crypto: api - Remove frontend argument from extsize/init_tfm
[linux-2.6.git] / crypto / shash.c
1 /*
2  * Synchronous Cryptographic Hash operations.
3  *
4  * Copyright (c) 2008 Herbert Xu <herbert@gondor.apana.org.au>
5  *
6  * This program is free software; you can redistribute it and/or modify it
7  * under the terms of the GNU General Public License as published by the Free
8  * Software Foundation; either version 2 of the License, or (at your option)
9  * any later version.
10  *
11  */
12
13 #include <crypto/scatterwalk.h>
14 #include <crypto/internal/hash.h>
15 #include <linux/err.h>
16 #include <linux/kernel.h>
17 #include <linux/module.h>
18 #include <linux/slab.h>
19 #include <linux/seq_file.h>
20
21 #include "internal.h"
22
23 static const struct crypto_type crypto_shash_type;
24
25 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
26                            unsigned int keylen)
27 {
28         return -ENOSYS;
29 }
30
31 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
32                                   unsigned int keylen)
33 {
34         struct shash_alg *shash = crypto_shash_alg(tfm);
35         unsigned long alignmask = crypto_shash_alignmask(tfm);
36         unsigned long absize;
37         u8 *buffer, *alignbuffer;
38         int err;
39
40         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
41         buffer = kmalloc(absize, GFP_KERNEL);
42         if (!buffer)
43                 return -ENOMEM;
44
45         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
46         memcpy(alignbuffer, key, keylen);
47         err = shash->setkey(tfm, alignbuffer, keylen);
48         memset(alignbuffer, 0, keylen);
49         kfree(buffer);
50         return err;
51 }
52
53 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
54                         unsigned int keylen)
55 {
56         struct shash_alg *shash = crypto_shash_alg(tfm);
57         unsigned long alignmask = crypto_shash_alignmask(tfm);
58
59         if ((unsigned long)key & alignmask)
60                 return shash_setkey_unaligned(tfm, key, keylen);
61
62         return shash->setkey(tfm, key, keylen);
63 }
64 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
65
66 static inline unsigned int shash_align_buffer_size(unsigned len,
67                                                    unsigned long mask)
68 {
69         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
70 }
71
72 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
73                                   unsigned int len)
74 {
75         struct crypto_shash *tfm = desc->tfm;
76         struct shash_alg *shash = crypto_shash_alg(tfm);
77         unsigned long alignmask = crypto_shash_alignmask(tfm);
78         unsigned int unaligned_len = alignmask + 1 -
79                                      ((unsigned long)data & alignmask);
80         u8 buf[shash_align_buffer_size(unaligned_len, alignmask)]
81                 __attribute__ ((aligned));
82
83         if (unaligned_len > len)
84                 unaligned_len = len;
85
86         memcpy(buf, data, unaligned_len);
87
88         return shash->update(desc, buf, unaligned_len) ?:
89                shash->update(desc, data + unaligned_len, len - unaligned_len);
90 }
91
92 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
93                         unsigned int len)
94 {
95         struct crypto_shash *tfm = desc->tfm;
96         struct shash_alg *shash = crypto_shash_alg(tfm);
97         unsigned long alignmask = crypto_shash_alignmask(tfm);
98
99         if ((unsigned long)data & alignmask)
100                 return shash_update_unaligned(desc, data, len);
101
102         return shash->update(desc, data, len);
103 }
104 EXPORT_SYMBOL_GPL(crypto_shash_update);
105
106 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
107 {
108         struct crypto_shash *tfm = desc->tfm;
109         unsigned long alignmask = crypto_shash_alignmask(tfm);
110         struct shash_alg *shash = crypto_shash_alg(tfm);
111         unsigned int ds = crypto_shash_digestsize(tfm);
112         u8 buf[shash_align_buffer_size(ds, alignmask)]
113                 __attribute__ ((aligned));
114         int err;
115
116         err = shash->final(desc, buf);
117         memcpy(out, buf, ds);
118         return err;
119 }
120
121 int crypto_shash_final(struct shash_desc *desc, u8 *out)
122 {
123         struct crypto_shash *tfm = desc->tfm;
124         struct shash_alg *shash = crypto_shash_alg(tfm);
125         unsigned long alignmask = crypto_shash_alignmask(tfm);
126
127         if ((unsigned long)out & alignmask)
128                 return shash_final_unaligned(desc, out);
129
130         return shash->final(desc, out);
131 }
132 EXPORT_SYMBOL_GPL(crypto_shash_final);
133
134 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
135                                  unsigned int len, u8 *out)
136 {
137         return crypto_shash_update(desc, data, len) ?:
138                crypto_shash_final(desc, out);
139 }
140
141 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
142                        unsigned int len, u8 *out)
143 {
144         struct crypto_shash *tfm = desc->tfm;
145         struct shash_alg *shash = crypto_shash_alg(tfm);
146         unsigned long alignmask = crypto_shash_alignmask(tfm);
147
148         if (((unsigned long)data | (unsigned long)out) & alignmask)
149                 return shash_finup_unaligned(desc, data, len, out);
150
151         return shash->finup(desc, data, len, out);
152 }
153 EXPORT_SYMBOL_GPL(crypto_shash_finup);
154
155 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
156                                   unsigned int len, u8 *out)
157 {
158         return crypto_shash_init(desc) ?:
159                crypto_shash_finup(desc, data, len, out);
160 }
161
162 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
163                         unsigned int len, u8 *out)
164 {
165         struct crypto_shash *tfm = desc->tfm;
166         struct shash_alg *shash = crypto_shash_alg(tfm);
167         unsigned long alignmask = crypto_shash_alignmask(tfm);
168
169         if (((unsigned long)data | (unsigned long)out) & alignmask)
170                 return shash_digest_unaligned(desc, data, len, out);
171
172         return shash->digest(desc, data, len, out);
173 }
174 EXPORT_SYMBOL_GPL(crypto_shash_digest);
175
176 static int shash_no_export(struct shash_desc *desc, void *out)
177 {
178         return -ENOSYS;
179 }
180
181 static int shash_no_import(struct shash_desc *desc, const void *in)
182 {
183         return -ENOSYS;
184 }
185
186 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
187                               unsigned int keylen)
188 {
189         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
190
191         return crypto_shash_setkey(*ctx, key, keylen);
192 }
193
194 static int shash_async_init(struct ahash_request *req)
195 {
196         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
197         struct shash_desc *desc = ahash_request_ctx(req);
198
199         desc->tfm = *ctx;
200         desc->flags = req->base.flags;
201
202         return crypto_shash_init(desc);
203 }
204
205 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
206 {
207         struct crypto_hash_walk walk;
208         int nbytes;
209
210         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
211              nbytes = crypto_hash_walk_done(&walk, nbytes))
212                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
213
214         return nbytes;
215 }
216 EXPORT_SYMBOL_GPL(shash_ahash_update);
217
218 static int shash_async_update(struct ahash_request *req)
219 {
220         return shash_ahash_update(req, ahash_request_ctx(req));
221 }
222
223 static int shash_async_final(struct ahash_request *req)
224 {
225         return crypto_shash_final(ahash_request_ctx(req), req->result);
226 }
227
228 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
229 {
230         struct scatterlist *sg = req->src;
231         unsigned int offset = sg->offset;
232         unsigned int nbytes = req->nbytes;
233         int err;
234
235         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
236                 void *data;
237
238                 data = crypto_kmap(sg_page(sg), 0);
239                 err = crypto_shash_digest(desc, data + offset, nbytes,
240                                           req->result);
241                 crypto_kunmap(data, 0);
242                 crypto_yield(desc->flags);
243         } else
244                 err = crypto_shash_init(desc) ?:
245                       shash_ahash_update(req, desc) ?:
246                       crypto_shash_final(desc, req->result);
247
248         return err;
249 }
250 EXPORT_SYMBOL_GPL(shash_ahash_digest);
251
252 static int shash_async_digest(struct ahash_request *req)
253 {
254         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
255         struct shash_desc *desc = ahash_request_ctx(req);
256
257         desc->tfm = *ctx;
258         desc->flags = req->base.flags;
259
260         return shash_ahash_digest(req, desc);
261 }
262
263 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
264 {
265         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
266
267         crypto_free_shash(*ctx);
268 }
269
270 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
271 {
272         struct crypto_alg *calg = tfm->__crt_alg;
273         struct shash_alg *alg = __crypto_shash_alg(calg);
274         struct ahash_tfm *crt = &tfm->crt_ahash;
275         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
276         struct crypto_shash *shash;
277
278         if (!crypto_mod_get(calg))
279                 return -EAGAIN;
280
281         shash = crypto_create_tfm(calg, &crypto_shash_type);
282         if (IS_ERR(shash)) {
283                 crypto_mod_put(calg);
284                 return PTR_ERR(shash);
285         }
286
287         *ctx = shash;
288         tfm->exit = crypto_exit_shash_ops_async;
289
290         crt->init = shash_async_init;
291         crt->update = shash_async_update;
292         crt->final  = shash_async_final;
293         crt->digest = shash_async_digest;
294         crt->setkey = shash_async_setkey;
295
296         crt->digestsize = alg->digestsize;
297         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
298
299         return 0;
300 }
301
302 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
303                                unsigned int keylen)
304 {
305         struct shash_desc **descp = crypto_hash_ctx(tfm);
306         struct shash_desc *desc = *descp;
307
308         return crypto_shash_setkey(desc->tfm, key, keylen);
309 }
310
311 static int shash_compat_init(struct hash_desc *hdesc)
312 {
313         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
314         struct shash_desc *desc = *descp;
315
316         desc->flags = hdesc->flags;
317
318         return crypto_shash_init(desc);
319 }
320
321 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
322                                unsigned int len)
323 {
324         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
325         struct shash_desc *desc = *descp;
326         struct crypto_hash_walk walk;
327         int nbytes;
328
329         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
330              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
331                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
332
333         return nbytes;
334 }
335
336 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
337 {
338         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
339
340         return crypto_shash_final(*descp, out);
341 }
342
343 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
344                                unsigned int nbytes, u8 *out)
345 {
346         unsigned int offset = sg->offset;
347         int err;
348
349         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
350                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
351                 struct shash_desc *desc = *descp;
352                 void *data;
353
354                 desc->flags = hdesc->flags;
355
356                 data = crypto_kmap(sg_page(sg), 0);
357                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
358                 crypto_kunmap(data, 0);
359                 crypto_yield(desc->flags);
360                 goto out;
361         }
362
363         err = shash_compat_init(hdesc);
364         if (err)
365                 goto out;
366
367         err = shash_compat_update(hdesc, sg, nbytes);
368         if (err)
369                 goto out;
370
371         err = shash_compat_final(hdesc, out);
372
373 out:
374         return err;
375 }
376
377 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
378 {
379         struct shash_desc **descp = crypto_tfm_ctx(tfm);
380         struct shash_desc *desc = *descp;
381
382         crypto_free_shash(desc->tfm);
383         kzfree(desc);
384 }
385
386 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
387 {
388         struct hash_tfm *crt = &tfm->crt_hash;
389         struct crypto_alg *calg = tfm->__crt_alg;
390         struct shash_alg *alg = __crypto_shash_alg(calg);
391         struct shash_desc **descp = crypto_tfm_ctx(tfm);
392         struct crypto_shash *shash;
393         struct shash_desc *desc;
394
395         if (!crypto_mod_get(calg))
396                 return -EAGAIN;
397
398         shash = crypto_create_tfm(calg, &crypto_shash_type);
399         if (IS_ERR(shash)) {
400                 crypto_mod_put(calg);
401                 return PTR_ERR(shash);
402         }
403
404         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
405                        GFP_KERNEL);
406         if (!desc) {
407                 crypto_free_shash(shash);
408                 return -ENOMEM;
409         }
410
411         *descp = desc;
412         desc->tfm = shash;
413         tfm->exit = crypto_exit_shash_ops_compat;
414
415         crt->init = shash_compat_init;
416         crt->update = shash_compat_update;
417         crt->final  = shash_compat_final;
418         crt->digest = shash_compat_digest;
419         crt->setkey = shash_compat_setkey;
420
421         crt->digestsize = alg->digestsize;
422
423         return 0;
424 }
425
426 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
427 {
428         switch (mask & CRYPTO_ALG_TYPE_MASK) {
429         case CRYPTO_ALG_TYPE_HASH_MASK:
430                 return crypto_init_shash_ops_compat(tfm);
431         case CRYPTO_ALG_TYPE_AHASH_MASK:
432                 return crypto_init_shash_ops_async(tfm);
433         }
434
435         return -EINVAL;
436 }
437
438 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
439                                          u32 mask)
440 {
441         switch (mask & CRYPTO_ALG_TYPE_MASK) {
442         case CRYPTO_ALG_TYPE_HASH_MASK:
443                 return sizeof(struct shash_desc *);
444         case CRYPTO_ALG_TYPE_AHASH_MASK:
445                 return sizeof(struct crypto_shash *);
446         }
447
448         return 0;
449 }
450
451 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
452 {
453         struct crypto_shash *hash = __crypto_shash_cast(tfm);
454
455         hash->descsize = crypto_shash_alg(hash)->descsize;
456         return 0;
457 }
458
459 static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
460 {
461         return alg->cra_ctxsize;
462 }
463
464 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
465         __attribute__ ((unused));
466 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
467 {
468         struct shash_alg *salg = __crypto_shash_alg(alg);
469
470         seq_printf(m, "type         : shash\n");
471         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
472         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
473 }
474
475 static const struct crypto_type crypto_shash_type = {
476         .ctxsize = crypto_shash_ctxsize,
477         .extsize = crypto_shash_extsize,
478         .init = crypto_init_shash_ops,
479         .init_tfm = crypto_shash_init_tfm,
480 #ifdef CONFIG_PROC_FS
481         .show = crypto_shash_show,
482 #endif
483         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
484         .maskset = CRYPTO_ALG_TYPE_MASK,
485         .type = CRYPTO_ALG_TYPE_SHASH,
486         .tfmsize = offsetof(struct crypto_shash, base),
487 };
488
489 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
490                                         u32 mask)
491 {
492         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
493 }
494 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
495
496 static int shash_prepare_alg(struct shash_alg *alg)
497 {
498         struct crypto_alg *base = &alg->base;
499
500         if (alg->digestsize > PAGE_SIZE / 8 ||
501             alg->descsize > PAGE_SIZE / 8 ||
502             alg->statesize > PAGE_SIZE / 8)
503                 return -EINVAL;
504
505         base->cra_type = &crypto_shash_type;
506         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
507         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
508
509         if (!alg->finup)
510                 alg->finup = shash_finup_unaligned;
511         if (!alg->digest)
512                 alg->digest = shash_digest_unaligned;
513         if (!alg->import)
514                 alg->import = shash_no_import;
515         if (!alg->export)
516                 alg->export = shash_no_export;
517         if (!alg->setkey)
518                 alg->setkey = shash_no_setkey;
519
520         return 0;
521 }
522
523 int crypto_register_shash(struct shash_alg *alg)
524 {
525         struct crypto_alg *base = &alg->base;
526         int err;
527
528         err = shash_prepare_alg(alg);
529         if (err)
530                 return err;
531
532         return crypto_register_alg(base);
533 }
534 EXPORT_SYMBOL_GPL(crypto_register_shash);
535
536 int crypto_unregister_shash(struct shash_alg *alg)
537 {
538         return crypto_unregister_alg(&alg->base);
539 }
540 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
541
542 int shash_register_instance(struct crypto_template *tmpl,
543                             struct shash_instance *inst)
544 {
545         int err;
546
547         err = shash_prepare_alg(&inst->alg);
548         if (err)
549                 return err;
550
551         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
552 }
553 EXPORT_SYMBOL_GPL(shash_register_instance);
554
555 void shash_free_instance(struct crypto_instance *inst)
556 {
557         crypto_drop_spawn(crypto_instance_ctx(inst));
558         kfree(shash_instance(inst));
559 }
560 EXPORT_SYMBOL_GPL(shash_free_instance);
561
562 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
563                             struct shash_alg *alg,
564                             struct crypto_instance *inst)
565 {
566         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
567                                   &crypto_shash_type);
568 }
569 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
570
571 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
572 {
573         struct crypto_alg *alg;
574
575         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
576         return IS_ERR(alg) ? ERR_CAST(alg) :
577                container_of(alg, struct shash_alg, base);
578 }
579 EXPORT_SYMBOL_GPL(shash_attr_alg);
580
581 MODULE_LICENSE("GPL");
582 MODULE_DESCRIPTION("Synchronous cryptographic hash type");