crypto: ahash - Add instance/spawn support
[linux-2.6.git] / crypto / ahash.c
1 /*
2  * Asynchronous Cryptographic Hash operations.
3  *
4  * This is the asynchronous version of hash.c with notification of
5  * completion via a callback.
6  *
7  * Copyright (c) 2008 Loc Ho <lho@amcc.com>
8  *
9  * This program is free software; you can redistribute it and/or modify it
10  * under the terms of the GNU General Public License as published by the Free
11  * Software Foundation; either version 2 of the License, or (at your option)
12  * any later version.
13  *
14  */
15
16 #include <crypto/internal/hash.h>
17 #include <crypto/scatterwalk.h>
18 #include <linux/err.h>
19 #include <linux/kernel.h>
20 #include <linux/module.h>
21 #include <linux/sched.h>
22 #include <linux/slab.h>
23 #include <linux/seq_file.h>
24
25 #include "internal.h"
26
27 static inline struct ahash_alg *crypto_ahash_alg(struct crypto_ahash *hash)
28 {
29         return container_of(crypto_hash_alg_common(hash), struct ahash_alg,
30                             halg);
31 }
32
33 static int hash_walk_next(struct crypto_hash_walk *walk)
34 {
35         unsigned int alignmask = walk->alignmask;
36         unsigned int offset = walk->offset;
37         unsigned int nbytes = min(walk->entrylen,
38                                   ((unsigned int)(PAGE_SIZE)) - offset);
39
40         walk->data = crypto_kmap(walk->pg, 0);
41         walk->data += offset;
42
43         if (offset & alignmask)
44                 nbytes = alignmask + 1 - (offset & alignmask);
45
46         walk->entrylen -= nbytes;
47         return nbytes;
48 }
49
50 static int hash_walk_new_entry(struct crypto_hash_walk *walk)
51 {
52         struct scatterlist *sg;
53
54         sg = walk->sg;
55         walk->pg = sg_page(sg);
56         walk->offset = sg->offset;
57         walk->entrylen = sg->length;
58
59         if (walk->entrylen > walk->total)
60                 walk->entrylen = walk->total;
61         walk->total -= walk->entrylen;
62
63         return hash_walk_next(walk);
64 }
65
66 int crypto_hash_walk_done(struct crypto_hash_walk *walk, int err)
67 {
68         unsigned int alignmask = walk->alignmask;
69         unsigned int nbytes = walk->entrylen;
70
71         walk->data -= walk->offset;
72
73         if (nbytes && walk->offset & alignmask && !err) {
74                 walk->offset += alignmask - 1;
75                 walk->offset = ALIGN(walk->offset, alignmask + 1);
76                 walk->data += walk->offset;
77
78                 nbytes = min(nbytes,
79                              ((unsigned int)(PAGE_SIZE)) - walk->offset);
80                 walk->entrylen -= nbytes;
81
82                 return nbytes;
83         }
84
85         crypto_kunmap(walk->data, 0);
86         crypto_yield(walk->flags);
87
88         if (err)
89                 return err;
90
91         if (nbytes) {
92                 walk->offset = 0;
93                 walk->pg++;
94                 return hash_walk_next(walk);
95         }
96
97         if (!walk->total)
98                 return 0;
99
100         walk->sg = scatterwalk_sg_next(walk->sg);
101
102         return hash_walk_new_entry(walk);
103 }
104 EXPORT_SYMBOL_GPL(crypto_hash_walk_done);
105
106 int crypto_hash_walk_first(struct ahash_request *req,
107                            struct crypto_hash_walk *walk)
108 {
109         walk->total = req->nbytes;
110
111         if (!walk->total)
112                 return 0;
113
114         walk->alignmask = crypto_ahash_alignmask(crypto_ahash_reqtfm(req));
115         walk->sg = req->src;
116         walk->flags = req->base.flags;
117
118         return hash_walk_new_entry(walk);
119 }
120 EXPORT_SYMBOL_GPL(crypto_hash_walk_first);
121
122 int crypto_hash_walk_first_compat(struct hash_desc *hdesc,
123                                   struct crypto_hash_walk *walk,
124                                   struct scatterlist *sg, unsigned int len)
125 {
126         walk->total = len;
127
128         if (!walk->total)
129                 return 0;
130
131         walk->alignmask = crypto_hash_alignmask(hdesc->tfm);
132         walk->sg = sg;
133         walk->flags = hdesc->flags;
134
135         return hash_walk_new_entry(walk);
136 }
137
138 static int ahash_setkey_unaligned(struct crypto_ahash *tfm, const u8 *key,
139                                 unsigned int keylen)
140 {
141         struct ahash_alg *ahash = crypto_ahash_alg(tfm);
142         unsigned long alignmask = crypto_ahash_alignmask(tfm);
143         int ret;
144         u8 *buffer, *alignbuffer;
145         unsigned long absize;
146
147         absize = keylen + alignmask;
148         buffer = kmalloc(absize, GFP_ATOMIC);
149         if (!buffer)
150                 return -ENOMEM;
151
152         alignbuffer = (u8 *)ALIGN((unsigned long)buffer, alignmask + 1);
153         memcpy(alignbuffer, key, keylen);
154         ret = ahash->setkey(tfm, alignbuffer, keylen);
155         memset(alignbuffer, 0, keylen);
156         kfree(buffer);
157         return ret;
158 }
159
160 static int ahash_setkey(struct crypto_ahash *tfm, const u8 *key,
161                         unsigned int keylen)
162 {
163         struct ahash_alg *ahash = crypto_ahash_alg(tfm);
164         unsigned long alignmask = crypto_ahash_alignmask(tfm);
165
166         if ((unsigned long)key & alignmask)
167                 return ahash_setkey_unaligned(tfm, key, keylen);
168
169         return ahash->setkey(tfm, key, keylen);
170 }
171
172 static int ahash_nosetkey(struct crypto_ahash *tfm, const u8 *key,
173                           unsigned int keylen)
174 {
175         return -ENOSYS;
176 }
177
178 static int crypto_init_ahash_ops(struct crypto_tfm *tfm, u32 type, u32 mask)
179 {
180         struct old_ahash_alg *alg = &tfm->__crt_alg->cra_ahash;
181         struct crypto_ahash *crt = __crypto_ahash_cast(tfm);
182         struct ahash_alg *nalg = crypto_ahash_alg(crt);
183
184         if (alg->digestsize > PAGE_SIZE / 8)
185                 return -EINVAL;
186
187         crt->init = alg->init;
188         crt->update = alg->update;
189         crt->final  = alg->final;
190         crt->digest = alg->digest;
191         crt->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
192         crt->digestsize = alg->digestsize;
193
194         nalg->setkey = alg->setkey;
195         nalg->halg.digestsize = alg->digestsize;
196
197         return 0;
198 }
199
200 static int crypto_ahash_init_tfm(struct crypto_tfm *tfm)
201 {
202         struct crypto_ahash *hash = __crypto_ahash_cast(tfm);
203         struct ahash_alg *alg = crypto_ahash_alg(hash);
204         struct old_ahash_alg *oalg = crypto_old_ahash_alg(hash);
205
206         if (tfm->__crt_alg->cra_type != &crypto_ahash_type)
207                 return crypto_init_shash_ops_async(tfm);
208
209         if (oalg->init)
210                 return crypto_init_ahash_ops(tfm, 0, 0);
211
212         hash->init = alg->init;
213         hash->update = alg->update;
214         hash->final  = alg->final;
215         hash->digest = alg->digest;
216         hash->setkey = alg->setkey ? ahash_setkey : ahash_nosetkey;
217         hash->digestsize = alg->halg.digestsize;
218
219         return 0;
220 }
221
222 static unsigned int crypto_ahash_extsize(struct crypto_alg *alg)
223 {
224         if (alg->cra_type == &crypto_ahash_type)
225                 return alg->cra_ctxsize;
226
227         return sizeof(struct crypto_shash *);
228 }
229
230 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
231         __attribute__ ((unused));
232 static void crypto_ahash_show(struct seq_file *m, struct crypto_alg *alg)
233 {
234         seq_printf(m, "type         : ahash\n");
235         seq_printf(m, "async        : %s\n", alg->cra_flags & CRYPTO_ALG_ASYNC ?
236                                              "yes" : "no");
237         seq_printf(m, "blocksize    : %u\n", alg->cra_blocksize);
238         seq_printf(m, "digestsize   : %u\n",
239                    __crypto_hash_alg_common(alg)->digestsize);
240 }
241
242 const struct crypto_type crypto_ahash_type = {
243         .extsize = crypto_ahash_extsize,
244         .init_tfm = crypto_ahash_init_tfm,
245 #ifdef CONFIG_PROC_FS
246         .show = crypto_ahash_show,
247 #endif
248         .maskclear = ~CRYPTO_ALG_TYPE_MASK,
249         .maskset = CRYPTO_ALG_TYPE_AHASH_MASK,
250         .type = CRYPTO_ALG_TYPE_AHASH,
251         .tfmsize = offsetof(struct crypto_ahash, base),
252 };
253 EXPORT_SYMBOL_GPL(crypto_ahash_type);
254
255 struct crypto_ahash *crypto_alloc_ahash(const char *alg_name, u32 type,
256                                         u32 mask)
257 {
258         return crypto_alloc_tfm(alg_name, &crypto_ahash_type, type, mask);
259 }
260 EXPORT_SYMBOL_GPL(crypto_alloc_ahash);
261
262 static int ahash_prepare_alg(struct ahash_alg *alg)
263 {
264         struct crypto_alg *base = &alg->halg.base;
265
266         if (alg->halg.digestsize > PAGE_SIZE / 8 ||
267             alg->halg.statesize > PAGE_SIZE / 8)
268                 return -EINVAL;
269
270         base->cra_type = &crypto_ahash_type;
271         base->cra_flags &= ~CRYPTO_ALG_TYPE_MASK;
272         base->cra_flags |= CRYPTO_ALG_TYPE_AHASH;
273
274         return 0;
275 }
276
277 int crypto_register_ahash(struct ahash_alg *alg)
278 {
279         struct crypto_alg *base = &alg->halg.base;
280         int err;
281
282         err = ahash_prepare_alg(alg);
283         if (err)
284                 return err;
285
286         return crypto_register_alg(base);
287 }
288 EXPORT_SYMBOL_GPL(crypto_register_ahash);
289
290 int crypto_unregister_ahash(struct ahash_alg *alg)
291 {
292         return crypto_unregister_alg(&alg->halg.base);
293 }
294 EXPORT_SYMBOL_GPL(crypto_unregister_ahash);
295
296 int ahash_register_instance(struct crypto_template *tmpl,
297                             struct ahash_instance *inst)
298 {
299         int err;
300
301         err = ahash_prepare_alg(&inst->alg);
302         if (err)
303                 return err;
304
305         return crypto_register_instance(tmpl, ahash_crypto_instance(inst));
306 }
307 EXPORT_SYMBOL_GPL(ahash_register_instance);
308
309 void ahash_free_instance(struct crypto_instance *inst)
310 {
311         crypto_drop_spawn(crypto_instance_ctx(inst));
312         kfree(ahash_instance(inst));
313 }
314 EXPORT_SYMBOL_GPL(ahash_free_instance);
315
316 int crypto_init_ahash_spawn(struct crypto_ahash_spawn *spawn,
317                             struct hash_alg_common *alg,
318                             struct crypto_instance *inst)
319 {
320         return crypto_init_spawn2(&spawn->base, &alg->base, inst,
321                                   &crypto_ahash_type);
322 }
323 EXPORT_SYMBOL_GPL(crypto_init_ahash_spawn);
324
325 struct hash_alg_common *ahash_attr_alg(struct rtattr *rta, u32 type, u32 mask)
326 {
327         struct crypto_alg *alg;
328
329         alg = crypto_attr_alg2(rta, &crypto_ahash_type, type, mask);
330         return IS_ERR(alg) ? ERR_CAST(alg) : __crypto_hash_alg_common(alg);
331 }
332 EXPORT_SYMBOL_GPL(ahash_attr_alg);
333
334 MODULE_LICENSE("GPL");
335 MODULE_DESCRIPTION("Asynchronous cryptographic hash type");