0d66c2edc6d8bec7e08f365651dbada1d58c6adc
[pandora-kernel.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 #include <linux/cryptouser.h>
21 #include <net/netlink.h>
22
23 #include "internal.h"
24
25 static const struct crypto_type crypto_shash_type;
26
27 int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
28                     unsigned int keylen)
29 {
30         return -ENOSYS;
31 }
32 EXPORT_SYMBOL_GPL(shash_no_setkey);
33
34 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
35                                   unsigned int keylen)
36 {
37         struct shash_alg *shash = crypto_shash_alg(tfm);
38         unsigned long alignmask = crypto_shash_alignmask(tfm);
39         unsigned long absize;
40         u8 *buffer, *alignbuffer;
41         int err;
42
43         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
44         buffer = kmalloc(absize, GFP_KERNEL);
45         if (!buffer)
46                 return -ENOMEM;
47
48         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
49         memcpy(alignbuffer, key, keylen);
50         err = shash->setkey(tfm, alignbuffer, keylen);
51         kzfree(buffer);
52         return err;
53 }
54
55 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
56                         unsigned int keylen)
57 {
58         struct shash_alg *shash = crypto_shash_alg(tfm);
59         unsigned long alignmask = crypto_shash_alignmask(tfm);
60
61         if ((unsigned long)key & alignmask)
62                 return shash_setkey_unaligned(tfm, key, keylen);
63
64         return shash->setkey(tfm, key, keylen);
65 }
66 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
67
68 static inline unsigned int shash_align_buffer_size(unsigned len,
69                                                    unsigned long mask)
70 {
71         return len + (mask & ~(__alignof__(u8 __attribute__ ((aligned))) - 1));
72 }
73
74 static int shash_update_unaligned(struct shash_desc *desc, const u8 *data,
75                                   unsigned int len)
76 {
77         struct crypto_shash *tfm = desc->tfm;
78         struct shash_alg *shash = crypto_shash_alg(tfm);
79         unsigned long alignmask = crypto_shash_alignmask(tfm);
80         unsigned int unaligned_len = alignmask + 1 -
81                                      ((unsigned long)data & alignmask);
82         u8 ubuf[shash_align_buffer_size(unaligned_len, alignmask)]
83                 __attribute__ ((aligned));
84         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
85         int err;
86
87         if (unaligned_len > len)
88                 unaligned_len = len;
89
90         memcpy(buf, data, unaligned_len);
91         err = shash->update(desc, buf, unaligned_len);
92         memset(buf, 0, unaligned_len);
93
94         return err ?:
95                shash->update(desc, data + unaligned_len, len - unaligned_len);
96 }
97
98 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
99                         unsigned int len)
100 {
101         struct crypto_shash *tfm = desc->tfm;
102         struct shash_alg *shash = crypto_shash_alg(tfm);
103         unsigned long alignmask = crypto_shash_alignmask(tfm);
104
105         if ((unsigned long)data & alignmask)
106                 return shash_update_unaligned(desc, data, len);
107
108         return shash->update(desc, data, len);
109 }
110 EXPORT_SYMBOL_GPL(crypto_shash_update);
111
112 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
113 {
114         struct crypto_shash *tfm = desc->tfm;
115         unsigned long alignmask = crypto_shash_alignmask(tfm);
116         struct shash_alg *shash = crypto_shash_alg(tfm);
117         unsigned int ds = crypto_shash_digestsize(tfm);
118         u8 ubuf[shash_align_buffer_size(ds, alignmask)]
119                 __attribute__ ((aligned));
120         u8 *buf = PTR_ALIGN(&ubuf[0], alignmask + 1);
121         int err;
122
123         err = shash->final(desc, buf);
124         if (err)
125                 goto out;
126
127         memcpy(out, buf, ds);
128
129 out:
130         memset(buf, 0, ds);
131         return err;
132 }
133
134 int crypto_shash_final(struct shash_desc *desc, u8 *out)
135 {
136         struct crypto_shash *tfm = desc->tfm;
137         struct shash_alg *shash = crypto_shash_alg(tfm);
138         unsigned long alignmask = crypto_shash_alignmask(tfm);
139
140         if ((unsigned long)out & alignmask)
141                 return shash_final_unaligned(desc, out);
142
143         return shash->final(desc, out);
144 }
145 EXPORT_SYMBOL_GPL(crypto_shash_final);
146
147 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
148                                  unsigned int len, u8 *out)
149 {
150         return crypto_shash_update(desc, data, len) ?:
151                crypto_shash_final(desc, out);
152 }
153
154 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
155                        unsigned int len, u8 *out)
156 {
157         struct crypto_shash *tfm = desc->tfm;
158         struct shash_alg *shash = crypto_shash_alg(tfm);
159         unsigned long alignmask = crypto_shash_alignmask(tfm);
160
161         if (((unsigned long)data | (unsigned long)out) & alignmask)
162                 return shash_finup_unaligned(desc, data, len, out);
163
164         return shash->finup(desc, data, len, out);
165 }
166 EXPORT_SYMBOL_GPL(crypto_shash_finup);
167
168 static int shash_digest_unaligned(struct shash_desc *desc, const u8 *data,
169                                   unsigned int len, u8 *out)
170 {
171         return crypto_shash_init(desc) ?:
172                crypto_shash_finup(desc, data, len, out);
173 }
174
175 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
176                         unsigned int len, u8 *out)
177 {
178         struct crypto_shash *tfm = desc->tfm;
179         struct shash_alg *shash = crypto_shash_alg(tfm);
180         unsigned long alignmask = crypto_shash_alignmask(tfm);
181
182         if (((unsigned long)data | (unsigned long)out) & alignmask)
183                 return shash_digest_unaligned(desc, data, len, out);
184
185         return shash->digest(desc, data, len, out);
186 }
187 EXPORT_SYMBOL_GPL(crypto_shash_digest);
188
189 static int shash_default_export(struct shash_desc *desc, void *out)
190 {
191         memcpy(out, shash_desc_ctx(desc), crypto_shash_descsize(desc->tfm));
192         return 0;
193 }
194
195 static int shash_default_import(struct shash_desc *desc, const void *in)
196 {
197         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(desc->tfm));
198         return 0;
199 }
200
201 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
202                               unsigned int keylen)
203 {
204         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
205
206         return crypto_shash_setkey(*ctx, key, keylen);
207 }
208
209 static int shash_async_init(struct ahash_request *req)
210 {
211         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
212         struct shash_desc *desc = ahash_request_ctx(req);
213
214         desc->tfm = *ctx;
215         desc->flags = req->base.flags;
216
217         return crypto_shash_init(desc);
218 }
219
220 int shash_ahash_update(struct ahash_request *req, struct shash_desc *desc)
221 {
222         struct crypto_hash_walk walk;
223         int nbytes;
224
225         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
226              nbytes = crypto_hash_walk_done(&walk, nbytes))
227                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
228
229         return nbytes;
230 }
231 EXPORT_SYMBOL_GPL(shash_ahash_update);
232
233 static int shash_async_update(struct ahash_request *req)
234 {
235         return shash_ahash_update(req, ahash_request_ctx(req));
236 }
237
238 static int shash_async_final(struct ahash_request *req)
239 {
240         return crypto_shash_final(ahash_request_ctx(req), req->result);
241 }
242
243 int shash_ahash_finup(struct ahash_request *req, struct shash_desc *desc)
244 {
245         struct crypto_hash_walk walk;
246         int nbytes;
247
248         nbytes = crypto_hash_walk_first(req, &walk);
249         if (!nbytes)
250                 return crypto_shash_final(desc, req->result);
251
252         do {
253                 nbytes = crypto_hash_walk_last(&walk) ?
254                          crypto_shash_finup(desc, walk.data, nbytes,
255                                             req->result) :
256                          crypto_shash_update(desc, walk.data, nbytes);
257                 nbytes = crypto_hash_walk_done(&walk, nbytes);
258         } while (nbytes > 0);
259
260         return nbytes;
261 }
262 EXPORT_SYMBOL_GPL(shash_ahash_finup);
263
264 static int shash_async_finup(struct ahash_request *req)
265 {
266         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
267         struct shash_desc *desc = ahash_request_ctx(req);
268
269         desc->tfm = *ctx;
270         desc->flags = req->base.flags;
271
272         return shash_ahash_finup(req, desc);
273 }
274
275 int shash_ahash_digest(struct ahash_request *req, struct shash_desc *desc)
276 {
277         unsigned int nbytes = req->nbytes;
278         struct scatterlist *sg;
279         unsigned int offset;
280         int err;
281
282         if (nbytes &&
283             (sg = req->src, offset = sg->offset,
284              nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset))) {
285                 void *data;
286
287                 data = crypto_kmap(sg_page(sg), 0);
288                 err = crypto_shash_digest(desc, data + offset, nbytes,
289                                           req->result);
290                 crypto_kunmap(data, 0);
291                 crypto_yield(desc->flags);
292         } else
293                 err = crypto_shash_init(desc) ?:
294                       shash_ahash_finup(req, desc);
295
296         return err;
297 }
298 EXPORT_SYMBOL_GPL(shash_ahash_digest);
299
300 static int shash_async_digest(struct ahash_request *req)
301 {
302         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
303         struct shash_desc *desc = ahash_request_ctx(req);
304
305         desc->tfm = *ctx;
306         desc->flags = req->base.flags;
307
308         return shash_ahash_digest(req, desc);
309 }
310
311 static int shash_async_export(struct ahash_request *req, void *out)
312 {
313         return crypto_shash_export(ahash_request_ctx(req), out);
314 }
315
316 static int shash_async_import(struct ahash_request *req, const void *in)
317 {
318         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
319         struct shash_desc *desc = ahash_request_ctx(req);
320
321         desc->tfm = *ctx;
322         desc->flags = req->base.flags;
323
324         return crypto_shash_import(desc, in);
325 }
326
327 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
328 {
329         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
330
331         crypto_free_shash(*ctx);
332 }
333
334 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
335 {
336         struct crypto_alg *calg = tfm->__crt_alg;
337         struct shash_alg *alg = __crypto_shash_alg(calg);
338         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
339         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
340         struct crypto_shash *shash;
341
342         if (!crypto_mod_get(calg))
343                 return -EAGAIN;
344
345         shash = crypto_create_tfm(calg, &crypto_shash_type);
346         if (IS_ERR(shash)) {
347                 crypto_mod_put(calg);
348                 return PTR_ERR(shash);
349         }
350
351         *ctx = shash;
352         tfm->exit = crypto_exit_shash_ops_async;
353
354         crt->init = shash_async_init;
355         crt->update = shash_async_update;
356         crt->final = shash_async_final;
357         crt->finup = shash_async_finup;
358         crt->digest = shash_async_digest;
359         crt->setkey = shash_async_setkey;
360
361         crt->has_setkey = alg->setkey != shash_no_setkey;
362
363         if (alg->export)
364                 crt->export = shash_async_export;
365         if (alg->import)
366                 crt->import = shash_async_import;
367
368         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
369
370         return 0;
371 }
372
373 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
374                                unsigned int keylen)
375 {
376         struct shash_desc **descp = crypto_hash_ctx(tfm);
377         struct shash_desc *desc = *descp;
378
379         return crypto_shash_setkey(desc->tfm, key, keylen);
380 }
381
382 static int shash_compat_init(struct hash_desc *hdesc)
383 {
384         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
385         struct shash_desc *desc = *descp;
386
387         desc->flags = hdesc->flags;
388
389         return crypto_shash_init(desc);
390 }
391
392 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
393                                unsigned int len)
394 {
395         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
396         struct shash_desc *desc = *descp;
397         struct crypto_hash_walk walk;
398         int nbytes;
399
400         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
401              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
402                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
403
404         return nbytes;
405 }
406
407 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
408 {
409         struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
410
411         return crypto_shash_final(*descp, out);
412 }
413
414 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
415                                unsigned int nbytes, u8 *out)
416 {
417         unsigned int offset = sg->offset;
418         int err;
419
420         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
421                 struct shash_desc **descp = crypto_hash_ctx(hdesc->tfm);
422                 struct shash_desc *desc = *descp;
423                 void *data;
424
425                 desc->flags = hdesc->flags;
426
427                 data = crypto_kmap(sg_page(sg), 0);
428                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
429                 crypto_kunmap(data, 0);
430                 crypto_yield(desc->flags);
431                 goto out;
432         }
433
434         err = shash_compat_init(hdesc);
435         if (err)
436                 goto out;
437
438         err = shash_compat_update(hdesc, sg, nbytes);
439         if (err)
440                 goto out;
441
442         err = shash_compat_final(hdesc, out);
443
444 out:
445         return err;
446 }
447
448 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
449 {
450         struct shash_desc **descp = crypto_tfm_ctx(tfm);
451         struct shash_desc *desc = *descp;
452
453         crypto_free_shash(desc->tfm);
454         kzfree(desc);
455 }
456
457 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
458 {
459         struct hash_tfm *crt = &tfm->crt_hash;
460         struct crypto_alg *calg = tfm->__crt_alg;
461         struct shash_alg *alg = __crypto_shash_alg(calg);
462         struct shash_desc **descp = crypto_tfm_ctx(tfm);
463         struct crypto_shash *shash;
464         struct shash_desc *desc;
465
466         if (!crypto_mod_get(calg))
467                 return -EAGAIN;
468
469         shash = crypto_create_tfm(calg, &crypto_shash_type);
470         if (IS_ERR(shash)) {
471                 crypto_mod_put(calg);
472                 return PTR_ERR(shash);
473         }
474
475         desc = kmalloc(sizeof(*desc) + crypto_shash_descsize(shash),
476                        GFP_KERNEL);
477         if (!desc) {
478                 crypto_free_shash(shash);
479                 return -ENOMEM;
480         }
481
482         *descp = desc;
483         desc->tfm = shash;
484         tfm->exit = crypto_exit_shash_ops_compat;
485
486         crt->init = shash_compat_init;
487         crt->update = shash_compat_update;
488         crt->final  = shash_compat_final;
489         crt->digest = shash_compat_digest;
490         crt->setkey = shash_compat_setkey;
491
492         crt->digestsize = alg->digestsize;
493
494         return 0;
495 }
496
497 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
498 {
499         switch (mask & CRYPTO_ALG_TYPE_MASK) {
500         case CRYPTO_ALG_TYPE_HASH_MASK:
501                 return crypto_init_shash_ops_compat(tfm);
502         }
503
504         return -EINVAL;
505 }
506
507 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
508                                          u32 mask)
509 {
510         switch (mask & CRYPTO_ALG_TYPE_MASK) {
511         case CRYPTO_ALG_TYPE_HASH_MASK:
512                 return sizeof(struct shash_desc *);
513         }
514
515         return 0;
516 }
517
518 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
519 {
520         struct crypto_shash *hash = __crypto_shash_cast(tfm);
521
522         hash->descsize = crypto_shash_alg(hash)->descsize;
523         return 0;
524 }
525
526 static unsigned int crypto_shash_extsize(struct crypto_alg *alg)
527 {
528         return alg->cra_ctxsize;
529 }
530
531 #ifdef CONFIG_NET
532 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
533 {
534         struct crypto_report_hash rhash;
535         struct shash_alg *salg = __crypto_shash_alg(alg);
536
537         strncpy(rhash.type, "shash", sizeof(rhash.type));
538
539         rhash.blocksize = alg->cra_blocksize;
540         rhash.digestsize = salg->digestsize;
541
542         NLA_PUT(skb, CRYPTOCFGA_REPORT_HASH,
543                 sizeof(struct crypto_report_hash), &rhash);
544
545         return 0;
546
547 nla_put_failure:
548         return -EMSGSIZE;
549 }
550 #else
551 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
552 {
553         return -ENOSYS;
554 }
555 #endif
556
557 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
558         __attribute__ ((unused));
559 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
560 {
561         struct shash_alg *salg = __crypto_shash_alg(alg);
562
563         seq_printf(m, "type         : shash\n");
564         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
565         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
566 }
567
568 static const struct crypto_type crypto_shash_type = {
569         .ctxsize = crypto_shash_ctxsize,
570         .extsize = crypto_shash_extsize,
571         .init = crypto_init_shash_ops,
572         .init_tfm = crypto_shash_init_tfm,
573 #ifdef CONFIG_PROC_FS
574         .show = crypto_shash_show,
575 #endif
576         .report = crypto_shash_report,
577         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
578         .maskset = CRYPTO_ALG_TYPE_MASK,
579         .type = CRYPTO_ALG_TYPE_SHASH,
580         .tfmsize = offsetof(struct crypto_shash, base),
581 };
582
583 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
584                                         u32 mask)
585 {
586         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
587 }
588 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
589
590 static int shash_prepare_alg(struct shash_alg *alg)
591 {
592         struct crypto_alg *base = &alg->base;
593
594         if (alg->digestsize > PAGE_SIZE / 8 ||
595             alg->descsize > PAGE_SIZE / 8 ||
596             alg->statesize > PAGE_SIZE / 8)
597                 return -EINVAL;
598
599         base->cra_type = &crypto_shash_type;
600         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
601         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
602
603         if (!alg->finup)
604                 alg->finup = shash_finup_unaligned;
605         if (!alg->digest)
606                 alg->digest = shash_digest_unaligned;
607         if (!alg->export) {
608                 alg->export = shash_default_export;
609                 alg->import = shash_default_import;
610                 alg->statesize = alg->descsize;
611         }
612         if (!alg->setkey)
613                 alg->setkey = shash_no_setkey;
614
615         return 0;
616 }
617
618 int crypto_register_shash(struct shash_alg *alg)
619 {
620         struct crypto_alg *base = &alg->base;
621         int err;
622
623         err = shash_prepare_alg(alg);
624         if (err)
625                 return err;
626
627         return crypto_register_alg(base);
628 }
629 EXPORT_SYMBOL_GPL(crypto_register_shash);
630
631 int crypto_unregister_shash(struct shash_alg *alg)
632 {
633         return crypto_unregister_alg(&alg->base);
634 }
635 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
636
637 int shash_register_instance(struct crypto_template *tmpl,
638                             struct shash_instance *inst)
639 {
640         int err;
641
642         err = shash_prepare_alg(&inst->alg);
643         if (err)
644                 return err;
645
646         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
647 }
648 EXPORT_SYMBOL_GPL(shash_register_instance);
649
650 void shash_free_instance(struct crypto_instance *inst)
651 {
652         crypto_drop_spawn(crypto_instance_ctx(inst));
653         kfree(shash_instance(inst));
654 }
655 EXPORT_SYMBOL_GPL(shash_free_instance);
656
657 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
658                             struct shash_alg *alg,
659                             struct crypto_instance *inst)
660 {
661         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
662                                   &crypto_shash_type);
663 }
664 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
665
666 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
667 {
668         struct crypto_alg *alg;
669
670         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
671         return IS_ERR(alg) ? ERR_CAST(alg) :
672                container_of(alg, struct shash_alg, base);
673 }
674 EXPORT_SYMBOL_GPL(shash_attr_alg);
675
676 MODULE_LICENSE("GPL");
677 MODULE_DESCRIPTION("Synchronous cryptographic hash type");