media: ov5640: change 1080p resolution to 1088p
[linux-2.6.git] / crypto / hmac.c
1 /*
2  * Cryptographic API.
3  *
4  * HMAC: Keyed-Hashing for Message Authentication (RFC2104).
5  *
6  * Copyright (c) 2002 James Morris <jmorris@intercode.com.au>
7  * Copyright (c) 2006 Herbert Xu <herbert@gondor.apana.org.au>
8  *
9  * The HMAC implementation is derived from USAGI.
10  * Copyright (c) 2002 Kazunori Miyazawa <miyazawa@linux-ipv6.org> / USAGI
11  *
12  * This program is free software; you can redistribute it and/or modify it
13  * under the terms of the GNU General Public License as published by the Free
14  * Software Foundation; either version 2 of the License, or (at your option)
15  * any later version.
16  *
17  */
18
19 #include <crypto/internal/hash.h>
20 #include <crypto/scatterwalk.h>
21 #include <linux/err.h>
22 #include <linux/init.h>
23 #include <linux/kernel.h>
24 #include <linux/module.h>
25 #include <linux/scatterlist.h>
26 #include <linux/string.h>
27
28 struct hmac_ctx {
29         struct crypto_shash *hash;
30 };
31
32 static inline void *align_ptr(void *p, unsigned int align)
33 {
34         return (void *)ALIGN((unsigned long)p, align);
35 }
36
37 static inline struct hmac_ctx *hmac_ctx(struct crypto_shash *tfm)
38 {
39         return align_ptr(crypto_shash_ctx_aligned(tfm) +
40                          crypto_shash_statesize(tfm) * 2,
41                          crypto_tfm_ctx_alignment());
42 }
43
44 static int hmac_setkey(struct crypto_shash *parent,
45                        const u8 *inkey, unsigned int keylen)
46 {
47         int bs = crypto_shash_blocksize(parent);
48         int ds = crypto_shash_digestsize(parent);
49         int ss = crypto_shash_statesize(parent);
50         char *ipad = crypto_shash_ctx_aligned(parent);
51         char *opad = ipad + ss;
52         struct hmac_ctx *ctx = align_ptr(opad + ss,
53                                          crypto_tfm_ctx_alignment());
54         struct crypto_shash *hash = ctx->hash;
55         struct {
56                 struct shash_desc shash;
57                 char ctx[crypto_shash_descsize(hash)];
58         } desc;
59         unsigned int i;
60
61         desc.shash.tfm = hash;
62         desc.shash.flags = crypto_shash_get_flags(parent) &
63                             CRYPTO_TFM_REQ_MAY_SLEEP;
64
65         if (keylen > bs) {
66                 int err;
67
68                 err = crypto_shash_digest(&desc.shash, inkey, keylen, ipad);
69                 if (err)
70                         return err;
71
72                 keylen = ds;
73         } else
74                 memcpy(ipad, inkey, keylen);
75
76         memset(ipad + keylen, 0, bs - keylen);
77         memcpy(opad, ipad, bs);
78
79         for (i = 0; i < bs; i++) {
80                 ipad[i] ^= 0x36;
81                 opad[i] ^= 0x5c;
82         }
83
84         return crypto_shash_init(&desc.shash) ?:
85                crypto_shash_update(&desc.shash, ipad, bs) ?:
86                crypto_shash_export(&desc.shash, ipad) ?:
87                crypto_shash_init(&desc.shash) ?:
88                crypto_shash_update(&desc.shash, opad, bs) ?:
89                crypto_shash_export(&desc.shash, opad);
90 }
91
92 static int hmac_export(struct shash_desc *pdesc, void *out)
93 {
94         struct shash_desc *desc = shash_desc_ctx(pdesc);
95
96         desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
97
98         return crypto_shash_export(desc, out);
99 }
100
101 static int hmac_import(struct shash_desc *pdesc, const void *in)
102 {
103         struct shash_desc *desc = shash_desc_ctx(pdesc);
104         struct hmac_ctx *ctx = hmac_ctx(pdesc->tfm);
105
106         desc->tfm = ctx->hash;
107         desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
108
109         return crypto_shash_import(desc, in);
110 }
111
112 static int hmac_init(struct shash_desc *pdesc)
113 {
114         return hmac_import(pdesc, crypto_shash_ctx_aligned(pdesc->tfm));
115 }
116
117 static int hmac_update(struct shash_desc *pdesc,
118                        const u8 *data, unsigned int nbytes)
119 {
120         struct shash_desc *desc = shash_desc_ctx(pdesc);
121
122         desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
123
124         return crypto_shash_update(desc, data, nbytes);
125 }
126
127 static int hmac_final(struct shash_desc *pdesc, u8 *out)
128 {
129         struct crypto_shash *parent = pdesc->tfm;
130         int ds = crypto_shash_digestsize(parent);
131         int ss = crypto_shash_statesize(parent);
132         char *opad = crypto_shash_ctx_aligned(parent) + ss;
133         struct shash_desc *desc = shash_desc_ctx(pdesc);
134
135         desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
136
137         return crypto_shash_final(desc, out) ?:
138                crypto_shash_import(desc, opad) ?:
139                crypto_shash_finup(desc, out, ds, out);
140 }
141
142 static int hmac_finup(struct shash_desc *pdesc, const u8 *data,
143                       unsigned int nbytes, u8 *out)
144 {
145
146         struct crypto_shash *parent = pdesc->tfm;
147         int ds = crypto_shash_digestsize(parent);
148         int ss = crypto_shash_statesize(parent);
149         char *opad = crypto_shash_ctx_aligned(parent) + ss;
150         struct shash_desc *desc = shash_desc_ctx(pdesc);
151
152         desc->flags = pdesc->flags & CRYPTO_TFM_REQ_MAY_SLEEP;
153
154         return crypto_shash_finup(desc, data, nbytes, out) ?:
155                crypto_shash_import(desc, opad) ?:
156                crypto_shash_finup(desc, out, ds, out);
157 }
158
159 static int hmac_init_tfm(struct crypto_tfm *tfm)
160 {
161         struct crypto_shash *parent = __crypto_shash_cast(tfm);
162         struct crypto_shash *hash;
163         struct crypto_instance *inst = (void *)tfm->__crt_alg;
164         struct crypto_shash_spawn *spawn = crypto_instance_ctx(inst);
165         struct hmac_ctx *ctx = hmac_ctx(parent);
166
167         hash = crypto_spawn_shash(spawn);
168         if (IS_ERR(hash))
169                 return PTR_ERR(hash);
170
171         parent->descsize = sizeof(struct shash_desc) +
172                            crypto_shash_descsize(hash);
173
174         ctx->hash = hash;
175         return 0;
176 }
177
178 static void hmac_exit_tfm(struct crypto_tfm *tfm)
179 {
180         struct hmac_ctx *ctx = hmac_ctx(__crypto_shash_cast(tfm));
181         crypto_free_shash(ctx->hash);
182 }
183
184 static int hmac_create(struct crypto_template *tmpl, struct rtattr **tb)
185 {
186         struct shash_instance *inst;
187         struct crypto_alg *alg;
188         struct shash_alg *salg;
189         int err;
190         int ds;
191         int ss;
192
193         err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_SHASH);
194         if (err)
195                 return err;
196
197         salg = shash_attr_alg(tb[1], 0, 0);
198         if (IS_ERR(salg))
199                 return PTR_ERR(salg);
200
201         err = -EINVAL;
202         ds = salg->digestsize;
203         ss = salg->statesize;
204         alg = &salg->base;
205         if (ds > alg->cra_blocksize ||
206             ss < alg->cra_blocksize)
207                 goto out_put_alg;
208
209         inst = shash_alloc_instance("hmac", alg);
210         err = PTR_ERR(inst);
211         if (IS_ERR(inst))
212                 goto out_put_alg;
213
214         err = crypto_init_shash_spawn(shash_instance_ctx(inst), salg,
215                                       shash_crypto_instance(inst));
216         if (err)
217                 goto out_free_inst;
218
219         inst->alg.base.cra_priority = alg->cra_priority;
220         inst->alg.base.cra_blocksize = alg->cra_blocksize;
221         inst->alg.base.cra_alignmask = alg->cra_alignmask;
222
223         ss = ALIGN(ss, alg->cra_alignmask + 1);
224         inst->alg.digestsize = ds;
225         inst->alg.statesize = ss;
226
227         inst->alg.base.cra_ctxsize = sizeof(struct hmac_ctx) +
228                                      ALIGN(ss * 2, crypto_tfm_ctx_alignment());
229
230         inst->alg.base.cra_init = hmac_init_tfm;
231         inst->alg.base.cra_exit = hmac_exit_tfm;
232
233         inst->alg.init = hmac_init;
234         inst->alg.update = hmac_update;
235         inst->alg.final = hmac_final;
236         inst->alg.finup = hmac_finup;
237         inst->alg.export = hmac_export;
238         inst->alg.import = hmac_import;
239         inst->alg.setkey = hmac_setkey;
240
241         err = shash_register_instance(tmpl, inst);
242         if (err) {
243 out_free_inst:
244                 shash_free_instance(shash_crypto_instance(inst));
245         }
246
247 out_put_alg:
248         crypto_mod_put(alg);
249         return err;
250 }
251
252 static struct crypto_template hmac_tmpl = {
253         .name = "hmac",
254         .create = hmac_create,
255         .free = shash_free_instance,
256         .module = THIS_MODULE,
257 };
258
259 static int __init hmac_module_init(void)
260 {
261         return crypto_register_template(&hmac_tmpl);
262 }
263
264 static void __exit hmac_module_exit(void)
265 {
266         crypto_unregister_template(&hmac_tmpl);
267 }
268
269 module_init(hmac_module_init);
270 module_exit(hmac_module_exit);
271
272 MODULE_LICENSE("GPL");
273 MODULE_DESCRIPTION("HMAC hash algorithm");