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_ct_ctr_init(br_aes_ct_ctr_keys * ctx,const void * key,size_t len)29*0957b409SSimon J. Gerraty br_aes_ct_ctr_init(br_aes_ct_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_ct_ctr_vtable;
33*0957b409SSimon J. Gerraty ctx->num_rounds = br_aes_ct_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_ct_ctr_run(const br_aes_ct_ctr_keys * ctx,const void * iv,uint32_t cc,void * data,size_t len)51*0957b409SSimon J. Gerraty br_aes_ct_ctr_run(const br_aes_ct_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 const unsigned char *ivbuf;
56*0957b409SSimon J. Gerraty uint32_t iv0, iv1, iv2;
57*0957b409SSimon J. Gerraty uint32_t sk_exp[120];
58*0957b409SSimon J. Gerraty
59*0957b409SSimon J. Gerraty br_aes_ct_skey_expand(sk_exp, ctx->num_rounds, ctx->skey);
60*0957b409SSimon J. Gerraty ivbuf = iv;
61*0957b409SSimon J. Gerraty iv0 = br_dec32le(ivbuf);
62*0957b409SSimon J. Gerraty iv1 = br_dec32le(ivbuf + 4);
63*0957b409SSimon J. Gerraty iv2 = br_dec32le(ivbuf + 8);
64*0957b409SSimon J. Gerraty buf = data;
65*0957b409SSimon J. Gerraty while (len > 0) {
66*0957b409SSimon J. Gerraty uint32_t q[8];
67*0957b409SSimon J. Gerraty unsigned char tmp[32];
68*0957b409SSimon J. Gerraty
69*0957b409SSimon J. Gerraty /*
70*0957b409SSimon J. Gerraty * TODO: see if we can save on the first br_aes_ct_ortho()
71*0957b409SSimon J. Gerraty * call, since iv0/iv1/iv2 are constant for the whole run.
72*0957b409SSimon J. Gerraty */
73*0957b409SSimon J. Gerraty q[0] = q[1] = iv0;
74*0957b409SSimon J. Gerraty q[2] = q[3] = iv1;
75*0957b409SSimon J. Gerraty q[4] = q[5] = iv2;
76*0957b409SSimon J. Gerraty q[6] = br_swap32(cc);
77*0957b409SSimon J. Gerraty q[7] = br_swap32(cc + 1);
78*0957b409SSimon J. Gerraty br_aes_ct_ortho(q);
79*0957b409SSimon J. Gerraty br_aes_ct_bitslice_encrypt(ctx->num_rounds, sk_exp, q);
80*0957b409SSimon J. Gerraty br_aes_ct_ortho(q);
81*0957b409SSimon J. Gerraty br_enc32le(tmp, q[0]);
82*0957b409SSimon J. Gerraty br_enc32le(tmp + 4, q[2]);
83*0957b409SSimon J. Gerraty br_enc32le(tmp + 8, q[4]);
84*0957b409SSimon J. Gerraty br_enc32le(tmp + 12, q[6]);
85*0957b409SSimon J. Gerraty br_enc32le(tmp + 16, q[1]);
86*0957b409SSimon J. Gerraty br_enc32le(tmp + 20, q[3]);
87*0957b409SSimon J. Gerraty br_enc32le(tmp + 24, q[5]);
88*0957b409SSimon J. Gerraty br_enc32le(tmp + 28, q[7]);
89*0957b409SSimon J. Gerraty
90*0957b409SSimon J. Gerraty if (len <= 32) {
91*0957b409SSimon J. Gerraty xorbuf(buf, tmp, len);
92*0957b409SSimon J. Gerraty cc ++;
93*0957b409SSimon J. Gerraty if (len > 16) {
94*0957b409SSimon J. Gerraty cc ++;
95*0957b409SSimon J. Gerraty }
96*0957b409SSimon J. Gerraty break;
97*0957b409SSimon J. Gerraty }
98*0957b409SSimon J. Gerraty xorbuf(buf, tmp, 32);
99*0957b409SSimon J. Gerraty buf += 32;
100*0957b409SSimon J. Gerraty len -= 32;
101*0957b409SSimon J. Gerraty cc += 2;
102*0957b409SSimon J. Gerraty }
103*0957b409SSimon J. Gerraty return cc;
104*0957b409SSimon J. Gerraty }
105*0957b409SSimon J. Gerraty
106*0957b409SSimon J. Gerraty /* see bearssl_block.h */
107*0957b409SSimon J. Gerraty const br_block_ctr_class br_aes_ct_ctr_vtable = {
108*0957b409SSimon J. Gerraty sizeof(br_aes_ct_ctr_keys),
109*0957b409SSimon J. Gerraty 16,
110*0957b409SSimon J. Gerraty 4,
111*0957b409SSimon J. Gerraty (void (*)(const br_block_ctr_class **, const void *, size_t))
112*0957b409SSimon J. Gerraty &br_aes_ct_ctr_init,
113*0957b409SSimon J. Gerraty (uint32_t (*)(const br_block_ctr_class *const *,
114*0957b409SSimon J. Gerraty const void *, uint32_t, void *, size_t))
115*0957b409SSimon J. Gerraty &br_aes_ct_ctr_run
116*0957b409SSimon J. Gerraty };
117