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
90 walk->data -= walk->offset;
91
92 if (walk->entrylen && (walk->offset & alignmask) && !err) {
93 unsigned int nbytes;
94
95 walk->offset = ALIGN(walk->offset, alignmask + 1);
96 nbytes = min(walk->entrylen,
97 (unsigned int)(PAGE_SIZE - walk->offset));
98 if (nbytes) {
99 walk->entrylen -= 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 (walk->entrylen) {
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
193static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
194 unsigned int keylen)
195{
196 return -ENOSYS;
197}
198
199static void ahash_set_needkey(struct crypto_ahash *tfm)
200{
201 const struct hash_alg_common *alg = crypto_hash_alg_common(tfm);
202
203 if (tfm->setkey != ahash_nosetkey &&
204 !(alg->base.cra_flags & CRYPTO_ALG_OPTIONAL_KEY))
205 crypto_ahash_set_flags(tfm, CRYPTO_TFM_NEED_KEY);
206}
207
208int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
209 unsigned int keylen)
210{
211 unsigned long alignmask = crypto_ahash_alignmask(tfm);
212 int err;
213
214 if ((unsigned long)key & alignmask)
215 err = ahash_setkey_unaligned(tfm, key, keylen);
216 else
217 err = tfm->setkey(tfm, key, keylen);
218
219 if (unlikely(err)) {
220 ahash_set_needkey(tfm);
221 return err;
222 }
223
224 crypto_ahash_clear_flags(tfm, CRYPTO_TFM_NEED_KEY);
225 return 0;
226}
227EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
228
229static inline unsigned int ahash_align_buffer_size(unsigned len,
230 unsigned long mask)
231{
232 return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
233}
234
235static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
236{
237 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
238 unsigned long alignmask = crypto_ahash_alignmask(tfm);
239 unsigned int ds = crypto_ahash_digestsize(tfm);
240 struct ahash_request_priv *priv;
241
242 priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
243 (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
244 GFP_KERNEL : GFP_ATOMIC);
245 if (!priv)
246 return -ENOMEM;
247
248 /*
249 * WARNING: Voodoo programming below!
250 *
251 * The code below is obscure and hard to understand, thus explanation
252 * is necessary. See include/crypto/hash.h and include/linux/crypto.h
253 * to understand the layout of structures used here!
254 *
255 * The code here will replace portions of the ORIGINAL request with
256 * pointers to new code and buffers so the hashing operation can store
257 * the result in aligned buffer. We will call the modified request
258 * an ADJUSTED request.
259 *
260 * The newly mangled request will look as such:
261 *
262 * req {
263 * .result = ADJUSTED[new aligned buffer]
264 * .base.complete = ADJUSTED[pointer to completion function]
265 * .base.data = ADJUSTED[*req (pointer to self)]
266 * .priv = ADJUSTED[new priv] {
267 * .result = ORIGINAL(result)
268 * .complete = ORIGINAL(base.complete)
269 * .data = ORIGINAL(base.data)
270 * }
271 */
272
273 priv->result = req->result;
274 priv->complete = req->base.complete;
275 priv->data = req->base.data;
276 priv->flags = req->base.flags;
277
278 /*
279 * WARNING: We do not backup req->priv here! The req->priv
280 * is for internal use of the Crypto API and the
281 * user must _NOT_ _EVER_ depend on it's content!
282 */
283
284 req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
285 req->base.complete = cplt;
286 req->base.data = req;
287 req->priv = priv;
288
289 return 0;
290}
291
292static void ahash_restore_req(struct ahash_request *req, int err)
293{
294 struct ahash_request_priv *priv = req->priv;
295
296 if (!err)
297 memcpy(priv->result, req->result,
298 crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
299
300 /* Restore the original crypto request. */
301 req->result = priv->result;
302
303 ahash_request_set_callback(req, priv->flags,
304 priv->complete, priv->data);
305 req->priv = NULL;
306
307 /* Free the req->priv.priv from the ADJUSTED request. */
308 kzfree(priv);
309}
310
311static void ahash_notify_einprogress(struct ahash_request *req)
312{
313 struct ahash_request_priv *priv = req->priv;
314 struct crypto_async_request oreq;
315
316 oreq.data = priv->data;
317
318 priv->complete(&oreq, -EINPROGRESS);
319}
320
321static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
322{
323 struct ahash_request *areq = req->data;
324
325 if (err == -EINPROGRESS) {
326 ahash_notify_einprogress(areq);
327 return;
328 }
329
330 /*
331 * Restore the original request, see ahash_op_unaligned() for what
332 * goes where.
333 *
334 * The "struct ahash_request *req" here is in fact the "req.base"
335 * from the ADJUSTED request from ahash_op_unaligned(), thus as it
336 * is a pointer to self, it is also the ADJUSTED "req" .
337 */
338
339 /* First copy req->result into req->priv.result */
340 ahash_restore_req(areq, err);
341
342 /* Complete the ORIGINAL request. */
343 areq->base.complete(&areq->base, err);
344}
345
346static int ahash_op_unaligned(struct ahash_request *req,
347 int (*op)(struct ahash_request *))
348{
349 int err;
350
351 err = ahash_save_req(req, ahash_op_unaligned_done);
352 if (err)
353 return err;
354
355 err = op(req);
356 if (err == -EINPROGRESS || err == -EBUSY)
357 return err;
358
359 ahash_restore_req(req, err);
360
361 return err;
362}
363
364static int crypto_ahash_op(struct ahash_request *req,
365 int (*op)(struct ahash_request *))
366{
367 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
368 unsigned long alignmask = crypto_ahash_alignmask(tfm);
369
370 if ((unsigned long)req->result & alignmask)
371 return ahash_op_unaligned(req, op);
372
373 return op(req);
374}
375
376int crypto_ahash_final(struct ahash_request *req)
377{
378 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
379 struct crypto_alg *alg = tfm->base.__crt_alg;
380 unsigned int nbytes = req->nbytes;
381 int ret;
382
383 crypto_stats_get(alg);
384 ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
385 crypto_stats_ahash_final(nbytes, ret, alg);
386 return ret;
387}
388EXPORT_SYMBOL_GPL(crypto_ahash_final);
389
390int crypto_ahash_finup(struct ahash_request *req)
391{
392 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
393 struct crypto_alg *alg = tfm->base.__crt_alg;
394 unsigned int nbytes = req->nbytes;
395 int ret;
396
397 crypto_stats_get(alg);
398 ret = crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
399 crypto_stats_ahash_final(nbytes, ret, alg);
400 return ret;
401}
402EXPORT_SYMBOL_GPL(crypto_ahash_finup);
403
404int crypto_ahash_digest(struct ahash_request *req)
405{
406 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
407 struct crypto_alg *alg = tfm->base.__crt_alg;
408 unsigned int nbytes = req->nbytes;
409 int ret;
410
411 crypto_stats_get(alg);
412 if (crypto_ahash_get_flags(tfm) & CRYPTO_TFM_NEED_KEY)
413 ret = -ENOKEY;
414 else
415 ret = crypto_ahash_op(req, tfm->digest);
416 crypto_stats_ahash_final(nbytes, ret, alg);
417 return ret;
418}
419EXPORT_SYMBOL_GPL(crypto_ahash_digest);
420
421static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
422{
423 struct ahash_request *areq = req->data;
424
425 if (err == -EINPROGRESS)
426 return;
427
428 ahash_restore_req(areq, err);
429
430 areq->base.complete(&areq->base, err);
431}
432
433static int ahash_def_finup_finish1(struct ahash_request *req, int err)
434{
435 if (err)
436 goto out;
437
438 req->base.complete = ahash_def_finup_done2;
439
440 err = crypto_ahash_reqtfm(req)->final(req);
441 if (err == -EINPROGRESS || err == -EBUSY)
442 return err;
443
444out:
445 ahash_restore_req(req, err);
446 return err;
447}
448
449static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
450{
451 struct ahash_request *areq = req->data;
452
453 if (err == -EINPROGRESS) {
454 ahash_notify_einprogress(areq);
455 return;
456 }
457
458 areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
459
460 err = ahash_def_finup_finish1(areq, err);
461 if (areq->priv)
462 return;
463
464 areq->base.complete(&areq->base, err);
465}
466
467static int ahash_def_finup(struct ahash_request *req)
468{
469 struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
470 int err;
471
472 err = ahash_save_req(req, ahash_def_finup_done1);
473 if (err)
474 return err;
475
476 err = tfm->update(req);
477 if (err == -EINPROGRESS || err == -EBUSY)
478 return err;
479
480 return ahash_def_finup_finish1(req, err);
481}
482
483static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
484{
485 struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
486 struct ahash_alg *alg = crypto_ahash_alg(hash);
487
488 hash->setkey = ahash_nosetkey;
489
490 if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
491 return crypto_init_shash_ops_async(tfm);
492
493 hash->init = alg->init;
494 hash->update = alg->update;
495 hash->final = alg->final;
496 hash->finup = alg->finup ?: ahash_def_finup;
497 hash->digest = alg->digest;
498 hash->export = alg->export;
499 hash->import = alg->import;
500
501 if (alg->setkey) {
502 hash->setkey = alg->setkey;
503 ahash_set_needkey(hash);
504 }
505
506 return 0;
507}
508
509static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
510{
511 if (alg->cra_type != &crypto_ahash_type)
512 return sizeof(struct crypto_shash *);
513
514 return crypto_alg_extsize(alg);
515}
516
517#ifdef CONFIG_NET
518static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
519{
520 struct crypto_report_hash rhash;
521
522 memset(&rhash, 0, sizeof(rhash));
523
524 strscpy(rhash.type, "ahash", sizeof(rhash.type));
525
526 rhash.blocksize = alg->cra_blocksize;
527 rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
528
529 return nla_put(skb, CRYPTOCFGA_REPORT_HASH, sizeof(rhash), &rhash);
530}
531#else
532static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
533{
534 return -ENOSYS;
535}
536#endif
537
538static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
539 __maybe_unused;
540static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
541{
542 seq_printf(m, "type : ahash\n");
543 seq_printf(m, "async : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
544 "yes" : "no");
545 seq_printf(m, "blocksize : %u\n", alg->cra_blocksize);
546 seq_printf(m, "digestsize : %u\n",
547 __crypto_hash_alg_common(alg)->digestsize);
548}
549
550const struct crypto_type crypto_ahash_type = {
551 .extsize = crypto_ahash_extsize,
552 .init_tfm = crypto_ahash_init_tfm,
553#ifdef CONFIG_PROC_FS
554 .show = crypto_ahash_show,
555#endif
556 .report = crypto_ahash_report,
557 .maskclear = ~CRYPTO_ALG_TYPE_MASK,
558 .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
559 .type = CRYPTO_ALG_TYPE_AHASH,
560 .tfmsize = offsetof(struct crypto_ahash, base),
561};
562EXPORT_SYMBOL_GPL(crypto_ahash_type);
563
564struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
565 u32 mask)
566{
567 return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
568}
569EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
570
571int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
572{
573 return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
574}
575EXPORT_SYMBOL_GPL(crypto_has_ahash);
576
577static int ahash_prepare_alg(struct ahash_alg *alg)
578{
579 struct crypto_alg *base = &alg->halg.base;
580
581 if (alg->halg.digestsize > HASH_MAX_DIGESTSIZE ||
582 alg->halg.statesize > HASH_MAX_STATESIZE ||
583 alg->halg.statesize == 0)
584 return -EINVAL;
585
586 base->cra_type = &crypto_ahash_type;
587 base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
588 base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
589
590 return 0;
591}
592
593int crypto_register_ahash(struct ahash_alg *alg)
594{
595 struct crypto_alg *base = &alg->halg.base;
596 int err;
597
598 err = ahash_prepare_alg(alg);
599 if (err)
600 return err;
601
602 return crypto_register_alg(base);
603}
604EXPORT_SYMBOL_GPL(crypto_register_ahash);
605
606int crypto_unregister_ahash(struct ahash_alg *alg)
607{
608 return crypto_unregister_alg(&alg->halg.base);
609}
610EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
611
612int crypto_register_ahashes(struct ahash_alg *algs, int count)
613{
614 int i, ret;
615
616 for (i = 0; i < count; i++) {
617 ret = crypto_register_ahash(&algs[i]);
618 if (ret)
619 goto err;
620 }
621
622 return 0;
623
624err:
625 for (--i; i >= 0; --i)
626 crypto_unregister_ahash(&algs[i]);
627
628 return ret;
629}
630EXPORT_SYMBOL_GPL(crypto_register_ahashes);
631
632void crypto_unregister_ahashes(struct ahash_alg *algs, int count)
633{
634 int i;
635
636 for (i = count - 1; i >= 0; --i)
637 crypto_unregister_ahash(&algs[i]);
638}
639EXPORT_SYMBOL_GPL(crypto_unregister_ahashes);
640
641int ahash_register_instance(struct crypto_template *tmpl,
642 struct ahash_instance *inst)
643{
644 int err;
645
646 err = ahash_prepare_alg(&inst->alg);
647 if (err)
648 return err;
649
650 return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
651}
652EXPORT_SYMBOL_GPL(ahash_register_instance);
653
654void ahash_free_instance(struct crypto_instance *inst)
655{
656 crypto_drop_spawn(crypto_instance_ctx(inst));
657 kfree(ahash_instance(inst));
658}
659EXPORT_SYMBOL_GPL(ahash_free_instance);
660
661int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
662 struct hash_alg_common *alg,
663 struct crypto_instance *inst)
664{
665 return crypto_init_spawn2(&spawn->base, &alg->base, inst,
666 &crypto_ahash_type);
667}
668EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
669
670struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
671{
672 struct crypto_alg *alg;
673
674 alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
675 return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
676}
677EXPORT_SYMBOL_GPL(ahash_attr_alg);
678
679bool crypto_hash_alg_has_setkey(struct hash_alg_common *halg)
680{
681 struct crypto_alg *alg = &halg->base;
682
683 if (alg->cra_type != &crypto_ahash_type)
684 return crypto_shash_alg_has_setkey(__crypto_shash_alg(alg));
685
686 return __crypto_ahash_alg(alg)->setkey != NULL;
687}
688EXPORT_SYMBOL_GPL(crypto_hash_alg_has_setkey);
689
690MODULE_LICENSE("GPL");
691MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
692