_INTERNAL)
236 alg = ERR_PTR(-EAGAIN);
237 else if (!crypto_mod_get(alg))
238 alg = ERR_PTR(-EAGAIN);
239 crypto_mod_put(&larval->alg);
240
241 if (!IS_ERR(alg) && crypto_is_larval(alg))
242 goto again;
243
244 return alg;
245}
246
247static struct crypto_alg *crypto_alg_lookup(const char *name, u32 type,
248 u32 mask)
249{
250 const u32 fips = CRYPTO_ALG_FIPS_INTERNAL;
251 struct crypto_alg *alg;
252 u32 test = 0;
253
254 if (!((type | mask) & CRYPTO_ALG_TESTED))
255 test |= CRYPTO_ALG_TESTED;
256
257 down_read(&crypto_alg_sem);
258 alg = __crypto_alg_lookup(name, (type | test) & ~fips,
259 (mask | test) & ~fips);
260 if (alg) {
261 if (((type | mask) ^ fips) & fips)
262 mask |= fips;
263 mask &= fips;
264
265 if (!crypto_is_larval(alg) &&
266 ((type ^ alg->cra_flags) & mask)) {
267 /* Algorithm is disallowed in FIPS mode. */
268 crypto_mod_put(alg);
269 alg = ERR_PTR(-ENOENT);
270 }
271 } else if (test) {
272 alg = __crypto_alg_lookup(name, type, mask);
273 if (alg && !crypto_is_larval(alg)) {
274 /* Test failed */
275 crypto_mod_put(alg);
276 alg = ERR_PTR(-ELIBBAD);
277 }
278 }
279 up_read(&crypto_alg_sem);
280
281 return alg;
282}
283
284static struct crypto_alg *crypto_larval_lookup(const char *name, u32 type,
285 u32 mask)
286{
287 struct crypto_alg *alg;
288
289 if (!name)
290 return ERR_PTR(-ENOENT);
291
292 type &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
293 mask &= ~(CRYPTO_ALG_LARVAL | CRYPTO_ALG_DEAD);
294
295 alg = crypto_alg_lookup(name, type, mask);
296 if (!alg && !(mask & CRYPTO_NOLOAD)) {
297 request_module("crypto-%s", name);
298
299 if (!((type ^ CRYPTO_ALG_NEED_FALLBACK) & mask &
300 CRYPTO_ALG_NEED_FALLBACK))
301 request_module("crypto-%s-all", name);
302
303 alg = crypto_alg_lookup(name, type, mask);
304 }
305
306 if (!IS_ERR_OR_NULL(alg) && crypto_is_larval(alg))
307 alg = crypto_larval_wait(alg);
308 else if (alg)
309 ;
310 else if (!(mask & CRYPTO_ALG_TESTED))
311 alg = crypto_larval_add(name, type, mask);
312 else
313 alg = ERR_PTR(-ENOENT);
314
315 return alg;
316}
317
318int crypto_probing_notify(unsigned long val, void *v)
319{
320 int ok;
321
322 ok = blocking_notifier_call_chain(&crypto_chain, val, v);
323 if (ok == NOTIFY_DONE) {
324 request_module("cryptomgr");
325 ok = blocking_notifier_call_chain(&crypto_chain, val, v);
326 }
327
328 return ok;
329}
330EXPORT_SYMBOL_GPL(crypto_probing_notify);
331
332struct crypto_alg *crypto_alg_mod_lookup(const char *name, u32 type, u32 mask)
333{
334 struct crypto_alg *alg;
335 struct crypto_alg *larval;
336 int ok;
337
338 /*
339 * If the internal flag is set for a cipher, require a caller to
340 * invoke the cipher with the internal flag to use that cipher.
341 * Also, if a caller wants to allocate a cipher that may or may
342 * not be an internal cipher, use type | CRYPTO_ALG_INTERNAL and
343 * !(mask & CRYPTO_ALG_INTERNAL).
344 */
345 if (!((type | mask) & CRYPTO_ALG_INTERNAL))
346 mask |= CRYPTO_ALG_INTERNAL;
347
348 larval = crypto_larval_lookup(name, type, mask);
349 if (IS_ERR(larval) || !crypto_is_larval(larval))
350 return larval;
351
352 ok = crypto_probing_notify(CRYPTO_MSG_ALG_REQUEST, larval);
353
354 if (ok == NOTIFY_STOP)
355 alg = crypto_larval_wait(larval);
356 else {
357 crypto_mod_put(larval);
358 alg = ERR_PTR(-ENOENT);
359 }
360 crypto_larval_kill(container_of(larval, struct crypto_larval, alg));
361 return alg;
362}
363EXPORT_SYMBOL_GPL(crypto_alg_mod_lookup);
364
365static void crypto_exit_ops(struct crypto_tfm *tfm)
366{
367 const struct crypto_type *type = tfm->__crt_alg->cra_type;
368
369 if (type && tfm->exit)
370 tfm->exit(tfm);
371}
372
373static unsigned int crypto_ctxsize(struct crypto_alg *alg, u32 type, u32 mask)
374{
375 const struct crypto_type *type_obj = alg->cra_type;
376 unsigned int len;
377
378 len = alg->cra_alignmask & ~(crypto_tfm_ctx_alignment() - 1);
379 if (type_obj)
380 return len + type_obj->ctxsize(alg, type, mask);
381
382 switch (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) {
383 default:
384 BUG();
385
386 case CRYPTO_ALG_TYPE_CIPHER:
387 len += crypto_cipher_ctxsize(alg);
388 break;
389
390 case CRYPTO_ALG_TYPE_COMPRESS:
391 len += crypto_compress_ctxsize(alg);
392 break;
393 }
394
395 return len;
396}
397
398void crypto_shoot_alg(struct crypto_alg *alg)
399{
400 down_write(&crypto_alg_sem);
401 alg->cra_flags |= CRYPTO_ALG_DYING;
402 up_write(&crypto_alg_sem);
403}
404EXPORT_SYMBOL_GPL(crypto_shoot_alg);
405
406struct crypto_tfm *__crypto_alloc_tfmgfp(struct crypto_alg *alg, u32 type,
407 u32 mask, gfp_t gfp)
408{
409 struct crypto_tfm *tfm;
410 unsigned int tfm_size;
411 int err = -ENOMEM;
412
413 tfm_size = sizeof(*tfm) + crypto_ctxsize(alg, type, mask);
414 tfm = kzalloc(tfm_size, gfp);
415 if (tfm == NULL)
416 goto out_err;
417
418 tfm->__crt_alg = alg;
419 refcount_set(&tfm->refcnt, 1);
420
421 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
422 goto cra_init_failed;
423
424 goto out;
425
426cra_init_failed:
427 crypto_exit_ops(tfm);
428 if (err == -EAGAIN)
429 crypto_shoot_alg(alg);
430 kfree(tfm);
431out_err:
432 tfm = ERR_PTR(err);
433out:
434 return tfm;
435}
436EXPORT_SYMBOL_GPL(__crypto_alloc_tfmgfp);
437
438struct crypto_tfm *__crypto_alloc_tfm(struct crypto_alg *alg, u32 type,
439 u32 mask)
440{
441 return __crypto_alloc_tfmgfp(alg, type, mask, GFP_KERNEL);
442}
443EXPORT_SYMBOL_GPL(__crypto_alloc_tfm);
444
445/*
446 * crypto_alloc_base - Locate algorithm and allocate transform
447 * @alg_name: Name of algorithm
448 * @type: Type of algorithm
449 * @mask: Mask for type comparison
450 *
451 * This function should not be used by new algorithm types.
452 * Please use crypto_alloc_tfm instead.
453 *
454 * crypto_alloc_base() will first attempt to locate an already loaded
455 * algorithm. If that fails and the kernel supports dynamically loadable
456 * modules, it will then attempt to load a module of the same name or
457 * alias. If that fails it will send a query to any loaded crypto manager
458 * to construct an algorithm on the fly. A refcount is grabbed on the
459 * algorithm which is then associated with the new transform.
460 *
461 * The returned transform is of a non-determinate type. Most people
462 * should use one of the more specific allocation functions such as
463 * crypto_alloc_skcipher().
464 *
465 * In case of error the return value is an error pointer.
466 */
467struct crypto_tfm *crypto_alloc_base(const char *alg_name, u32 type, u32 mask)
468{
469 struct crypto_tfm *tfm;
470 int err;
471
472 for (;;) {
473 struct crypto_alg *alg;
474
475 alg = crypto_alg_mod_lookup(alg_name, type, mask);
476 if (IS_ERR(alg)) {
477 err = PTR_ERR(alg);
478 goto err;
479 }
480
481 tfm = __crypto_alloc_tfm(alg, type, mask);
482 if (!IS_ERR(tfm))
483 return tfm;
484
485 crypto_mod_put(alg);
486 err = PTR_ERR(tfm);
487
488err:
489 if (err != -EAGAIN)
490 break;
491 if (fatal_signal_pending(current)) {
492 err = -EINTR;
493 break;
494 }
495 }
496
497 return ERR_PTR(err);
498}
499EXPORT_SYMBOL_GPL(crypto_alloc_base);
500
501static void *crypto_alloc_tfmmem(struct crypto_alg *alg,
502 const struct crypto_type *frontend, int node,
503 gfp_t gfp)
504{
505 struct crypto_tfm *tfm;
506 unsigned int tfmsize;
507 unsigned int total;
508 char *mem;
509
510 tfmsize = frontend->tfmsize;
511 total = tfmsize + sizeof(*tfm) + frontend->extsize(alg);
512
513 mem = kzalloc_node(total, gfp, node);
514 if (mem == NULL)
515 return ERR_PTR(-ENOMEM);
516
517 tfm = (struct crypto_tfm *)(mem + tfmsize);
518 tfm->__crt_alg = alg;
519 tfm->node = node;
520 refcount_set(&tfm->refcnt, 1);
521
522 return mem;
523}
524
525void *crypto_create_tfm_node(struct crypto_alg *alg,
526 const struct crypto_type *frontend,
527 int node)
528{
529 struct crypto_tfm *tfm;
530 char *mem;
531 int err;
532
533 mem = crypto_alloc_tfmmem(alg, frontend, node, GFP_KERNEL);
534 if (IS_ERR(mem))
535 goto out;
536
537 tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
538
539 err = frontend->init_tfm(tfm);
540 if (err)
541 goto out_free_tfm;
542
543 if (!tfm->exit && alg->cra_init && (err = alg->cra_init(tfm)))
544 goto cra_init_failed;
545
546 goto out;
547
548cra_init_failed:
549 crypto_exit_ops(tfm);
550out_free_tfm:
551 if (err == -EAGAIN)
552 crypto_shoot_alg(alg);
553 kfree(mem);
554 mem = ERR_PTR(err);
555out:
556 return mem;
557}
558EXPORT_SYMBOL_GPL(crypto_create_tfm_node);
559
560void *crypto_clone_tfm(const struct crypto_type *frontend,
561 struct crypto_tfm *otfm)
562{
563 struct crypto_alg *alg = otfm->__crt_alg;
564 struct crypto_tfm *tfm;
565 char *mem;
566
567 mem = ERR_PTR(-ESTALE);
568 if (unlikely(!crypto_mod_get(alg)))
569 goto out;
570
571 mem = crypto_alloc_tfmmem(alg, frontend, otfm->node, GFP_ATOMIC);
572 if (IS_ERR(mem)) {
573 crypto_mod_put(alg);
574 goto out;
575 }
576
577 tfm = (struct crypto_tfm *)(mem + frontend->tfmsize);
578 tfm->crt_flags = otfm->crt_flags;
579 tfm->exit = otfm->exit;
580
581out:
582 return mem;
583}
584EXPORT_SYMBOL_GPL(crypto_clone_tfm);
585
586struct crypto_alg *crypto_find_alg(const char *alg_name,
587 const struct crypto_type *frontend,
588 u32 type, u32 mask)
589{
590 if (frontend) {
591 type &= frontend->maskclear;
592 mask &= frontend->maskclear;
593 type |= frontend->type;
594 mask |= frontend->maskset;
595 }
596
597 return crypto_alg_mod_lookup(alg_name, type, mask);
598}
599EXPORT_SYMBOL_GPL(crypto_find_alg);
600
601/*
602 * crypto_alloc_tfm_node - Locate algorithm and allocate transform
603 * @alg_name: Name of algorithm
604 * @frontend: Frontend algorithm type
605 * @type: Type of algorithm
606 * @mask: Mask for type comparison
607 * @node: NUMA node in which users desire to put requests, if node is
608 * NUMA_NO_NODE, it means users have no special requirement.
609 *
610 * crypto_alloc_tfm() will first attempt to locate an already loaded
611 * algorithm. If that fails and the kernel supports dynamically loadable
612 * modules, it will then attempt to load a module of the same name or
613 * alias. If that fails it will send a query to any loaded crypto manager
614 * to construct an algorithm on the fly. A refcount is grabbed on the
615 * algorithm which is then associated with the new transform.
616 *
617 * The returned transform is of a non-determinate type. Most people
618 * should use one of the more specific allocation functions such as
619 * crypto_alloc_skcipher().
620 *
621 * In case of error the return value is an error pointer.
622 */
623
624void *crypto_alloc_tfm_node(const char *alg_name,
625 const struct crypto_type *frontend, u32 type, u32 mask,
626 int node)
627{
628 void *tfm;
629 int err;
630
631 for (;;) {
632 struct crypto_alg *alg;
633
634 alg = crypto_find_alg(alg_name, frontend, type, mask);
635 if (IS_ERR(alg)) {
636 err = PTR_ERR(alg);
637 goto err;
638 }
639
640 tfm = crypto_create_tfm_node(alg, frontend, node);
641 if (!IS_ERR(tfm))
642 return tfm;
643
644 crypto_mod_put(alg);
645 err = PTR_ERR(tfm);
646
647err:
648 if (err != -EAGAIN)
649 break;
650 if (fatal_signal_pending(current)) {
651 err = -EINTR;
652 break;
653 }
654 }
655
656 return ERR_PTR(err);
657}
658EXPORT_SYMBOL_GPL(crypto_alloc_tfm_node);
659
660/*
661 * crypto_destroy_tfm - Free crypto transform
662 * @mem: Start of tfm slab
663 * @tfm: Transform to free
664 *
665 * This function frees up the transform and any associated resources,
666 * then drops the refcount on the associated algorithm.
667 */
668void crypto_destroy_tfm(void *mem, struct crypto_tfm *tfm)
669{
670 struct crypto_alg *alg;
671
672 if (IS_ERR_OR_NULL(mem))
673 return;
674
675 if (!refcount_dec_and_test(&tfm->refcnt))
676 return;
677 alg = tfm->__crt_alg;
678
679 if (!tfm->exit && alg->cra_exit)
680 alg->cra_exit(tfm);
681 crypto_exit_ops(tfm);
682 crypto_mod_put(alg);
683 kfree_sensitive(mem);
684}
685EXPORT_SYMBOL_GPL(crypto_destroy_tfm);
686
687int crypto_has_alg(const char *name, u32 type, u32 mask)
688{
689 int ret = 0;
690 struct crypto_alg *alg = crypto_alg_mod_lookup(name, type, mask);
691
692 if (!IS_ERR(alg)) {
693 crypto_mod_put(alg);
694 ret = 1;
695 }
696
697 return ret;
698}
699EXPORT_SYMBOL_GPL(crypto_has_alg);
700
701void crypto_req_done(void *data, int err)
702{
703 struct crypto_wait *wait = data;
704
705 if (err == -EINPROGRESS)
706 return;
707
708 wait->err = err;
709 complete(&wait->completion);
710}
711EXPORT_SYMBOL_GPL(crypto_req_done);
712
713MODULE_DESCRIPTION("Cryptographic core API");
714MODULE_LICENSE("GPL");