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