Added generic API for date range validation (with callbacks).
[BearSSL] / int / i15_encode.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_i15_encode(void *dst, size_t len, const uint16_t *x)
30 {
31 unsigned char *buf;
32 size_t u, xlen;
33 uint32_t acc;
34 int acc_len;
35
36 xlen = (x[0] + 15) >> 4;
37 if (xlen == 0) {
38 memset(dst, 0, len);
39 return;
40 }
41 u = 1;
42 acc = 0;
43 acc_len = 0;
44 buf = dst;
45 while (len -- > 0) {
46 if (acc_len < 8) {
47 if (u <= xlen) {
48 acc += (uint32_t)x[u ++] << acc_len;
49 }
50 acc_len += 15;
51 }
52 buf[len] = (unsigned char)acc;
53 acc >>= 8;
54 acc_len -= 8;
55 }
56 }