1 /*
2 * Copyright (c) 2018 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 br_asn1_uint
br_asn1_uint_prepare(const void * xdata,size_t xlen)29 br_asn1_uint_prepare(const void *xdata, size_t xlen)
30 {
31 const unsigned char *x;
32 br_asn1_uint t;
33
34 x = xdata;
35 while (xlen > 0 && *x == 0) {
36 x ++;
37 xlen --;
38 }
39 t.data = x;
40 t.len = xlen;
41 t.asn1len = xlen;
42 if (xlen == 0 || x[0] >= 0x80) {
43 t.asn1len ++;
44 }
45 return t;
46 }
47
48 /* see inner.h */
49 size_t
br_asn1_encode_length(void * dest,size_t len)50 br_asn1_encode_length(void *dest, size_t len)
51 {
52 unsigned char *buf;
53 size_t z;
54 int i, j;
55
56 buf = dest;
57 if (len < 0x80) {
58 if (buf != NULL) {
59 *buf = len;
60 }
61 return 1;
62 }
63 i = 0;
64 for (z = len; z != 0; z >>= 8) {
65 i ++;
66 }
67 if (buf != NULL) {
68 *buf ++ = 0x80 + i;
69 for (j = i - 1; j >= 0; j --) {
70 *buf ++ = len >> (j << 3);
71 }
72 }
73 return i + 1;
74 }
75
76 /* see inner.h */
77 size_t
br_asn1_encode_uint(void * dest,br_asn1_uint pp)78 br_asn1_encode_uint(void *dest, br_asn1_uint pp)
79 {
80 unsigned char *buf;
81 size_t lenlen;
82
83 if (dest == NULL) {
84 return 1 + br_asn1_encode_length(NULL, pp.asn1len) + pp.asn1len;
85 }
86 buf = dest;
87 *buf ++ = 0x02;
88 lenlen = br_asn1_encode_length(buf, pp.asn1len);
89 buf += lenlen;
90 *buf = 0x00;
91 memcpy(buf + pp.asn1len - pp.len, pp.data, pp.len);
92 return 1 + lenlen + pp.asn1len;
93 }
94