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333b0d7e KM |
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> | |
24 | #include <linux/kernel.h> | |
25 | #include <linux/mm.h> | |
26 | #include <linux/rtnetlink.h> | |
27 | #include <linux/slab.h> | |
28 | #include <linux/scatterlist.h> | |
29 | #include "internal.h" | |
30 | ||
31 | u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101, | |
32 | 0x02020202, 0x02020202, 0x02020202, 0x02020202, | |
33 | 0x03030303, 0x03030303, 0x03030303, 0x03030303}; | |
34 | /* | |
35 | * +------------------------ | |
36 | * | <parent tfm> | |
37 | * +------------------------ | |
38 | * | crypto_xcbc_ctx | |
39 | * +------------------------ | |
40 | * | odds (block size) | |
41 | * +------------------------ | |
42 | * | prev (block size) | |
43 | * +------------------------ | |
44 | * | key (block size) | |
45 | * +------------------------ | |
46 | * | consts (block size * 3) | |
47 | * +------------------------ | |
48 | */ | |
49 | struct crypto_xcbc_ctx { | |
50 | struct crypto_tfm *child; | |
51 | u8 *odds; | |
52 | u8 *prev; | |
53 | u8 *key; | |
54 | u8 *consts; | |
55 | void (*xor)(u8 *a, const u8 *b, unsigned int bs); | |
56 | unsigned int keylen; | |
57 | unsigned int len; | |
58 | }; | |
59 | ||
60 | static void xor_128(u8 *a, const u8 *b, unsigned int bs) | |
61 | { | |
62 | ((u32 *)a)[0] ^= ((u32 *)b)[0]; | |
63 | ((u32 *)a)[1] ^= ((u32 *)b)[1]; | |
64 | ((u32 *)a)[2] ^= ((u32 *)b)[2]; | |
65 | ((u32 *)a)[3] ^= ((u32 *)b)[3]; | |
66 | } | |
67 | ||
68 | static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent, | |
69 | struct crypto_xcbc_ctx *ctx) | |
70 | { | |
71 | int bs = crypto_hash_blocksize(parent); | |
72 | int err = 0; | |
73 | u8 key1[bs]; | |
74 | ||
75 | if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen))) | |
76 | return err; | |
77 | ||
78 | ctx->child->__crt_alg->cra_cipher.cia_encrypt(ctx->child, key1, | |
79 | ctx->consts); | |
80 | ||
81 | return crypto_cipher_setkey(ctx->child, key1, bs); | |
82 | } | |
83 | ||
84 | static int crypto_xcbc_digest_setkey(struct crypto_hash *parent, | |
85 | const u8 *inkey, unsigned int keylen) | |
86 | { | |
87 | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent); | |
88 | ||
89 | if (keylen != crypto_tfm_alg_blocksize(ctx->child)) | |
90 | return -EINVAL; | |
91 | ||
92 | ctx->keylen = keylen; | |
93 | memcpy(ctx->key, inkey, keylen); | |
94 | ctx->consts = (u8*)ks; | |
95 | ||
96 | return _crypto_xcbc_digest_setkey(parent, ctx); | |
97 | } | |
98 | ||
99 | int crypto_xcbc_digest_init(struct hash_desc *pdesc) | |
100 | { | |
101 | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm); | |
102 | int bs = crypto_hash_blocksize(pdesc->tfm); | |
103 | ||
104 | ctx->len = 0; | |
105 | memset(ctx->odds, 0, bs); | |
106 | memset(ctx->prev, 0, bs); | |
107 | ||
108 | return 0; | |
109 | } | |
110 | ||
111 | int crypto_xcbc_digest_update(struct hash_desc *pdesc, struct scatterlist *sg, unsigned int nbytes) | |
112 | { | |
113 | struct crypto_hash *parent = pdesc->tfm; | |
114 | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent); | |
115 | struct crypto_tfm *tfm = ctx->child; | |
116 | int bs = crypto_hash_blocksize(parent); | |
117 | unsigned int i = 0; | |
118 | ||
119 | do { | |
120 | ||
121 | struct page *pg = sg[i].page; | |
122 | unsigned int offset = sg[i].offset; | |
123 | unsigned int slen = sg[i].length; | |
124 | ||
125 | while (slen > 0) { | |
126 | unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset); | |
127 | char *p = crypto_kmap(pg, 0) + offset; | |
128 | ||
129 | /* checking the data can fill the block */ | |
130 | if ((ctx->len + len) <= bs) { | |
131 | memcpy(ctx->odds + ctx->len, p, len); | |
132 | ctx->len += len; | |
133 | slen -= len; | |
134 | ||
135 | /* checking the rest of the page */ | |
136 | if (len + offset >= PAGE_SIZE) { | |
137 | offset = 0; | |
138 | pg++; | |
139 | } else | |
140 | offset += len; | |
141 | ||
142 | crypto_kunmap(p, 0); | |
143 | crypto_yield(tfm->crt_flags); | |
144 | continue; | |
145 | } | |
146 | ||
147 | /* filling odds with new data and encrypting it */ | |
148 | memcpy(ctx->odds + ctx->len, p, bs - ctx->len); | |
149 | len -= bs - ctx->len; | |
150 | p += bs - ctx->len; | |
151 | ||
152 | ctx->xor(ctx->prev, ctx->odds, bs); | |
153 | tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev); | |
154 | ||
155 | /* clearing the length */ | |
156 | ctx->len = 0; | |
157 | ||
158 | /* encrypting the rest of data */ | |
159 | while (len > bs) { | |
160 | ctx->xor(ctx->prev, p, bs); | |
161 | tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, ctx->prev, ctx->prev); | |
162 | p += bs; | |
163 | len -= bs; | |
164 | } | |
165 | ||
166 | /* keeping the surplus of blocksize */ | |
167 | if (len) { | |
168 | memcpy(ctx->odds, p, len); | |
169 | ctx->len = len; | |
170 | } | |
171 | crypto_kunmap(p, 0); | |
172 | crypto_yield(tfm->crt_flags); | |
173 | slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset); | |
174 | offset = 0; | |
175 | pg++; | |
176 | } | |
177 | nbytes-=sg[i].length; | |
178 | i++; | |
179 | } while (nbytes>0); | |
180 | ||
181 | return 0; | |
182 | } | |
183 | ||
184 | int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out) | |
185 | { | |
186 | struct crypto_hash *parent = pdesc->tfm; | |
187 | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent); | |
188 | struct crypto_tfm *tfm = ctx->child; | |
189 | int bs = crypto_hash_blocksize(parent); | |
190 | int err = 0; | |
191 | ||
192 | if (ctx->len == bs) { | |
193 | u8 key2[bs]; | |
194 | ||
195 | if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0) | |
196 | return err; | |
197 | ||
198 | tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key2, (const u8*)(ctx->consts+bs)); | |
199 | ||
200 | ctx->xor(ctx->prev, ctx->odds, bs); | |
201 | ctx->xor(ctx->prev, key2, bs); | |
202 | _crypto_xcbc_digest_setkey(parent, ctx); | |
203 | ||
204 | tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev); | |
205 | } else { | |
206 | u8 key3[bs]; | |
207 | unsigned int rlen; | |
208 | u8 *p = ctx->odds + ctx->len; | |
209 | *p = 0x80; | |
210 | p++; | |
211 | ||
212 | rlen = bs - ctx->len -1; | |
213 | if (rlen) | |
214 | memset(p, 0, rlen); | |
215 | ||
216 | if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0) | |
217 | return err; | |
218 | ||
219 | tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, key3, (const u8*)(ctx->consts+bs*2)); | |
220 | ||
221 | ctx->xor(ctx->prev, ctx->odds, bs); | |
222 | ctx->xor(ctx->prev, key3, bs); | |
223 | ||
224 | _crypto_xcbc_digest_setkey(parent, ctx); | |
225 | ||
226 | tfm->__crt_alg->cra_cipher.cia_encrypt(tfm, out, ctx->prev); | |
227 | } | |
228 | ||
229 | return 0; | |
230 | } | |
231 | ||
232 | static int crypto_xcbc_digest(struct hash_desc *pdesc, | |
233 | struct scatterlist *sg, unsigned int nbytes, u8 *out) | |
234 | { | |
235 | crypto_xcbc_digest_init(pdesc); | |
236 | crypto_xcbc_digest_update(pdesc, sg, nbytes); | |
237 | return crypto_xcbc_digest_final(pdesc, out); | |
238 | } | |
239 | ||
240 | static int xcbc_init_tfm(struct crypto_tfm *tfm) | |
241 | { | |
242 | struct crypto_instance *inst = (void *)tfm->__crt_alg; | |
243 | struct crypto_spawn *spawn = crypto_instance_ctx(inst); | |
244 | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm)); | |
245 | int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm)); | |
246 | ||
247 | tfm = crypto_spawn_tfm(spawn); | |
248 | if (IS_ERR(tfm)) | |
249 | return PTR_ERR(tfm); | |
250 | ||
251 | switch(bs) { | |
252 | case 16: | |
253 | ctx->xor = xor_128; | |
254 | break; | |
255 | default: | |
256 | return -EINVAL; | |
257 | } | |
258 | ||
259 | ctx->child = crypto_cipher_cast(tfm); | |
260 | ctx->odds = (u8*)(ctx+1); | |
261 | ctx->prev = ctx->odds + bs; | |
262 | ctx->key = ctx->prev + bs; | |
263 | ||
264 | return 0; | |
265 | }; | |
266 | ||
267 | static void xcbc_exit_tfm(struct crypto_tfm *tfm) | |
268 | { | |
269 | struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm)); | |
270 | crypto_free_cipher(ctx->child); | |
271 | } | |
272 | ||
273 | static struct crypto_instance *xcbc_alloc(void *param, unsigned int len) | |
274 | { | |
275 | struct crypto_instance *inst; | |
276 | struct crypto_alg *alg; | |
277 | alg = crypto_get_attr_alg(param, len, CRYPTO_ALG_TYPE_CIPHER, | |
278 | CRYPTO_ALG_TYPE_HASH_MASK | CRYPTO_ALG_ASYNC); | |
279 | if (IS_ERR(alg)) | |
280 | return ERR_PTR(PTR_ERR(alg)); | |
281 | ||
282 | switch(alg->cra_blocksize) { | |
283 | case 16: | |
284 | break; | |
285 | default: | |
286 | return ERR_PTR(PTR_ERR(alg)); | |
287 | } | |
288 | ||
289 | inst = crypto_alloc_instance("xcbc", alg); | |
290 | if (IS_ERR(inst)) | |
291 | goto out_put_alg; | |
292 | ||
293 | inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH; | |
294 | inst->alg.cra_priority = alg->cra_priority; | |
295 | inst->alg.cra_blocksize = alg->cra_blocksize; | |
296 | inst->alg.cra_alignmask = alg->cra_alignmask; | |
297 | inst->alg.cra_type = &crypto_hash_type; | |
298 | ||
299 | inst->alg.cra_hash.digestsize = | |
300 | (alg->cra_flags & CRYPTO_ALG_TYPE_MASK) == | |
301 | CRYPTO_ALG_TYPE_HASH ? alg->cra_hash.digestsize : | |
302 | alg->cra_blocksize; | |
303 | inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) + | |
304 | ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *)); | |
305 | inst->alg.cra_init = xcbc_init_tfm; | |
306 | inst->alg.cra_exit = xcbc_exit_tfm; | |
307 | ||
308 | inst->alg.cra_hash.init = crypto_xcbc_digest_init; | |
309 | inst->alg.cra_hash.update = crypto_xcbc_digest_update; | |
310 | inst->alg.cra_hash.final = crypto_xcbc_digest_final; | |
311 | inst->alg.cra_hash.digest = crypto_xcbc_digest; | |
312 | inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey; | |
313 | ||
314 | out_put_alg: | |
315 | crypto_mod_put(alg); | |
316 | return inst; | |
317 | } | |
318 | ||
319 | static void xcbc_free(struct crypto_instance *inst) | |
320 | { | |
321 | crypto_drop_spawn(crypto_instance_ctx(inst)); | |
322 | kfree(inst); | |
323 | } | |
324 | ||
325 | static struct crypto_template crypto_xcbc_tmpl = { | |
326 | .name = "xcbc", | |
327 | .alloc = xcbc_alloc, | |
328 | .free = xcbc_free, | |
329 | .module = THIS_MODULE, | |
330 | }; | |
331 | ||
332 | static int __init crypto_xcbc_module_init(void) | |
333 | { | |
334 | return crypto_register_template(&crypto_xcbc_tmpl); | |
335 | } | |
336 | ||
337 | static void __exit crypto_xcbc_module_exit(void) | |
338 | { | |
339 | crypto_unregister_template(&crypto_xcbc_tmpl); | |
340 | } | |
341 | ||
342 | module_init(crypto_xcbc_module_init); | |
343 | module_exit(crypto_xcbc_module_exit); | |
344 | ||
345 | MODULE_LICENSE("GPL"); | |
346 | MODULE_DESCRIPTION("XCBC keyed hash algorithm"); |