source: src/linux/universal/linux-4.9/crypto/ahash.c @ 31885

Last change on this file since 31885 was 31885, checked in by brainslayer, 6 weeks ago

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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        u32 flags;
35        void *ubuf[] CRYPTO_MINALIGN_ATTR;
36};
37
38static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
39{
40        return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
41                            halg);
42}
43
44static int hash_walk_next(struct crypto_hash_walk *walk)
45{
46        unsigned int alignmask = walk->alignmask;
47        unsigned int offset = walk->offset;
48        unsigned int nbytes = min(walk->entrylen,
49                                  ((unsigned int)(PAGE_SIZE)) - offset);
50
51        if (walk->flags & CRYPTO_ALG_ASYNC)
52                walk->data = kmap(walk->pg);
53        else
54                walk->data = kmap_atomic(walk->pg);
55        walk->data += offset;
56
57        if (offset & alignmask) {
58                unsigned int unaligned = alignmask + 1 - (offset & alignmask);
59
60                if (nbytes > unaligned)
61                        nbytes = unaligned;
62        }
63
64        walk->entrylen -= nbytes;
65        return nbytes;
66}
67
68static int hash_walk_new_entry(struct crypto_hash_walk *walk)
69{
70        struct scatterlist *sg;
71
72        sg = walk->sg;
73        walk->offset = sg->offset;
74        walk->pg = sg_page(walk->sg) + (walk->offset >> PAGE_SHIFT);
75        walk->offset = offset_in_page(walk->offset);
76        walk->entrylen = sg->length;
77
78        if (walk->entrylen > walk->total)
79                walk->entrylen = walk->total;
80        walk->total -= walk->entrylen;
81
82        return hash_walk_next(walk);
83}
84
85int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
86{
87        unsigned int alignmask = walk->alignmask;
88        unsigned int nbytes = walk->entrylen;
89
90        walk->data -= walk->offset;
91
92        if (nbytes && walk->offset & alignmask && !err) {
93                walk->offset = ALIGN(walk->offset, alignmask + 1);
94                walk->data += walk->offset;
95
96                nbytes = min(nbytes,
97                             ((unsigned int)(PAGE_SIZE)) - walk->offset);
98                walk->entrylen -= nbytes;
99
100                return nbytes;
101        }
102
103        if (walk->flags & CRYPTO_ALG_ASYNC)
104                kunmap(walk->pg);
105        else {
106                kunmap_atomic(walk->data);
107                /*
108                 * The may sleep test only makes sense for sync users.
109                 * Async users don't need to sleep here anyway.
110                 */
111                crypto_yield(walk->flags);
112        }
113
114        if (err)
115                return err;
116
117        if (nbytes) {
118                walk->offset = 0;
119                walk->pg++;
120                return hash_walk_next(walk);
121        }
122
123        if (!walk->total)
124                return 0;
125
126        walk->sg = sg_next(walk->sg);
127
128        return hash_walk_new_entry(walk);
129}
130EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
131
132int crypto_hash_walk_first(struct ahash_request *req,
133                           struct crypto_hash_walk *walk)
134{
135        walk->total = req->nbytes;
136
137        if (!walk->total) {
138                walk->entrylen = 0;
139                return 0;
140        }
141
142        walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
143        walk->sg = req->src;
144        walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
145
146        return hash_walk_new_entry(walk);
147}
148EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
149
150int crypto_ahash_walk_first(struct ahash_request *req,
151                            struct crypto_hash_walk *walk)
152{
153        walk->total = req->nbytes;
154
155        if (!walk->total) {
156                walk->entrylen = 0;
157                return 0;
158        }
159
160        walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
161        walk->sg = req->src;
162        walk->flags = req->base.flags & CRYPTO_TFM_REQ_MASK;
163        walk->flags |= CRYPTO_ALG_ASYNC;
164
165        BUILD_BUG_ON(CRYPTO_TFM_REQ_MASK & CRYPTO_ALG_ASYNC);
166
167        return hash_walk_new_entry(walk);
168}
169EXPORT_SYMBOL_GPL(crypto_ahash_walk_first);
170
171static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
172                                unsigned int keylen)
173{
174        unsigned long alignmask = crypto_ahash_alignmask(tfm);
175        int ret;
176        u8 *buffer, *alignbuffer;
177        unsigned long absize;
178
179        absize = keylen + alignmask;
180        buffer = kmalloc(absize, GFP_KERNEL);
181        if (!buffer)
182                return -ENOMEM;
183
184        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
185        memcpy(alignbuffer, key, keylen);
186        ret = tfm->setkey(tfm, alignbuffer, keylen);
187        kzfree(buffer);
188        return ret;
189}
190
191int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
192                        unsigned int keylen)
193{
194        unsigned long alignmask = crypto_ahash_alignmask(tfm);
195
196        if ((unsigned long)key & alignmask)
197                return ahash_setkey_unaligned(tfm, key, keylen);
198
199        return tfm->setkey(tfm, key, keylen);
200}
201EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
202
203static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
204                          unsigned int keylen)
205{
206        return -ENOSYS;
207}
208
209static inline unsigned int ahash_align_buffer_size(unsigned len,
210                                                   unsigned long mask)
211{
212        return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
213}
214
215static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
216{
217        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
218        unsigned long alignmask = crypto_ahash_alignmask(tfm);
219        unsigned int ds = crypto_ahash_digestsize(tfm);
220        struct ahash_request_priv *priv;
221
222        priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
223                       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
224                       GFP_KERNEL : GFP_ATOMIC);
225        if (!priv)
226                return -ENOMEM;
227
228        /*
229         * WARNING: Voodoo programming below!
230         *
231         * The code below is obscure and hard to understand, thus explanation
232         * is necessary. See include/crypto/hash.h and include/linux/crypto.h
233         * to understand the layout of structures used here!
234         *
235         * The code here will replace portions of the ORIGINAL request with
236         * pointers to new code and buffers so the hashing operation can store
237         * the result in aligned buffer. We will call the modified request
238         * an ADJUSTED request.
239         *
240         * The newly mangled request will look as such:
241         *
242         * req {
243         *   .result        = ADJUSTED[new aligned buffer]
244         *   .base.complete = ADJUSTED[pointer to completion function]
245         *   .base.data     = ADJUSTED[*req (pointer to self)]
246         *   .priv          = ADJUSTED[new priv] {
247         *           .result   = ORIGINAL(result)
248         *           .complete = ORIGINAL(base.complete)
249         *           .data     = ORIGINAL(base.data)
250         *   }
251         */
252
253        priv->result = req->result;
254        priv->complete = req->base.complete;
255        priv->data = req->base.data;
256        priv->flags = req->base.flags;
257
258        /*
259         * WARNING: We do not backup req->priv here! The req->priv
260         *          is for internal use of the Crypto API and the
261         *          user must _NOT_ _EVER_ depend on it's content!
262         */
263
264        req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
265        req->base.complete = cplt;
266        req->base.data = req;
267        req->priv = priv;
268
269        return 0;
270}
271
272static void ahash_restore_req(struct ahash_request *req, int err)
273{
274        struct ahash_request_priv *priv = req->priv;
275
276        if (!err)
277                memcpy(priv->result, req->result,
278                       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
279
280        /* Restore the original crypto request. */
281        req->result = priv->result;
282
283        ahash_request_set_callback(req, priv->flags,
284                                   priv->complete, priv->data);
285        req->priv = NULL;
286
287        /* Free the req->priv.priv from the ADJUSTED request. */
288        kzfree(priv);
289}
290
291static void ahash_notify_einprogress(struct ahash_request *req)
292{
293        struct ahash_request_priv *priv = req->priv;
294        struct crypto_async_request oreq;
295
296        oreq.data = priv->data;
297
298        priv->complete(&oreq, -EINPROGRESS);
299}
300
301static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
302{
303        struct ahash_request *areq = req->data;
304
305        if (err == -EINPROGRESS) {
306                ahash_notify_einprogress(areq);
307                return;
308        }
309
310        /*
311         * Restore the original request, see ahash_op_unaligned() for what
312         * goes where.
313         *
314         * The "struct ahash_request *req" here is in fact the "req.base"
315         * from the ADJUSTED request from ahash_op_unaligned(), thus as it
316         * is a pointer to self, it is also the ADJUSTED "req" .
317         */
318
319        /* First copy req->result into req->priv.result */
320        ahash_restore_req(areq, err);
321
322        /* Complete the ORIGINAL request. */
323        areq->base.complete(&areq->base, err);
324}
325
326static int ahash_op_unaligned(struct ahash_request *req,
327                              int (*op)(struct ahash_request *))
328{
329        int err;
330
331        err = ahash_save_req(req, ahash_op_unaligned_done);
332        if (err)
333                return err;
334
335        err = op(req);
336        if (err == -EINPROGRESS ||
337            (err == -EBUSY && (ahash_request_flags(req) &
338                               CRYPTO_TFM_REQ_MAY_BACKLOG)))
339                return err;
340
341        ahash_restore_req(req, err);
342
343        return err;
344}
345
346static int crypto_ahash_op(struct ahash_request *req,
347                           int (*op)(struct ahash_request *))
348{
349        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
350        unsigned long alignmask = crypto_ahash_alignmask(tfm);
351
352        if ((unsigned long)req->result & alignmask)
353                return ahash_op_unaligned(req, op);
354
355        return op(req);
356}
357
358int crypto_ahash_final(struct ahash_request *req)
359{
360        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
361}
362EXPORT_SYMBOL_GPL(crypto_ahash_final);
363
364int crypto_ahash_finup(struct ahash_request *req)
365{
366        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
367}
368EXPORT_SYMBOL_GPL(crypto_ahash_finup);
369
370int crypto_ahash_digest(struct ahash_request *req)
371{
372        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
373}
374EXPORT_SYMBOL_GPL(crypto_ahash_digest);
375
376static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
377{
378        struct ahash_request *areq = req->data;
379
380        if (err == -EINPROGRESS)
381                return;
382
383        ahash_restore_req(areq, err);
384
385        areq->base.complete(&areq->base, err);
386}
387
388static int ahash_def_finup_finish1(struct ahash_request *req, int err)
389{
390        if (err)
391                goto out;
392
393        req->base.complete = ahash_def_finup_done2;
394
395        err = crypto_ahash_reqtfm(req)->final(req);
396        if (err == -EINPROGRESS ||
397            (err == -EBUSY && (ahash_request_flags(req) &
398                               CRYPTO_TFM_REQ_MAY_BACKLOG)))
399                return err;
400
401out:
402        ahash_restore_req(req, err);
403        return err;
404}
405
406static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
407{
408        struct ahash_request *areq = req->data;
409
410        if (err == -EINPROGRESS) {
411                ahash_notify_einprogress(areq);
412                return;
413        }
414
415        areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
416
417        err = ahash_def_finup_finish1(areq, err);
418        if (areq->priv)
419                return;
420
421        areq->base.complete(&areq->base, 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);
430        if (err)
431                return err;
432
433        err = tfm->update(req);
434        if (err == -EINPROGRESS ||
435            (err == -EBUSY && (ahash_request_flags(req) &
436                               CRYPTO_TFM_REQ_MAY_BACKLOG)))
437                return err;
438
439        return ahash_def_finup_finish1(req, err);
440}
441
442static int ahash_no_export(struct ahash_request *req, void *out)
443{
444        return -ENOSYS;
445}
446
447static int ahash_no_import(struct ahash_request *req, const void *in)
448{
449        return -ENOSYS;
450}
451
452static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
453{
454        struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
455        struct ahash_alg *alg = crypto_ahash_alg(hash);
456
457        hash->setkey = ahash_nosetkey;
458        hash->has_setkey = false;
459        hash->export = ahash_no_export;
460        hash->import = ahash_no_import;
461
462        if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
463                return crypto_init_shash_ops_async(tfm);
464
465        hash->init = alg->init;
466        hash->update = alg->update;
467        hash->final = alg->final;
468        hash->finup = alg->finup ?: ahash_def_finup;
469        hash->digest = alg->digest;
470
471        if (alg->setkey) {
472                hash->setkey = alg->setkey;
473                hash->has_setkey = true;
474        }
475        if (alg->export)
476                hash->export = alg->export;
477        if (alg->import)
478                hash->import = alg->import;
479
480        return 0;
481}
482
483static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
484{
485        if (alg->cra_type != &crypto_ahash_type)
486                return sizeof(struct crypto_shash *);
487
488        return crypto_alg_extsize(alg);
489}
490
491#ifdef CONFIG_NET
492static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
493{
494        struct crypto_report_hash rhash;
495
496        strncpy(rhash.type, "ahash", sizeof(rhash.type));
497
498        rhash.blocksize = alg->cra_blocksize;
499        rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
500
501        if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
502                    sizeof(struct crypto_report_hash), &rhash))
503                goto nla_put_failure;
504        return 0;
505
506nla_put_failure:
507        return -EMSGSIZE;
508}
509#else
510static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
511{
512        return -ENOSYS;
513}
514#endif
515
516static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
517        __attribute__ ((unused));
518static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
519{
520        seq_printf(m, "type         : ahash\n");
521        seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
522                                             "yes" : "no");
523        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
524        seq_printf(m, "digestsize   : %u\n",
525                   __crypto_hash_alg_common(alg)->digestsize);
526}
527
528const struct crypto_type crypto_ahash_type = {
529        .extsize = crypto_ahash_extsize,
530        .init_tfm = crypto_ahash_init_tfm,
531#ifdef CONFIG_PROC_FS
532        .show = crypto_ahash_show,
533#endif
534        .report = crypto_ahash_report,
535        .maskclear = ~CRYPTO_ALG_TYPE_MASK,
536        .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
537        .type = CRYPTO_ALG_TYPE_AHASH,
538        .tfmsize = offsetof(struct crypto_ahash, base),
539};
540EXPORT_SYMBOL_GPL(crypto_ahash_type);
541
542struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
543                                        u32 mask)
544{
545        return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
546}
547EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
548
549int crypto_has_ahash(const char *alg_name, u32 type, u32 mask)
550{
551        return crypto_type_has_alg(alg_name, &crypto_ahash_type, type, mask);
552}
553EXPORT_SYMBOL_GPL(crypto_has_ahash);
554
555static int ahash_prepare_alg(struct ahash_alg *alg)
556{
557        struct crypto_alg *base = &alg->halg.base;
558
559        if (alg->halg.digestsize > PAGE_SIZE / 8 ||
560            alg->halg.statesize > PAGE_SIZE / 8 ||
561            alg->halg.statesize == 0)
562                return -EINVAL;
563
564        base->cra_type = &crypto_ahash_type;
565        base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
566        base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
567
568        return 0;
569}
570
571int crypto_register_ahash(struct ahash_alg *alg)
572{
573        struct crypto_alg *base = &alg->halg.base;
574        int err;
575
576        err = ahash_prepare_alg(alg);
577        if (err)
578                return err;
579
580        return crypto_register_alg(base);
581}
582EXPORT_SYMBOL_GPL(crypto_register_ahash);
583
584int crypto_unregister_ahash(struct ahash_alg *alg)
585{
586        return crypto_unregister_alg(&alg->halg.base);
587}
588EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
589
590int ahash_register_instance(struct crypto_template *tmpl,
591                            struct ahash_instance *inst)
592{
593        int err;
594
595        err = ahash_prepare_alg(&inst->alg);
596        if (err)
597                return err;
598
599        return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
600}
601EXPORT_SYMBOL_GPL(ahash_register_instance);
602
603void ahash_free_instance(struct crypto_instance *inst)
604{
605        crypto_drop_spawn(crypto_instance_ctx(inst));
606        kfree(ahash_instance(inst));
607}
608EXPORT_SYMBOL_GPL(ahash_free_instance);
609
610int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
611                            struct hash_alg_common *alg,
612                            struct crypto_instance *inst)
613{
614        return crypto_init_spawn2(&spawn->base, &alg->base, inst,
615                                  &crypto_ahash_type);
616}
617EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
618
619struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
620{
621        struct crypto_alg *alg;
622
623        alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
624        return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
625}
626EXPORT_SYMBOL_GPL(ahash_attr_alg);
627
628MODULE_LICENSE("GPL");
629MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
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