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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 static const struct crypto_type crypto_shash_type;
22
23 static inline struct crypto_shash *__crypto_shash_cast(struct crypto_tfm *tfm)
24 {
25         return container_of(tfm, struct crypto_shash, base);
26 }
27
28 #include "internal.h"
29
30 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
31                                   unsigned int keylen)
32 {
33         struct shash_alg *shash = crypto_shash_alg(tfm);
34         unsigned long alignmask = crypto_shash_alignmask(tfm);
35         unsigned long absize;
36         u8 *buffer, *alignbuffer;
37         int err;
38
39         absize = keylen + (alignmask & ~(CRYPTO_MINALIGN - 1));
40         buffer = kmalloc(absize, GFP_KERNEL);
41         if (!buffer)
42                 return -ENOMEM;
43
44         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
45         memcpy(alignbuffer, key, keylen);
46         err = shash->setkey(tfm, alignbuffer, keylen);
47         memset(alignbuffer, 0, keylen);
48         kfree(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 (!shash->setkey)
59                 return -ENOSYS;
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 buf[shash_align_buffer_size(unaligned_len, alignmask)]
83                 __attribute__ ((aligned));
84
85         memcpy(buf, data, unaligned_len);
86
87         return shash->update(desc, buf, unaligned_len) ?:
88                shash->update(desc, data + unaligned_len, len - unaligned_len);
89 }
90
91 int crypto_shash_update(struct shash_desc *desc, const u8 *data,
92                         unsigned int len)
93 {
94         struct crypto_shash *tfm = desc->tfm;
95         struct shash_alg *shash = crypto_shash_alg(tfm);
96         unsigned long alignmask = crypto_shash_alignmask(tfm);
97
98         if ((unsigned long)data & alignmask)
99                 return shash_update_unaligned(desc, data, len);
100
101         return shash->update(desc, data, len);
102 }
103 EXPORT_SYMBOL_GPL(crypto_shash_update);
104
105 static int shash_final_unaligned(struct shash_desc *desc, u8 *out)
106 {
107         struct crypto_shash *tfm = desc->tfm;
108         unsigned long alignmask = crypto_shash_alignmask(tfm);
109         struct shash_alg *shash = crypto_shash_alg(tfm);
110         unsigned int ds = crypto_shash_digestsize(tfm);
111         u8 buf[shash_align_buffer_size(ds, alignmask)]
112                 __attribute__ ((aligned));
113         int err;
114
115         err = shash->final(desc, buf);
116         memcpy(out, buf, ds);
117         return err;
118 }
119
120 int crypto_shash_final(struct shash_desc *desc, u8 *out)
121 {
122         struct crypto_shash *tfm = desc->tfm;
123         struct shash_alg *shash = crypto_shash_alg(tfm);
124         unsigned long alignmask = crypto_shash_alignmask(tfm);
125
126         if ((unsigned long)out & alignmask)
127                 return shash_final_unaligned(desc, out);
128
129         return shash->final(desc, out);
130 }
131 EXPORT_SYMBOL_GPL(crypto_shash_final);
132
133 static int shash_finup_unaligned(struct shash_desc *desc, const u8 *data,
134                                  unsigned int len, u8 *out)
135 {
136         return crypto_shash_update(desc, data, len) ?:
137                crypto_shash_final(desc, out);
138 }
139
140 int crypto_shash_finup(struct shash_desc *desc, const u8 *data,
141                        unsigned int len, u8 *out)
142 {
143         struct crypto_shash *tfm = desc->tfm;
144         struct shash_alg *shash = crypto_shash_alg(tfm);
145         unsigned long alignmask = crypto_shash_alignmask(tfm);
146
147         if (((unsigned long)data | (unsigned long)out) & alignmask ||
148             !shash->finup)
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_update(desc, data, len) ?:
160                crypto_shash_final(desc, out);
161 }
162
163 int crypto_shash_digest(struct shash_desc *desc, const u8 *data,
164                         unsigned int len, u8 *out)
165 {
166         struct crypto_shash *tfm = desc->tfm;
167         struct shash_alg *shash = crypto_shash_alg(tfm);
168         unsigned long alignmask = crypto_shash_alignmask(tfm);
169
170         if (((unsigned long)data | (unsigned long)out) & alignmask ||
171             !shash->digest)
172                 return shash_digest_unaligned(desc, data, len, out);
173
174         return shash->digest(desc, data, len, out);
175 }
176 EXPORT_SYMBOL_GPL(crypto_shash_digest);
177
178 int crypto_shash_import(struct shash_desc *desc, const u8 *in)
179 {
180         struct crypto_shash *tfm = desc->tfm;
181         struct shash_alg *alg = crypto_shash_alg(tfm);
182
183         memcpy(shash_desc_ctx(desc), in, crypto_shash_descsize(tfm));
184
185         if (alg->reinit)
186                 alg->reinit(desc);
187
188         return 0;
189 }
190 EXPORT_SYMBOL_GPL(crypto_shash_import);
191
192 static int shash_async_setkey(struct crypto_ahash *tfm, const u8 *key,
193                               unsigned int keylen)
194 {
195         struct crypto_shash **ctx = crypto_ahash_ctx(tfm);
196
197         return crypto_shash_setkey(*ctx, key, keylen);
198 }
199
200 static int shash_async_init(struct ahash_request *req)
201 {
202         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
203         struct shash_desc *desc = ahash_request_ctx(req);
204
205         desc->tfm = *ctx;
206         desc->flags = req->base.flags;
207
208         return crypto_shash_init(desc);
209 }
210
211 static int shash_async_update(struct ahash_request *req)
212 {
213         struct shash_desc *desc = ahash_request_ctx(req);
214         struct crypto_hash_walk walk;
215         int nbytes;
216
217         for (nbytes = crypto_hash_walk_first(req, &walk); nbytes > 0;
218              nbytes = crypto_hash_walk_done(&walk, nbytes))
219                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
220
221         return nbytes;
222 }
223
224 static int shash_async_final(struct ahash_request *req)
225 {
226         return crypto_shash_final(ahash_request_ctx(req), req->result);
227 }
228
229 static int shash_async_digest(struct ahash_request *req)
230 {
231         struct scatterlist *sg = req->src;
232         unsigned int offset = sg->offset;
233         unsigned int nbytes = req->nbytes;
234         int err;
235
236         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
237                 struct crypto_shash **ctx =
238                         crypto_ahash_ctx(crypto_ahash_reqtfm(req));
239                 struct shash_desc *desc = ahash_request_ctx(req);
240                 void *data;
241
242                 desc->tfm = *ctx;
243                 desc->flags = req->base.flags;
244
245                 data = crypto_kmap(sg_page(sg), 0);
246                 err = crypto_shash_digest(desc, data + offset, nbytes,
247                                           req->result);
248                 crypto_kunmap(data, 0);
249                 crypto_yield(desc->flags);
250                 goto out;
251         }
252
253         err = shash_async_init(req);
254         if (err)
255                 goto out;
256
257         err = shash_async_update(req);
258         if (err)
259                 goto out;
260
261         err = shash_async_final(req);
262
263 out:
264         return err;
265 }
266
267 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
268 {
269         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
270
271         crypto_free_shash(*ctx);
272 }
273
274 static int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
275 {
276         struct crypto_alg *calg = tfm->__crt_alg;
277         struct shash_alg *alg = __crypto_shash_alg(calg);
278         struct ahash_tfm *crt = &tfm->crt_ahash;
279         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
280         struct crypto_shash *shash;
281
282         if (!crypto_mod_get(calg))
283                 return -EAGAIN;
284
285         shash = __crypto_shash_cast(crypto_create_tfm(
286                 calg, &crypto_shash_type));
287         if (IS_ERR(shash)) {
288                 crypto_mod_put(calg);
289                 return PTR_ERR(shash);
290         }
291
292         *ctx = shash;
293         tfm->exit = crypto_exit_shash_ops_async;
294
295         crt->init = shash_async_init;
296         crt->update = shash_async_update;
297         crt->final  = shash_async_final;
298         crt->digest = shash_async_digest;
299         crt->setkey = shash_async_setkey;
300
301         crt->digestsize = alg->digestsize;
302         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
303
304         return 0;
305 }
306
307 static int shash_compat_setkey(struct crypto_hash *tfm, const u8 *key,
308                                unsigned int keylen)
309 {
310         struct shash_desc *desc = crypto_hash_ctx(tfm);
311
312         return crypto_shash_setkey(desc->tfm, key, keylen);
313 }
314
315 static int shash_compat_init(struct hash_desc *hdesc)
316 {
317         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
318
319         desc->flags = hdesc->flags;
320
321         return crypto_shash_init(desc);
322 }
323
324 static int shash_compat_update(struct hash_desc *hdesc, struct scatterlist *sg,
325                                unsigned int len)
326 {
327         struct shash_desc *desc = crypto_hash_ctx(hdesc->tfm);
328         struct crypto_hash_walk walk;
329         int nbytes;
330
331         for (nbytes = crypto_hash_walk_first_compat(hdesc, &walk, sg, len);
332              nbytes > 0; nbytes = crypto_hash_walk_done(&walk, nbytes))
333                 nbytes = crypto_shash_update(desc, walk.data, nbytes);
334
335         return nbytes;
336 }
337
338 static int shash_compat_final(struct hash_desc *hdesc, u8 *out)
339 {
340         return crypto_shash_final(crypto_hash_ctx(hdesc->tfm), 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 *desc = crypto_hash_ctx(hdesc->tfm);
351                 void *data;
352
353                 desc->flags = hdesc->flags;
354
355                 data = crypto_kmap(sg_page(sg), 0);
356                 err = crypto_shash_digest(desc, data + offset, nbytes, out);
357                 crypto_kunmap(data, 0);
358                 crypto_yield(desc->flags);
359                 goto out;
360         }
361
362         err = shash_compat_init(hdesc);
363         if (err)
364                 goto out;
365
366         err = shash_compat_update(hdesc, sg, nbytes);
367         if (err)
368                 goto out;
369
370         err = shash_compat_final(hdesc, out);
371
372 out:
373         return err;
374 }
375
376 static void crypto_exit_shash_ops_compat(struct crypto_tfm *tfm)
377 {
378         struct shash_desc *desc= crypto_tfm_ctx(tfm);
379
380         crypto_free_shash(desc->tfm);
381 }
382
383 static int crypto_init_shash_ops_compat(struct crypto_tfm *tfm)
384 {
385         struct hash_tfm *crt = &tfm->crt_hash;
386         struct crypto_alg *calg = tfm->__crt_alg;
387         struct shash_alg *alg = __crypto_shash_alg(calg);
388         struct shash_desc *desc = crypto_tfm_ctx(tfm);
389         struct crypto_shash *shash;
390
391         shash = __crypto_shash_cast(crypto_create_tfm(
392                 calg, &crypto_shash_type));
393         if (IS_ERR(shash))
394                 return PTR_ERR(shash);
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         if (frontend->type != CRYPTO_ALG_TYPE_SHASH)
441                 return -EINVAL;
442         return 0;
443 }
444
445 static unsigned int crypto_shash_extsize(struct crypto_alg *alg,
446                                          const struct crypto_type *frontend)
447 {
448         return alg->cra_ctxsize;
449 }
450
451 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
452         __attribute__ ((unused));
453 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
454 {
455         struct shash_alg *salg = __crypto_shash_alg(alg);
456
457         seq_printf(m, "type         : shash\n");
458         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
459         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
460         seq_printf(m, "descsize     : %u\n", salg->descsize);
461 }
462
463 static const struct crypto_type crypto_shash_type = {
464         .ctxsize = crypto_shash_ctxsize,
465         .extsize = crypto_shash_extsize,
466         .init = crypto_init_shash_ops,
467         .init_tfm = crypto_shash_init_tfm,
468 #ifdef CONFIG_PROC_FS
469         .show = crypto_shash_show,
470 #endif
471         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
472         .maskset = CRYPTO_ALG_TYPE_MASK,
473         .type = CRYPTO_ALG_TYPE_SHASH,
474         .tfmsize = offsetof(struct crypto_shash, base),
475 };
476
477 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
478                                         u32 mask)
479 {
480         return __crypto_shash_cast(
481                 crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask));
482 }
483 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
484
485 int crypto_register_shash(struct shash_alg *alg)
486 {
487         struct crypto_alg *base = &alg->base;
488
489         if (alg->digestsize > PAGE_SIZE / 8 ||
490             alg->descsize > PAGE_SIZE / 8)
491                 return -EINVAL;
492
493         base->cra_type = &crypto_shash_type;
494         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
495         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
496
497         return crypto_register_alg(base);
498 }
499 EXPORT_SYMBOL_GPL(crypto_register_shash);
500
501 int crypto_unregister_shash(struct shash_alg *alg)
502 {
503         return crypto_unregister_alg(&alg->base);
504 }
505 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
506
507 MODULE_LICENSE("GPL");
508 MODULE_DESCRIPTION("Synchronous cryptographic hash type");