Added support for CCM and CCM_8 cipher suites.
[BearSSL] / src / ec / ecdsa_i15_bits.c
1 /*
2 * Copyright (c) 2017 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
29 br_ecdsa_i15_bits2int(uint16_t *x,
30 const void *src, size_t len, uint32_t ebitlen)
31 {
32 uint32_t bitlen, hbitlen;
33 int sc;
34
35 bitlen = ebitlen - (ebitlen >> 4);
36 hbitlen = (uint32_t)len << 3;
37 if (hbitlen > bitlen) {
38 len = (bitlen + 7) >> 3;
39 sc = (int)((hbitlen - bitlen) & 7);
40 } else {
41 sc = 0;
42 }
43 br_i15_zero(x, ebitlen);
44 br_i15_decode(x, src, len);
45 br_i15_rshift(x, sc);
46 x[0] = ebitlen;
47 }