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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 static int shash_no_setkey(struct crypto_shash *tfm, const u8 *key,
28                            unsigned int keylen)
29 {
30         return -ENOSYS;
31 }
32
33 static int shash_setkey_unaligned(struct crypto_shash *tfm, const u8 *key,
34                                   unsigned int keylen)
35 {
36         struct shash_alg *shash = crypto_shash_alg(tfm);
37         unsigned long alignmask = crypto_shash_alignmask(tfm);
38         unsigned long absize;
39         u8 *buffer, *alignbuffer;
40         int err;
41
42         absize = keylen + (alignmask & ~(crypto_tfm_ctx_alignment() - 1));
43         buffer = kmalloc(absize, GFP_KERNEL);
44         if (!buffer)
45                 return -ENOMEM;
46
47         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
48         memcpy(alignbuffer, key, keylen);
49         err = shash->setkey(tfm, alignbuffer, keylen);
50         kzfree(buffer);
51         return err;
52 }
53
54 int crypto_shash_setkey(struct crypto_shash *tfm, const u8 *key,
55                         unsigned int keylen)
56 {
57         struct shash_alg *shash = crypto_shash_alg(tfm);
58         unsigned long alignmask = crypto_shash_alignmask(tfm);
59
60         if ((unsigned long)key & alignmask)
61                 return shash_setkey_unaligned(tfm, key, keylen);
62
63         return shash->setkey(tfm, key, keylen);
64 }
65 EXPORT_SYMBOL_GPL(crypto_shash_setkey);
66
67 static inline unsigned int shash_align_buffer_size(unsigned len,
68                                                    unsigned long mask)
69 {
70         typedef u8 __attribute__ ((aligned)) u8_aligned;
71         return len + (mask & ~(__alignof__(u8_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         struct scatterlist *sg = req->src;
278         unsigned int offset = sg->offset;
279         unsigned int nbytes = req->nbytes;
280         int err;
281
282         if (nbytes < min(sg->length, ((unsigned int)(PAGE_SIZE)) - offset)) {
283                 void *data;
284
285                 data = kmap_atomic(sg_page(sg));
286                 err = crypto_shash_digest(desc, data + offset, nbytes,
287                                           req->result);
288                 kunmap_atomic(data);
289                 crypto_yield(desc->flags);
290         } else
291                 err = crypto_shash_init(desc) ?:
292                       shash_ahash_finup(req, desc);
293
294         return err;
295 }
296 EXPORT_SYMBOL_GPL(shash_ahash_digest);
297
298 static int shash_async_digest(struct ahash_request *req)
299 {
300         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
301         struct shash_desc *desc = ahash_request_ctx(req);
302
303         desc->tfm = *ctx;
304         desc->flags = req->base.flags;
305
306         return shash_ahash_digest(req, desc);
307 }
308
309 static int shash_async_export(struct ahash_request *req, void *out)
310 {
311         return crypto_shash_export(ahash_request_ctx(req), out);
312 }
313
314 static int shash_async_import(struct ahash_request *req, const void *in)
315 {
316         struct crypto_shash **ctx = crypto_ahash_ctx(crypto_ahash_reqtfm(req));
317         struct shash_desc *desc = ahash_request_ctx(req);
318
319         desc->tfm = *ctx;
320         desc->flags = req->base.flags;
321
322         return crypto_shash_import(desc, in);
323 }
324
325 static void crypto_exit_shash_ops_async(struct crypto_tfm *tfm)
326 {
327         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
328
329         crypto_free_shash(*ctx);
330 }
331
332 int crypto_init_shash_ops_async(struct crypto_tfm *tfm)
333 {
334         struct crypto_alg *calg = tfm->__crt_alg;
335         struct shash_alg *alg = __crypto_shash_alg(calg);
336         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
337         struct crypto_shash **ctx = crypto_tfm_ctx(tfm);
338         struct crypto_shash *shash;
339
340         if (!crypto_mod_get(calg))
341                 return -EAGAIN;
342
343         shash = crypto_create_tfm(calg, &crypto_shash_type);
344         if (IS_ERR(shash)) {
345                 crypto_mod_put(calg);
346                 return PTR_ERR(shash);
347         }
348
349         *ctx = shash;
350         tfm->exit = crypto_exit_shash_ops_async;
351
352         crt->init = shash_async_init;
353         crt->update = shash_async_update;
354         crt->final = shash_async_final;
355         crt->finup = shash_async_finup;
356         crt->digest = shash_async_digest;
357         crt->setkey = shash_async_setkey;
358
359         crt->has_setkey = alg->setkey != shash_no_setkey;
360
361         if (alg->export)
362                 crt->export = shash_async_export;
363         if (alg->import)
364                 crt->import = shash_async_import;
365
366         crt->reqsize = sizeof(struct shash_desc) + crypto_shash_descsize(shash);
367
368         return 0;
369 }
370
371 static int crypto_shash_init_tfm(struct crypto_tfm *tfm)
372 {
373         struct crypto_shash *hash = __crypto_shash_cast(tfm);
374
375         hash->descsize = crypto_shash_alg(hash)->descsize;
376         return 0;
377 }
378
379 #ifdef CONFIG_NET
380 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
381 {
382         struct crypto_report_hash rhash;
383         struct shash_alg *salg = __crypto_shash_alg(alg);
384
385         strncpy(rhash.type, "shash", sizeof(rhash.type));
386
387         rhash.blocksize = alg->cra_blocksize;
388         rhash.digestsize = salg->digestsize;
389
390         if (nla_put(skb, CRYPTOCFGA_REPORT_HASH,
391                     sizeof(struct crypto_report_hash), &rhash))
392                 goto nla_put_failure;
393         return 0;
394
395 nla_put_failure:
396         return -EMSGSIZE;
397 }
398 #else
399 static int crypto_shash_report(struct sk_buff *skb, struct crypto_alg *alg)
400 {
401         return -ENOSYS;
402 }
403 #endif
404
405 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
406         __attribute__ ((unused));
407 static void crypto_shash_show(struct seq_file *m, struct crypto_alg *alg)
408 {
409         struct shash_alg *salg = __crypto_shash_alg(alg);
410
411         seq_printf(m, "type         : shash\n");
412         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
413         seq_printf(m, "digestsize   : %u\n", salg->digestsize);
414 }
415
416 static const struct crypto_type crypto_shash_type = {
417         .extsize = crypto_alg_extsize,
418         .init_tfm = crypto_shash_init_tfm,
419 #ifdef CONFIG_PROC_FS
420         .show = crypto_shash_show,
421 #endif
422         .report = crypto_shash_report,
423         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
424         .maskset = CRYPTO_ALG_TYPE_MASK,
425         .type = CRYPTO_ALG_TYPE_SHASH,
426         .tfmsize = offsetof(struct crypto_shash, base),
427 };
428
429 struct crypto_shash *crypto_alloc_shash(const char *alg_name, u32 type,
430                                         u32 mask)
431 {
432         return crypto_alloc_tfm(alg_name, &crypto_shash_type, type, mask);
433 }
434 EXPORT_SYMBOL_GPL(crypto_alloc_shash);
435
436 static int shash_prepare_alg(struct shash_alg *alg)
437 {
438         struct crypto_alg *base = &alg->base;
439
440         if (alg->digestsize > PAGE_SIZE / 8 ||
441             alg->descsize > PAGE_SIZE / 8 ||
442             alg->statesize > PAGE_SIZE / 8)
443                 return -EINVAL;
444
445         base->cra_type = &crypto_shash_type;
446         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
447         base->cra_flags |= CRYPTO_ALG_TYPE_SHASH;
448
449         if (!alg->finup)
450                 alg->finup = shash_finup_unaligned;
451         if (!alg->digest)
452                 alg->digest = shash_digest_unaligned;
453         if (!alg->export) {
454                 alg->export = shash_default_export;
455                 alg->import = shash_default_import;
456                 alg->statesize = alg->descsize;
457         }
458         if (!alg->setkey)
459                 alg->setkey = shash_no_setkey;
460
461         return 0;
462 }
463
464 int crypto_register_shash(struct shash_alg *alg)
465 {
466         struct crypto_alg *base = &alg->base;
467         int err;
468
469         err = shash_prepare_alg(alg);
470         if (err)
471                 return err;
472
473         return crypto_register_alg(base);
474 }
475 EXPORT_SYMBOL_GPL(crypto_register_shash);
476
477 int crypto_unregister_shash(struct shash_alg *alg)
478 {
479         return crypto_unregister_alg(&alg->base);
480 }
481 EXPORT_SYMBOL_GPL(crypto_unregister_shash);
482
483 int crypto_register_shashes(struct shash_alg *algs, int count)
484 {
485         int i, ret;
486
487         for (i = 0; i < count; i++) {
488                 ret = crypto_register_shash(&algs[i]);
489                 if (ret)
490                         goto err;
491         }
492
493         return 0;
494
495 err:
496         for (--i; i >= 0; --i)
497                 crypto_unregister_shash(&algs[i]);
498
499         return ret;
500 }
501 EXPORT_SYMBOL_GPL(crypto_register_shashes);
502
503 int crypto_unregister_shashes(struct shash_alg *algs, int count)
504 {
505         int i, ret;
506
507         for (i = count - 1; i >= 0; --i) {
508                 ret = crypto_unregister_shash(&algs[i]);
509                 if (ret)
510                         pr_err("Failed to unregister %s %s: %d\n",
511                                algs[i].base.cra_driver_name,
512                                algs[i].base.cra_name, ret);
513         }
514
515         return 0;
516 }
517 EXPORT_SYMBOL_GPL(crypto_unregister_shashes);
518
519 int shash_register_instance(struct crypto_template *tmpl,
520                             struct shash_instance *inst)
521 {
522         int err;
523
524         err = shash_prepare_alg(&inst->alg);
525         if (err)
526                 return err;
527
528         return crypto_register_instance(tmpl, shash_crypto_instance(inst));
529 }
530 EXPORT_SYMBOL_GPL(shash_register_instance);
531
532 void shash_free_instance(struct crypto_instance *inst)
533 {
534         crypto_drop_spawn(crypto_instance_ctx(inst));
535         kfree(shash_instance(inst));
536 }
537 EXPORT_SYMBOL_GPL(shash_free_instance);
538
539 int crypto_init_shash_spawn(struct crypto_shash_spawn *spawn,
540                             struct shash_alg *alg,
541                             struct crypto_instance *inst)
542 {
543         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
544                                   &crypto_shash_type);
545 }
546 EXPORT_SYMBOL_GPL(crypto_init_shash_spawn);
547
548 struct shash_alg *shash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
549 {
550         struct crypto_alg *alg;
551
552         alg = crypto_attr_alg2(rta, &crypto_shash_type, type, mask);
553         return IS_ERR(alg) ? ERR_CAST(alg) :
554                container_of(alg, struct shash_alg, base);
555 }
556 EXPORT_SYMBOL_GPL(shash_attr_alg);
557
558 MODULE_LICENSE("GPL");
559 MODULE_DESCRIPTION("Synchronous cryptographic hash type");