xref: /linux/crypto/shash.c (revision 2a96fd7417a0eb501edfde9713555bd7c2eda302)
1 /*
2  * Synchronous Cryptographic Hash operations.
3  *
4  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  *
11  */
12 
13 #include <crypto/scatterwalk.h>
14 #include <crypto/internal/hash.h>
15 #include <linux/err.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/seq_file.h>
20 #include <linux/cryptouser.h>
21 #include <net/netlink.h>
22 
23 #include "internal.h"
24 
25 static const struct crypto_type crypto_shash_type;
26 
27 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
28 			   unsigned int keylen)
29 {
30 	return -ENOSYS;
31 }
32 
33 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
34 				  unsigned int keylen)
35 {
36 	struct shash_alg *shash = crypto_shash_alg(tfm);
37 	unsigned long alignmask = crypto_shash_alignmask(tfm);
38 	unsigned long absize;
39 	u8 *buffer, *alignbuffer;
40 	int err;
41 
42 	absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
43 	buffer = kmalloc(absize, GFP_KERNEL);
44 	if (!buffer)
45 		return -ENOMEM;
46 
47 	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
48 	memcpy(alignbuffer, key, keylen);
49 	err = shash->setkey(tfm, alignbuffer, keylen);
50 	kzfree(buffer);
51 	return err;
52 }
53 
54 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
55 			unsigned int keylen)
56 {
57 	struct shash_alg *shash = crypto_shash_alg(tfm);
58 	unsigned long alignmask = crypto_shash_alignmask(tfm);
59 
60 	if ((unsigned long)key & alignmask)
61 		return shash_setkey_unaligned(tfm, key, keylen);
62 
63 	return shash->setkey(tfm, key, keylen);
64 }
65 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
66 
67 static inline unsigned int shash_align_buffer_size(unsigned len,
68 						   unsigned long mask)
69 {
70 	typedef u8 __attribute__ ((aligned)) u8_aligned;
71 	return len + (mask & ~(__alignof__(u8_aligned) - 1));
72 }
73 
74 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
75 				  unsigned int len)
76 {
77 	struct crypto_shash *tfm = desc->tfm;
78 	struct shash_alg *shash = crypto_shash_alg(tfm);
79 	unsigned long alignmask = crypto_shash_alignmask(tfm);
80 	unsigned int unaligned_len = alignmask + 1 -
81 				     ((unsigned long)data & alignmask);
82 	u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
83 		__attribute__ ((aligned));
84 	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
85 	int err;
86 
87 	if (unaligned_len > len)
88 		unaligned_len = len;
89 
90 	memcpy(buf, data, unaligned_len);
91 	err = shash->update(desc, buf, unaligned_len);
92 	memset(buf, 0, unaligned_len);
93 
94 	return err ?:
95 	       shash->update(desc, data + unaligned_len, len - unaligned_len);
96 }
97 
98 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
99 			unsigned int len)
100 {
101 	struct crypto_shash *tfm = desc->tfm;
102 	struct shash_alg *shash = crypto_shash_alg(tfm);
103 	unsigned long alignmask = crypto_shash_alignmask(tfm);
104 
105 	if ((unsigned long)data & alignmask)
106 		return shash_update_unaligned(desc, data, len);
107 
108 	return shash->update(desc, data, len);
109 }
110 EXPORT_SYMBOL_GPL(crypto_shash_update);
111 
112 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
113 {
114 	struct crypto_shash *tfm = desc->tfm;
115 	unsigned long alignmask = crypto_shash_alignmask(tfm);
116 	struct shash_alg *shash = crypto_shash_alg(tfm);
117 	unsigned int ds = crypto_shash_digestsize(tfm);
118 	u8 ubuf[shash_align_buffer_size(ds, alignmask)]
119 		__attribute__ ((aligned));
120 	u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
121 	int err;
122 
123 	err = shash->final(desc, buf);
124 	if (err)
125 		goto out;
126 
127 	memcpy(out, buf, ds);
128 
129 out:
130 	memset(buf, 0, ds);
131 	return err;
132 }
133 
134 int crypto_shash_final(struct shash_desc *desc, u8 *out)
135 {
136 	struct crypto_shash *tfm = desc->tfm;
137 	struct shash_alg *shash = crypto_shash_alg(tfm);
138 	unsigned long alignmask = crypto_shash_alignmask(tfm);
139 
140 	if ((unsigned long)out & alignmask)
141 		return shash_final_unaligned(desc, out);
142 
143 	return shash->final(desc, out);
144 }
145 EXPORT_SYMBOL_GPL(crypto_shash_final);
146 
147 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
148 				 unsigned int len, u8 *out)
149 {
150 	return crypto_shash_update(desc, data, len) ?:
151 	       crypto_shash_final(desc, out);
152 }
153 
154 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
155 		       unsigned int len, u8 *out)
156 {
157 	struct crypto_shash *tfm = desc->tfm;
158 	struct shash_alg *shash = crypto_shash_alg(tfm);
159 	unsigned long alignmask = crypto_shash_alignmask(tfm);
160 
161 	if (((unsigned long)data | (unsigned long)out) & alignmask)
162 		return shash_finup_unaligned(desc, data, len, out);
163 
164 	return shash->finup(desc, data, len, out);
165 }
166 EXPORT_SYMBOL_GPL(crypto_shash_finup);
167 
168 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
169 				  unsigned int len, u8 *out)
170 {
171 	return crypto_shash_init(desc) ?:
172 	       crypto_shash_finup(desc, data, len, out);
173 }
174 
175 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
176 			unsigned int len, u8 *out)
177 {
178 	struct crypto_shash *tfm = desc->tfm;
179 	struct shash_alg *shash = crypto_shash_alg(tfm);
180 	unsigned long alignmask = crypto_shash_alignmask(tfm);
181 
182 	if (((unsigned long)data | (unsigned long)out) & alignmask)
183 		return shash_digest_unaligned(desc, data, len, out);
184 
185 	return shash->digest(desc, data, len, out);
186 }
187 EXPORT_SYMBOL_GPL(crypto_shash_digest);
188 
189 static int shash_default_export(struct shash_desc *desc, void *out)
190 {
191 	memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
192 	return 0;
193 }
194 
195 static int shash_default_import(struct shash_desc *desc, const void *in)
196 {
197 	memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
198 	return 0;
199 }
200 
201 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
202 			      unsigned int keylen)
203 {
204 	struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
205 
206 	return crypto_shash_setkey(*ctx, key, keylen);
207 }
208 
209 static int shash_async_init(struct ahash_request *req)
210 {
211 	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
212 	struct shash_desc *desc = ahash_request_ctx(req);
213 
214 	desc->tfm = *ctx;
215 	desc->flags = req->base.flags;
216 
217 	return crypto_shash_init(desc);
218 }
219 
220 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
221 {
222 	struct crypto_hash_walk walk;
223 	int nbytes;
224 
225 	for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
226 	     nbytes = crypto_hash_walk_done(&walk, nbytes))
227 		nbytes = crypto_shash_update(desc, walk.data, nbytes);
228 
229 	return nbytes;
230 }
231 EXPORT_SYMBOL_GPL(shash_ahash_update);
232 
233 static int shash_async_update(struct ahash_request *req)
234 {
235 	return shash_ahash_update(req, ahash_request_ctx(req));
236 }
237 
238 static int shash_async_final(struct ahash_request *req)
239 {
240 	return crypto_shash_final(ahash_request_ctx(req), req->result);
241 }
242 
243 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
244 {
245 	struct crypto_hash_walk walk;
246 	int nbytes;
247 
248 	nbytes = crypto_hash_walk_first(req, &walk);
249 	if (!nbytes)
250 		return crypto_shash_final(desc, req->result);
251 
252 	do {
253 		nbytes = crypto_hash_walk_last(&walk) ?
254 			 crypto_shash_finup(desc, walk.data, nbytes,
255 					    req->result) :
256 			 crypto_shash_update(desc, walk.data, nbytes);
257 		nbytes = crypto_hash_walk_done(&walk, nbytes);
258 	} while (nbytes > 0);
259 
260 	return nbytes;
261 }
262 EXPORT_SYMBOL_GPL(shash_ahash_finup);
263 
264 static int shash_async_finup(struct ahash_request *req)
265 {
266 	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
267 	struct shash_desc *desc = ahash_request_ctx(req);
268 
269 	desc->tfm = *ctx;
270 	desc->flags = req->base.flags;
271 
272 	return shash_ahash_finup(req, desc);
273 }
274 
275 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
276 {
277 	struct scatterlist *sg = req->src;
278 	unsigned int offset = sg->offset;
279 	unsigned int nbytes = req->nbytes;
280 	int err;
281 
282 	if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
283 		void *data;
284 
285 		data = kmap_atomic(sg_page(sg));
286 		err = crypto_shash_digest(desc, data + offset, nbytes,
287 					  req->result);
288 		kunmap_atomic(data);
289 		crypto_yield(desc->flags);
290 	} else
291 		err = crypto_shash_init(desc) ?:
292 		      shash_ahash_finup(req, desc);
293 
294 	return err;
295 }
296 EXPORT_SYMBOL_GPL(shash_ahash_digest);
297 
298 static int shash_async_digest(struct ahash_request *req)
299 {
300 	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
301 	struct shash_desc *desc = ahash_request_ctx(req);
302 
303 	desc->tfm = *ctx;
304 	desc->flags = req->base.flags;
305 
306 	return shash_ahash_digest(req, desc);
307 }
308 
309 static int shash_async_export(struct ahash_request *req, void *out)
310 {
311 	return crypto_shash_export(ahash_request_ctx(req), out);
312 }
313 
314 static int shash_async_import(struct ahash_request *req, const void *in)
315 {
316 	struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
317 	struct shash_desc *desc = ahash_request_ctx(req);
318 
319 	desc->tfm = *ctx;
320 	desc->flags = req->base.flags;
321 
322 	return crypto_shash_import(desc, in);
323 }
324 
325 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
326 {
327 	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
328 
329 	crypto_free_shash(*ctx);
330 }
331 
332 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
333 {
334 	struct crypto_alg *calg = tfm->__crt_alg;
335 	struct shash_alg *alg = __crypto_shash_alg(calg);
336 	struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
337 	struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
338 	struct crypto_shash *shash;
339 
340 	if (!crypto_mod_get(calg))
341 		return -EAGAIN;
342 
343 	shash = crypto_create_tfm(calg, &crypto_shash_type);
344 	if (IS_ERR(shash)) {
345 		crypto_mod_put(calg);
346 		return PTR_ERR(shash);
347 	}
348 
349 	*ctx = shash;
350 	tfm->exit = crypto_exit_shash_ops_async;
351 
352 	crt->init = shash_async_init;
353 	crt->update = shash_async_update;
354 	crt->final = shash_async_final;
355 	crt->finup = shash_async_finup;
356 	crt->digest = shash_async_digest;
357 	crt->setkey = shash_async_setkey;
358 
359 	crt->has_setkey = alg->setkey != shash_no_setkey;
360 
361 	if (alg->export)
362 		crt->export = shash_async_export;
363 	if (alg->import)
364 		crt->import = shash_async_import;
365 
366 	crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
367 
368 	return 0;
369 }
370 
371 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
372 			       unsigned int keylen)
373 {
374 	struct shash_desc **descp = crypto_hash_ctx(tfm);
375 	struct shash_desc *desc = *descp;
376 
377 	return crypto_shash_setkey(desc->tfm, key, keylen);
378 }
379 
380 static int shash_compat_init(struct hash_desc *hdesc)
381 {
382 	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
383 	struct shash_desc *desc = *descp;
384 
385 	desc->flags = hdesc->flags;
386 
387 	return crypto_shash_init(desc);
388 }
389 
390 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
391 			       unsigned int len)
392 {
393 	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
394 	struct shash_desc *desc = *descp;
395 	struct crypto_hash_walk walk;
396 	int nbytes;
397 
398 	for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
399 	     nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
400 		nbytes = crypto_shash_update(desc, walk.data, nbytes);
401 
402 	return nbytes;
403 }
404 
405 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
406 {
407 	struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
408 
409 	return crypto_shash_final(*descp, out);
410 }
411 
412 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
413 			       unsigned int nbytes, u8 *out)
414 {
415 	unsigned int offset = sg->offset;
416 	int err;
417 
418 	if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
419 		struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
420 		struct shash_desc *desc = *descp;
421 		void *data;
422 
423 		desc->flags = hdesc->flags;
424 
425 		data = kmap_atomic(sg_page(sg));
426 		err = crypto_shash_digest(desc, data + offset, nbytes, out);
427 		kunmap_atomic(data);
428 		crypto_yield(desc->flags);
429 		goto out;
430 	}
431 
432 	err = shash_compat_init(hdesc);
433 	if (err)
434 		goto out;
435 
436 	err = shash_compat_update(hdesc, sg, nbytes);
437 	if (err)
438 		goto out;
439 
440 	err = shash_compat_final(hdesc, out);
441 
442 out:
443 	return err;
444 }
445 
446 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
447 {
448 	struct shash_desc **descp = crypto_tfm_ctx(tfm);
449 	struct shash_desc *desc = *descp;
450 
451 	crypto_free_shash(desc->tfm);
452 	kzfree(desc);
453 }
454 
455 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
456 {
457 	struct hash_tfm *crt = &tfm->crt_hash;
458 	struct crypto_alg *calg = tfm->__crt_alg;
459 	struct shash_alg *alg = __crypto_shash_alg(calg);
460 	struct shash_desc **descp = crypto_tfm_ctx(tfm);
461 	struct crypto_shash *shash;
462 	struct shash_desc *desc;
463 
464 	if (!crypto_mod_get(calg))
465 		return -EAGAIN;
466 
467 	shash = crypto_create_tfm(calg, &crypto_shash_type);
468 	if (IS_ERR(shash)) {
469 		crypto_mod_put(calg);
470 		return PTR_ERR(shash);
471 	}
472 
473 	desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
474 		       GFP_KERNEL);
475 	if (!desc) {
476 		crypto_free_shash(shash);
477 		return -ENOMEM;
478 	}
479 
480 	*descp = desc;
481 	desc->tfm = shash;
482 	tfm->exit = crypto_exit_shash_ops_compat;
483 
484 	crt->init = shash_compat_init;
485 	crt->update = shash_compat_update;
486 	crt->final  = shash_compat_final;
487 	crt->digest = shash_compat_digest;
488 	crt->setkey = shash_compat_setkey;
489 
490 	crt->digestsize = alg->digestsize;
491 
492 	return 0;
493 }
494 
495 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
496 {
497 	switch (mask & CRYPTO_ALG_TYPE_MASK) {
498 	case CRYPTO_ALG_TYPE_HASH_MASK:
499 		return crypto_init_shash_ops_compat(tfm);
500 	}
501 
502 	return -EINVAL;
503 }
504 
505 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
506 					 u32 mask)
507 {
508 	switch (mask & CRYPTO_ALG_TYPE_MASK) {
509 	case CRYPTO_ALG_TYPE_HASH_MASK:
510 		return sizeof(struct shash_desc *);
511 	}
512 
513 	return 0;
514 }
515 
516 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
517 {
518 	struct crypto_shash *hash = __crypto_shash_cast(tfm);
519 
520 	hash->descsize = crypto_shash_alg(hash)->descsize;
521 	return 0;
522 }
523 
524 #ifdef CONFIG_NET
525 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
526 {
527 	struct crypto_report_hash rhash;
528 	struct shash_alg *salg = __crypto_shash_alg(alg);
529 
530 	strncpy(rhash.type, "shash", sizeof(rhash.type));
531 
532 	rhash.blocksize = alg->cra_blocksize;
533 	rhash.digestsize = salg->digestsize;
534 
535 	if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
536 		    sizeof(struct crypto_report_hash), &rhash))
537 		goto nla_put_failure;
538 	return 0;
539 
540 nla_put_failure:
541 	return -EMSGSIZE;
542 }
543 #else
544 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
545 {
546 	return -ENOSYS;
547 }
548 #endif
549 
550 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
551 	__attribute__ ((unused));
552 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
553 {
554 	struct shash_alg *salg = __crypto_shash_alg(alg);
555 
556 	seq_printf(m, "type         : shash\n");
557 	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
558 	seq_printf(m, "digestsize   : %u\n", salg->digestsize);
559 }
560 
561 static const struct crypto_type crypto_shash_type = {
562 	.ctxsize = crypto_shash_ctxsize,
563 	.extsize = crypto_alg_extsize,
564 	.init = crypto_init_shash_ops,
565 	.init_tfm = crypto_shash_init_tfm,
566 #ifdef CONFIG_PROC_FS
567 	.show = crypto_shash_show,
568 #endif
569 	.report = crypto_shash_report,
570 	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
571 	.maskset = CRYPTO_ALG_TYPE_MASK,
572 	.type = CRYPTO_ALG_TYPE_SHASH,
573 	.tfmsize = offsetof(struct crypto_shash, base),
574 };
575 
576 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
577 					u32 mask)
578 {
579 	return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
580 }
581 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
582 
583 static int shash_prepare_alg(struct shash_alg *alg)
584 {
585 	struct crypto_alg *base = &alg->base;
586 
587 	if (alg->digestsize > PAGE_SIZE / 8 ||
588 	    alg->descsize > PAGE_SIZE / 8 ||
589 	    alg->statesize > PAGE_SIZE / 8)
590 		return -EINVAL;
591 
592 	base->cra_type = &crypto_shash_type;
593 	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
594 	base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
595 
596 	if (!alg->finup)
597 		alg->finup = shash_finup_unaligned;
598 	if (!alg->digest)
599 		alg->digest = shash_digest_unaligned;
600 	if (!alg->export) {
601 		alg->export = shash_default_export;
602 		alg->import = shash_default_import;
603 		alg->statesize = alg->descsize;
604 	}
605 	if (!alg->setkey)
606 		alg->setkey = shash_no_setkey;
607 
608 	return 0;
609 }
610 
611 int crypto_register_shash(struct shash_alg *alg)
612 {
613 	struct crypto_alg *base = &alg->base;
614 	int err;
615 
616 	err = shash_prepare_alg(alg);
617 	if (err)
618 		return err;
619 
620 	return crypto_register_alg(base);
621 }
622 EXPORT_SYMBOL_GPL(crypto_register_shash);
623 
624 int crypto_unregister_shash(struct shash_alg *alg)
625 {
626 	return crypto_unregister_alg(&alg->base);
627 }
628 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
629 
630 int crypto_register_shashes(struct shash_alg *algs, int count)
631 {
632 	int i, ret;
633 
634 	for (i = 0; i < count; i++) {
635 		ret = crypto_register_shash(&algs[i]);
636 		if (ret)
637 			goto err;
638 	}
639 
640 	return 0;
641 
642 err:
643 	for (--i; i >= 0; --i)
644 		crypto_unregister_shash(&algs[i]);
645 
646 	return ret;
647 }
648 EXPORT_SYMBOL_GPL(crypto_register_shashes);
649 
650 int crypto_unregister_shashes(struct shash_alg *algs, int count)
651 {
652 	int i, ret;
653 
654 	for (i = count - 1; i >= 0; --i) {
655 		ret = crypto_unregister_shash(&algs[i]);
656 		if (ret)
657 			pr_err("Failed to unregister %s %s: %d\n",
658 			       algs[i].base.cra_driver_name,
659 			       algs[i].base.cra_name, ret);
660 	}
661 
662 	return 0;
663 }
664 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
665 
666 int shash_register_instance(struct crypto_template *tmpl,
667 			    struct shash_instance *inst)
668 {
669 	int err;
670 
671 	err = shash_prepare_alg(&inst->alg);
672 	if (err)
673 		return err;
674 
675 	return crypto_register_instance(tmpl, shash_crypto_instance(inst));
676 }
677 EXPORT_SYMBOL_GPL(shash_register_instance);
678 
679 void shash_free_instance(struct crypto_instance *inst)
680 {
681 	crypto_drop_spawn(crypto_instance_ctx(inst));
682 	kfree(shash_instance(inst));
683 }
684 EXPORT_SYMBOL_GPL(shash_free_instance);
685 
686 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
687 			    struct shash_alg *alg,
688 			    struct crypto_instance *inst)
689 {
690 	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
691 				  &crypto_shash_type);
692 }
693 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
694 
695 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
696 {
697 	struct crypto_alg *alg;
698 
699 	alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
700 	return IS_ERR(alg) ? ERR_CAST(alg) :
701 	       container_of(alg, struct shash_alg, base);
702 }
703 EXPORT_SYMBOL_GPL(shash_attr_alg);
704 
705 MODULE_LICENSE("GPL");
706 MODULE_DESCRIPTION("Synchronous cryptographic hash type");
707