source: src/linux/universal/linux-4.4/crypto/ahash.c @ 31885

Last change on this file since 31885 was 31885, checked in by brainslayer, 5 weeks ago

update

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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
171int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
172                                  struct crypto_hash_walk *walk,
173                                  struct scatterlist *sg, unsigned int len)
174{
175        walk->total = len;
176
177        if (!walk->total) {
178                walk->entrylen = 0;
179                return 0;
180        }
181
182        walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
183        walk->sg = sg;
184        walk->flags = hdesc->flags & CRYPTO_TFM_REQ_MASK;
185
186        return hash_walk_new_entry(walk);
187}
188
189static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
190                                unsigned int keylen)
191{
192        unsigned long alignmask = crypto_ahash_alignmask(tfm);
193        int ret;
194        u8 *buffer, *alignbuffer;
195        unsigned long absize;
196
197        absize = keylen + alignmask;
198        buffer = kmalloc(absize, GFP_KERNEL);
199        if (!buffer)
200                return -ENOMEM;
201
202        alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
203        memcpy(alignbuffer, key, keylen);
204        ret = tfm->setkey(tfm, alignbuffer, keylen);
205        kzfree(buffer);
206        return ret;
207}
208
209int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
210                        unsigned int keylen)
211{
212        unsigned long alignmask = crypto_ahash_alignmask(tfm);
213
214        if ((unsigned long)key & alignmask)
215                return ahash_setkey_unaligned(tfm, key, keylen);
216
217        return tfm->setkey(tfm, key, keylen);
218}
219EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
220
221static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
222                          unsigned int keylen)
223{
224        return -ENOSYS;
225}
226
227static inline unsigned int ahash_align_buffer_size(unsigned len,
228                                                   unsigned long mask)
229{
230        return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
231}
232
233static int ahash_save_req(struct ahash_request *req, crypto_completion_t cplt)
234{
235        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
236        unsigned long alignmask = crypto_ahash_alignmask(tfm);
237        unsigned int ds = crypto_ahash_digestsize(tfm);
238        struct ahash_request_priv *priv;
239
240        priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
241                       (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
242                       GFP_KERNEL : GFP_ATOMIC);
243        if (!priv)
244                return -ENOMEM;
245
246        /*
247         * WARNING: Voodoo programming below!
248         *
249         * The code below is obscure and hard to understand, thus explanation
250         * is necessary. See include/crypto/hash.h and include/linux/crypto.h
251         * to understand the layout of structures used here!
252         *
253         * The code here will replace portions of the ORIGINAL request with
254         * pointers to new code and buffers so the hashing operation can store
255         * the result in aligned buffer. We will call the modified request
256         * an ADJUSTED request.
257         *
258         * The newly mangled request will look as such:
259         *
260         * req {
261         *   .result        = ADJUSTED[new aligned buffer]
262         *   .base.complete = ADJUSTED[pointer to completion function]
263         *   .base.data     = ADJUSTED[*req (pointer to self)]
264         *   .priv          = ADJUSTED[new priv] {
265         *           .result   = ORIGINAL(result)
266         *           .complete = ORIGINAL(base.complete)
267         *           .data     = ORIGINAL(base.data)
268         *   }
269         */
270
271        priv->result = req->result;
272        priv->complete = req->base.complete;
273        priv->data = req->base.data;
274        priv->flags = req->base.flags;
275
276        /*
277         * WARNING: We do not backup req->priv here! The req->priv
278         *          is for internal use of the Crypto API and the
279         *          user must _NOT_ _EVER_ depend on it's content!
280         */
281
282        req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
283        req->base.complete = cplt;
284        req->base.data = req;
285        req->priv = priv;
286
287        return 0;
288}
289
290static void ahash_restore_req(struct ahash_request *req, int err)
291{
292        struct ahash_request_priv *priv = req->priv;
293
294        if (!err)
295                memcpy(priv->result, req->result,
296                       crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
297
298        /* Restore the original crypto request. */
299        req->result = priv->result;
300
301        ahash_request_set_callback(req, priv->flags,
302                                   priv->complete, priv->data);
303        req->priv = NULL;
304
305        /* Free the req->priv.priv from the ADJUSTED request. */
306        kzfree(priv);
307}
308
309static void ahash_notify_einprogress(struct ahash_request *req)
310{
311        struct ahash_request_priv *priv = req->priv;
312        struct crypto_async_request oreq;
313
314        oreq.data = priv->data;
315
316        priv->complete(&oreq, -EINPROGRESS);
317}
318
319static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
320{
321        struct ahash_request *areq = req->data;
322
323        if (err == -EINPROGRESS) {
324                ahash_notify_einprogress(areq);
325                return;
326        }
327
328        /*
329         * Restore the original request, see ahash_op_unaligned() for what
330         * goes where.
331         *
332         * The "struct ahash_request *req" here is in fact the "req.base"
333         * from the ADJUSTED request from ahash_op_unaligned(), thus as it
334         * is a pointer to self, it is also the ADJUSTED "req" .
335         */
336
337        /* First copy req->result into req->priv.result */
338        ahash_restore_req(areq, err);
339
340        /* Complete the ORIGINAL request. */
341        areq->base.complete(&areq->base, err);
342}
343
344static int ahash_op_unaligned(struct ahash_request *req,
345                              int (*op)(struct ahash_request *))
346{
347        int err;
348
349        err = ahash_save_req(req, ahash_op_unaligned_done);
350        if (err)
351                return err;
352
353        err = op(req);
354        if (err == -EINPROGRESS ||
355            (err == -EBUSY && (ahash_request_flags(req) &
356                               CRYPTO_TFM_REQ_MAY_BACKLOG)))
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        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
379}
380EXPORT_SYMBOL_GPL(crypto_ahash_final);
381
382int crypto_ahash_finup(struct ahash_request *req)
383{
384        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
385}
386EXPORT_SYMBOL_GPL(crypto_ahash_finup);
387
388int crypto_ahash_digest(struct ahash_request *req)
389{
390        return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
391}
392EXPORT_SYMBOL_GPL(crypto_ahash_digest);
393
394static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
395{
396        struct ahash_request *areq = req->data;
397
398        if (err == -EINPROGRESS)
399                return;
400
401        ahash_restore_req(areq, err);
402
403        areq->base.complete(&areq->base, err);
404}
405
406static int ahash_def_finup_finish1(struct ahash_request *req, int err)
407{
408        if (err)
409                goto out;
410
411        req->base.complete = ahash_def_finup_done2;
412
413        err = crypto_ahash_reqtfm(req)->final(req);
414        if (err == -EINPROGRESS ||
415            (err == -EBUSY && (ahash_request_flags(req) &
416                               CRYPTO_TFM_REQ_MAY_BACKLOG)))
417                return err;
418
419out:
420        ahash_restore_req(req, err);
421        return err;
422}
423
424static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
425{
426        struct ahash_request *areq = req->data;
427
428        if (err == -EINPROGRESS) {
429                ahash_notify_einprogress(areq);
430                return;
431        }
432
433        areq->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
434
435        err = ahash_def_finup_finish1(areq, err);
436        if (areq->priv)
437                return;
438
439        areq->base.complete(&areq->base, err);
440}
441
442static int ahash_def_finup(struct ahash_request *req)
443{
444        struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
445        int err;
446
447        err = ahash_save_req(req, ahash_def_finup_done1);
448        if (err)
449                return err;
450
451        err = tfm->update(req);
452        if (err == -EINPROGRESS ||
453            (err == -EBUSY && (ahash_request_flags(req) &
454                               CRYPTO_TFM_REQ_MAY_BACKLOG)))
455                return err;
456
457        return ahash_def_finup_finish1(req, err);
458}
459
460static int ahash_no_export(struct ahash_request *req, void *out)
461{
462        return -ENOSYS;
463}
464
465static int ahash_no_import(struct ahash_request *req, const void *in)
466{
467        return -ENOSYS;
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        hash->setkey = ahash_nosetkey;
476        hash->has_setkey = false;
477        hash->export = ahash_no_export;
478        hash->import = ahash_no_import;
479
480        if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
481                return crypto_init_shash_ops_async(tfm);
482
483        hash->init = alg->init;
484        hash->update = alg->update;
485        hash->final = alg->final;
486        hash->finup = alg->finup ?: ahash_def_finup;
487        hash->digest = alg->digest;
488
489        if (alg->setkey) {
490                hash->setkey = alg->setkey;
491                hash->has_setkey = true;
492        }
493        if (alg->export)
494                hash->export = alg->export;
495        if (alg->import)
496                hash->import = alg->import;
497
498        return 0;
499}
500
501static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
502{
503        if (alg->cra_type == &crypto_ahash_type)
504                return alg->cra_ctxsize;
505
506        return sizeof(struct crypto_shash *);
507}
508
509#ifdef CONFIG_NET
510static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
511{
512        struct crypto_report_hash rhash;
513
514        strncpy(rhash.type, "ahash", sizeof(rhash.type));
515
516        rhash.blocksize = alg->cra_blocksize;
517        rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
518
519        if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
520                    sizeof(struct crypto_report_hash), &rhash))
521                goto nla_put_failure;
522        return 0;
523
524nla_put_failure:
525        return -EMSGSIZE;
526}
527#else
528static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
529{
530        return -ENOSYS;
531}
532#endif
533
534static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
535        __attribute__ ((unused));
536static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
537{
538        seq_printf(m, "type         : ahash\n");
539        seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
540                                             "yes" : "no");
541        seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
542        seq_printf(m, "digestsize   : %u\n",
543                   __crypto_hash_alg_common(alg)->digestsize);
544}
545
546const struct crypto_type crypto_ahash_type = {
547        .extsize = crypto_ahash_extsize,
548        .init_tfm = crypto_ahash_init_tfm,
549#ifdef CONFIG_PROC_FS
550        .show = crypto_ahash_show,
551#endif
552        .report = crypto_ahash_report,
553        .maskclear = ~CRYPTO_ALG_TYPE_MASK,
554        .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
555        .type = CRYPTO_ALG_TYPE_AHASH,
556        .tfmsize = offsetof(struct crypto_ahash, base),
557};
558EXPORT_SYMBOL_GPL(crypto_ahash_type);
559
560struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
561                                        u32 mask)
562{
563        return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
564}
565EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
566
567static int ahash_prepare_alg(struct ahash_alg *alg)
568{
569        struct crypto_alg *base = &alg->halg.base;
570
571        if (alg->halg.digestsize > PAGE_SIZE / 8 ||
572            alg->halg.statesize > PAGE_SIZE / 8 ||
573            alg->halg.statesize == 0)
574                return -EINVAL;
575
576        base->cra_type = &crypto_ahash_type;
577        base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
578        base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
579
580        return 0;
581}
582
583int crypto_register_ahash(struct ahash_alg *alg)
584{
585        struct crypto_alg *base = &alg->halg.base;
586        int err;
587
588        err = ahash_prepare_alg(alg);
589        if (err)
590                return err;
591
592        return crypto_register_alg(base);
593}
594EXPORT_SYMBOL_GPL(crypto_register_ahash);
595
596int crypto_unregister_ahash(struct ahash_alg *alg)
597{
598        return crypto_unregister_alg(&alg->halg.base);
599}
600EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
601
602int ahash_register_instance(struct crypto_template *tmpl,
603                            struct ahash_instance *inst)
604{
605        int err;
606
607        err = ahash_prepare_alg(&inst->alg);
608        if (err)
609                return err;
610
611        return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
612}
613EXPORT_SYMBOL_GPL(ahash_register_instance);
614
615void ahash_free_instance(struct crypto_instance *inst)
616{
617        crypto_drop_spawn(crypto_instance_ctx(inst));
618        kfree(ahash_instance(inst));
619}
620EXPORT_SYMBOL_GPL(ahash_free_instance);
621
622int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
623                            struct hash_alg_common *alg,
624                            struct crypto_instance *inst)
625{
626        return crypto_init_spawn2(&spawn->base, &alg->base, inst,
627                                  &crypto_ahash_type);
628}
629EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
630
631struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
632{
633        struct crypto_alg *alg;
634
635        alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
636        return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
637}
638EXPORT_SYMBOL_GPL(ahash_attr_alg);
639
640MODULE_LICENSE("GPL");
641MODULE_DESCRIPTION("Asynchronous cryptographic hash type");
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