1*0957b409SSimon J. Gerraty /*
2*0957b409SSimon J. Gerraty * Copyright (c) 2018 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 inner.h */
28*0957b409SSimon J. Gerraty void
br_mgf1_xor(void * data,size_t len,const br_hash_class * dig,const void * seed,size_t seed_len)29*0957b409SSimon J. Gerraty br_mgf1_xor(void *data, size_t len,
30*0957b409SSimon J. Gerraty const br_hash_class *dig, const void *seed, size_t seed_len)
31*0957b409SSimon J. Gerraty {
32*0957b409SSimon J. Gerraty unsigned char *buf;
33*0957b409SSimon J. Gerraty size_t u, hlen;
34*0957b409SSimon J. Gerraty uint32_t c;
35*0957b409SSimon J. Gerraty
36*0957b409SSimon J. Gerraty buf = data;
37*0957b409SSimon J. Gerraty hlen = br_digest_size(dig);
38*0957b409SSimon J. Gerraty for (u = 0, c = 0; u < len; u += hlen, c ++) {
39*0957b409SSimon J. Gerraty br_hash_compat_context hc;
40*0957b409SSimon J. Gerraty unsigned char tmp[64];
41*0957b409SSimon J. Gerraty size_t v;
42*0957b409SSimon J. Gerraty
43*0957b409SSimon J. Gerraty hc.vtable = dig;
44*0957b409SSimon J. Gerraty dig->init(&hc.vtable);
45*0957b409SSimon J. Gerraty dig->update(&hc.vtable, seed, seed_len);
46*0957b409SSimon J. Gerraty br_enc32be(tmp, c);
47*0957b409SSimon J. Gerraty dig->update(&hc.vtable, tmp, 4);
48*0957b409SSimon J. Gerraty dig->out(&hc.vtable, tmp);
49*0957b409SSimon J. Gerraty for (v = 0; v < hlen; v ++) {
50*0957b409SSimon J. Gerraty if ((u + v) >= len) {
51*0957b409SSimon J. Gerraty break;
52*0957b409SSimon J. Gerraty }
53*0957b409SSimon J. Gerraty buf[u + v] ^= tmp[v];
54*0957b409SSimon J. Gerraty }
55*0957b409SSimon J. Gerraty }
56*0957b409SSimon J. Gerraty }
57