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1// SPDX-License-Identifier: GPL-2.0-or-later
2/*
3 * Asynchronous Cryptographic Hash operations.
4 *
5 * This is the implementation of the ahash (asynchronous hash) API. It differs
6 * from shash (synchronous hash) in that ahash supports asynchronous operations,
7 * and it hashes data from scatterlists instead of virtually addressed buffers.
8 *
9 * The ahash API provides access to both ahash and shash algorithms. The shash
10 * API only provides access to shash algorithms.
11 *
12 * Copyright (c) 2008 Loc Ho <lho@amcc.com>
13 */
14
15#include <crypto/scatterwalk.h>
16#include <linux/cryptouser.h>
17#include <linux/err.h>
18#include <linux/kernel.h>
19#include <linux/module.h>
20#include <linux/sched.h>
21#include <linux/slab.h>
22#include <linux/seq_file.h>
23#include <linux/string.h>
24#include <net/netlink.h>
25
26#include "hash.h"
27
28#define CRYPTO_ALG_TYPE_AHASH_MASK 0x0000000e
29
30/*
31 * For an ahash tfm that is using an shash algorithm (instead of an ahash
32 * algorithm), this returns the underlying shash tfm.
33 */
34static inline struct crypto_shash *ahash_to_shash(struct crypto_ahash *tfm)
35{
36 return *(struct crypto_shash **)crypto_ahash_ctx(tfm);
37}
38
39static inline struct shash_desc *prepare_shash_desc(struct ahash_request *req,
40 struct crypto_ahash *tfm)
41{
42 struct shash_desc *desc = ahash_request_ctx(req);
43
44 desc->tfm = ahash_to_shash(tfm);
45 return desc;
46}
47
48int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
49{
50 struct crypto_hash_walk walk;
51 int nbytes;
52
53 for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
54 nbytes = crypto_hash_walk_done(&walk, nbytes))
55 nbytes = crypto_shash_update(desc, walk.data, nbytes);
56
57 return nbytes;
58}
59EXPORT_SYMBOL_GPL(shash_ahash_update);
60
61int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
62{
63 struct crypto_hash_walk walk;
64 int nbytes;
65
66 nbytes = crypto_hash_walk_first(req, &walk);
67 if (!nbytes)
68 return crypto_shash_final(desc, req->result);
69
70 do {
71 nbytes = crypto_hash_walk_last(&walk) ?
72 crypto_shash_finup(desc, walk.data, nbytes,
73 req->result) :
74 crypto_shash_update(desc, walk.data, nbytes);
75 nbytes = crypto_hash_walk_done(&walk, nbytes);
76 } while (nbytes > 0);
77
78 return nbytes;
79}
80EXPORT_SYMBOL_GPL(shash_ahash_finup);
81
82int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
83{
84 unsigned int nbytes = req->nbytes;
85 struct scatterlist *sg;
86 unsigned int offset;
87 int err;
88
89 if (nbytes &&
90 (sg = req->src, offset = sg->offset,
91 nbytes <= min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
92 void *data;
93
94 data = kmap_local_page(sg_page(sg));
95 err = crypto_shash_digest(desc, data + offset, nbytes,
96 req->result);
97 kunmap_local(data);
98 } else
99 err = crypto_shash_init(desc) ?:
100 shash_ahash_finup(req, desc);
101
102 return err;
103}
104EXPORT_SYMBOL_GPL(shash_ahash_digest);
105
106static void crypto_exit_ahash_using_shash(struct crypto_tfm *tfm)
107{
108 struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
109
110 crypto_free_shash(*ctx);
111}
112
113static int crypto_init_ahash_using_shash(struct crypto_tfm *tfm)
114{
115 struct crypto_alg *calg = tfm->__crt_alg;
116 struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
117 struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
118 struct crypto_shash *shash;
119
120 if (!crypto_mod_get(calg))
121 return -EAGAIN;
122
123 shash = crypto_create_tfm(calg, &crypto_shash_type);
124 if (IS_ERR(shash)) {
125 crypto_mod_put(calg);
126 return PTR_ERR(shash);
127 }
128
129 crt->using_shash = true;
130 *ctx = shash;
131 tfm->exit = crypto_exit_ahash_using_shash;
132
133 crypto_ahash_set_flags(crt, crypto_shash_get_flags(shash) &
134 CRYPTO_TFM_NEED_KEY);
135 crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
136
137 return 0;
138}
139
140static int hash_walk_next(struct crypto_hash_walk *walk)
141{
142 unsigned int offset = walk->offset;
143 unsigned int nbytes = min(walk->entrylen,
144 ((unsigned int)(PAGE_SIZE)) - offset);
145
146 walk->data = kmap_local_page(walk->pg);
147 walk->data += offset;
148 walk->entrylen -= nbytes;
149 return nbytes;
150}
151
152static int hash_walk_new_entry(struct crypto_hash_walk *walk)
153{
154 struct scatterlist *sg;
155
156 sg = walk->sg;
157 walk->offset = sg->offset;
158 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
159 walk->offset = offset_in_page(walk->offset);
160 walk->entrylen = sg->length;
161
162 if (walk->entrylen > walk->total)
163 walk->entrylen = walk->total;
164 walk->total -= walk->entrylen;
165
166 return hash_walk_next(walk);
167}
168
169int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
170{
171 walk->data -= walk->offset;
172
173 kunmap_local(walk->data);
174 crypto_yield(walk->flags);
175
176 if (err)
177 return err;
178
179 if (walk->entrylen) {
180 walk->offset = 0;
181 walk->pg++;
182 return hash_walk_next(walk);
183 }
184
185 if (!walk->total)
186 return 0;
187
188 walk->sg = sg_next(walk->sg);
189
190 return hash_walk_new_entry(walk);
191}
192EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
193
194int crypto_hash_walk_first(struct ahash_request *req,
195 struct crypto_hash_walk *walk)
196{
197 walk->total = req->nbytes;
198
199 if (!walk->total) {
200 walk->entrylen = 0;
201 return 0;
202 }
203
204 walk->sg = req->src;
205 walk->flags = req->base.flags;
206
207 return hash_walk_new_entry(walk);
208}
209EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
210
211static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
212 unsigned int keylen)
213{
214 return -ENOSYS;
215}
216
217static void ahash_set_needkey(struct crypto_ahash *tfm, struct ahash_alg *alg)
218{
219 if (alg->setkey != ahash_nosetkey &&
220 !(alg->halg.base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
221 crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
222}
223
224int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
225 unsigned int keylen)
226{
227 if (likely(tfm->using_shash)) {
228 struct crypto_shash *shash = ahash_to_shash(tfm);
229 int err;
230
231 err = crypto_shash_setkey(shash, key, keylen);
232 if (unlikely(err)) {
233 crypto_ahash_set_flags(tfm,
234 crypto_shash_get_flags(shash) &
235 CRYPTO_TFM_NEED_KEY);
236 return err;
237 }
238 } else {
239 struct ahash_alg *alg = crypto_ahash_alg(tfm);
240 int err;
241
242 err = alg->setkey(tfm, key, keylen);
243 if (unlikely(err)) {
244 ahash_set_needkey(tfm, alg);
245 return err;
246 }
247 }
248 crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
249 return 0;
250}
251EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
252
253int crypto_ahash_init(struct ahash_request *req)
254{
255 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
256
257 if (likely(tfm->using_shash))
258 return crypto_shash_init(prepare_shash_desc(req, tfm));
259 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
260 return -ENOKEY;
261 return crypto_ahash_alg(tfm)->init(req);
262}
263EXPORT_SYMBOL_GPL(crypto_ahash_init);
264
265static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt,
266 bool has_state)
267{
268 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
269 unsigned int ds = crypto_ahash_digestsize(tfm);
270 struct ahash_request *subreq;
271 unsigned int subreq_size;
272 unsigned int reqsize;
273 u8 *result;
274 gfp_t gfp;
275 u32 flags;
276
277 subreq_size = sizeof(*subreq);
278 reqsize = crypto_ahash_reqsize(tfm);
279 reqsize = ALIGN(reqsize, crypto_tfm_ctx_alignment());
280 subreq_size += reqsize;
281 subreq_size += ds;
282
283 flags = ahash_request_flags(req);
284 gfp = (flags & CRYPTO_TFM_REQ_MAY_SLEEP) ? GFP_KERNEL : GFP_ATOMIC;
285 subreq = kmalloc(subreq_size, gfp);
286 if (!subreq)
287 return -ENOMEM;
288
289 ahash_request_set_tfm(subreq, tfm);
290 ahash_request_set_callback(subreq, flags, cplt, req);
291
292 result = (u8 *)(subreq + 1) + reqsize;
293
294 ahash_request_set_crypt(subreq, req->src, result, req->nbytes);
295
296 if (has_state) {
297 void *state;
298
299 state = kmalloc(crypto_ahash_statesize(tfm), gfp);
300 if (!state) {
301 kfree(subreq);
302 return -ENOMEM;
303 }
304
305 crypto_ahash_export(req, state);
306 crypto_ahash_import(subreq, state);
307 kfree_sensitive(state);
308 }
309
310 req->priv = subreq;
311
312 return 0;
313}
314
315static void ahash_restore_req(struct ahash_request *req, int err)
316{
317 struct ahash_request *subreq = req->priv;
318
319 if (!err)
320 memcpy(req->result, subreq->result,
321 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
322
323 req->priv = NULL;
324
325 kfree_sensitive(subreq);
326}
327
328int crypto_ahash_update(struct ahash_request *req)
329{
330 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
331
332 if (likely(tfm->using_shash))
333 return shash_ahash_update(req, ahash_request_ctx(req));
334
335 return crypto_ahash_alg(tfm)->update(req);
336}
337EXPORT_SYMBOL_GPL(crypto_ahash_update);
338
339int crypto_ahash_final(struct ahash_request *req)
340{
341 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
342
343 if (likely(tfm->using_shash))
344 return crypto_shash_final(ahash_request_ctx(req), req->result);
345
346 return crypto_ahash_alg(tfm)->final(req);
347}
348EXPORT_SYMBOL_GPL(crypto_ahash_final);
349
350int crypto_ahash_finup(struct ahash_request *req)
351{
352 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
353
354 if (likely(tfm->using_shash))
355 return shash_ahash_finup(req, ahash_request_ctx(req));
356
357 return crypto_ahash_alg(tfm)->finup(req);
358}
359EXPORT_SYMBOL_GPL(crypto_ahash_finup);
360
361int crypto_ahash_digest(struct ahash_request *req)
362{
363 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
364
365 if (likely(tfm->using_shash))
366 return shash_ahash_digest(req, prepare_shash_desc(req, tfm));
367
368 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
369 return -ENOKEY;
370
371 return crypto_ahash_alg(tfm)->digest(req);
372}
373EXPORT_SYMBOL_GPL(crypto_ahash_digest);
374
375static void ahash_def_finup_done2(void *data, int err)
376{
377 struct ahash_request *areq = data;
378
379 if (err == -EINPROGRESS)
380 return;
381
382 ahash_restore_req(areq, err);
383
384 ahash_request_complete(areq, err);
385}
386
387static int ahash_def_finup_finish1(struct ahash_request *req, int err)
388{
389 struct ahash_request *subreq = req->priv;
390
391 if (err)
392 goto out;
393
394 subreq->base.complete = ahash_def_finup_done2;
395
396 err = crypto_ahash_alg(crypto_ahash_reqtfm(req))->final(subreq);
397 if (err == -EINPROGRESS || err == -EBUSY)
398 return err;
399
400out:
401 ahash_restore_req(req, err);
402 return err;
403}
404
405static void ahash_def_finup_done1(void *data, int err)
406{
407 struct ahash_request *areq = data;
408 struct ahash_request *subreq;
409
410 if (err == -EINPROGRESS)
411 goto out;
412
413 subreq = areq->priv;
414 subreq->base.flags &= CRYPTO_TFM_REQ_MAY_BACKLOG;
415
416 err = ahash_def_finup_finish1(areq, err);
417 if (err == -EINPROGRESS || err == -EBUSY)
418 return;
419
420out:
421 ahash_request_complete(areq, err);
422}
423
424static int ahash_def_finup(struct ahash_request *req)
425{
426 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
427 int err;
428
429 err = ahash_save_req(req, ahash_def_finup_done1, true);
430 if (err)
431 return err;
432
433 err = crypto_ahash_alg(tfm)->update(req->priv);
434 if (err == -EINPROGRESS || err == -EBUSY)
435 return err;
436
437 return ahash_def_finup_finish1(req, err);
438}
439
440int crypto_ahash_export(struct ahash_request *req, void *out)
441{
442 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
443
444 if (likely(tfm->using_shash))
445 return crypto_shash_export(ahash_request_ctx(req), out);
446 return crypto_ahash_alg(tfm)->export(req, out);
447}
448EXPORT_SYMBOL_GPL(crypto_ahash_export);
449
450int crypto_ahash_import(struct ahash_request *req, const void *in)
451{
452 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
453
454 if (likely(tfm->using_shash))
455 return crypto_shash_import(prepare_shash_desc(req, tfm), in);
456 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
457 return -ENOKEY;
458 return crypto_ahash_alg(tfm)->import(req, in);
459}
460EXPORT_SYMBOL_GPL(crypto_ahash_import);
461
462static void crypto_ahash_exit_tfm(struct crypto_tfm *tfm)
463{
464 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
465 struct ahash_alg *alg = crypto_ahash_alg(hash);
466
467 alg->exit_tfm(hash);
468}
469
470static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
471{
472 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
473 struct ahash_alg *alg = crypto_ahash_alg(hash);
474
475 crypto_ahash_set_statesize(hash, alg->halg.statesize);
476
477 if (tfm->__crt_alg->cra_type == &crypto_shash_type)
478 return crypto_init_ahash_using_shash(tfm);
479
480 ahash_set_needkey(hash, alg);
481
482 if (alg->exit_tfm)
483 tfm->exit = crypto_ahash_exit_tfm;
484
485 return alg->init_tfm ? alg->init_tfm(hash) : 0;
486}
487
488static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
489{
490 if (alg->cra_type == &crypto_shash_type)
491 return sizeof(struct crypto_shash *);
492
493 return crypto_alg_extsize(alg);
494}
495
496static void crypto_ahash_free_instance(struct crypto_instance *inst)
497{
498 struct ahash_instance *ahash = ahash_instance(inst);
499
500 ahash->free(ahash);
501}
502
503static int __maybe_unused crypto_ahash_report(
504 struct sk_buff *skb, struct crypto_alg *alg)
505{
506 struct crypto_report_hash rhash;
507
508 memset(&rhash, 0, sizeof(rhash));
509
510 strscpy(rhash.type, "ahash", sizeof(rhash.type));
511
512 rhash.blocksize = alg->cra_blocksize;
513 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
514
515 return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
516}
517
518static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
519 __maybe_unused;
520static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
521{
522 seq_printf(m, "type : ahash\n");
523 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
524 "yes" : "no");
525 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
526 seq_printf(m, "digestsize : %u\n",
527 __crypto_hash_alg_common(alg)->digestsize);
528}
529
530static const struct crypto_type crypto_ahash_type = {
531 .extsize = crypto_ahash_extsize,
532 .init_tfm = crypto_ahash_init_tfm,
533 .free = crypto_ahash_free_instance,
534#ifdef CONFIG_PROC_FS
535 .show = crypto_ahash_show,
536#endif
537#if IS_ENABLED(CONFIG_CRYPTO_USER)
538 .report = crypto_ahash_report,
539#endif
540 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
541 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
542 .type = CRYPTO_ALG_TYPE_AHASH,
543 .tfmsize = offsetof(struct crypto_ahash, base),
544};
545
546int crypto_grab_ahash(struct crypto_ahash_spawn *spawn,
547 struct crypto_instance *inst,
548 const char *name, u32 type, u32 mask)
549{
550 spawn->base.frontend = &crypto_ahash_type;
551 return crypto_grab_spawn(&spawn->base, inst, name, type, mask);
552}
553EXPORT_SYMBOL_GPL(crypto_grab_ahash);
554
555struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
556 u32 mask)
557{
558 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
559}
560EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
561
562int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
563{
564 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
565}
566EXPORT_SYMBOL_GPL(crypto_has_ahash);
567
568static bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
569{
570 struct crypto_alg *alg = &halg->base;
571
572 if (alg->cra_type == &crypto_shash_type)
573 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
574
575 return __crypto_ahash_alg(alg)->setkey != ahash_nosetkey;
576}
577
578struct crypto_ahash *crypto_clone_ahash(struct crypto_ahash *hash)
579{
580 struct hash_alg_common *halg = crypto_hash_alg_common(hash);
581 struct crypto_tfm *tfm = crypto_ahash_tfm(hash);
582 struct crypto_ahash *nhash;
583 struct ahash_alg *alg;
584 int err;
585
586 if (!crypto_hash_alg_has_setkey(halg)) {
587 tfm = crypto_tfm_get(tfm);
588 if (IS_ERR(tfm))
589 return ERR_CAST(tfm);
590
591 return hash;
592 }
593
594 nhash = crypto_clone_tfm(&crypto_ahash_type, tfm);
595
596 if (IS_ERR(nhash))
597 return nhash;
598
599 nhash->reqsize = hash->reqsize;
600 nhash->statesize = hash->statesize;
601
602 if (likely(hash->using_shash)) {
603 struct crypto_shash **nctx = crypto_ahash_ctx(nhash);
604 struct crypto_shash *shash;
605
606 shash = crypto_clone_shash(ahash_to_shash(hash));
607 if (IS_ERR(shash)) {
608 err = PTR_ERR(shash);
609 goto out_free_nhash;
610 }
611 nhash->using_shash = true;
612 *nctx = shash;
613 return nhash;
614 }
615
616 err = -ENOSYS;
617 alg = crypto_ahash_alg(hash);
618 if (!alg->clone_tfm)
619 goto out_free_nhash;
620
621 err = alg->clone_tfm(nhash, hash);
622 if (err)
623 goto out_free_nhash;
624
625 return nhash;
626
627out_free_nhash:
628 crypto_free_ahash(nhash);
629 return ERR_PTR(err);
630}
631EXPORT_SYMBOL_GPL(crypto_clone_ahash);
632
633static int ahash_prepare_alg(struct ahash_alg *alg)
634{
635 struct crypto_alg *base = &alg->halg.base;
636 int err;
637
638 if (alg->halg.statesize == 0)
639 return -EINVAL;
640
641 err = hash_prepare_alg(&alg->halg);
642 if (err)
643 return err;
644
645 base->cra_type = &crypto_ahash_type;
646 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
647
648 if (!alg->finup)
649 alg->finup = ahash_def_finup;
650 if (!alg->setkey)
651 alg->setkey = ahash_nosetkey;
652
653 return 0;
654}
655
656int crypto_register_ahash(struct ahash_alg *alg)
657{
658 struct crypto_alg *base = &alg->halg.base;
659 int err;
660
661 err = ahash_prepare_alg(alg);
662 if (err)
663 return err;
664
665 return crypto_register_alg(base);
666}
667EXPORT_SYMBOL_GPL(crypto_register_ahash);
668
669void crypto_unregister_ahash(struct ahash_alg *alg)
670{
671 crypto_unregister_alg(&alg->halg.base);
672}
673EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
674
675int crypto_register_ahashes(struct ahash_alg *algs, int count)
676{
677 int i, ret;
678
679 for (i = 0; i < count; i++) {
680 ret = crypto_register_ahash(&algs[i]);
681 if (ret)
682 goto err;
683 }
684
685 return 0;
686
687err:
688 for (--i; i >= 0; --i)
689 crypto_unregister_ahash(&algs[i]);
690
691 return ret;
692}
693EXPORT_SYMBOL_GPL(crypto_register_ahashes);
694
695void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
696{
697 int i;
698
699 for (i = count - 1; i >= 0; --i)
700 crypto_unregister_ahash(&algs[i]);
701}
702EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
703
704int ahash_register_instance(struct crypto_template *tmpl,
705 struct ahash_instance *inst)
706{
707 int err;
708
709 if (WARN_ON(!inst->free))
710 return -EINVAL;
711
712 err = ahash_prepare_alg(&inst->alg);
713 if (err)
714 return err;
715
716 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
717}
718EXPORT_SYMBOL_GPL(ahash_register_instance);
719
720MODULE_LICENSE("GPL");
721MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
1/*
2 * Asynchronous Cryptographic Hash operations.
3 *
4 * This is the asynchronous version of hash.c with notification of
5 * completion via a callback.
6 *
7 * Copyright (c) 2008 Loc Ho <lho@amcc.com>
8 *
9 * This program is free software; you can redistribute it and/or modify it
10 * under the terms of the GNU General Public License as published by the Free
11 * Software Foundation; either version 2 of the License, or (at your option)
12 * any later version.
13 *
14 */
15
16#include <crypto/internal/hash.h>
17#include <crypto/scatterwalk.h>
18#include <linux/bug.h>
19#include <linux/err.h>
20#include <linux/kernel.h>
21#include <linux/module.h>
22#include <linux/sched.h>
23#include <linux/slab.h>
24#include <linux/seq_file.h>
25#include <linux/cryptouser.h>
26#include <linux/compiler.h>
27#include <net/netlink.h>
28
29#include "internal.h"
30
31struct ahash_request_priv {
32 crypto_completion_t complete;
33 void *data;
34 u8 *result;
35 u32 flags;
36 void *ubuf[] CRYPTO_MINALIGN_ATTR;
37};
38
39static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
40{
41 return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
42 halg);
43}
44
45static int hash_walk_next(struct crypto_hash_walk *walk)
46{
47 unsigned int alignmask = walk->alignmask;
48 unsigned int offset = walk->offset;
49 unsigned int nbytes = min(walk->entrylen,
50 ((unsigned int)(PAGE_SIZE)) - offset);
51
52 if (walk->flags & CRYPTO_ALG_ASYNC)
53 walk->data = kmap(walk->pg);
54 else
55 walk->data = kmap_atomic(walk->pg);
56 walk->data += offset;
57
58 if (offset & alignmask) {
59 unsigned int unaligned = alignmask + 1 - (offset & alignmask);
60
61 if (nbytes > unaligned)
62 nbytes = unaligned;
63 }
64
65 walk->entrylen -= nbytes;
66 return nbytes;
67}
68
69static int hash_walk_new_entry(struct crypto_hash_walk *walk)
70{
71 struct scatterlist *sg;
72
73 sg = walk->sg;
74 walk->offset = sg->offset;
75 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
76 walk->offset = offset_in_page(walk->offset);
77 walk->entrylen = sg->length;
78
79 if (walk->entrylen > walk->total)
80 walk->entrylen = walk->total;
81 walk->total -= walk->entrylen;
82
83 return hash_walk_next(walk);
84}
85
86int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
87{
88 unsigned int alignmask = walk->alignmask;
89 unsigned int nbytes = walk->entrylen;
90
91 walk->data -= walk->offset;
92
93 if (nbytes && walk->offset & alignmask && !err) {
94 walk->offset = ALIGN(walk->offset, alignmask + 1);
95 nbytes = min(nbytes,
96 ((unsigned int)(PAGE_SIZE)) - walk->offset);
97 walk->entrylen -= nbytes;
98
99 if (nbytes) {
100 walk->data += walk->offset;
101 return nbytes;
102 }
103 }
104
105 if (walk->flags & CRYPTO_ALG_ASYNC)
106 kunmap(walk->pg);
107 else {
108 kunmap_atomic(walk->data);
109 /*
110 * The may sleep test only makes sense for sync users.
111 * Async users don't need to sleep here anyway.
112 */
113 crypto_yield(walk->flags);
114 }
115
116 if (err)
117 return err;
118
119 if (nbytes) {
120 walk->offset = 0;
121 walk->pg++;
122 return hash_walk_next(walk);
123 }
124
125 if (!walk->total)
126 return 0;
127
128 walk->sg = sg_next(walk->sg);
129
130 return hash_walk_new_entry(walk);
131}
132EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
133
134int crypto_hash_walk_first(struct ahash_request *req,
135 struct crypto_hash_walk *walk)
136{
137 walk->total = req->nbytes;
138
139 if (!walk->total) {
140 walk->entrylen = 0;
141 return 0;
142 }
143
144 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
145 walk->sg = req->src;
146 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
147
148 return hash_walk_new_entry(walk);
149}
150EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
151
152int crypto_ahash_walk_first(struct ahash_request *req,
153 struct crypto_hash_walk *walk)
154{
155 walk->total = req->nbytes;
156
157 if (!walk->total) {
158 walk->entrylen = 0;
159 return 0;
160 }
161
162 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
163 walk->sg = req->src;
164 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
165 walk->flags |= CRYPTO_ALG_ASYNC;
166
167 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
168
169 return hash_walk_new_entry(walk);
170}
171EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
172
173static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
174 unsigned int keylen)
175{
176 unsigned long alignmask = crypto_ahash_alignmask(tfm);
177 int ret;
178 u8 *buffer, *alignbuffer;
179 unsigned long absize;
180
181 absize = keylen + alignmask;
182 buffer = kmalloc(absize, GFP_KERNEL);
183 if (!buffer)
184 return -ENOMEM;
185
186 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
187 memcpy(alignbuffer, key, keylen);
188 ret = tfm->setkey(tfm, alignbuffer, keylen);
189 kzfree(buffer);
190 return ret;
191}
192
193int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
194 unsigned int keylen)
195{
196 unsigned long alignmask = crypto_ahash_alignmask(tfm);
197 int err;
198
199 if ((unsigned long)key & alignmask)
200 err = ahash_setkey_unaligned(tfm, key, keylen);
201 else
202 err = tfm->setkey(tfm, key, keylen);
203
204 if (err)
205 return err;
206
207 crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
208 return 0;
209}
210EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
211
212static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
213 unsigned int keylen)
214{
215 return -ENOSYS;
216}
217
218static inline unsigned int ahash_align_buffer_size(unsigned len,
219 unsigned long mask)
220{
221 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
222}
223
224static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
225{
226 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
227 unsigned long alignmask = crypto_ahash_alignmask(tfm);
228 unsigned int ds = crypto_ahash_digestsize(tfm);
229 struct ahash_request_priv *priv;
230
231 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
232 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
233 GFP_KERNEL : GFP_ATOMIC);
234 if (!priv)
235 return -ENOMEM;
236
237 /*
238 * WARNING: Voodoo programming below!
239 *
240 * The code below is obscure and hard to understand, thus explanation
241 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
242 * to understand the layout of structures used here!
243 *
244 * The code here will replace portions of the ORIGINAL request with
245 * pointers to new code and buffers so the hashing operation can store
246 * the result in aligned buffer. We will call the modified request
247 * an ADJUSTED request.
248 *
249 * The newly mangled request will look as such:
250 *
251 * req {
252 * .result = ADJUSTED[new aligned buffer]
253 * .base.complete = ADJUSTED[pointer to completion function]
254 * .base.data = ADJUSTED[*req (pointer to self)]
255 * .priv = ADJUSTED[new priv] {
256 * .result = ORIGINAL(result)
257 * .complete = ORIGINAL(base.complete)
258 * .data = ORIGINAL(base.data)
259 * }
260 */
261
262 priv->result = req->result;
263 priv->complete = req->base.complete;
264 priv->data = req->base.data;
265 priv->flags = req->base.flags;
266
267 /*
268 * WARNING: We do not backup req->priv here! The req->priv
269 * is for internal use of the Crypto API and the
270 * user must _NOT_ _EVER_ depend on it's content!
271 */
272
273 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
274 req->base.complete = cplt;
275 req->base.data = req;
276 req->priv = priv;
277
278 return 0;
279}
280
281static void ahash_restore_req(struct ahash_request *req, int err)
282{
283 struct ahash_request_priv *priv = req->priv;
284
285 if (!err)
286 memcpy(priv->result, req->result,
287 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
288
289 /* Restore the original crypto request. */
290 req->result = priv->result;
291
292 ahash_request_set_callback(req, priv->flags,
293 priv->complete, priv->data);
294 req->priv = NULL;
295
296 /* Free the req->priv.priv from the ADJUSTED request. */
297 kzfree(priv);
298}
299
300static void ahash_notify_einprogress(struct ahash_request *req)
301{
302 struct ahash_request_priv *priv = req->priv;
303 struct crypto_async_request oreq;
304
305 oreq.data = priv->data;
306
307 priv->complete(&oreq, -EINPROGRESS);
308}
309
310static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
311{
312 struct ahash_request *areq = req->data;
313
314 if (err == -EINPROGRESS) {
315 ahash_notify_einprogress(areq);
316 return;
317 }
318
319 /*
320 * Restore the original request, see ahash_op_unaligned() for what
321 * goes where.
322 *
323 * The "struct ahash_request *req" here is in fact the "req.base"
324 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
325 * is a pointer to self, it is also the ADJUSTED "req" .
326 */
327
328 /* First copy req->result into req->priv.result */
329 ahash_restore_req(areq, err);
330
331 /* Complete the ORIGINAL request. */
332 areq->base.complete(&areq->base, err);
333}
334
335static int ahash_op_unaligned(struct ahash_request *req,
336 int (*op)(struct ahash_request *))
337{
338 int err;
339
340 err = ahash_save_req(req, ahash_op_unaligned_done);
341 if (err)
342 return err;
343
344 err = op(req);
345 if (err == -EINPROGRESS || err == -EBUSY)
346 return err;
347
348 ahash_restore_req(req, err);
349
350 return err;
351}
352
353static int crypto_ahash_op(struct ahash_request *req,
354 int (*op)(struct ahash_request *))
355{
356 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
357 unsigned long alignmask = crypto_ahash_alignmask(tfm);
358
359 if ((unsigned long)req->result & alignmask)
360 return ahash_op_unaligned(req, op);
361
362 return op(req);
363}
364
365int crypto_ahash_final(struct ahash_request *req)
366{
367 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
368}
369EXPORT_SYMBOL_GPL(crypto_ahash_final);
370
371int crypto_ahash_finup(struct ahash_request *req)
372{
373 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
374}
375EXPORT_SYMBOL_GPL(crypto_ahash_finup);
376
377int crypto_ahash_digest(struct ahash_request *req)
378{
379 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
380
381 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
382 return -ENOKEY;
383
384 return crypto_ahash_op(req, tfm->digest);
385}
386EXPORT_SYMBOL_GPL(crypto_ahash_digest);
387
388static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
389{
390 struct ahash_request *areq = req->data;
391
392 if (err == -EINPROGRESS)
393 return;
394
395 ahash_restore_req(areq, err);
396
397 areq->base.complete(&areq->base, err);
398}
399
400static int ahash_def_finup_finish1(struct ahash_request *req, int err)
401{
402 if (err)
403 goto out;
404
405 req->base.complete = ahash_def_finup_done2;
406
407 err = crypto_ahash_reqtfm(req)->final(req);
408 if (err == -EINPROGRESS || err == -EBUSY)
409 return err;
410
411out:
412 ahash_restore_req(req, err);
413 return err;
414}
415
416static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
417{
418 struct ahash_request *areq = req->data;
419
420 if (err == -EINPROGRESS) {
421 ahash_notify_einprogress(areq);
422 return;
423 }
424
425 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
426
427 err = ahash_def_finup_finish1(areq, err);
428 if (areq->priv)
429 return;
430
431 areq->base.complete(&areq->base, err);
432}
433
434static int ahash_def_finup(struct ahash_request *req)
435{
436 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
437 int err;
438
439 err = ahash_save_req(req, ahash_def_finup_done1);
440 if (err)
441 return err;
442
443 err = tfm->update(req);
444 if (err == -EINPROGRESS || err == -EBUSY)
445 return err;
446
447 return ahash_def_finup_finish1(req, err);
448}
449
450static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
451{
452 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
453 struct ahash_alg *alg = crypto_ahash_alg(hash);
454
455 hash->setkey = ahash_nosetkey;
456
457 if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
458 return crypto_init_shash_ops_async(tfm);
459
460 hash->init = alg->init;
461 hash->update = alg->update;
462 hash->final = alg->final;
463 hash->finup = alg->finup ?: ahash_def_finup;
464 hash->digest = alg->digest;
465 hash->export = alg->export;
466 hash->import = alg->import;
467
468 if (alg->setkey) {
469 hash->setkey = alg->setkey;
470 if (!(alg->halg.base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
471 crypto_ahash_set_flags(hash, CRYPTO_TFM_NEED_KEY);
472 }
473
474 return 0;
475}
476
477static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
478{
479 if (alg->cra_type != &crypto_ahash_type)
480 return sizeof(struct crypto_shash *);
481
482 return crypto_alg_extsize(alg);
483}
484
485#ifdef CONFIG_NET
486static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
487{
488 struct crypto_report_hash rhash;
489
490 strncpy(rhash.type, "ahash", sizeof(rhash.type));
491
492 rhash.blocksize = alg->cra_blocksize;
493 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
494
495 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
496 sizeof(struct crypto_report_hash), &rhash))
497 goto nla_put_failure;
498 return 0;
499
500nla_put_failure:
501 return -EMSGSIZE;
502}
503#else
504static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
505{
506 return -ENOSYS;
507}
508#endif
509
510static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
511 __maybe_unused;
512static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
513{
514 seq_printf(m, "type : ahash\n");
515 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
516 "yes" : "no");
517 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
518 seq_printf(m, "digestsize : %u\n",
519 __crypto_hash_alg_common(alg)->digestsize);
520}
521
522const struct crypto_type crypto_ahash_type = {
523 .extsize = crypto_ahash_extsize,
524 .init_tfm = crypto_ahash_init_tfm,
525#ifdef CONFIG_PROC_FS
526 .show = crypto_ahash_show,
527#endif
528 .report = crypto_ahash_report,
529 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
530 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
531 .type = CRYPTO_ALG_TYPE_AHASH,
532 .tfmsize = offsetof(struct crypto_ahash, base),
533};
534EXPORT_SYMBOL_GPL(crypto_ahash_type);
535
536struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
537 u32 mask)
538{
539 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
540}
541EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
542
543int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
544{
545 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
546}
547EXPORT_SYMBOL_GPL(crypto_has_ahash);
548
549static int ahash_prepare_alg(struct ahash_alg *alg)
550{
551 struct crypto_alg *base = &alg->halg.base;
552
553 if (alg->halg.digestsize > PAGE_SIZE / 8 ||
554 alg->halg.statesize > PAGE_SIZE / 8 ||
555 alg->halg.statesize == 0)
556 return -EINVAL;
557
558 base->cra_type = &crypto_ahash_type;
559 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
560 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
561
562 return 0;
563}
564
565int crypto_register_ahash(struct ahash_alg *alg)
566{
567 struct crypto_alg *base = &alg->halg.base;
568 int err;
569
570 err = ahash_prepare_alg(alg);
571 if (err)
572 return err;
573
574 return crypto_register_alg(base);
575}
576EXPORT_SYMBOL_GPL(crypto_register_ahash);
577
578int crypto_unregister_ahash(struct ahash_alg *alg)
579{
580 return crypto_unregister_alg(&alg->halg.base);
581}
582EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
583
584int crypto_register_ahashes(struct ahash_alg *algs, int count)
585{
586 int i, ret;
587
588 for (i = 0; i < count; i++) {
589 ret = crypto_register_ahash(&algs[i]);
590 if (ret)
591 goto err;
592 }
593
594 return 0;
595
596err:
597 for (--i; i >= 0; --i)
598 crypto_unregister_ahash(&algs[i]);
599
600 return ret;
601}
602EXPORT_SYMBOL_GPL(crypto_register_ahashes);
603
604void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
605{
606 int i;
607
608 for (i = count - 1; i >= 0; --i)
609 crypto_unregister_ahash(&algs[i]);
610}
611EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
612
613int ahash_register_instance(struct crypto_template *tmpl,
614 struct ahash_instance *inst)
615{
616 int err;
617
618 err = ahash_prepare_alg(&inst->alg);
619 if (err)
620 return err;
621
622 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
623}
624EXPORT_SYMBOL_GPL(ahash_register_instance);
625
626void ahash_free_instance(struct crypto_instance *inst)
627{
628 crypto_drop_spawn(crypto_instance_ctx(inst));
629 kfree(ahash_instance(inst));
630}
631EXPORT_SYMBOL_GPL(ahash_free_instance);
632
633int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
634 struct hash_alg_common *alg,
635 struct crypto_instance *inst)
636{
637 return crypto_init_spawn2(&spawn->base, &alg->base, inst,
638 &crypto_ahash_type);
639}
640EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
641
642struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
643{
644 struct crypto_alg *alg;
645
646 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
647 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
648}
649EXPORT_SYMBOL_GPL(ahash_attr_alg);
650
651bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
652{
653 struct crypto_alg *alg = &halg->base;
654
655 if (alg->cra_type != &crypto_ahash_type)
656 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
657
658 return __crypto_ahash_alg(alg)->setkey != NULL;
659}
660EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
661
662MODULE_LICENSE("GPL");
663MODULE_DESCRIPTION("Asynchronous cryptographic hash type");