xref: /openbmc/linux/crypto/ahash.c (revision 6de298ff) 
1 // SPDX-License-Identifier: GPL-2.0-or-later
2 /*
3  * Asynchronous Cryptographic Hash operations.
4  *
5  * This is the asynchronous version of hash.c with notification of
6  * completion via a callback.
7  *
8  * Copyright (c) 2008 Loc Ho <lho@amcc.com>
9  */
10 
11 #include <crypto/scatterwalk.h>
12 #include <linux/cryptouser.h>
13 #include <linux/err.h>
14 #include <linux/kernel.h>
15 #include <linux/module.h>
16 #include <linux/sched.h>
17 #include <linux/slab.h>
18 #include <linux/seq_file.h>
19 #include <linux/string.h>
20 #include <net/netlink.h>
21 
22 #include "hash.h"
23 
24 static const struct crypto_type crypto_ahash_type;
25 
26 struct ahash_request_priv {
27 	crypto_completion_t complete;
28 	void *data;
29 	u8 *result;
30 	u32 flags;
31 	void *ubuf[] CRYPTO_MINALIGN_ATTR;
32 };
33 
34 static int hash_walk_next(struct crypto_hash_walk *walk)
35 {
36 	unsigned int alignmask = walk->alignmask;
37 	unsigned int offset = walk->offset;
38 	unsigned int nbytes = min(walk->entrylen,
39 				  ((unsigned int)(PAGE_SIZE)) - offset);
40 
41 	walk->data = kmap_local_page(walk->pg);
42 	walk->data += offset;
43 
44 	if (offset & alignmask) {
45 		unsigned int unaligned = alignmask + 1 - (offset & alignmask);
46 
47 		if (nbytes > unaligned)
48 			nbytes = unaligned;
49 	}
50 
51 	walk->entrylen -= nbytes;
52 	return nbytes;
53 }
54 
55 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
56 {
57 	struct scatterlist *sg;
58 
59 	sg = walk->sg;
60 	walk->offset = sg->offset;
61 	walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
62 	walk->offset = offset_in_page(walk->offset);
63 	walk->entrylen = sg->length;
64 
65 	if (walk->entrylen > walk->total)
66 		walk->entrylen = walk->total;
67 	walk->total -= walk->entrylen;
68 
69 	return hash_walk_next(walk);
70 }
71 
72 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
73 {
74 	unsigned int alignmask = walk->alignmask;
75 
76 	walk->data -= walk->offset;
77 
78 	if (walk->entrylen && (walk->offset & alignmask) && !err) {
79 		unsigned int nbytes;
80 
81 		walk->offset = ALIGN(walk->offset, alignmask + 1);
82 		nbytes = min(walk->entrylen,
83 			     (unsigned int)(PAGE_SIZE - walk->offset));
84 		if (nbytes) {
85 			walk->entrylen -= nbytes;
86 			walk->data += walk->offset;
87 			return nbytes;
88 		}
89 	}
90 
91 	kunmap_local(walk->data);
92 	crypto_yield(walk->flags);
93 
94 	if (err)
95 		return err;
96 
97 	if (walk->entrylen) {
98 		walk->offset = 0;
99 		walk->pg++;
100 		return hash_walk_next(walk);
101 	}
102 
103 	if (!walk->total)
104 		return 0;
105 
106 	walk->sg = sg_next(walk->sg);
107 
108 	return hash_walk_new_entry(walk);
109 }
110 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
111 
112 int crypto_hash_walk_first(struct ahash_request *req,
113 			   struct crypto_hash_walk *walk)
114 {
115 	walk->total = req->nbytes;
116 
117 	if (!walk->total) {
118 		walk->entrylen = 0;
119 		return 0;
120 	}
121 
122 	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
123 	walk->sg = req->src;
124 	walk->flags = req->base.flags;
125 
126 	return hash_walk_new_entry(walk);
127 }
128 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
129 
130 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
131 				unsigned int keylen)
132 {
133 	unsigned long alignmask = crypto_ahash_alignmask(tfm);
134 	int ret;
135 	u8 *buffer, *alignbuffer;
136 	unsigned long absize;
137 
138 	absize = keylen + alignmask;
139 	buffer = kmalloc(absize, GFP_KERNEL);
140 	if (!buffer)
141 		return -ENOMEM;
142 
143 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
144 	memcpy(alignbuffer, key, keylen);
145 	ret = tfm->setkey(tfm, alignbuffer, keylen);
146 	kfree_sensitive(buffer);
147 	return ret;
148 }
149 
150 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
151 			  unsigned int keylen)
152 {
153 	return -ENOSYS;
154 }
155 
156 static void ahash_set_needkey(struct crypto_ahash *tfm)
157 {
158 	const struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
159 
160 	if (tfm->setkey != ahash_nosetkey &&
161 	    !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
162 		crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
163 }
164 
165 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
166 			unsigned int keylen)
167 {
168 	unsigned long alignmask = crypto_ahash_alignmask(tfm);
169 	int err;
170 
171 	if ((unsigned long)key & alignmask)
172 		err = ahash_setkey_unaligned(tfm, key, keylen);
173 	else
174 		err = tfm->setkey(tfm, key, keylen);
175 
176 	if (unlikely(err)) {
177 		ahash_set_needkey(tfm);
178 		return err;
179 	}
180 
181 	crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
182 	return 0;
183 }
184 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
185 
186 static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt,
187 			  bool has_state)
188 {
189 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
190 	unsigned long alignmask = crypto_ahash_alignmask(tfm);
191 	unsigned int ds = crypto_ahash_digestsize(tfm);
192 	struct ahash_request *subreq;
193 	unsigned int subreq_size;
194 	unsigned int reqsize;
195 	u8 *result;
196 	gfp_t gfp;
197 	u32 flags;
198 
199 	subreq_size = sizeof(*subreq);
200 	reqsize = crypto_ahash_reqsize(tfm);
201 	reqsize = ALIGN(reqsize, crypto_tfm_ctx_alignment());
202 	subreq_size += reqsize;
203 	subreq_size += ds;
204 	subreq_size += alignmask & ~(crypto_tfm_ctx_alignment() - 1);
205 
206 	flags = ahash_request_flags(req);
207 	gfp = (flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?  GFP_KERNEL : GFP_ATOMIC;
208 	subreq = kmalloc(subreq_size, gfp);
209 	if (!subreq)
210 		return -ENOMEM;
211 
212 	ahash_request_set_tfm(subreq, tfm);
213 	ahash_request_set_callback(subreq, flags, cplt, req);
214 
215 	result = (u8 *)(subreq + 1) + reqsize;
216 	result = PTR_ALIGN(result, alignmask + 1);
217 
218 	ahash_request_set_crypt(subreq, req->src, result, req->nbytes);
219 
220 	if (has_state) {
221 		void *state;
222 
223 		state = kmalloc(crypto_ahash_statesize(tfm), gfp);
224 		if (!state) {
225 			kfree(subreq);
226 			return -ENOMEM;
227 		}
228 
229 		crypto_ahash_export(req, state);
230 		crypto_ahash_import(subreq, state);
231 		kfree_sensitive(state);
232 	}
233 
234 	req->priv = subreq;
235 
236 	return 0;
237 }
238 
239 static void ahash_restore_req(struct ahash_request *req, int err)
240 {
241 	struct ahash_request *subreq = req->priv;
242 
243 	if (!err)
244 		memcpy(req->result, subreq->result,
245 		       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
246 
247 	req->priv = NULL;
248 
249 	kfree_sensitive(subreq);
250 }
251 
252 static void ahash_op_unaligned_done(void *data, int err)
253 {
254 	struct ahash_request *areq = data;
255 
256 	if (err == -EINPROGRESS)
257 		goto out;
258 
259 	/* First copy req->result into req->priv.result */
260 	ahash_restore_req(areq, err);
261 
262 out:
263 	/* Complete the ORIGINAL request. */
264 	ahash_request_complete(areq, err);
265 }
266 
267 static int ahash_op_unaligned(struct ahash_request *req,
268 			      int (*op)(struct ahash_request *),
269 			      bool has_state)
270 {
271 	int err;
272 
273 	err = ahash_save_req(req, ahash_op_unaligned_done, has_state);
274 	if (err)
275 		return err;
276 
277 	err = op(req->priv);
278 	if (err == -EINPROGRESS || err == -EBUSY)
279 		return err;
280 
281 	ahash_restore_req(req, err);
282 
283 	return err;
284 }
285 
286 static int crypto_ahash_op(struct ahash_request *req,
287 			   int (*op)(struct ahash_request *),
288 			   bool has_state)
289 {
290 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
291 	unsigned long alignmask = crypto_ahash_alignmask(tfm);
292 	int err;
293 
294 	if ((unsigned long)req->result & alignmask)
295 		err = ahash_op_unaligned(req, op, has_state);
296 	else
297 		err = op(req);
298 
299 	return crypto_hash_errstat(crypto_hash_alg_common(tfm), err);
300 }
301 
302 int crypto_ahash_final(struct ahash_request *req)
303 {
304 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
305 	struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
306 
307 	if (IS_ENABLED(CONFIG_CRYPTO_STATS))
308 		atomic64_inc(&hash_get_stat(alg)->hash_cnt);
309 
310 	return crypto_ahash_op(req, tfm->final, true);
311 }
312 EXPORT_SYMBOL_GPL(crypto_ahash_final);
313 
314 int crypto_ahash_finup(struct ahash_request *req)
315 {
316 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
317 	struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
318 
319 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
320 		struct crypto_istat_hash *istat = hash_get_stat(alg);
321 
322 		atomic64_inc(&istat->hash_cnt);
323 		atomic64_add(req->nbytes, &istat->hash_tlen);
324 	}
325 
326 	return crypto_ahash_op(req, tfm->finup, true);
327 }
328 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
329 
330 int crypto_ahash_digest(struct ahash_request *req)
331 {
332 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
333 	struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
334 
335 	if (IS_ENABLED(CONFIG_CRYPTO_STATS)) {
336 		struct crypto_istat_hash *istat = hash_get_stat(alg);
337 
338 		atomic64_inc(&istat->hash_cnt);
339 		atomic64_add(req->nbytes, &istat->hash_tlen);
340 	}
341 
342 	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
343 		return crypto_hash_errstat(alg, -ENOKEY);
344 
345 	return crypto_ahash_op(req, tfm->digest, false);
346 }
347 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
348 
349 static void ahash_def_finup_done2(void *data, int err)
350 {
351 	struct ahash_request *areq = data;
352 
353 	if (err == -EINPROGRESS)
354 		return;
355 
356 	ahash_restore_req(areq, err);
357 
358 	ahash_request_complete(areq, err);
359 }
360 
361 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
362 {
363 	struct ahash_request *subreq = req->priv;
364 
365 	if (err)
366 		goto out;
367 
368 	subreq->base.complete = ahash_def_finup_done2;
369 
370 	err = crypto_ahash_reqtfm(req)->final(subreq);
371 	if (err == -EINPROGRESS || err == -EBUSY)
372 		return err;
373 
374 out:
375 	ahash_restore_req(req, err);
376 	return err;
377 }
378 
379 static void ahash_def_finup_done1(void *data, int err)
380 {
381 	struct ahash_request *areq = data;
382 	struct ahash_request *subreq;
383 
384 	if (err == -EINPROGRESS)
385 		goto out;
386 
387 	subreq = areq->priv;
388 	subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
389 
390 	err = ahash_def_finup_finish1(areq, err);
391 	if (err == -EINPROGRESS || err == -EBUSY)
392 		return;
393 
394 out:
395 	ahash_request_complete(areq, err);
396 }
397 
398 static int ahash_def_finup(struct ahash_request *req)
399 {
400 	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
401 	int err;
402 
403 	err = ahash_save_req(req, ahash_def_finup_done1, true);
404 	if (err)
405 		return err;
406 
407 	err = tfm->update(req->priv);
408 	if (err == -EINPROGRESS || err == -EBUSY)
409 		return err;
410 
411 	return ahash_def_finup_finish1(req, err);
412 }
413 
414 static void crypto_ahash_exit_tfm(struct crypto_tfm *tfm)
415 {
416 	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
417 	struct ahash_alg *alg = crypto_ahash_alg(hash);
418 
419 	alg->exit_tfm(hash);
420 }
421 
422 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
423 {
424 	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
425 	struct ahash_alg *alg = crypto_ahash_alg(hash);
426 
427 	hash->setkey = ahash_nosetkey;
428 
429 	crypto_ahash_set_statesize(hash, alg->halg.statesize);
430 
431 	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
432 		return crypto_init_shash_ops_async(tfm);
433 
434 	hash->init = alg->init;
435 	hash->update = alg->update;
436 	hash->final = alg->final;
437 	hash->finup = alg->finup ?: ahash_def_finup;
438 	hash->digest = alg->digest;
439 	hash->export = alg->export;
440 	hash->import = alg->import;
441 
442 	if (alg->setkey) {
443 		hash->setkey = alg->setkey;
444 		ahash_set_needkey(hash);
445 	}
446 
447 	if (alg->exit_tfm)
448 		tfm->exit = crypto_ahash_exit_tfm;
449 
450 	return alg->init_tfm ? alg->init_tfm(hash) : 0;
451 }
452 
453 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
454 {
455 	if (alg->cra_type != &crypto_ahash_type)
456 		return sizeof(struct crypto_shash *);
457 
458 	return crypto_alg_extsize(alg);
459 }
460 
461 static void crypto_ahash_free_instance(struct crypto_instance *inst)
462 {
463 	struct ahash_instance *ahash = ahash_instance(inst);
464 
465 	ahash->free(ahash);
466 }
467 
468 static int __maybe_unused crypto_ahash_report(
469 	struct sk_buff *skb, struct crypto_alg *alg)
470 {
471 	struct crypto_report_hash rhash;
472 
473 	memset(&rhash, 0, sizeof(rhash));
474 
475 	strscpy(rhash.type, "ahash", sizeof(rhash.type));
476 
477 	rhash.blocksize = alg->cra_blocksize;
478 	rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
479 
480 	return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
481 }
482 
483 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
484 	__maybe_unused;
485 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
486 {
487 	seq_printf(m, "type         : ahash\n");
488 	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
489 					     "yes" : "no");
490 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
491 	seq_printf(m, "digestsize   : %u\n",
492 		   __crypto_hash_alg_common(alg)->digestsize);
493 }
494 
495 static int __maybe_unused crypto_ahash_report_stat(
496 	struct sk_buff *skb, struct crypto_alg *alg)
497 {
498 	return crypto_hash_report_stat(skb, alg, "ahash");
499 }
500 
501 static const struct crypto_type crypto_ahash_type = {
502 	.extsize = crypto_ahash_extsize,
503 	.init_tfm = crypto_ahash_init_tfm,
504 	.free = crypto_ahash_free_instance,
505 #ifdef CONFIG_PROC_FS
506 	.show = crypto_ahash_show,
507 #endif
508 #if IS_ENABLED(CONFIG_CRYPTO_USER)
509 	.report = crypto_ahash_report,
510 #endif
511 #ifdef CONFIG_CRYPTO_STATS
512 	.report_stat = crypto_ahash_report_stat,
513 #endif
514 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
515 	.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
516 	.type = CRYPTO_ALG_TYPE_AHASH,
517 	.tfmsize = offsetof(struct crypto_ahash, base),
518 };
519 
520 int crypto_grab_ahash(struct crypto_ahash_spawn *spawn,
521 		      struct crypto_instance *inst,
522 		      const char *name, u32 type, u32 mask)
523 {
524 	spawn->base.frontend = &crypto_ahash_type;
525 	return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
526 }
527 EXPORT_SYMBOL_GPL(crypto_grab_ahash);
528 
529 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
530 					u32 mask)
531 {
532 	return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
533 }
534 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
535 
536 int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
537 {
538 	return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
539 }
540 EXPORT_SYMBOL_GPL(crypto_has_ahash);
541 
542 struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *hash)
543 {
544 	struct hash_alg_common *halg = crypto_hash_alg_common(hash);
545 	struct crypto_tfm *tfm = crypto_ahash_tfm(hash);
546 	struct crypto_ahash *nhash;
547 	struct ahash_alg *alg;
548 	int err;
549 
550 	if (!crypto_hash_alg_has_setkey(halg)) {
551 		tfm = crypto_tfm_get(tfm);
552 		if (IS_ERR(tfm))
553 			return ERR_CAST(tfm);
554 
555 		return hash;
556 	}
557 
558 	nhash = crypto_clone_tfm(&crypto_ahash_type, tfm);
559 
560 	if (IS_ERR(nhash))
561 		return nhash;
562 
563 	nhash->init = hash->init;
564 	nhash->update = hash->update;
565 	nhash->final = hash->final;
566 	nhash->finup = hash->finup;
567 	nhash->digest = hash->digest;
568 	nhash->export = hash->export;
569 	nhash->import = hash->import;
570 	nhash->setkey = hash->setkey;
571 	nhash->reqsize = hash->reqsize;
572 	nhash->statesize = hash->statesize;
573 
574 	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
575 		return crypto_clone_shash_ops_async(nhash, hash);
576 
577 	err = -ENOSYS;
578 	alg = crypto_ahash_alg(hash);
579 	if (!alg->clone_tfm)
580 		goto out_free_nhash;
581 
582 	err = alg->clone_tfm(nhash, hash);
583 	if (err)
584 		goto out_free_nhash;
585 
586 	return nhash;
587 
588 out_free_nhash:
589 	crypto_free_ahash(nhash);
590 	return ERR_PTR(err);
591 }
592 EXPORT_SYMBOL_GPL(crypto_clone_ahash);
593 
594 static int ahash_prepare_alg(struct ahash_alg *alg)
595 {
596 	struct crypto_alg *base = &alg->halg.base;
597 	int err;
598 
599 	if (alg->halg.statesize == 0)
600 		return -EINVAL;
601 
602 	err = hash_prepare_alg(&alg->halg);
603 	if (err)
604 		return err;
605 
606 	base->cra_type = &crypto_ahash_type;
607 	base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
608 
609 	return 0;
610 }
611 
612 int crypto_register_ahash(struct ahash_alg *alg)
613 {
614 	struct crypto_alg *base = &alg->halg.base;
615 	int err;
616 
617 	err = ahash_prepare_alg(alg);
618 	if (err)
619 		return err;
620 
621 	return crypto_register_alg(base);
622 }
623 EXPORT_SYMBOL_GPL(crypto_register_ahash);
624 
625 void crypto_unregister_ahash(struct ahash_alg *alg)
626 {
627 	crypto_unregister_alg(&alg->halg.base);
628 }
629 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
630 
631 int crypto_register_ahashes(struct ahash_alg *algs, int count)
632 {
633 	int i, ret;
634 
635 	for (i = 0; i < count; i++) {
636 		ret = crypto_register_ahash(&algs[i]);
637 		if (ret)
638 			goto err;
639 	}
640 
641 	return 0;
642 
643 err:
644 	for (--i; i >= 0; --i)
645 		crypto_unregister_ahash(&algs[i]);
646 
647 	return ret;
648 }
649 EXPORT_SYMBOL_GPL(crypto_register_ahashes);
650 
651 void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
652 {
653 	int i;
654 
655 	for (i = count - 1; i >= 0; --i)
656 		crypto_unregister_ahash(&algs[i]);
657 }
658 EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
659 
660 int ahash_register_instance(struct crypto_template *tmpl,
661 			    struct ahash_instance *inst)
662 {
663 	int err;
664 
665 	if (WARN_ON(!inst->free))
666 		return -EINVAL;
667 
668 	err = ahash_prepare_alg(&inst->alg);
669 	if (err)
670 		return err;
671 
672 	return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
673 }
674 EXPORT_SYMBOL_GPL(ahash_register_instance);
675 
676 bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
677 {
678 	struct crypto_alg *alg = &halg->base;
679 
680 	if (alg->cra_type != &crypto_ahash_type)
681 		return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
682 
683 	return __crypto_ahash_alg(alg)->setkey != NULL;
684 }
685 EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
686 
687 MODULE_LICENSE("GPL");
688 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
689