[CRYPTO] api: Allow multiple frontends per backend
[deliverable/linux.git] / crypto / xcbc.c
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1/*
2 * Copyright (C)2006 USAGI/WIDE Project
3 *
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2 of the License, or
7 * (at your option) any later version.
8 *
9 * This program is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write to the Free Software
16 * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
17 *
18 * Author:
19 * Kazunori Miyazawa <miyazawa@linux-ipv6.org>
20 */
21
22#include <linux/crypto.h>
23#include <linux/err.h>
fb469840 24#include <linux/hardirq.h>
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25#include <linux/kernel.h>
26#include <linux/mm.h>
27#include <linux/rtnetlink.h>
28#include <linux/slab.h>
29#include <linux/scatterlist.h>
30#include "internal.h"
31
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32static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
33 0x02020202, 0x02020202, 0x02020202, 0x02020202,
34 0x03030303, 0x03030303, 0x03030303, 0x03030303};
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35/*
36 * +------------------------
37 * | <parent tfm>
38 * +------------------------
39 * | crypto_xcbc_ctx
40 * +------------------------
41 * | odds (block size)
42 * +------------------------
43 * | prev (block size)
44 * +------------------------
45 * | key (block size)
46 * +------------------------
47 * | consts (block size * 3)
48 * +------------------------
49 */
50struct crypto_xcbc_ctx {
51 struct crypto_tfm *child;
52 u8 *odds;
53 u8 *prev;
54 u8 *key;
55 u8 *consts;
56 void (*xor)(u8 *a, const u8 *b, unsigned int bs);
57 unsigned int keylen;
58 unsigned int len;
59};
60
61static void xor_128(u8 *a, const u8 *b, unsigned int bs)
62{
63 ((u32 *)a)[0] ^= ((u32 *)b)[0];
64 ((u32 *)a)[1] ^= ((u32 *)b)[1];
65 ((u32 *)a)[2] ^= ((u32 *)b)[2];
66 ((u32 *)a)[3] ^= ((u32 *)b)[3];
67}
68
69static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent,
70 struct crypto_xcbc_ctx *ctx)
71{
72 int bs = crypto_hash_blocksize(parent);
73 int err = 0;
74 u8 key1[bs];
75
76 if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
77 return err;
78
79 ctx->child->__crt_alg->cra_cipher.cia_encrypt(ctx->child, key1,
80 ctx->consts);
81
82 return crypto_cipher_setkey(ctx->child, key1, bs);
83}
84
85static int crypto_xcbc_digest_setkey(struct crypto_hash *parent,
86 const u8 *inkey, unsigned int keylen)
87{
88 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
89
90 if (keylen != crypto_tfm_alg_blocksize(ctx->child))
91 return -EINVAL;
92
93 ctx->keylen = keylen;
94 memcpy(ctx->key, inkey, keylen);
95 ctx->consts = (u8*)ks;
96
97 return _crypto_xcbc_digest_setkey(parent, ctx);
98}
99
5b37538a 100static int crypto_xcbc_digest_init(struct hash_desc *pdesc)
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101{
102 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm);
103 int bs = crypto_hash_blocksize(pdesc->tfm);
104
105 ctx->len = 0;
106 memset(ctx->odds, 0, bs);
107 memset(ctx->prev, 0, bs);
108
109 return 0;
110}
111
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112static int crypto_xcbc_digest_update2(struct hash_desc *pdesc,
113 struct scatterlist *sg,
114 unsigned int nbytes)
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115{
116 struct crypto_hash *parent = pdesc->tfm;
117 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
118 struct crypto_tfm *tfm = ctx->child;
119 int bs = crypto_hash_blocksize(parent);
120 unsigned int i = 0;
121
122 do {
123
124 struct page *pg = sg[i].page;
125 unsigned int offset = sg[i].offset;
126 unsigned int slen = sg[i].length;
127
128 while (slen > 0) {
129 unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
130 char *p = crypto_kmap(pg, 0) + offset;
131
132 /* checking the data can fill the block */
133 if ((ctx->len + len) <= bs) {
134 memcpy(ctx->odds + ctx->len, p, len);
135 ctx->len += len;
136 slen -= len;
137
138 /* checking the rest of the page */
139 if (len + offset >= PAGE_SIZE) {
140 offset = 0;
141 pg++;
142 } else
143 offset += len;
144
145 crypto_kunmap(p, 0);
146 crypto_yield(tfm->crt_flags);
147 continue;
148 }
149
150 /* filling odds with new data and encrypting it */
151 memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
152 len -= bs - ctx->len;
153 p += bs - ctx->len;
154
155 ctx->xor(ctx->prev, ctx->odds, bs);
156 tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev);
157
158 /* clearing the length */
159 ctx->len = 0;
160
161 /* encrypting the rest of data */
162 while (len > bs) {
163 ctx->xor(ctx->prev, p, bs);
164 tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev);
165 p += bs;
166 len -= bs;
167 }
168
169 /* keeping the surplus of blocksize */
170 if (len) {
171 memcpy(ctx->odds, p, len);
172 ctx->len = len;
173 }
174 crypto_kunmap(p, 0);
175 crypto_yield(tfm->crt_flags);
176 slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
177 offset = 0;
178 pg++;
179 }
180 nbytes-=sg[i].length;
181 i++;
182 } while (nbytes>0);
183
184 return 0;
185}
186
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187static int crypto_xcbc_digest_update(struct hash_desc *pdesc,
188 struct scatterlist *sg,
189 unsigned int nbytes)
190{
191 if (WARN_ON_ONCE(in_irq()))
192 return -EDEADLK;
193 return crypto_xcbc_digest_update2(pdesc, sg, nbytes);
194}
195
5b37538a 196static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out)
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197{
198 struct crypto_hash *parent = pdesc->tfm;
199 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
200 struct crypto_tfm *tfm = ctx->child;
201 int bs = crypto_hash_blocksize(parent);
202 int err = 0;
203
204 if (ctx->len == bs) {
205 u8 key2[bs];
206
207 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
208 return err;
209
210 tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key2, (const u8*)(ctx->consts+bs));
211
212 ctx->xor(ctx->prev, ctx->odds, bs);
213 ctx->xor(ctx->prev, key2, bs);
214 _crypto_xcbc_digest_setkey(parent, ctx);
215
216 tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev);
217 } else {
218 u8 key3[bs];
219 unsigned int rlen;
220 u8 *p = ctx->odds + ctx->len;
221 *p = 0x80;
222 p++;
223
224 rlen = bs - ctx->len -1;
225 if (rlen)
226 memset(p, 0, rlen);
227
228 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
229 return err;
230
231 tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key3, (const u8*)(ctx->consts+bs*2));
232
233 ctx->xor(ctx->prev, ctx->odds, bs);
234 ctx->xor(ctx->prev, key3, bs);
235
236 _crypto_xcbc_digest_setkey(parent, ctx);
237
238 tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev);
239 }
240
241 return 0;
242}
243
244static int crypto_xcbc_digest(struct hash_desc *pdesc,
245 struct scatterlist *sg, unsigned int nbytes, u8 *out)
246{
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247 if (WARN_ON_ONCE(in_irq()))
248 return -EDEADLK;
249
333b0d7e 250 crypto_xcbc_digest_init(pdesc);
fb469840 251 crypto_xcbc_digest_update2(pdesc, sg, nbytes);
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252 return crypto_xcbc_digest_final(pdesc, out);
253}
254
255static int xcbc_init_tfm(struct crypto_tfm *tfm)
256{
2e306ee0 257 struct crypto_cipher *cipher;
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258 struct crypto_instance *inst = (void *)tfm->__crt_alg;
259 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
260 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
261 int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
262
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263 cipher = crypto_spawn_cipher(spawn);
264 if (IS_ERR(cipher))
265 return PTR_ERR(cipher);
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266
267 switch(bs) {
268 case 16:
269 ctx->xor = xor_128;
270 break;
271 default:
272 return -EINVAL;
273 }
274
2e306ee0 275 ctx->child = cipher;
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276 ctx->odds = (u8*)(ctx+1);
277 ctx->prev = ctx->odds + bs;
278 ctx->key = ctx->prev + bs;
279
280 return 0;
281};
282
283static void xcbc_exit_tfm(struct crypto_tfm *tfm)
284{
285 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
286 crypto_free_cipher(ctx->child);
287}
288
289static struct crypto_instance *xcbc_alloc(void *param, unsigned int len)
290{
291 struct crypto_instance *inst;
292 struct crypto_alg *alg;
293 alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER,
294 CRYPTO_ALG_TYPE_HASH_MASK | CRYPTO_ALG_ASYNC);
295 if (IS_ERR(alg))
296 return ERR_PTR(PTR_ERR(alg));
297
298 switch(alg->cra_blocksize) {
299 case 16:
300 break;
301 default:
302 return ERR_PTR(PTR_ERR(alg));
303 }
304
305 inst = crypto_alloc_instance("xcbc", alg);
306 if (IS_ERR(inst))
307 goto out_put_alg;
308
309 inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
310 inst->alg.cra_priority = alg->cra_priority;
311 inst->alg.cra_blocksize = alg->cra_blocksize;
312 inst->alg.cra_alignmask = alg->cra_alignmask;
313 inst->alg.cra_type = &crypto_hash_type;
314
315 inst->alg.cra_hash.digestsize =
316 (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) ==
317 CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize :
318 alg->cra_blocksize;
319 inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
320 ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
321 inst->alg.cra_init = xcbc_init_tfm;
322 inst->alg.cra_exit = xcbc_exit_tfm;
323
324 inst->alg.cra_hash.init = crypto_xcbc_digest_init;
325 inst->alg.cra_hash.update = crypto_xcbc_digest_update;
326 inst->alg.cra_hash.final = crypto_xcbc_digest_final;
327 inst->alg.cra_hash.digest = crypto_xcbc_digest;
328 inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
329
330out_put_alg:
331 crypto_mod_put(alg);
332 return inst;
333}
334
335static void xcbc_free(struct crypto_instance *inst)
336{
337 crypto_drop_spawn(crypto_instance_ctx(inst));
338 kfree(inst);
339}
340
341static struct crypto_template crypto_xcbc_tmpl = {
342 .name = "xcbc",
343 .alloc = xcbc_alloc,
344 .free = xcbc_free,
345 .module = THIS_MODULE,
346};
347
348static int __init crypto_xcbc_module_init(void)
349{
350 return crypto_register_template(&crypto_xcbc_tmpl);
351}
352
353static void __exit crypto_xcbc_module_exit(void)
354{
355 crypto_unregister_template(&crypto_xcbc_tmpl);
356}
357
358module_init(crypto_xcbc_module_init);
359module_exit(crypto_xcbc_module_exit);
360
361MODULE_LICENSE("GPL");
362MODULE_DESCRIPTION("XCBC keyed hash algorithm");
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