xref: /freebsd/contrib/bearssl/src/symcipher/aes_small_cbcenc.c (revision 0957b409a90fd597c1e9124cbaf3edd2b488f4ac)
1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty  * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3*0957b409SSimon J. Gerraty  *
4*0957b409SSimon J. Gerraty  * Permission is hereby granted, free of charge, to any person obtaining
5*0957b409SSimon J. Gerraty  * a copy of this software and associated documentation files (the
6*0957b409SSimon J. Gerraty  * "Software"), to deal in the Software without restriction, including
7*0957b409SSimon J. Gerraty  * without limitation the rights to use, copy, modify, merge, publish,
8*0957b409SSimon J. Gerraty  * distribute, sublicense, and/or sell copies of the Software, and to
9*0957b409SSimon J. Gerraty  * permit persons to whom the Software is furnished to do so, subject to
10*0957b409SSimon J. Gerraty  * the following conditions:
11*0957b409SSimon J. Gerraty  *
12*0957b409SSimon J. Gerraty  * The above copyright notice and this permission notice shall be
13*0957b409SSimon J. Gerraty  * included in all copies or substantial portions of the Software.
14*0957b409SSimon J. Gerraty  *
15*0957b409SSimon J. Gerraty  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16*0957b409SSimon J. Gerraty  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17*0957b409SSimon J. Gerraty  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18*0957b409SSimon J. Gerraty  * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19*0957b409SSimon J. Gerraty  * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20*0957b409SSimon J. Gerraty  * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21*0957b409SSimon J. Gerraty  * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22*0957b409SSimon J. Gerraty  * SOFTWARE.
23*0957b409SSimon J. Gerraty  */
24*0957b409SSimon J. Gerraty 
25*0957b409SSimon J. Gerraty #include "inner.h"
26*0957b409SSimon J. Gerraty 
27*0957b409SSimon J. Gerraty /* see bearssl_block.h */
28*0957b409SSimon J. Gerraty void
29*0957b409SSimon J. Gerraty br_aes_small_cbcenc_init(br_aes_small_cbcenc_keys *ctx,
30*0957b409SSimon J. Gerraty 	const void *key, size_t len)
31*0957b409SSimon J. Gerraty {
32*0957b409SSimon J. Gerraty 	ctx->vtable = &br_aes_small_cbcenc_vtable;
33*0957b409SSimon J. Gerraty 	ctx->num_rounds = br_aes_keysched(ctx->skey, key, len);
34*0957b409SSimon J. Gerraty }
35*0957b409SSimon J. Gerraty 
36*0957b409SSimon J. Gerraty /* see bearssl_block.h */
37*0957b409SSimon J. Gerraty void
38*0957b409SSimon J. Gerraty br_aes_small_cbcenc_run(const br_aes_small_cbcenc_keys *ctx,
39*0957b409SSimon J. Gerraty 	void *iv, void *data, size_t len)
40*0957b409SSimon J. Gerraty {
41*0957b409SSimon J. Gerraty 	unsigned char *buf, *ivbuf;
42*0957b409SSimon J. Gerraty 
43*0957b409SSimon J. Gerraty 	ivbuf = iv;
44*0957b409SSimon J. Gerraty 	buf = data;
45*0957b409SSimon J. Gerraty 	while (len > 0) {
46*0957b409SSimon J. Gerraty 		int i;
47*0957b409SSimon J. Gerraty 
48*0957b409SSimon J. Gerraty 		for (i = 0; i < 16; i ++) {
49*0957b409SSimon J. Gerraty 			buf[i] ^= ivbuf[i];
50*0957b409SSimon J. Gerraty 		}
51*0957b409SSimon J. Gerraty 		br_aes_small_encrypt(ctx->num_rounds, ctx->skey, buf);
52*0957b409SSimon J. Gerraty 		memcpy(ivbuf, buf, 16);
53*0957b409SSimon J. Gerraty 		buf += 16;
54*0957b409SSimon J. Gerraty 		len -= 16;
55*0957b409SSimon J. Gerraty 	}
56*0957b409SSimon J. Gerraty }
57*0957b409SSimon J. Gerraty 
58*0957b409SSimon J. Gerraty /* see bearssl_block.h */
59*0957b409SSimon J. Gerraty const br_block_cbcenc_class br_aes_small_cbcenc_vtable = {
60*0957b409SSimon J. Gerraty 	sizeof(br_aes_small_cbcenc_keys),
61*0957b409SSimon J. Gerraty 	16,
62*0957b409SSimon J. Gerraty 	4,
63*0957b409SSimon J. Gerraty 	(void (*)(const br_block_cbcenc_class **, const void *, size_t))
64*0957b409SSimon J. Gerraty 		&br_aes_small_cbcenc_init,
65*0957b409SSimon J. Gerraty 	(void (*)(const br_block_cbcenc_class *const *, void *, void *, size_t))
66*0957b409SSimon J. Gerraty 		&br_aes_small_cbcenc_run
67*0957b409SSimon J. Gerraty };
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