crypto: shash - Move null setkey check to registration time
[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 static int shash_async_update(struct ahash_request *req)
206 {
207         struct shash_desc *desc = ahash_request_ctx(req);
208         struct crypto_hash_walk walk;
209         int nbytes;
210
211         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
212              nbytes = crypto_hash_walk_done(&walk, nbytes))
213                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
214
215         return nbytes;
216 }
217
218 static int shash_async_final(struct ahash_request *req)
219 {
220         return crypto_shash_final(ahash_request_ctx(req), req->result);
221 }
222
223 static int shash_async_digest(struct ahash_request *req)
224 {
225         struct scatterlist *sg = req->src;
226         unsigned int offset = sg->offset;
227         unsigned int nbytes = req->nbytes;
228         int err;
229
230         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
231                 struct crypto_shash **ctx =
232                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
233                 struct shash_desc *desc = ahash_request_ctx(req);
234                 void *data;
235
236                 desc->tfm = *ctx;
237                 desc->flags = req->base.flags;
238
239                 data = crypto_kmap(sg_page(sg), 0);
240                 err = crypto_shash_digest(desc, data + offset, nbytes,
241                                           req->result);
242                 crypto_kunmap(data, 0);
243                 crypto_yield(desc->flags);
244                 goto out;
245         }
246
247         err = shash_async_init(req);
248         if (err)
249                 goto out;
250
251         err = shash_async_update(req);
252         if (err)
253                 goto out;
254
255         err = shash_async_final(req);
256
257 out:
258         return err;
259 }
260
261 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
262 {
263         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
264
265         crypto_free_shash(*ctx);
266 }
267
268 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
269 {
270         struct crypto_alg *calg = tfm->__crt_alg;
271         struct shash_alg *alg = __crypto_shash_alg(calg);
272         struct ahash_tfm *crt = &tfm->crt_ahash;
273         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
274         struct crypto_shash *shash;
275
276         if (!crypto_mod_get(calg))
277                 return -EAGAIN;
278
279         shash = crypto_create_tfm(calg, &crypto_shash_type);
280         if (IS_ERR(shash)) {
281                 crypto_mod_put(calg);
282                 return PTR_ERR(shash);
283         }
284
285         *ctx = shash;
286         tfm->exit = crypto_exit_shash_ops_async;
287
288         crt->init = shash_async_init;
289         crt->update = shash_async_update;
290         crt->final  = shash_async_final;
291         crt->digest = shash_async_digest;
292         crt->setkey = shash_async_setkey;
293
294         crt->digestsize = alg->digestsize;
295         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
296
297         return 0;
298 }
299
300 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
301                                unsigned int keylen)
302 {
303         struct shash_desc *desc = crypto_hash_ctx(tfm);
304
305         return crypto_shash_setkey(desc->tfm, key, keylen);
306 }
307
308 static int shash_compat_init(struct hash_desc *hdesc)
309 {
310         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
311
312         desc->flags = hdesc->flags;
313
314         return crypto_shash_init(desc);
315 }
316
317 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
318                                unsigned int len)
319 {
320         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
321         struct crypto_hash_walk walk;
322         int nbytes;
323
324         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
325              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
326                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
327
328         return nbytes;
329 }
330
331 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
332 {
333         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), out);
334 }
335
336 static int shash_compat_digest(struct hash_desc *hdesc, struct scatterlist *sg,
337                                unsigned int nbytes, u8 *out)
338 {
339         unsigned int offset = sg->offset;
340         int err;
341
342         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
343                 struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
344                 void *data;
345
346                 desc->flags = hdesc->flags;
347
348                 data = crypto_kmap(sg_page(sg), 0);
349                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
350                 crypto_kunmap(data, 0);
351                 crypto_yield(desc->flags);
352                 goto out;
353         }
354
355         err = shash_compat_init(hdesc);
356         if (err)
357                 goto out;
358
359         err = shash_compat_update(hdesc, sg, nbytes);
360         if (err)
361                 goto out;
362
363         err = shash_compat_final(hdesc, out);
364
365 out:
366         return err;
367 }
368
369 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
370 {
371         struct shash_desc *desc= crypto_tfm_ctx(tfm);
372
373         crypto_free_shash(desc->tfm);
374 }
375
376 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
377 {
378         struct hash_tfm *crt = &tfm->crt_hash;
379         struct crypto_alg *calg = tfm->__crt_alg;
380         struct shash_alg *alg = __crypto_shash_alg(calg);
381         struct shash_desc *desc = crypto_tfm_ctx(tfm);
382         struct crypto_shash *shash;
383
384         if (!crypto_mod_get(calg))
385                 return -EAGAIN;
386
387         shash = crypto_create_tfm(calg, &crypto_shash_type);
388         if (IS_ERR(shash)) {
389                 crypto_mod_put(calg);
390                 return PTR_ERR(shash);
391         }
392
393         desc->tfm = shash;
394         tfm->exit = crypto_exit_shash_ops_compat;
395
396         crt->init = shash_compat_init;
397         crt->update = shash_compat_update;
398         crt->final  = shash_compat_final;
399         crt->digest = shash_compat_digest;
400         crt->setkey = shash_compat_setkey;
401
402         crt->digestsize = alg->digestsize;
403
404         return 0;
405 }
406
407 static int crypto_init_shash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
408 {
409         switch (mask & CRYPTO_ALG_TYPE_MASK) {
410         case CRYPTO_ALG_TYPE_HASH_MASK:
411                 return crypto_init_shash_ops_compat(tfm);
412         case CRYPTO_ALG_TYPE_AHASH_MASK:
413                 return crypto_init_shash_ops_async(tfm);
414         }
415
416         return -EINVAL;
417 }
418
419 static unsigned int crypto_shash_ctxsize(struct crypto_alg *alg, u32 type,
420                                          u32 mask)
421 {
422         struct shash_alg *salg = __crypto_shash_alg(alg);
423
424         switch (mask & CRYPTO_ALG_TYPE_MASK) {
425         case CRYPTO_ALG_TYPE_HASH_MASK:
426                 return sizeof(struct shash_desc) + salg->descsize;
427         case CRYPTO_ALG_TYPE_AHASH_MASK:
428                 return sizeof(struct crypto_shash *);
429         }
430
431         return 0;
432 }
433
434 static int crypto_shash_init_tfm(struct crypto_tfm *tfm,
435                                  const struct crypto_type *frontend)
436 {
437         return 0;
438 }
439
440 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
441                                          const struct crypto_type *frontend)
442 {
443         return alg->cra_ctxsize;
444 }
445
446 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
447         __attribute__ ((unused));
448 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
449 {
450         struct shash_alg *salg = __crypto_shash_alg(alg);
451
452         seq_printf(m, "type         : shash\n");
453         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
454         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
455         seq_printf(m, "descsize     : %u\n", salg->descsize);
456 }
457
458 static const struct crypto_type crypto_shash_type = {
459         .ctxsize = crypto_shash_ctxsize,
460         .extsize = crypto_shash_extsize,
461         .init = crypto_init_shash_ops,
462         .init_tfm = crypto_shash_init_tfm,
463 #ifdef CONFIG_PROC_FS
464         .show = crypto_shash_show,
465 #endif
466         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
467         .maskset = CRYPTO_ALG_TYPE_MASK,
468         .type = CRYPTO_ALG_TYPE_SHASH,
469         .tfmsize = offsetof(struct crypto_shash, base),
470 };
471
472 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
473                                         u32 mask)
474 {
475         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
476 }
477 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
478
479 static int shash_prepare_alg(struct shash_alg *alg)
480 {
481         struct crypto_alg *base = &alg->base;
482
483         if (alg->digestsize > PAGE_SIZE / 8 ||
484             alg->descsize > PAGE_SIZE / 8 ||
485             alg->statesize > PAGE_SIZE / 8)
486                 return -EINVAL;
487
488         base->cra_type = &crypto_shash_type;
489         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
490         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
491
492         if (!alg->finup)
493                 alg->finup = shash_finup_unaligned;
494         if (!alg->digest)
495                 alg->digest = shash_digest_unaligned;
496         if (!alg->import)
497                 alg->import = shash_no_import;
498         if (!alg->export)
499                 alg->export = shash_no_export;
500         if (!alg->setkey)
501                 alg->setkey = shash_no_setkey;
502
503         return 0;
504 }
505
506 int crypto_register_shash(struct shash_alg *alg)
507 {
508         struct crypto_alg *base = &alg->base;
509         int err;
510
511         err = shash_prepare_alg(alg);
512         if (err)
513                 return err;
514
515         return crypto_register_alg(base);
516 }
517 EXPORT_SYMBOL_GPL(crypto_register_shash);
518
519 int crypto_unregister_shash(struct shash_alg *alg)
520 {
521         return crypto_unregister_alg(&alg->base);
522 }
523 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
524
525 int shash_register_instance(struct crypto_template *tmpl,
526                             struct shash_instance *inst)
527 {
528         int err;
529
530         err = shash_prepare_alg(&inst->alg);
531         if (err)
532                 return err;
533
534         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
535 }
536 EXPORT_SYMBOL_GPL(shash_register_instance);
537
538 void shash_free_instance(struct crypto_instance *inst)
539 {
540         crypto_drop_spawn(crypto_instance_ctx(inst));
541         kfree(shash_instance(inst));
542 }
543 EXPORT_SYMBOL_GPL(shash_free_instance);
544
545 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
546                             struct shash_alg *alg,
547                             struct crypto_instance *inst)
548 {
549         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
550                                   &crypto_shash_type);
551 }
552 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
553
554 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
555 {
556         struct crypto_alg *alg;
557
558         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
559         return IS_ERR(alg) ? ERR_CAST(alg) :
560                container_of(alg, struct shash_alg, base);
561 }
562 EXPORT_SYMBOL_GPL(shash_attr_alg);
563
564 MODULE_LICENSE("GPL");
565 MODULE_DESCRIPTION("Synchronous cryptographic hash type");