chiark / gitweb /
Remove some redundant includes.
[disorder] / lib / hex.c
CommitLineData
460b9539 1/*
2 * This file is part of DisOrder
3c95f40e 3 * Copyright (C) 2004, 2005, 2007-9, 2013 Richard Kettlewell
460b9539 4 *
e7eb3a27 5 * This program is free software: you can redistribute it and/or modify
460b9539 6 * it under the terms of the GNU General Public License as published by
e7eb3a27 7 * the Free Software Foundation, either version 3 of the License, or
460b9539 8 * (at your option) any later version.
e7eb3a27
RK
9 *
10 * This program is distributed in the hope that it will be useful,
11 * but WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 * GNU General Public License for more details.
14 *
460b9539 15 * You should have received a copy of the GNU General Public License
e7eb3a27 16 * along with this program. If not, see <http://www.gnu.org/licenses/>.
460b9539 17 */
ed422be7 18/** @file lib/hex.c @brief Hexadecimal encoding and decoding */
460b9539 19
05b75f8d 20#include "common.h"
460b9539 21
22#include "hex.h"
23#include "mem.h"
24#include "log.h"
3c95f40e 25#include "printf.h"
460b9539 26
ed422be7
RK
27/** @brief Convert a byte sequence to hex
28 * @param ptr Pointer to first byte
29 * @param n Number of bytes
30 * @return Allocated string containing hexdump
31 */
460b9539 32char *hex(const uint8_t *ptr, size_t n) {
33 char *buf = xmalloc_noptr(n * 2 + 1), *p = buf;
34
35 while(n-- > 0)
3c95f40e 36 p += byte_snprintf(p, 3, "%02x", (unsigned)*ptr++);
ef582771 37 *p = 0;
460b9539 38 return buf;
39}
40
ed422be7
RK
41/** @brief Convert a character to its value as a hex digit
42 * @param c Character code
43 * @return Value has hex digit or -1
44 *
45 * The 'q' stands for 'quiet' - this function does not report errors.
46 */
460b9539 47int unhexdigitq(int c) {
48 switch(c) {
49 case '0': return 0;
50 case '1': return 1;
51 case '2': return 2;
52 case '3': return 3;
53 case '4': return 4;
54 case '5': return 5;
55 case '6': return 6;
56 case '7': return 7;
57 case '8': return 8;
58 case '9': return 9;
59 case 'a': case 'A': return 10;
60 case 'b': case 'B': return 11;
61 case 'c': case 'C': return 12;
62 case 'd': case 'D': return 13;
63 case 'e': case 'E': return 14;
64 case 'f': case 'F': return 15;
65 default: return -1;
66 }
67}
68
ed422be7
RK
69/** @brief Convert a character to its value as a hex digit
70 * @param c Character code
71 * @return Value has hex digit or -1
72 *
73 * If the character is not a valid hex digit then an error is logged.
74 * See @ref unhexdigitq() if that is a problem.
75 */
460b9539 76int unhexdigit(int c) {
77 int d;
78
2e9ba080
RK
79 if((d = unhexdigitq(c)) < 0)
80 disorder_error(0, "invalid hex digit");
460b9539 81 return d;
82}
83
ed422be7
RK
84/** @brief Convert a hex string to bytes
85 * @param s Pointer to hex string
86 * @param np Where to store byte string length or NULL
87 * @return Allocated buffer, or 0
88 *
89 * @p s should point to a 0-terminated string containing an even number
90 * of hex digits. They are converted to bytes and returned via the return
91 * value and optionally the length via @p np.
92 *
93 * On any error a message is logged and a null pointer is returned.
94 */
460b9539 95uint8_t *unhex(const char *s, size_t *np) {
96 size_t l;
97 uint8_t *buf, *p;
98 int d1, d2;
99
100 if((l = strlen(s)) & 1) {
2e9ba080 101 disorder_error(0, "hex string has odd length");
460b9539 102 return 0;
103 }
104 p = buf = xmalloc_noptr(l / 2);
105 while(*s) {
106 if((d1 = unhexdigit(*s++)) < 0) return 0;
107 if((d2 = unhexdigit(*s++)) < 0) return 0;
108 *p++ = d1 * 16 + d2;
109 }
110 if(np)
111 *np = l / 2;
112 return buf;
113}
114
115/*
116Local Variables:
117c-basic-offset:2
118comment-column:40
119End:
120*/