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_ct64_cbcdec_init(br_aes_ct64_cbcdec_keys * ctx,const void * key,size_t len)29*0957b409SSimon J. Gerraty br_aes_ct64_cbcdec_init(br_aes_ct64_cbcdec_keys *ctx,
30*0957b409SSimon J. Gerraty const void *key, size_t len)
31*0957b409SSimon J. Gerraty {
32*0957b409SSimon J. Gerraty ctx->vtable = &br_aes_ct64_cbcdec_vtable;
33*0957b409SSimon J. Gerraty ctx->num_rounds = br_aes_ct64_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
br_aes_ct64_cbcdec_run(const br_aes_ct64_cbcdec_keys * ctx,void * iv,void * data,size_t len)38*0957b409SSimon J. Gerraty br_aes_ct64_cbcdec_run(const br_aes_ct64_cbcdec_keys *ctx,
39*0957b409SSimon J. Gerraty void *iv, void *data, size_t len)
40*0957b409SSimon J. Gerraty {
41*0957b409SSimon J. Gerraty unsigned char *buf;
42*0957b409SSimon J. Gerraty uint64_t sk_exp[120];
43*0957b409SSimon J. Gerraty uint32_t ivw[4];
44*0957b409SSimon J. Gerraty
45*0957b409SSimon J. Gerraty br_aes_ct64_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
46*0957b409SSimon J. Gerraty br_range_dec32le(ivw, 4, iv);
47*0957b409SSimon J. Gerraty buf = data;
48*0957b409SSimon J. Gerraty while (len > 0) {
49*0957b409SSimon J. Gerraty uint64_t q[8];
50*0957b409SSimon J. Gerraty uint32_t w1[16], w2[16];
51*0957b409SSimon J. Gerraty int i;
52*0957b409SSimon J. Gerraty
53*0957b409SSimon J. Gerraty if (len >= 64) {
54*0957b409SSimon J. Gerraty br_range_dec32le(w1, 16, buf);
55*0957b409SSimon J. Gerraty } else {
56*0957b409SSimon J. Gerraty br_range_dec32le(w1, len >> 2, buf);
57*0957b409SSimon J. Gerraty }
58*0957b409SSimon J. Gerraty for (i = 0; i < 4; i ++) {
59*0957b409SSimon J. Gerraty br_aes_ct64_interleave_in(
60*0957b409SSimon J. Gerraty &q[i], &q[i + 4], w1 + (i << 2));
61*0957b409SSimon J. Gerraty }
62*0957b409SSimon J. Gerraty br_aes_ct64_ortho(q);
63*0957b409SSimon J. Gerraty br_aes_ct64_bitslice_decrypt(ctx->num_rounds, sk_exp, q);
64*0957b409SSimon J. Gerraty br_aes_ct64_ortho(q);
65*0957b409SSimon J. Gerraty for (i = 0; i < 4; i ++) {
66*0957b409SSimon J. Gerraty br_aes_ct64_interleave_out(
67*0957b409SSimon J. Gerraty w2 + (i << 2), q[i], q[i + 4]);
68*0957b409SSimon J. Gerraty }
69*0957b409SSimon J. Gerraty for (i = 0; i < 4; i ++) {
70*0957b409SSimon J. Gerraty w2[i] ^= ivw[i];
71*0957b409SSimon J. Gerraty }
72*0957b409SSimon J. Gerraty if (len >= 64) {
73*0957b409SSimon J. Gerraty for (i = 4; i < 16; i ++) {
74*0957b409SSimon J. Gerraty w2[i] ^= w1[i - 4];
75*0957b409SSimon J. Gerraty }
76*0957b409SSimon J. Gerraty memcpy(ivw, w1 + 12, sizeof ivw);
77*0957b409SSimon J. Gerraty br_range_enc32le(buf, w2, 16);
78*0957b409SSimon J. Gerraty } else {
79*0957b409SSimon J. Gerraty int j;
80*0957b409SSimon J. Gerraty
81*0957b409SSimon J. Gerraty j = (int)(len >> 2);
82*0957b409SSimon J. Gerraty for (i = 4; i < j; i ++) {
83*0957b409SSimon J. Gerraty w2[i] ^= w1[i - 4];
84*0957b409SSimon J. Gerraty }
85*0957b409SSimon J. Gerraty memcpy(ivw, w1 + j - 4, sizeof ivw);
86*0957b409SSimon J. Gerraty br_range_enc32le(buf, w2, j);
87*0957b409SSimon J. Gerraty break;
88*0957b409SSimon J. Gerraty }
89*0957b409SSimon J. Gerraty buf += 64;
90*0957b409SSimon J. Gerraty len -= 64;
91*0957b409SSimon J. Gerraty }
92*0957b409SSimon J. Gerraty br_range_enc32le(iv, ivw, 4);
93*0957b409SSimon J. Gerraty }
94*0957b409SSimon J. Gerraty
95*0957b409SSimon J. Gerraty /* see bearssl_block.h */
96*0957b409SSimon J. Gerraty const br_block_cbcdec_class br_aes_ct64_cbcdec_vtable = {
97*0957b409SSimon J. Gerraty sizeof(br_aes_ct64_cbcdec_keys),
98*0957b409SSimon J. Gerraty 16,
99*0957b409SSimon J. Gerraty 4,
100*0957b409SSimon J. Gerraty (void (*)(const br_block_cbcdec_class **, const void *, size_t))
101*0957b409SSimon J. Gerraty &br_aes_ct64_cbcdec_init,
102*0957b409SSimon J. Gerraty (void (*)(const br_block_cbcdec_class *const *, void *, void *, size_t))
103*0957b409SSimon J. Gerraty &br_aes_ct64_cbcdec_run
104*0957b409SSimon J. Gerraty };
105