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_des_ct_cbcdec_init(br_des_ct_cbcdec_keys * ctx,const void * key,size_t len)29*0957b409SSimon J. Gerraty br_des_ct_cbcdec_init(br_des_ct_cbcdec_keys *ctx,
30*0957b409SSimon J. Gerraty const void *key, size_t len)
31*0957b409SSimon J. Gerraty {
32*0957b409SSimon J. Gerraty ctx->vtable = &br_des_ct_cbcdec_vtable;
33*0957b409SSimon J. Gerraty ctx->num_rounds = br_des_ct_keysched(ctx->skey, key, len);
34*0957b409SSimon J. Gerraty if (len == 8) {
35*0957b409SSimon J. Gerraty br_des_rev_skey(ctx->skey);
36*0957b409SSimon J. Gerraty } else {
37*0957b409SSimon J. Gerraty int i;
38*0957b409SSimon J. Gerraty
39*0957b409SSimon J. Gerraty for (i = 0; i < 48; i += 2) {
40*0957b409SSimon J. Gerraty uint32_t t;
41*0957b409SSimon J. Gerraty
42*0957b409SSimon J. Gerraty t = ctx->skey[i];
43*0957b409SSimon J. Gerraty ctx->skey[i] = ctx->skey[94 - i];
44*0957b409SSimon J. Gerraty ctx->skey[94 - i] = t;
45*0957b409SSimon J. Gerraty t = ctx->skey[i + 1];
46*0957b409SSimon J. Gerraty ctx->skey[i + 1] = ctx->skey[95 - i];
47*0957b409SSimon J. Gerraty ctx->skey[95 - i] = t;
48*0957b409SSimon J. Gerraty }
49*0957b409SSimon J. Gerraty }
50*0957b409SSimon J. Gerraty }
51*0957b409SSimon J. Gerraty
52*0957b409SSimon J. Gerraty /* see bearssl_block.h */
53*0957b409SSimon J. Gerraty void
br_des_ct_cbcdec_run(const br_des_ct_cbcdec_keys * ctx,void * iv,void * data,size_t len)54*0957b409SSimon J. Gerraty br_des_ct_cbcdec_run(const br_des_ct_cbcdec_keys *ctx,
55*0957b409SSimon J. Gerraty void *iv, void *data, size_t len)
56*0957b409SSimon J. Gerraty {
57*0957b409SSimon J. Gerraty unsigned char *buf, *ivbuf;
58*0957b409SSimon J. Gerraty uint32_t sk_exp[288];
59*0957b409SSimon J. Gerraty
60*0957b409SSimon J. Gerraty br_des_ct_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
61*0957b409SSimon J. Gerraty ivbuf = iv;
62*0957b409SSimon J. Gerraty buf = data;
63*0957b409SSimon J. Gerraty while (len > 0) {
64*0957b409SSimon J. Gerraty unsigned char tmp[8];
65*0957b409SSimon J. Gerraty int i;
66*0957b409SSimon J. Gerraty
67*0957b409SSimon J. Gerraty memcpy(tmp, buf, 8);
68*0957b409SSimon J. Gerraty br_des_ct_process_block(ctx->num_rounds, sk_exp, buf);
69*0957b409SSimon J. Gerraty for (i = 0; i < 8; i ++) {
70*0957b409SSimon J. Gerraty buf[i] ^= ivbuf[i];
71*0957b409SSimon J. Gerraty }
72*0957b409SSimon J. Gerraty memcpy(ivbuf, tmp, 8);
73*0957b409SSimon J. Gerraty buf += 8;
74*0957b409SSimon J. Gerraty len -= 8;
75*0957b409SSimon J. Gerraty }
76*0957b409SSimon J. Gerraty }
77*0957b409SSimon J. Gerraty
78*0957b409SSimon J. Gerraty /* see bearssl_block.h */
79*0957b409SSimon J. Gerraty const br_block_cbcdec_class br_des_ct_cbcdec_vtable = {
80*0957b409SSimon J. Gerraty sizeof(br_des_ct_cbcdec_keys),
81*0957b409SSimon J. Gerraty 8,
82*0957b409SSimon J. Gerraty 3,
83*0957b409SSimon J. Gerraty (void (*)(const br_block_cbcdec_class **, const void *, size_t))
84*0957b409SSimon J. Gerraty &br_des_ct_cbcdec_init,
85*0957b409SSimon J. Gerraty (void (*)(const br_block_cbcdec_class *const *, void *, void *, size_t))
86*0957b409SSimon J. Gerraty &br_des_ct_cbcdec_run
87*0957b409SSimon J. Gerraty };
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