xref: /kernel/linux/linux-6.6/crypto/ahash.c (revision 62306a36) 
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
24static const struct crypto_type crypto_ahash_type;
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 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
55static 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
72int 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}
110EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
111
112int 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}
128EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
129
130static 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
150static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
151			  unsigned int keylen)
152{
153	return -ENOSYS;
154}
155
156static 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
165int 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}
184EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
185
186static 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
239static 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
252static 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
262out:
263	/* Complete the ORIGINAL request. */
264	ahash_request_complete(areq, err);
265}
266
267static 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
286static 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
302int 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}
312EXPORT_SYMBOL_GPL(crypto_ahash_final);
313
314int 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}
328EXPORT_SYMBOL_GPL(crypto_ahash_finup);
329
330int 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}
347EXPORT_SYMBOL_GPL(crypto_ahash_digest);
348
349static 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
361static 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
374out:
375	ahash_restore_req(req, err);
376	return err;
377}
378
379static 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
394out:
395	ahash_request_complete(areq, err);
396}
397
398static 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
414static 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
422static 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
453static 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
461static 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
468static 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
483static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
484	__maybe_unused;
485static 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
495static 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
501static 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
520int 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}
527EXPORT_SYMBOL_GPL(crypto_grab_ahash);
528
529struct 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}
534EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
535
536int 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}
540EXPORT_SYMBOL_GPL(crypto_has_ahash);
541
542struct 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
588out_free_nhash:
589	crypto_free_ahash(nhash);
590	return ERR_PTR(err);
591}
592EXPORT_SYMBOL_GPL(crypto_clone_ahash);
593
594static 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
612int 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}
623EXPORT_SYMBOL_GPL(crypto_register_ahash);
624
625void crypto_unregister_ahash(struct ahash_alg *alg)
626{
627	crypto_unregister_alg(&alg->halg.base);
628}
629EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
630
631int 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
643err:
644	for (--i; i >= 0; --i)
645		crypto_unregister_ahash(&algs[i]);
646
647	return ret;
648}
649EXPORT_SYMBOL_GPL(crypto_register_ahashes);
650
651void 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}
658EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
659
660int 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}
674EXPORT_SYMBOL_GPL(ahash_register_instance);
675
676bool 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}
685EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
686
687MODULE_LICENSE("GPL");
688MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
689