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v5.4
  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/internal/hash.h>
 12#include <crypto/scatterwalk.h>
 13#include <linux/bug.h>
 14#include <linux/err.h>
 15#include <linux/kernel.h>
 16#include <linux/module.h>
 17#include <linux/sched.h>
 18#include <linux/slab.h>
 19#include <linux/seq_file.h>
 20#include <linux/cryptouser.h>
 21#include <linux/compiler.h>
 22#include <net/netlink.h>
 23
 24#include "internal.h"
 25
 26struct 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
 34static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
 35{
 36	return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
 37			    halg);
 38}
 39
 40static int hash_walk_next(struct crypto_hash_walk *walk)
 41{
 42	unsigned int alignmask = walk->alignmask;
 43	unsigned int offset = walk->offset;
 44	unsigned int nbytes = min(walk->entrylen,
 45				  ((unsigned int)(PAGE_SIZE)) - offset);
 46
 47	if (walk->flags & CRYPTO_ALG_ASYNC)
 48		walk->data = kmap(walk->pg);
 49	else
 50		walk->data = kmap_atomic(walk->pg);
 51	walk->data += offset;
 52
 53	if (offset & alignmask) {
 54		unsigned int unaligned = alignmask + 1 - (offset & alignmask);
 55
 56		if (nbytes > unaligned)
 57			nbytes = unaligned;
 58	}
 59
 60	walk->entrylen -= nbytes;
 61	return nbytes;
 62}
 63
 64static int hash_walk_new_entry(struct crypto_hash_walk *walk)
 65{
 66	struct scatterlist *sg;
 67
 68	sg = walk->sg;
 69	walk->offset = sg->offset;
 70	walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
 71	walk->offset = offset_in_page(walk->offset);
 72	walk->entrylen = sg->length;
 73
 74	if (walk->entrylen > walk->total)
 75		walk->entrylen = walk->total;
 76	walk->total -= walk->entrylen;
 77
 78	return hash_walk_next(walk);
 79}
 80
 81int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
 82{
 83	unsigned int alignmask = walk->alignmask;
 84
 85	walk->data -= walk->offset;
 86
 87	if (walk->entrylen && (walk->offset & alignmask) && !err) {
 88		unsigned int nbytes;
 89
 90		walk->offset = ALIGN(walk->offset, alignmask + 1);
 91		nbytes = min(walk->entrylen,
 92			     (unsigned int)(PAGE_SIZE - walk->offset));
 93		if (nbytes) {
 94			walk->entrylen -= nbytes;
 95			walk->data += walk->offset;
 96			return nbytes;
 97		}
 98	}
 99
100	if (walk->flags & CRYPTO_ALG_ASYNC)
101		kunmap(walk->pg);
102	else {
103		kunmap_atomic(walk->data);
104		/*
105		 * The may sleep test only makes sense for sync users.
106		 * Async users don't need to sleep here anyway.
107		 */
108		crypto_yield(walk->flags);
109	}
110
111	if (err)
112		return err;
113
114	if (walk->entrylen) {
115		walk->offset = 0;
116		walk->pg++;
117		return hash_walk_next(walk);
118	}
119
120	if (!walk->total)
121		return 0;
122
123	walk->sg = sg_next(walk->sg);
124
125	return hash_walk_new_entry(walk);
126}
127EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
128
129int crypto_hash_walk_first(struct ahash_request *req,
130			   struct crypto_hash_walk *walk)
131{
132	walk->total = req->nbytes;
133
134	if (!walk->total) {
135		walk->entrylen = 0;
136		return 0;
137	}
138
139	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
140	walk->sg = req->src;
141	walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
142
143	return hash_walk_new_entry(walk);
144}
145EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
146
147int crypto_ahash_walk_first(struct ahash_request *req,
148			    struct crypto_hash_walk *walk)
149{
150	walk->total = req->nbytes;
151
152	if (!walk->total) {
153		walk->entrylen = 0;
154		return 0;
155	}
156
157	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
158	walk->sg = req->src;
159	walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
160	walk->flags |= CRYPTO_ALG_ASYNC;
161
162	BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
163
164	return hash_walk_new_entry(walk);
165}
166EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
167
168static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
169				unsigned int keylen)
170{
171	unsigned long alignmask = crypto_ahash_alignmask(tfm);
172	int ret;
173	u8 *buffer, *alignbuffer;
174	unsigned long absize;
175
176	absize = keylen + alignmask;
177	buffer = kmalloc(absize, GFP_KERNEL);
178	if (!buffer)
179		return -ENOMEM;
180
181	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
182	memcpy(alignbuffer, key, keylen);
183	ret = tfm->setkey(tfm, alignbuffer, keylen);
184	kzfree(buffer);
185	return ret;
186}
187
188static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
189			  unsigned int keylen)
190{
191	return -ENOSYS;
192}
193
194static void ahash_set_needkey(struct crypto_ahash *tfm)
195{
196	const struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
197
198	if (tfm->setkey != ahash_nosetkey &&
199	    !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
200		crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
201}
202
203int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
204			unsigned int keylen)
205{
206	unsigned long alignmask = crypto_ahash_alignmask(tfm);
207	int err;
208
209	if ((unsigned long)key & alignmask)
210		err = ahash_setkey_unaligned(tfm, key, keylen);
211	else
212		err = tfm->setkey(tfm, key, keylen);
213
214	if (unlikely(err)) {
215		ahash_set_needkey(tfm);
216		return err;
217	}
218
219	crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
220	return 0;
221}
222EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
223
224static inline unsigned int ahash_align_buffer_size(unsigned len,
225						   unsigned long mask)
226{
227	return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
228}
229
230static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
231{
232	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
233	unsigned long alignmask = crypto_ahash_alignmask(tfm);
234	unsigned int ds = crypto_ahash_digestsize(tfm);
235	struct ahash_request_priv *priv;
236
237	priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
238		       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
239		       GFP_KERNEL : GFP_ATOMIC);
240	if (!priv)
241		return -ENOMEM;
242
243	/*
244	 * WARNING: Voodoo programming below!
245	 *
246	 * The code below is obscure and hard to understand, thus explanation
247	 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
248	 * to understand the layout of structures used here!
249	 *
250	 * The code here will replace portions of the ORIGINAL request with
251	 * pointers to new code and buffers so the hashing operation can store
252	 * the result in aligned buffer. We will call the modified request
253	 * an ADJUSTED request.
254	 *
255	 * The newly mangled request will look as such:
256	 *
257	 * req {
258	 *   .result        = ADJUSTED[new aligned buffer]
259	 *   .base.complete = ADJUSTED[pointer to completion function]
260	 *   .base.data     = ADJUSTED[*req (pointer to self)]
261	 *   .priv          = ADJUSTED[new priv] {
262	 *           .result   = ORIGINAL(result)
263	 *           .complete = ORIGINAL(base.complete)
264	 *           .data     = ORIGINAL(base.data)
265	 *   }
266	 */
267
268	priv->result = req->result;
269	priv->complete = req->base.complete;
270	priv->data = req->base.data;
271	priv->flags = req->base.flags;
272
273	/*
274	 * WARNING: We do not backup req->priv here! The req->priv
275	 *          is for internal use of the Crypto API and the
276	 *          user must _NOT_ _EVER_ depend on it's content!
277	 */
278
279	req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
280	req->base.complete = cplt;
281	req->base.data = req;
282	req->priv = priv;
283
284	return 0;
285}
286
287static void ahash_restore_req(struct ahash_request *req, int err)
288{
289	struct ahash_request_priv *priv = req->priv;
290
291	if (!err)
292		memcpy(priv->result, req->result,
293		       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
294
295	/* Restore the original crypto request. */
296	req->result = priv->result;
297
298	ahash_request_set_callback(req, priv->flags,
299				   priv->complete, priv->data);
300	req->priv = NULL;
301
302	/* Free the req->priv.priv from the ADJUSTED request. */
303	kzfree(priv);
304}
305
306static void ahash_notify_einprogress(struct ahash_request *req)
307{
308	struct ahash_request_priv *priv = req->priv;
309	struct crypto_async_request oreq;
310
311	oreq.data = priv->data;
312
313	priv->complete(&oreq, -EINPROGRESS);
314}
315
316static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
317{
318	struct ahash_request *areq = req->data;
319
320	if (err == -EINPROGRESS) {
321		ahash_notify_einprogress(areq);
322		return;
323	}
324
325	/*
326	 * Restore the original request, see ahash_op_unaligned() for what
327	 * goes where.
328	 *
329	 * The "struct ahash_request *req" here is in fact the "req.base"
330	 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
331	 * is a pointer to self, it is also the ADJUSTED "req" .
332	 */
333
334	/* First copy req->result into req->priv.result */
335	ahash_restore_req(areq, err);
336
337	/* Complete the ORIGINAL request. */
338	areq->base.complete(&areq->base, err);
339}
340
341static int ahash_op_unaligned(struct ahash_request *req,
342			      int (*op)(struct ahash_request *))
343{
344	int err;
345
346	err = ahash_save_req(req, ahash_op_unaligned_done);
347	if (err)
348		return err;
349
350	err = op(req);
351	if (err == -EINPROGRESS || err == -EBUSY)
352		return err;
353
354	ahash_restore_req(req, err);
355
356	return err;
357}
358
359static int crypto_ahash_op(struct ahash_request *req,
360			   int (*op)(struct ahash_request *))
361{
362	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
363	unsigned long alignmask = crypto_ahash_alignmask(tfm);
364
365	if ((unsigned long)req->result & alignmask)
366		return ahash_op_unaligned(req, op);
367
368	return op(req);
369}
370
371int crypto_ahash_final(struct ahash_request *req)
372{
373	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
374	struct crypto_alg *alg = tfm->base.__crt_alg;
375	unsigned int nbytes = req->nbytes;
376	int ret;
377
378	crypto_stats_get(alg);
379	ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
380	crypto_stats_ahash_final(nbytes, ret, alg);
381	return ret;
382}
383EXPORT_SYMBOL_GPL(crypto_ahash_final);
384
385int crypto_ahash_finup(struct ahash_request *req)
386{
387	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
388	struct crypto_alg *alg = tfm->base.__crt_alg;
389	unsigned int nbytes = req->nbytes;
390	int ret;
391
392	crypto_stats_get(alg);
393	ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
394	crypto_stats_ahash_final(nbytes, ret, alg);
395	return ret;
396}
397EXPORT_SYMBOL_GPL(crypto_ahash_finup);
398
399int crypto_ahash_digest(struct ahash_request *req)
400{
401	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
402	struct crypto_alg *alg = tfm->base.__crt_alg;
403	unsigned int nbytes = req->nbytes;
404	int ret;
405
406	crypto_stats_get(alg);
407	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
408		ret = -ENOKEY;
409	else
410		ret = crypto_ahash_op(req, tfm->digest);
411	crypto_stats_ahash_final(nbytes, ret, alg);
412	return ret;
413}
414EXPORT_SYMBOL_GPL(crypto_ahash_digest);
415
416static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
417{
418	struct ahash_request *areq = req->data;
419
420	if (err == -EINPROGRESS)
421		return;
422
423	ahash_restore_req(areq, err);
424
425	areq->base.complete(&areq->base, err);
426}
427
428static int ahash_def_finup_finish1(struct ahash_request *req, int err)
429{
430	if (err)
431		goto out;
432
433	req->base.complete = ahash_def_finup_done2;
434
435	err = crypto_ahash_reqtfm(req)->final(req);
436	if (err == -EINPROGRESS || err == -EBUSY)
437		return err;
438
439out:
440	ahash_restore_req(req, err);
441	return err;
442}
443
444static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
445{
446	struct ahash_request *areq = req->data;
447
448	if (err == -EINPROGRESS) {
449		ahash_notify_einprogress(areq);
450		return;
451	}
452
453	areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
454
455	err = ahash_def_finup_finish1(areq, err);
456	if (areq->priv)
457		return;
458
459	areq->base.complete(&areq->base, err);
460}
461
462static int ahash_def_finup(struct ahash_request *req)
463{
464	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
465	int err;
466
467	err = ahash_save_req(req, ahash_def_finup_done1);
468	if (err)
469		return err;
470
471	err = tfm->update(req);
472	if (err == -EINPROGRESS || err == -EBUSY)
473		return err;
474
475	return ahash_def_finup_finish1(req, err);
476}
477
478static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
479{
480	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
481	struct ahash_alg *alg = crypto_ahash_alg(hash);
482
483	hash->setkey = ahash_nosetkey;
484
485	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
486		return crypto_init_shash_ops_async(tfm);
487
488	hash->init = alg->init;
489	hash->update = alg->update;
490	hash->final = alg->final;
491	hash->finup = alg->finup ?: ahash_def_finup;
492	hash->digest = alg->digest;
493	hash->export = alg->export;
494	hash->import = alg->import;
495
496	if (alg->setkey) {
497		hash->setkey = alg->setkey;
498		ahash_set_needkey(hash);
499	}
500
501	return 0;
502}
503
504static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
505{
506	if (alg->cra_type != &crypto_ahash_type)
507		return sizeof(struct crypto_shash *);
508
509	return crypto_alg_extsize(alg);
510}
511
512#ifdef CONFIG_NET
513static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
514{
515	struct crypto_report_hash rhash;
516
517	memset(&rhash, 0, sizeof(rhash));
518
519	strscpy(rhash.type, "ahash", sizeof(rhash.type));
520
521	rhash.blocksize = alg->cra_blocksize;
522	rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
523
524	return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
525}
526#else
527static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
528{
529	return -ENOSYS;
530}
531#endif
532
533static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
534	__maybe_unused;
535static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
536{
537	seq_printf(m, "type         : ahash\n");
538	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
539					     "yes" : "no");
540	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
541	seq_printf(m, "digestsize   : %u\n",
542		   __crypto_hash_alg_common(alg)->digestsize);
543}
544
545const struct crypto_type crypto_ahash_type = {
546	.extsize = crypto_ahash_extsize,
547	.init_tfm = crypto_ahash_init_tfm,
548#ifdef CONFIG_PROC_FS
549	.show = crypto_ahash_show,
550#endif
551	.report = crypto_ahash_report,
552	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
553	.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
554	.type = CRYPTO_ALG_TYPE_AHASH,
555	.tfmsize = offsetof(struct crypto_ahash, base),
556};
557EXPORT_SYMBOL_GPL(crypto_ahash_type);
558
559struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
560					u32 mask)
561{
562	return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
563}
564EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
565
566int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
567{
568	return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
569}
570EXPORT_SYMBOL_GPL(crypto_has_ahash);
571
572static int ahash_prepare_alg(struct ahash_alg *alg)
573{
574	struct crypto_alg *base = &alg->halg.base;
575
576	if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE ||
577	    alg->halg.statesize > HASH_MAX_STATESIZE ||
578	    alg->halg.statesize == 0)
579		return -EINVAL;
580
581	base->cra_type = &crypto_ahash_type;
582	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
583	base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
584
585	return 0;
586}
587
588int crypto_register_ahash(struct ahash_alg *alg)
589{
590	struct crypto_alg *base = &alg->halg.base;
591	int err;
592
593	err = ahash_prepare_alg(alg);
594	if (err)
595		return err;
596
597	return crypto_register_alg(base);
598}
599EXPORT_SYMBOL_GPL(crypto_register_ahash);
600
601int crypto_unregister_ahash(struct ahash_alg *alg)
602{
603	return crypto_unregister_alg(&alg->halg.base);
604}
605EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
606
607int crypto_register_ahashes(struct ahash_alg *algs, int count)
608{
609	int i, ret;
610
611	for (i = 0; i < count; i++) {
612		ret = crypto_register_ahash(&algs[i]);
613		if (ret)
614			goto err;
615	}
616
617	return 0;
618
619err:
620	for (--i; i >= 0; --i)
621		crypto_unregister_ahash(&algs[i]);
622
623	return ret;
624}
625EXPORT_SYMBOL_GPL(crypto_register_ahashes);
626
627void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
628{
629	int i;
630
631	for (i = count - 1; i >= 0; --i)
632		crypto_unregister_ahash(&algs[i]);
633}
634EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
635
636int ahash_register_instance(struct crypto_template *tmpl,
637			    struct ahash_instance *inst)
638{
639	int err;
640
641	err = ahash_prepare_alg(&inst->alg);
642	if (err)
643		return err;
644
645	return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
646}
647EXPORT_SYMBOL_GPL(ahash_register_instance);
648
649void ahash_free_instance(struct crypto_instance *inst)
650{
651	crypto_drop_spawn(crypto_instance_ctx(inst));
652	kfree(ahash_instance(inst));
653}
654EXPORT_SYMBOL_GPL(ahash_free_instance);
655
656int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
657			    struct hash_alg_common *alg,
658			    struct crypto_instance *inst)
659{
660	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
661				  &crypto_ahash_type);
662}
663EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
664
665struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
666{
667	struct crypto_alg *alg;
668
669	alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
670	return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
671}
672EXPORT_SYMBOL_GPL(ahash_attr_alg);
673
674bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
675{
676	struct crypto_alg *alg = &halg->base;
677
678	if (alg->cra_type != &crypto_ahash_type)
679		return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
680
681	return __crypto_ahash_alg(alg)->setkey != NULL;
682}
683EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
684
685MODULE_LICENSE("GPL");
686MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
v5.4
  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/internal/hash.h>
 12#include <crypto/scatterwalk.h>
 13#include <linux/bug.h>
 14#include <linux/err.h>
 15#include <linux/kernel.h>
 16#include <linux/module.h>
 17#include <linux/sched.h>
 18#include <linux/slab.h>
 19#include <linux/seq_file.h>
 20#include <linux/cryptouser.h>
 21#include <linux/compiler.h>
 22#include <net/netlink.h>
 23
 24#include "internal.h"
 25
 26struct 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
 34static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
 35{
 36	return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
 37			    halg);
 38}
 39
 40static int hash_walk_next(struct crypto_hash_walk *walk)
 41{
 42	unsigned int alignmask = walk->alignmask;
 43	unsigned int offset = walk->offset;
 44	unsigned int nbytes = min(walk->entrylen,
 45				  ((unsigned int)(PAGE_SIZE)) - offset);
 46
 47	if (walk->flags & CRYPTO_ALG_ASYNC)
 48		walk->data = kmap(walk->pg);
 49	else
 50		walk->data = kmap_atomic(walk->pg);
 51	walk->data += offset;
 52
 53	if (offset & alignmask) {
 54		unsigned int unaligned = alignmask + 1 - (offset & alignmask);
 55
 56		if (nbytes > unaligned)
 57			nbytes = unaligned;
 58	}
 59
 60	walk->entrylen -= nbytes;
 61	return nbytes;
 62}
 63
 64static int hash_walk_new_entry(struct crypto_hash_walk *walk)
 65{
 66	struct scatterlist *sg;
 67
 68	sg = walk->sg;
 69	walk->offset = sg->offset;
 70	walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
 71	walk->offset = offset_in_page(walk->offset);
 72	walk->entrylen = sg->length;
 73
 74	if (walk->entrylen > walk->total)
 75		walk->entrylen = walk->total;
 76	walk->total -= walk->entrylen;
 77
 78	return hash_walk_next(walk);
 79}
 80
 81int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
 82{
 83	unsigned int alignmask = walk->alignmask;
 84
 85	walk->data -= walk->offset;
 86
 87	if (walk->entrylen && (walk->offset & alignmask) && !err) {
 88		unsigned int nbytes;
 89
 90		walk->offset = ALIGN(walk->offset, alignmask + 1);
 91		nbytes = min(walk->entrylen,
 92			     (unsigned int)(PAGE_SIZE - walk->offset));
 93		if (nbytes) {
 94			walk->entrylen -= nbytes;
 95			walk->data += walk->offset;
 96			return nbytes;
 97		}
 98	}
 99
100	if (walk->flags & CRYPTO_ALG_ASYNC)
101		kunmap(walk->pg);
102	else {
103		kunmap_atomic(walk->data);
104		/*
105		 * The may sleep test only makes sense for sync users.
106		 * Async users don't need to sleep here anyway.
107		 */
108		crypto_yield(walk->flags);
109	}
110
111	if (err)
112		return err;
113
114	if (walk->entrylen) {
115		walk->offset = 0;
116		walk->pg++;
117		return hash_walk_next(walk);
118	}
119
120	if (!walk->total)
121		return 0;
122
123	walk->sg = sg_next(walk->sg);
124
125	return hash_walk_new_entry(walk);
126}
127EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
128
129int crypto_hash_walk_first(struct ahash_request *req,
130			   struct crypto_hash_walk *walk)
131{
132	walk->total = req->nbytes;
133
134	if (!walk->total) {
135		walk->entrylen = 0;
136		return 0;
137	}
138
139	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
140	walk->sg = req->src;
141	walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
142
143	return hash_walk_new_entry(walk);
144}
145EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
146
147int crypto_ahash_walk_first(struct ahash_request *req,
148			    struct crypto_hash_walk *walk)
149{
150	walk->total = req->nbytes;
151
152	if (!walk->total) {
153		walk->entrylen = 0;
154		return 0;
155	}
156
157	walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
158	walk->sg = req->src;
159	walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
160	walk->flags |= CRYPTO_ALG_ASYNC;
161
162	BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
163
164	return hash_walk_new_entry(walk);
165}
166EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
167
168static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
169				unsigned int keylen)
170{
171	unsigned long alignmask = crypto_ahash_alignmask(tfm);
172	int ret;
173	u8 *buffer, *alignbuffer;
174	unsigned long absize;
175
176	absize = keylen + alignmask;
177	buffer = kmalloc(absize, GFP_KERNEL);
178	if (!buffer)
179		return -ENOMEM;
180
181	alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
182	memcpy(alignbuffer, key, keylen);
183	ret = tfm->setkey(tfm, alignbuffer, keylen);
184	kzfree(buffer);
185	return ret;
186}
187
188static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
189			  unsigned int keylen)
190{
191	return -ENOSYS;
192}
193
194static void ahash_set_needkey(struct crypto_ahash *tfm)
195{
196	const struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
197
198	if (tfm->setkey != ahash_nosetkey &&
199	    !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
200		crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
201}
202
203int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
204			unsigned int keylen)
205{
206	unsigned long alignmask = crypto_ahash_alignmask(tfm);
207	int err;
208
209	if ((unsigned long)key & alignmask)
210		err = ahash_setkey_unaligned(tfm, key, keylen);
211	else
212		err = tfm->setkey(tfm, key, keylen);
213
214	if (unlikely(err)) {
215		ahash_set_needkey(tfm);
216		return err;
217	}
218
219	crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
220	return 0;
221}
222EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
223
224static inline unsigned int ahash_align_buffer_size(unsigned len,
225						   unsigned long mask)
226{
227	return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
228}
229
230static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
231{
232	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
233	unsigned long alignmask = crypto_ahash_alignmask(tfm);
234	unsigned int ds = crypto_ahash_digestsize(tfm);
235	struct ahash_request_priv *priv;
236
237	priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
238		       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
239		       GFP_KERNEL : GFP_ATOMIC);
240	if (!priv)
241		return -ENOMEM;
242
243	/*
244	 * WARNING: Voodoo programming below!
245	 *
246	 * The code below is obscure and hard to understand, thus explanation
247	 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
248	 * to understand the layout of structures used here!
249	 *
250	 * The code here will replace portions of the ORIGINAL request with
251	 * pointers to new code and buffers so the hashing operation can store
252	 * the result in aligned buffer. We will call the modified request
253	 * an ADJUSTED request.
254	 *
255	 * The newly mangled request will look as such:
256	 *
257	 * req {
258	 *   .result        = ADJUSTED[new aligned buffer]
259	 *   .base.complete = ADJUSTED[pointer to completion function]
260	 *   .base.data     = ADJUSTED[*req (pointer to self)]
261	 *   .priv          = ADJUSTED[new priv] {
262	 *           .result   = ORIGINAL(result)
263	 *           .complete = ORIGINAL(base.complete)
264	 *           .data     = ORIGINAL(base.data)
265	 *   }
266	 */
267
268	priv->result = req->result;
269	priv->complete = req->base.complete;
270	priv->data = req->base.data;
271	priv->flags = req->base.flags;
272
273	/*
274	 * WARNING: We do not backup req->priv here! The req->priv
275	 *          is for internal use of the Crypto API and the
276	 *          user must _NOT_ _EVER_ depend on it's content!
277	 */
278
279	req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
280	req->base.complete = cplt;
281	req->base.data = req;
282	req->priv = priv;
283
284	return 0;
285}
286
287static void ahash_restore_req(struct ahash_request *req, int err)
288{
289	struct ahash_request_priv *priv = req->priv;
290
291	if (!err)
292		memcpy(priv->result, req->result,
293		       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
294
295	/* Restore the original crypto request. */
296	req->result = priv->result;
297
298	ahash_request_set_callback(req, priv->flags,
299				   priv->complete, priv->data);
300	req->priv = NULL;
301
302	/* Free the req->priv.priv from the ADJUSTED request. */
303	kzfree(priv);
304}
305
306static void ahash_notify_einprogress(struct ahash_request *req)
307{
308	struct ahash_request_priv *priv = req->priv;
309	struct crypto_async_request oreq;
310
311	oreq.data = priv->data;
312
313	priv->complete(&oreq, -EINPROGRESS);
314}
315
316static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
317{
318	struct ahash_request *areq = req->data;
319
320	if (err == -EINPROGRESS) {
321		ahash_notify_einprogress(areq);
322		return;
323	}
324
325	/*
326	 * Restore the original request, see ahash_op_unaligned() for what
327	 * goes where.
328	 *
329	 * The "struct ahash_request *req" here is in fact the "req.base"
330	 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
331	 * is a pointer to self, it is also the ADJUSTED "req" .
332	 */
333
334	/* First copy req->result into req->priv.result */
335	ahash_restore_req(areq, err);
336
337	/* Complete the ORIGINAL request. */
338	areq->base.complete(&areq->base, err);
339}
340
341static int ahash_op_unaligned(struct ahash_request *req,
342			      int (*op)(struct ahash_request *))
343{
344	int err;
345
346	err = ahash_save_req(req, ahash_op_unaligned_done);
347	if (err)
348		return err;
349
350	err = op(req);
351	if (err == -EINPROGRESS || err == -EBUSY)
352		return err;
353
354	ahash_restore_req(req, err);
355
356	return err;
357}
358
359static int crypto_ahash_op(struct ahash_request *req,
360			   int (*op)(struct ahash_request *))
361{
362	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
363	unsigned long alignmask = crypto_ahash_alignmask(tfm);
364
365	if ((unsigned long)req->result & alignmask)
366		return ahash_op_unaligned(req, op);
367
368	return op(req);
369}
370
371int crypto_ahash_final(struct ahash_request *req)
372{
373	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
374	struct crypto_alg *alg = tfm->base.__crt_alg;
375	unsigned int nbytes = req->nbytes;
376	int ret;
377
378	crypto_stats_get(alg);
379	ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
380	crypto_stats_ahash_final(nbytes, ret, alg);
381	return ret;
382}
383EXPORT_SYMBOL_GPL(crypto_ahash_final);
384
385int crypto_ahash_finup(struct ahash_request *req)
386{
387	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
388	struct crypto_alg *alg = tfm->base.__crt_alg;
389	unsigned int nbytes = req->nbytes;
390	int ret;
391
392	crypto_stats_get(alg);
393	ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
394	crypto_stats_ahash_final(nbytes, ret, alg);
395	return ret;
396}
397EXPORT_SYMBOL_GPL(crypto_ahash_finup);
398
399int crypto_ahash_digest(struct ahash_request *req)
400{
401	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
402	struct crypto_alg *alg = tfm->base.__crt_alg;
403	unsigned int nbytes = req->nbytes;
404	int ret;
405
406	crypto_stats_get(alg);
407	if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
408		ret = -ENOKEY;
409	else
410		ret = crypto_ahash_op(req, tfm->digest);
411	crypto_stats_ahash_final(nbytes, ret, alg);
412	return ret;
413}
414EXPORT_SYMBOL_GPL(crypto_ahash_digest);
415
416static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
417{
418	struct ahash_request *areq = req->data;
419
420	if (err == -EINPROGRESS)
421		return;
422
423	ahash_restore_req(areq, err);
424
425	areq->base.complete(&areq->base, err);
426}
427
428static int ahash_def_finup_finish1(struct ahash_request *req, int err)
429{
430	if (err)
431		goto out;
432
433	req->base.complete = ahash_def_finup_done2;
434
435	err = crypto_ahash_reqtfm(req)->final(req);
436	if (err == -EINPROGRESS || err == -EBUSY)
437		return err;
438
439out:
440	ahash_restore_req(req, err);
441	return err;
442}
443
444static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
445{
446	struct ahash_request *areq = req->data;
447
448	if (err == -EINPROGRESS) {
449		ahash_notify_einprogress(areq);
450		return;
451	}
452
453	areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
454
455	err = ahash_def_finup_finish1(areq, err);
456	if (areq->priv)
457		return;
458
459	areq->base.complete(&areq->base, err);
460}
461
462static int ahash_def_finup(struct ahash_request *req)
463{
464	struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
465	int err;
466
467	err = ahash_save_req(req, ahash_def_finup_done1);
468	if (err)
469		return err;
470
471	err = tfm->update(req);
472	if (err == -EINPROGRESS || err == -EBUSY)
473		return err;
474
475	return ahash_def_finup_finish1(req, err);
476}
477
478static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
479{
480	struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
481	struct ahash_alg *alg = crypto_ahash_alg(hash);
482
483	hash->setkey = ahash_nosetkey;
484
485	if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
486		return crypto_init_shash_ops_async(tfm);
487
488	hash->init = alg->init;
489	hash->update = alg->update;
490	hash->final = alg->final;
491	hash->finup = alg->finup ?: ahash_def_finup;
492	hash->digest = alg->digest;
493	hash->export = alg->export;
494	hash->import = alg->import;
495
496	if (alg->setkey) {
497		hash->setkey = alg->setkey;
498		ahash_set_needkey(hash);
499	}
500
501	return 0;
502}
503
504static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
505{
506	if (alg->cra_type != &crypto_ahash_type)
507		return sizeof(struct crypto_shash *);
508
509	return crypto_alg_extsize(alg);
510}
511
512#ifdef CONFIG_NET
513static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
514{
515	struct crypto_report_hash rhash;
516
517	memset(&rhash, 0, sizeof(rhash));
518
519	strscpy(rhash.type, "ahash", sizeof(rhash.type));
520
521	rhash.blocksize = alg->cra_blocksize;
522	rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
523
524	return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
525}
526#else
527static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
528{
529	return -ENOSYS;
530}
531#endif
532
533static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
534	__maybe_unused;
535static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
536{
537	seq_printf(m, "type         : ahash\n");
538	seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
539					     "yes" : "no");
540	seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
541	seq_printf(m, "digestsize   : %u\n",
542		   __crypto_hash_alg_common(alg)->digestsize);
543}
544
545const struct crypto_type crypto_ahash_type = {
546	.extsize = crypto_ahash_extsize,
547	.init_tfm = crypto_ahash_init_tfm,
548#ifdef CONFIG_PROC_FS
549	.show = crypto_ahash_show,
550#endif
551	.report = crypto_ahash_report,
552	.maskclear = ~CRYPTO_ALG_TYPE_MASK,
553	.maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
554	.type = CRYPTO_ALG_TYPE_AHASH,
555	.tfmsize = offsetof(struct crypto_ahash, base),
556};
557EXPORT_SYMBOL_GPL(crypto_ahash_type);
558
559struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
560					u32 mask)
561{
562	return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
563}
564EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
565
566int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
567{
568	return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
569}
570EXPORT_SYMBOL_GPL(crypto_has_ahash);
571
572static int ahash_prepare_alg(struct ahash_alg *alg)
573{
574	struct crypto_alg *base = &alg->halg.base;
575
576	if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE ||
577	    alg->halg.statesize > HASH_MAX_STATESIZE ||
578	    alg->halg.statesize == 0)
579		return -EINVAL;
580
581	base->cra_type = &crypto_ahash_type;
582	base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
583	base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
584
585	return 0;
586}
587
588int crypto_register_ahash(struct ahash_alg *alg)
589{
590	struct crypto_alg *base = &alg->halg.base;
591	int err;
592
593	err = ahash_prepare_alg(alg);
594	if (err)
595		return err;
596
597	return crypto_register_alg(base);
598}
599EXPORT_SYMBOL_GPL(crypto_register_ahash);
600
601int crypto_unregister_ahash(struct ahash_alg *alg)
602{
603	return crypto_unregister_alg(&alg->halg.base);
604}
605EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
606
607int crypto_register_ahashes(struct ahash_alg *algs, int count)
608{
609	int i, ret;
610
611	for (i = 0; i < count; i++) {
612		ret = crypto_register_ahash(&algs[i]);
613		if (ret)
614			goto err;
615	}
616
617	return 0;
618
619err:
620	for (--i; i >= 0; --i)
621		crypto_unregister_ahash(&algs[i]);
622
623	return ret;
624}
625EXPORT_SYMBOL_GPL(crypto_register_ahashes);
626
627void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
628{
629	int i;
630
631	for (i = count - 1; i >= 0; --i)
632		crypto_unregister_ahash(&algs[i]);
633}
634EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
635
636int ahash_register_instance(struct crypto_template *tmpl,
637			    struct ahash_instance *inst)
638{
639	int err;
640
641	err = ahash_prepare_alg(&inst->alg);
642	if (err)
643		return err;
644
645	return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
646}
647EXPORT_SYMBOL_GPL(ahash_register_instance);
648
649void ahash_free_instance(struct crypto_instance *inst)
650{
651	crypto_drop_spawn(crypto_instance_ctx(inst));
652	kfree(ahash_instance(inst));
653}
654EXPORT_SYMBOL_GPL(ahash_free_instance);
655
656int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
657			    struct hash_alg_common *alg,
658			    struct crypto_instance *inst)
659{
660	return crypto_init_spawn2(&spawn->base, &alg->base, inst,
661				  &crypto_ahash_type);
662}
663EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
664
665struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
666{
667	struct crypto_alg *alg;
668
669	alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
670	return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
671}
672EXPORT_SYMBOL_GPL(ahash_attr_alg);
673
674bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
675{
676	struct crypto_alg *alg = &halg->base;
677
678	if (alg->cra_type != &crypto_ahash_type)
679		return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
680
681	return __crypto_ahash_alg(alg)->setkey != NULL;
682}
683EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
684
685MODULE_LICENSE("GPL");
686MODULE_DESCRIPTION("Asynchronous cryptographic hash type");