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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 <net/netlink.h>
27
28#include "internal.h"
29
30struct ahash_request_priv {
31 crypto_completion_t complete;
32 void *data;
33 u8 *result;
34 void *ubuf[] CRYPTO_MINALIGN_ATTR;
35};
36
37static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
38{
39 return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
40 halg);
41}
42
43static int hash_walk_next(struct crypto_hash_walk *walk)
44{
45 unsigned int alignmask = walk->alignmask;
46 unsigned int offset = walk->offset;
47 unsigned int nbytes = min(walk->entrylen,
48 ((unsigned int)(PAGE_SIZE)) - offset);
49
50 if (walk->flags & CRYPTO_ALG_ASYNC)
51 walk->data = kmap(walk->pg);
52 else
53 walk->data = kmap_atomic(walk->pg);
54 walk->data += offset;
55
56 if (offset & alignmask) {
57 unsigned int unaligned = alignmask + 1 - (offset & alignmask);
58
59 if (nbytes > unaligned)
60 nbytes = unaligned;
61 }
62
63 walk->entrylen -= nbytes;
64 return nbytes;
65}
66
67static int hash_walk_new_entry(struct crypto_hash_walk *walk)
68{
69 struct scatterlist *sg;
70
71 sg = walk->sg;
72 walk->offset = sg->offset;
73 walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
74 walk->offset = offset_in_page(walk->offset);
75 walk->entrylen = sg->length;
76
77 if (walk->entrylen > walk->total)
78 walk->entrylen = walk->total;
79 walk->total -= walk->entrylen;
80
81 return hash_walk_next(walk);
82}
83
84int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
85{
86 unsigned int alignmask = walk->alignmask;
87 unsigned int nbytes = walk->entrylen;
88
89 walk->data -= walk->offset;
90
91 if (nbytes && walk->offset & alignmask && !err) {
92 walk->offset = ALIGN(walk->offset, alignmask + 1);
93 walk->data += walk->offset;
94
95 nbytes = min(nbytes,
96 ((unsigned int)(PAGE_SIZE)) - walk->offset);
97 walk->entrylen -= nbytes;
98
99 return nbytes;
100 }
101
102 if (walk->flags & CRYPTO_ALG_ASYNC)
103 kunmap(walk->pg);
104 else {
105 kunmap_atomic(walk->data);
106 /*
107 * The may sleep test only makes sense for sync users.
108 * Async users don't need to sleep here anyway.
109 */
110 crypto_yield(walk->flags);
111 }
112
113 if (err)
114 return err;
115
116 if (nbytes) {
117 walk->offset = 0;
118 walk->pg++;
119 return hash_walk_next(walk);
120 }
121
122 if (!walk->total)
123 return 0;
124
125 walk->sg = sg_next(walk->sg);
126
127 return hash_walk_new_entry(walk);
128}
129EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
130
131int crypto_hash_walk_first(struct ahash_request *req,
132 struct crypto_hash_walk *walk)
133{
134 walk->total = req->nbytes;
135
136 if (!walk->total) {
137 walk->entrylen = 0;
138 return 0;
139 }
140
141 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
142 walk->sg = req->src;
143 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
144
145 return hash_walk_new_entry(walk);
146}
147EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
148
149int crypto_ahash_walk_first(struct ahash_request *req,
150 struct crypto_hash_walk *walk)
151{
152 walk->total = req->nbytes;
153
154 if (!walk->total) {
155 walk->entrylen = 0;
156 return 0;
157 }
158
159 walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
160 walk->sg = req->src;
161 walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
162 walk->flags |= CRYPTO_ALG_ASYNC;
163
164 BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
165
166 return hash_walk_new_entry(walk);
167}
168EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
169
170static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
171 unsigned int keylen)
172{
173 unsigned long alignmask = crypto_ahash_alignmask(tfm);
174 int ret;
175 u8 *buffer, *alignbuffer;
176 unsigned long absize;
177
178 absize = keylen + alignmask;
179 buffer = kmalloc(absize, GFP_KERNEL);
180 if (!buffer)
181 return -ENOMEM;
182
183 alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
184 memcpy(alignbuffer, key, keylen);
185 ret = tfm->setkey(tfm, alignbuffer, keylen);
186 kzfree(buffer);
187 return ret;
188}
189
190int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
191 unsigned int keylen)
192{
193 unsigned long alignmask = crypto_ahash_alignmask(tfm);
194
195 if ((unsigned long)key & alignmask)
196 return ahash_setkey_unaligned(tfm, key, keylen);
197
198 return tfm->setkey(tfm, key, keylen);
199}
200EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
201
202static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
203 unsigned int keylen)
204{
205 return -ENOSYS;
206}
207
208static inline unsigned int ahash_align_buffer_size(unsigned len,
209 unsigned long mask)
210{
211 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
212}
213
214static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
215{
216 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
217 unsigned long alignmask = crypto_ahash_alignmask(tfm);
218 unsigned int ds = crypto_ahash_digestsize(tfm);
219 struct ahash_request_priv *priv;
220
221 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
222 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
223 GFP_KERNEL : GFP_ATOMIC);
224 if (!priv)
225 return -ENOMEM;
226
227 /*
228 * WARNING: Voodoo programming below!
229 *
230 * The code below is obscure and hard to understand, thus explanation
231 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
232 * to understand the layout of structures used here!
233 *
234 * The code here will replace portions of the ORIGINAL request with
235 * pointers to new code and buffers so the hashing operation can store
236 * the result in aligned buffer. We will call the modified request
237 * an ADJUSTED request.
238 *
239 * The newly mangled request will look as such:
240 *
241 * req {
242 * .result = ADJUSTED[new aligned buffer]
243 * .base.complete = ADJUSTED[pointer to completion function]
244 * .base.data = ADJUSTED[*req (pointer to self)]
245 * .priv = ADJUSTED[new priv] {
246 * .result = ORIGINAL(result)
247 * .complete = ORIGINAL(base.complete)
248 * .data = ORIGINAL(base.data)
249 * }
250 */
251
252 priv->result = req->result;
253 priv->complete = req->base.complete;
254 priv->data = req->base.data;
255 /*
256 * WARNING: We do not backup req->priv here! The req->priv
257 * is for internal use of the Crypto API and the
258 * user must _NOT_ _EVER_ depend on it's content!
259 */
260
261 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
262 req->base.complete = cplt;
263 req->base.data = req;
264 req->priv = priv;
265
266 return 0;
267}
268
269static void ahash_restore_req(struct ahash_request *req)
270{
271 struct ahash_request_priv *priv = req->priv;
272
273 /* Restore the original crypto request. */
274 req->result = priv->result;
275 req->base.complete = priv->complete;
276 req->base.data = priv->data;
277 req->priv = NULL;
278
279 /* Free the req->priv.priv from the ADJUSTED request. */
280 kzfree(priv);
281}
282
283static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
284{
285 struct ahash_request_priv *priv = req->priv;
286
287 if (err == -EINPROGRESS)
288 return;
289
290 if (!err)
291 memcpy(priv->result, req->result,
292 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
293
294 ahash_restore_req(req);
295}
296
297static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
298{
299 struct ahash_request *areq = req->data;
300
301 /*
302 * Restore the original request, see ahash_op_unaligned() for what
303 * goes where.
304 *
305 * The "struct ahash_request *req" here is in fact the "req.base"
306 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
307 * is a pointer to self, it is also the ADJUSTED "req" .
308 */
309
310 /* First copy req->result into req->priv.result */
311 ahash_op_unaligned_finish(areq, err);
312
313 /* Complete the ORIGINAL request. */
314 areq->base.complete(&areq->base, err);
315}
316
317static int ahash_op_unaligned(struct ahash_request *req,
318 int (*op)(struct ahash_request *))
319{
320 int err;
321
322 err = ahash_save_req(req, ahash_op_unaligned_done);
323 if (err)
324 return err;
325
326 err = op(req);
327 ahash_op_unaligned_finish(req, err);
328
329 return err;
330}
331
332static int crypto_ahash_op(struct ahash_request *req,
333 int (*op)(struct ahash_request *))
334{
335 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
336 unsigned long alignmask = crypto_ahash_alignmask(tfm);
337
338 if ((unsigned long)req->result & alignmask)
339 return ahash_op_unaligned(req, op);
340
341 return op(req);
342}
343
344int crypto_ahash_final(struct ahash_request *req)
345{
346 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
347}
348EXPORT_SYMBOL_GPL(crypto_ahash_final);
349
350int crypto_ahash_finup(struct ahash_request *req)
351{
352 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
353}
354EXPORT_SYMBOL_GPL(crypto_ahash_finup);
355
356int crypto_ahash_digest(struct ahash_request *req)
357{
358 return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
359}
360EXPORT_SYMBOL_GPL(crypto_ahash_digest);
361
362static void ahash_def_finup_finish2(struct ahash_request *req, int err)
363{
364 struct ahash_request_priv *priv = req->priv;
365
366 if (err == -EINPROGRESS)
367 return;
368
369 if (!err)
370 memcpy(priv->result, req->result,
371 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
372
373 ahash_restore_req(req);
374}
375
376static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
377{
378 struct ahash_request *areq = req->data;
379
380 ahash_def_finup_finish2(areq, err);
381
382 areq->base.complete(&areq->base, err);
383}
384
385static int ahash_def_finup_finish1(struct ahash_request *req, int err)
386{
387 if (err)
388 goto out;
389
390 req->base.complete = ahash_def_finup_done2;
391 req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
392 err = crypto_ahash_reqtfm(req)->final(req);
393
394out:
395 ahash_def_finup_finish2(req, err);
396 return err;
397}
398
399static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
400{
401 struct ahash_request *areq = req->data;
402
403 err = ahash_def_finup_finish1(areq, err);
404
405 areq->base.complete(&areq->base, err);
406}
407
408static int ahash_def_finup(struct ahash_request *req)
409{
410 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
411 int err;
412
413 err = ahash_save_req(req, ahash_def_finup_done1);
414 if (err)
415 return err;
416
417 err = tfm->update(req);
418 return ahash_def_finup_finish1(req, err);
419}
420
421static int ahash_no_export(struct ahash_request *req, void *out)
422{
423 return -ENOSYS;
424}
425
426static int ahash_no_import(struct ahash_request *req, const void *in)
427{
428 return -ENOSYS;
429}
430
431static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
432{
433 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
434 struct ahash_alg *alg = crypto_ahash_alg(hash);
435
436 hash->setkey = ahash_nosetkey;
437 hash->has_setkey = false;
438 hash->export = ahash_no_export;
439 hash->import = ahash_no_import;
440
441 if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
442 return crypto_init_shash_ops_async(tfm);
443
444 hash->init = alg->init;
445 hash->update = alg->update;
446 hash->final = alg->final;
447 hash->finup = alg->finup ?: ahash_def_finup;
448 hash->digest = alg->digest;
449
450 if (alg->setkey) {
451 hash->setkey = alg->setkey;
452 hash->has_setkey = true;
453 }
454 if (alg->export)
455 hash->export = alg->export;
456 if (alg->import)
457 hash->import = alg->import;
458
459 return 0;
460}
461
462static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
463{
464 if (alg->cra_type == &crypto_ahash_type)
465 return alg->cra_ctxsize;
466
467 return sizeof(struct crypto_shash *);
468}
469
470#ifdef CONFIG_NET
471static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
472{
473 struct crypto_report_hash rhash;
474
475 strncpy(rhash.type, "ahash", sizeof(rhash.type));
476
477 rhash.blocksize = alg->cra_blocksize;
478 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
479
480 if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
481 sizeof(struct crypto_report_hash), &rhash))
482 goto nla_put_failure;
483 return 0;
484
485nla_put_failure:
486 return -EMSGSIZE;
487}
488#else
489static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
490{
491 return -ENOSYS;
492}
493#endif
494
495static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
496 __attribute__ ((unused));
497static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
498{
499 seq_printf(m, "type : ahash\n");
500 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
501 "yes" : "no");
502 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
503 seq_printf(m, "digestsize : %u\n",
504 __crypto_hash_alg_common(alg)->digestsize);
505}
506
507const struct crypto_type crypto_ahash_type = {
508 .extsize = crypto_ahash_extsize,
509 .init_tfm = crypto_ahash_init_tfm,
510#ifdef CONFIG_PROC_FS
511 .show = crypto_ahash_show,
512#endif
513 .report = crypto_ahash_report,
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};
519EXPORT_SYMBOL_GPL(crypto_ahash_type);
520
521struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
522 u32 mask)
523{
524 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
525}
526EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
527
528int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
529{
530 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
531}
532EXPORT_SYMBOL_GPL(crypto_has_ahash);
533
534static int ahash_prepare_alg(struct ahash_alg *alg)
535{
536 struct crypto_alg *base = &alg->halg.base;
537
538 if (alg->halg.digestsize > PAGE_SIZE / 8 ||
539 alg->halg.statesize > PAGE_SIZE / 8 ||
540 alg->halg.statesize == 0)
541 return -EINVAL;
542
543 base->cra_type = &crypto_ahash_type;
544 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
545 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
546
547 return 0;
548}
549
550int crypto_register_ahash(struct ahash_alg *alg)
551{
552 struct crypto_alg *base = &alg->halg.base;
553 int err;
554
555 err = ahash_prepare_alg(alg);
556 if (err)
557 return err;
558
559 return crypto_register_alg(base);
560}
561EXPORT_SYMBOL_GPL(crypto_register_ahash);
562
563int crypto_unregister_ahash(struct ahash_alg *alg)
564{
565 return crypto_unregister_alg(&alg->halg.base);
566}
567EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
568
569int ahash_register_instance(struct crypto_template *tmpl,
570 struct ahash_instance *inst)
571{
572 int err;
573
574 err = ahash_prepare_alg(&inst->alg);
575 if (err)
576 return err;
577
578 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
579}
580EXPORT_SYMBOL_GPL(ahash_register_instance);
581
582void ahash_free_instance(struct crypto_instance *inst)
583{
584 crypto_drop_spawn(crypto_instance_ctx(inst));
585 kfree(ahash_instance(inst));
586}
587EXPORT_SYMBOL_GPL(ahash_free_instance);
588
589int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
590 struct hash_alg_common *alg,
591 struct crypto_instance *inst)
592{
593 return crypto_init_spawn2(&spawn->base, &alg->base, inst,
594 &crypto_ahash_type);
595}
596EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
597
598struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
599{
600 struct crypto_alg *alg;
601
602 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
603 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
604}
605EXPORT_SYMBOL_GPL(ahash_attr_alg);
606
607MODULE_LICENSE("GPL");
608MODULE_DESCRIPTION("Asynchronous cryptographic hash type");