[media] uvcvideo: improve urb buffer allocation
[linux-3.10.git] / crypto / ahash.c
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/err.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/seq_file.h>
24 #include <linux/cryptouser.h>
25 #include <net/netlink.h>
26
27 #include "internal.h"
28
29 struct ahash_request_priv {
30         crypto_completion_t complete;
31         void *data;
32         u8 *result;
33         void *ubuf[] CRYPTO_MINALIGN_ATTR;
34 };
35
36 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
37 {
38         return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
39                             halg);
40 }
41
42 static int hash_walk_next(struct crypto_hash_walk *walk)
43 {
44         unsigned int alignmask = walk->alignmask;
45         unsigned int offset = walk->offset;
46         unsigned int nbytes = min(walk->entrylen,
47                                   ((unsigned int)(PAGE_SIZE)) - offset);
48
49         walk->data = kmap_atomic(walk->pg);
50         walk->data += offset;
51
52         if (offset & alignmask) {
53                 unsigned int unaligned = alignmask + 1 - (offset & alignmask);
54                 if (nbytes > unaligned)
55                         nbytes = unaligned;
56         }
57
58         walk->entrylen -= nbytes;
59         return nbytes;
60 }
61
62 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
63 {
64         struct scatterlist *sg;
65
66         sg = walk->sg;
67         walk->pg = sg_page(sg);
68         walk->offset = sg->offset;
69         walk->entrylen = sg->length;
70
71         if (walk->entrylen > walk->total)
72                 walk->entrylen = walk->total;
73         walk->total -= walk->entrylen;
74
75         return hash_walk_next(walk);
76 }
77
78 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
79 {
80         unsigned int alignmask = walk->alignmask;
81         unsigned int nbytes = walk->entrylen;
82
83         walk->data -= walk->offset;
84
85         if (nbytes && walk->offset & alignmask && !err) {
86                 walk->offset = ALIGN(walk->offset, alignmask + 1);
87                 walk->data += walk->offset;
88
89                 nbytes = min(nbytes,
90                              ((unsigned int)(PAGE_SIZE)) - walk->offset);
91                 walk->entrylen -= nbytes;
92
93                 return nbytes;
94         }
95
96         kunmap_atomic(walk->data);
97         crypto_yield(walk->flags);
98
99         if (err)
100                 return err;
101
102         if (nbytes) {
103                 walk->offset = 0;
104                 walk->pg++;
105                 return hash_walk_next(walk);
106         }
107
108         if (!walk->total)
109                 return 0;
110
111         walk->sg = scatterwalk_sg_next(walk->sg);
112
113         return hash_walk_new_entry(walk);
114 }
115 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
116
117 int crypto_hash_walk_first(struct ahash_request *req,
118                            struct crypto_hash_walk *walk)
119 {
120         walk->total = req->nbytes;
121
122         if (!walk->total)
123                 return 0;
124
125         walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
126         walk->sg = req->src;
127         walk->flags = req->base.flags;
128
129         return hash_walk_new_entry(walk);
130 }
131 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
132
133 int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
134                                   struct crypto_hash_walk *walk,
135                                   struct scatterlist *sg, unsigned int len)
136 {
137         walk->total = len;
138
139         if (!walk->total)
140                 return 0;
141
142         walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
143         walk->sg = sg;
144         walk->flags = hdesc->flags;
145
146         return hash_walk_new_entry(walk);
147 }
148
149 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
150                                 unsigned int keylen)
151 {
152         unsigned long alignmask = crypto_ahash_alignmask(tfm);
153         int ret;
154         u8 *buffer, *alignbuffer;
155         unsigned long absize;
156
157         absize = keylen + alignmask;
158         buffer = kmalloc(absize, GFP_KERNEL);
159         if (!buffer)
160                 return -ENOMEM;
161
162         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
163         memcpy(alignbuffer, key, keylen);
164         ret = tfm->setkey(tfm, alignbuffer, keylen);
165         kzfree(buffer);
166         return ret;
167 }
168
169 int crypto_ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
170                         unsigned int keylen)
171 {
172         unsigned long alignmask = crypto_ahash_alignmask(tfm);
173
174         if ((unsigned long)key & alignmask)
175                 return ahash_setkey_unaligned(tfm, key, keylen);
176
177         return tfm->setkey(tfm, key, keylen);
178 }
179 EXPORT_SYMBOL_GPL(crypto_ahash_setkey);
180
181 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
182                           unsigned int keylen)
183 {
184         return -ENOSYS;
185 }
186
187 static inline unsigned int ahash_align_buffer_size(unsigned len,
188                                                    unsigned long mask)
189 {
190         return len + (mask & ~(crypto_tfm_ctx_alignment() - 1));
191 }
192
193 static void ahash_op_unaligned_finish(struct ahash_request *req, int err)
194 {
195         struct ahash_request_priv *priv = req->priv;
196
197         if (err == -EINPROGRESS)
198                 return;
199
200         if (!err)
201                 memcpy(priv->result, req->result,
202                        crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
203
204         kzfree(priv);
205 }
206
207 static void ahash_op_unaligned_done(struct crypto_async_request *req, int err)
208 {
209         struct ahash_request *areq = req->data;
210         struct ahash_request_priv *priv = areq->priv;
211         crypto_completion_t complete = priv->complete;
212         void *data = priv->data;
213
214         ahash_op_unaligned_finish(areq, err);
215
216         complete(data, err);
217 }
218
219 static int ahash_op_unaligned(struct ahash_request *req,
220                               int (*op)(struct ahash_request *))
221 {
222         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
223         unsigned long alignmask = crypto_ahash_alignmask(tfm);
224         unsigned int ds = crypto_ahash_digestsize(tfm);
225         struct ahash_request_priv *priv;
226         int err;
227
228         priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
229                        (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
230                        GFP_KERNEL : GFP_ATOMIC);
231         if (!priv)
232                 return -ENOMEM;
233
234         priv->result = req->result;
235         priv->complete = req->base.complete;
236         priv->data = req->base.data;
237
238         req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
239         req->base.complete = ahash_op_unaligned_done;
240         req->base.data = req;
241         req->priv = priv;
242
243         err = op(req);
244         ahash_op_unaligned_finish(req, err);
245
246         return err;
247 }
248
249 static int crypto_ahash_op(struct ahash_request *req,
250                            int (*op)(struct ahash_request *))
251 {
252         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
253         unsigned long alignmask = crypto_ahash_alignmask(tfm);
254
255         if ((unsigned long)req->result & alignmask)
256                 return ahash_op_unaligned(req, op);
257
258         return op(req);
259 }
260
261 int crypto_ahash_final(struct ahash_request *req)
262 {
263         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->final);
264 }
265 EXPORT_SYMBOL_GPL(crypto_ahash_final);
266
267 int crypto_ahash_finup(struct ahash_request *req)
268 {
269         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->finup);
270 }
271 EXPORT_SYMBOL_GPL(crypto_ahash_finup);
272
273 int crypto_ahash_digest(struct ahash_request *req)
274 {
275         return crypto_ahash_op(req, crypto_ahash_reqtfm(req)->digest);
276 }
277 EXPORT_SYMBOL_GPL(crypto_ahash_digest);
278
279 static void ahash_def_finup_finish2(struct ahash_request *req, int err)
280 {
281         struct ahash_request_priv *priv = req->priv;
282
283         if (err == -EINPROGRESS)
284                 return;
285
286         if (!err)
287                 memcpy(priv->result, req->result,
288                        crypto_ahash_digestsize(crypto_ahash_reqtfm(req)));
289
290         kzfree(priv);
291 }
292
293 static void ahash_def_finup_done2(struct crypto_async_request *req, int err)
294 {
295         struct ahash_request *areq = req->data;
296         struct ahash_request_priv *priv = areq->priv;
297         crypto_completion_t complete = priv->complete;
298         void *data = priv->data;
299
300         ahash_def_finup_finish2(areq, err);
301
302         complete(data, err);
303 }
304
305 static int ahash_def_finup_finish1(struct ahash_request *req, int err)
306 {
307         if (err)
308                 goto out;
309
310         req->base.complete = ahash_def_finup_done2;
311         req->base.flags &= ~CRYPTO_TFM_REQ_MAY_SLEEP;
312         err = crypto_ahash_reqtfm(req)->final(req);
313
314 out:
315         ahash_def_finup_finish2(req, err);
316         return err;
317 }
318
319 static void ahash_def_finup_done1(struct crypto_async_request *req, int err)
320 {
321         struct ahash_request *areq = req->data;
322         struct ahash_request_priv *priv = areq->priv;
323         crypto_completion_t complete = priv->complete;
324         void *data = priv->data;
325
326         err = ahash_def_finup_finish1(areq, err);
327
328         complete(data, err);
329 }
330
331 static int ahash_def_finup(struct ahash_request *req)
332 {
333         struct crypto_ahash *tfm = crypto_ahash_reqtfm(req);
334         unsigned long alignmask = crypto_ahash_alignmask(tfm);
335         unsigned int ds = crypto_ahash_digestsize(tfm);
336         struct ahash_request_priv *priv;
337
338         priv = kmalloc(sizeof(*priv) + ahash_align_buffer_size(ds, alignmask),
339                        (req->base.flags & CRYPTO_TFM_REQ_MAY_SLEEP) ?
340                        GFP_KERNEL : GFP_ATOMIC);
341         if (!priv)
342                 return -ENOMEM;
343
344         priv->result = req->result;
345         priv->complete = req->base.complete;
346         priv->data = req->base.data;
347
348         req->result = PTR_ALIGN((u8 *)priv->ubuf, alignmask + 1);
349         req->base.complete = ahash_def_finup_done1;
350         req->base.data = req;
351         req->priv = priv;
352
353         return ahash_def_finup_finish1(req, tfm->update(req));
354 }
355
356 static int ahash_no_export(struct ahash_request *req, void *out)
357 {
358         return -ENOSYS;
359 }
360
361 static int ahash_no_import(struct ahash_request *req, const void *in)
362 {
363         return -ENOSYS;
364 }
365
366 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
367 {
368         struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
369         struct ahash_alg *alg = crypto_ahash_alg(hash);
370
371         hash->setkey = ahash_nosetkey;
372         hash->export = ahash_no_export;
373         hash->import = ahash_no_import;
374
375         if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
376                 return crypto_init_shash_ops_async(tfm);
377
378         hash->init = alg->init;
379         hash->update = alg->update;
380         hash->final = alg->final;
381         hash->finup = alg->finup ?: ahash_def_finup;
382         hash->digest = alg->digest;
383
384         if (alg->setkey)
385                 hash->setkey = alg->setkey;
386         if (alg->export)
387                 hash->export = alg->export;
388         if (alg->import)
389                 hash->import = alg->import;
390
391         return 0;
392 }
393
394 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
395 {
396         if (alg->cra_type == &crypto_ahash_type)
397                 return alg->cra_ctxsize;
398
399         return sizeof(struct crypto_shash *);
400 }
401
402 #ifdef CONFIG_NET
403 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
404 {
405         struct crypto_report_hash rhash;
406
407         strncpy(rhash.type, "ahash", sizeof(rhash.type));
408
409         rhash.blocksize = alg->cra_blocksize;
410         rhash.digestsize = __crypto_hash_alg_common(alg)->digestsize;
411
412         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
413                     sizeof(struct crypto_report_hash), &rhash))
414                 goto nla_put_failure;
415         return 0;
416
417 nla_put_failure:
418         return -EMSGSIZE;
419 }
420 #else
421 static int crypto_ahash_report(struct sk_buff *skb, struct crypto_alg *alg)
422 {
423         return -ENOSYS;
424 }
425 #endif
426
427 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
428         __attribute__ ((unused));
429 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
430 {
431         seq_printf(m, "type         : ahash\n");
432         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
433                                              "yes" : "no");
434         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
435         seq_printf(m, "digestsize   : %u\n",
436                    __crypto_hash_alg_common(alg)->digestsize);
437 }
438
439 const struct crypto_type crypto_ahash_type = {
440         .extsize = crypto_ahash_extsize,
441         .init_tfm = crypto_ahash_init_tfm,
442 #ifdef CONFIG_PROC_FS
443         .show = crypto_ahash_show,
444 #endif
445         .report = crypto_ahash_report,
446         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
447         .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
448         .type = CRYPTO_ALG_TYPE_AHASH,
449         .tfmsize = offsetof(struct crypto_ahash, base),
450 };
451 EXPORT_SYMBOL_GPL(crypto_ahash_type);
452
453 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
454                                         u32 mask)
455 {
456         return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
457 }
458 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
459
460 static int ahash_prepare_alg(struct ahash_alg *alg)
461 {
462         struct crypto_alg *base = &alg->halg.base;
463
464         if (alg->halg.digestsize > PAGE_SIZE / 8 ||
465             alg->halg.statesize > PAGE_SIZE / 8)
466                 return -EINVAL;
467
468         base->cra_type = &crypto_ahash_type;
469         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
470         base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
471
472         return 0;
473 }
474
475 int crypto_register_ahash(struct ahash_alg *alg)
476 {
477         struct crypto_alg *base = &alg->halg.base;
478         int err;
479
480         err = ahash_prepare_alg(alg);
481         if (err)
482                 return err;
483
484         return crypto_register_alg(base);
485 }
486 EXPORT_SYMBOL_GPL(crypto_register_ahash);
487
488 int crypto_unregister_ahash(struct ahash_alg *alg)
489 {
490         return crypto_unregister_alg(&alg->halg.base);
491 }
492 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
493
494 int ahash_register_instance(struct crypto_template *tmpl,
495                             struct ahash_instance *inst)
496 {
497         int err;
498
499         err = ahash_prepare_alg(&inst->alg);
500         if (err)
501                 return err;
502
503         return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
504 }
505 EXPORT_SYMBOL_GPL(ahash_register_instance);
506
507 void ahash_free_instance(struct crypto_instance *inst)
508 {
509         crypto_drop_spawn(crypto_instance_ctx(inst));
510         kfree(ahash_instance(inst));
511 }
512 EXPORT_SYMBOL_GPL(ahash_free_instance);
513
514 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
515                             struct hash_alg_common *alg,
516                             struct crypto_instance *inst)
517 {
518         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
519                                   &crypto_ahash_type);
520 }
521 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
522
523 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
524 {
525         struct crypto_alg *alg;
526
527         alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
528         return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
529 }
530 EXPORT_SYMBOL_GPL(ahash_attr_alg);
531
532 MODULE_LICENSE("GPL");
533 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");