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