2 * Copyright (C)2006 USAGI/WIDE Project
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.
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.
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
19 * Kazunori Miyazawa <miyazawa@linux-ipv6.org>
22 #include <crypto/scatterwalk.h>
23 #include <linux/crypto.h>
24 #include <linux/err.h>
25 #include <linux/hardirq.h>
26 #include <linux/kernel.h>
28 #include <linux/rtnetlink.h>
29 #include <linux/slab.h>
30 #include <linux/scatterlist.h>
32 static u_int32_t ks[12] = {0x01010101, 0x01010101, 0x01010101, 0x01010101,
33 0x02020202, 0x02020202, 0x02020202, 0x02020202,
34 0x03030303, 0x03030303, 0x03030303, 0x03030303};
36 * +------------------------
38 * +------------------------
40 * +------------------------
42 * +------------------------
44 * +------------------------
46 * +------------------------
47 * | consts (block size * 3)
48 * +------------------------
50 struct crypto_xcbc_ctx {
51 struct crypto_cipher *child;
56 void (*xor)(u8 *a, const u8 *b, unsigned int bs);
61 static void xor_128(u8 *a, const u8 *b, unsigned int bs)
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];
69 static int _crypto_xcbc_digest_setkey(struct crypto_hash *parent,
70 struct crypto_xcbc_ctx *ctx)
72 int bs = crypto_hash_blocksize(parent);
76 if ((err = crypto_cipher_setkey(ctx->child, ctx->key, ctx->keylen)))
79 crypto_cipher_encrypt_one(ctx->child, key1, ctx->consts);
81 return crypto_cipher_setkey(ctx->child, key1, bs);
84 static int crypto_xcbc_digest_setkey(struct crypto_hash *parent,
85 const u8 *inkey, unsigned int keylen)
87 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
89 if (keylen != crypto_cipher_blocksize(ctx->child))
93 memcpy(ctx->key, inkey, keylen);
94 ctx->consts = (u8*)ks;
96 return _crypto_xcbc_digest_setkey(parent, ctx);
99 static int crypto_xcbc_digest_init(struct hash_desc *pdesc)
101 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(pdesc->tfm);
102 int bs = crypto_hash_blocksize(pdesc->tfm);
105 memset(ctx->odds, 0, bs);
106 memset(ctx->prev, 0, bs);
111 static int crypto_xcbc_digest_update2(struct hash_desc *pdesc,
112 struct scatterlist *sg,
115 struct crypto_hash *parent = pdesc->tfm;
116 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
117 struct crypto_cipher *tfm = ctx->child;
118 int bs = crypto_hash_blocksize(parent);
121 struct page *pg = sg_page(sg);
122 unsigned int offset = sg->offset;
123 unsigned int slen = sg->length;
125 if (unlikely(slen > nbytes))
131 unsigned int len = min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
132 char *p = crypto_kmap(pg, 0) + offset;
134 /* checking the data can fill the block */
135 if ((ctx->len + len) <= bs) {
136 memcpy(ctx->odds + ctx->len, p, len);
140 /* checking the rest of the page */
141 if (len + offset >= PAGE_SIZE) {
148 crypto_yield(pdesc->flags);
152 /* filling odds with new data and encrypting it */
153 memcpy(ctx->odds + ctx->len, p, bs - ctx->len);
154 len -= bs - ctx->len;
157 ctx->xor(ctx->prev, ctx->odds, bs);
158 crypto_cipher_encrypt_one(tfm, ctx->prev, ctx->prev);
160 /* clearing the length */
163 /* encrypting the rest of data */
165 ctx->xor(ctx->prev, p, bs);
166 crypto_cipher_encrypt_one(tfm, ctx->prev,
172 /* keeping the surplus of blocksize */
174 memcpy(ctx->odds, p, len);
178 crypto_yield(pdesc->flags);
179 slen -= min(slen, ((unsigned int)(PAGE_SIZE)) - offset);
186 sg = scatterwalk_sg_next(sg);
192 static int crypto_xcbc_digest_update(struct hash_desc *pdesc,
193 struct scatterlist *sg,
196 if (WARN_ON_ONCE(in_irq()))
198 return crypto_xcbc_digest_update2(pdesc, sg, nbytes);
201 static int crypto_xcbc_digest_final(struct hash_desc *pdesc, u8 *out)
203 struct crypto_hash *parent = pdesc->tfm;
204 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(parent);
205 struct crypto_cipher *tfm = ctx->child;
206 int bs = crypto_hash_blocksize(parent);
209 if (ctx->len == bs) {
212 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
215 crypto_cipher_encrypt_one(tfm, key2,
216 (u8 *)(ctx->consts + bs));
218 ctx->xor(ctx->prev, ctx->odds, bs);
219 ctx->xor(ctx->prev, key2, bs);
220 _crypto_xcbc_digest_setkey(parent, ctx);
222 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
226 u8 *p = ctx->odds + ctx->len;
230 rlen = bs - ctx->len -1;
234 if ((err = crypto_cipher_setkey(tfm, ctx->key, ctx->keylen)) != 0)
237 crypto_cipher_encrypt_one(tfm, key3,
238 (u8 *)(ctx->consts + bs * 2));
240 ctx->xor(ctx->prev, ctx->odds, bs);
241 ctx->xor(ctx->prev, key3, bs);
243 _crypto_xcbc_digest_setkey(parent, ctx);
245 crypto_cipher_encrypt_one(tfm, out, ctx->prev);
251 static int crypto_xcbc_digest(struct hash_desc *pdesc,
252 struct scatterlist *sg, unsigned int nbytes, u8 *out)
254 if (WARN_ON_ONCE(in_irq()))
257 crypto_xcbc_digest_init(pdesc);
258 crypto_xcbc_digest_update2(pdesc, sg, nbytes);
259 return crypto_xcbc_digest_final(pdesc, out);
262 static int xcbc_init_tfm(struct crypto_tfm *tfm)
264 struct crypto_cipher *cipher;
265 struct crypto_instance *inst = (void *)tfm->__crt_alg;
266 struct crypto_spawn *spawn = crypto_instance_ctx(inst);
267 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
268 int bs = crypto_hash_blocksize(__crypto_hash_cast(tfm));
270 cipher = crypto_spawn_cipher(spawn);
272 return PTR_ERR(cipher);
283 ctx->odds = (u8*)(ctx+1);
284 ctx->prev = ctx->odds + bs;
285 ctx->key = ctx->prev + bs;
290 static void xcbc_exit_tfm(struct crypto_tfm *tfm)
292 struct crypto_xcbc_ctx *ctx = crypto_hash_ctx_aligned(__crypto_hash_cast(tfm));
293 crypto_free_cipher(ctx->child);
296 static struct crypto_instance *xcbc_alloc(struct rtattr **tb)
298 struct crypto_instance *inst;
299 struct crypto_alg *alg;
302 err = crypto_check_attr_type(tb, CRYPTO_ALG_TYPE_HASH);
306 alg = crypto_get_attr_alg(tb, CRYPTO_ALG_TYPE_CIPHER,
307 CRYPTO_ALG_TYPE_MASK);
309 return ERR_CAST(alg);
311 switch(alg->cra_blocksize) {
315 inst = ERR_PTR(-EINVAL);
319 inst = crypto_alloc_instance("xcbc", alg);
323 inst->alg.cra_flags = CRYPTO_ALG_TYPE_HASH;
324 inst->alg.cra_priority = alg->cra_priority;
325 inst->alg.cra_blocksize = alg->cra_blocksize;
326 inst->alg.cra_alignmask = alg->cra_alignmask;
327 inst->alg.cra_type = &crypto_hash_type;
329 inst->alg.cra_hash.digestsize = alg->cra_blocksize;
330 inst->alg.cra_ctxsize = sizeof(struct crypto_xcbc_ctx) +
331 ALIGN(inst->alg.cra_blocksize * 3, sizeof(void *));
332 inst->alg.cra_init = xcbc_init_tfm;
333 inst->alg.cra_exit = xcbc_exit_tfm;
335 inst->alg.cra_hash.init = crypto_xcbc_digest_init;
336 inst->alg.cra_hash.update = crypto_xcbc_digest_update;
337 inst->alg.cra_hash.final = crypto_xcbc_digest_final;
338 inst->alg.cra_hash.digest = crypto_xcbc_digest;
339 inst->alg.cra_hash.setkey = crypto_xcbc_digest_setkey;
346 static void xcbc_free(struct crypto_instance *inst)
348 crypto_drop_spawn(crypto_instance_ctx(inst));
352 static struct crypto_template crypto_xcbc_tmpl = {
356 .module = THIS_MODULE,
359 static int __init crypto_xcbc_module_init(void)
361 return crypto_register_template(&crypto_xcbc_tmpl);
364 static void __exit crypto_xcbc_module_exit(void)
366 crypto_unregister_template(&crypto_xcbc_tmpl);
369 module_init(crypto_xcbc_module_init);
370 module_exit(crypto_xcbc_module_exit);
372 MODULE_LICENSE("GPL");
373 MODULE_DESCRIPTION("XCBC keyed hash algorithm");