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
br_aes_big_ctr_init(br_aes_big_ctr_keys * ctx,const void * key,size_t len)29*0957b409SSimon J. Gerraty br_aes_big_ctr_init(br_aes_big_ctr_keys *ctx,
30*0957b409SSimon J. Gerraty const void *key, size_t len)
31*0957b409SSimon J. Gerraty {
32*0957b409SSimon J. Gerraty ctx->vtable = &br_aes_big_ctr_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 static void
xorbuf(void * dst,const void * src,size_t len)37*0957b409SSimon J. Gerraty xorbuf(void *dst, const void *src, size_t len)
38*0957b409SSimon J. Gerraty {
39*0957b409SSimon J. Gerraty unsigned char *d;
40*0957b409SSimon J. Gerraty const unsigned char *s;
41*0957b409SSimon J. Gerraty
42*0957b409SSimon J. Gerraty d = dst;
43*0957b409SSimon J. Gerraty s = src;
44*0957b409SSimon J. Gerraty while (len -- > 0) {
45*0957b409SSimon J. Gerraty *d ++ ^= *s ++;
46*0957b409SSimon J. Gerraty }
47*0957b409SSimon J. Gerraty }
48*0957b409SSimon J. Gerraty
49*0957b409SSimon J. Gerraty /* see bearssl_block.h */
50*0957b409SSimon J. Gerraty uint32_t
br_aes_big_ctr_run(const br_aes_big_ctr_keys * ctx,const void * iv,uint32_t cc,void * data,size_t len)51*0957b409SSimon J. Gerraty br_aes_big_ctr_run(const br_aes_big_ctr_keys *ctx,
52*0957b409SSimon J. Gerraty const void *iv, uint32_t cc, void *data, size_t len)
53*0957b409SSimon J. Gerraty {
54*0957b409SSimon J. Gerraty unsigned char *buf;
55*0957b409SSimon J. Gerraty
56*0957b409SSimon J. Gerraty buf = data;
57*0957b409SSimon J. Gerraty while (len > 0) {
58*0957b409SSimon J. Gerraty unsigned char tmp[16];
59*0957b409SSimon J. Gerraty
60*0957b409SSimon J. Gerraty memcpy(tmp, iv, 12);
61*0957b409SSimon J. Gerraty br_enc32be(tmp + 12, cc ++);
62*0957b409SSimon J. Gerraty br_aes_big_encrypt(ctx->num_rounds, ctx->skey, tmp);
63*0957b409SSimon J. Gerraty if (len <= 16) {
64*0957b409SSimon J. Gerraty xorbuf(buf, tmp, len);
65*0957b409SSimon J. Gerraty break;
66*0957b409SSimon J. Gerraty }
67*0957b409SSimon J. Gerraty xorbuf(buf, tmp, 16);
68*0957b409SSimon J. Gerraty buf += 16;
69*0957b409SSimon J. Gerraty len -= 16;
70*0957b409SSimon J. Gerraty }
71*0957b409SSimon J. Gerraty return cc;
72*0957b409SSimon J. Gerraty }
73*0957b409SSimon J. Gerraty
74*0957b409SSimon J. Gerraty /* see bearssl_block.h */
75*0957b409SSimon J. Gerraty const br_block_ctr_class br_aes_big_ctr_vtable = {
76*0957b409SSimon J. Gerraty sizeof(br_aes_big_ctr_keys),
77*0957b409SSimon J. Gerraty 16,
78*0957b409SSimon J. Gerraty 4,
79*0957b409SSimon J. Gerraty (void (*)(const br_block_ctr_class **, const void *, size_t))
80*0957b409SSimon J. Gerraty &br_aes_big_ctr_init,
81*0957b409SSimon J. Gerraty (uint32_t (*)(const br_block_ctr_class *const *,
82*0957b409SSimon J. Gerraty const void *, uint32_t, void *, size_t))
83*0957b409SSimon J. Gerraty &br_aes_big_ctr_run
84*0957b409SSimon J. Gerraty };
85