1 /*
2 * Copyright (c) 2016 Thomas Pornin <pornin@bolet.org>
3 *
4 * Permission is hereby granted, free of charge, to any person obtaining
5 * a copy of this software and associated documentation files (the
6 * "Software"), to deal in the Software without restriction, including
7 * without limitation the rights to use, copy, modify, merge, publish,
8 * distribute, sublicense, and/or sell copies of the Software, and to
9 * permit persons to whom the Software is furnished to do so, subject to
10 * the following conditions:
11 *
12 * The above copyright notice and this permission notice shall be
13 * included in all copies or substantial portions of the Software.
14 *
15 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
16 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
17 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
18 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS
19 * BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN
20 * ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
21 * CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
22 * SOFTWARE.
23 */
24
25 #include "inner.h"
26
27 /* see inner.h */
28 void
br_tls_phash(void * dst,size_t len,const br_hash_class * dig,const void * secret,size_t secret_len,const char * label,size_t seed_num,const br_tls_prf_seed_chunk * seed)29 br_tls_phash(void *dst, size_t len,
30 const br_hash_class *dig,
31 const void *secret, size_t secret_len, const char *label,
32 size_t seed_num, const br_tls_prf_seed_chunk *seed)
33 {
34 unsigned char *buf;
35 unsigned char tmp[64], a[64];
36 br_hmac_key_context kc;
37 br_hmac_context hc;
38 size_t label_len, hlen, u;
39
40 if (len == 0) {
41 return;
42 }
43 buf = dst;
44 for (label_len = 0; label[label_len]; label_len ++);
45 hlen = br_digest_size(dig);
46 br_hmac_key_init(&kc, dig, secret, secret_len);
47 br_hmac_init(&hc, &kc, 0);
48 br_hmac_update(&hc, label, label_len);
49 for (u = 0; u < seed_num; u ++) {
50 br_hmac_update(&hc, seed[u].data, seed[u].len);
51 }
52 br_hmac_out(&hc, a);
53 for (;;) {
54 br_hmac_init(&hc, &kc, 0);
55 br_hmac_update(&hc, a, hlen);
56 br_hmac_update(&hc, label, label_len);
57 for (u = 0; u < seed_num; u ++) {
58 br_hmac_update(&hc, seed[u].data, seed[u].len);
59 }
60 br_hmac_out(&hc, tmp);
61 for (u = 0; u < hlen && u < len; u ++) {
62 buf[u] ^= tmp[u];
63 }
64 buf += u;
65 len -= u;
66 if (len == 0) {
67 return;
68 }
69 br_hmac_init(&hc, &kc, 0);
70 br_hmac_update(&hc, a, hlen);
71 br_hmac_out(&hc, a);
72 }
73 }
74