Commit | Line | Data |
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460b9539 | 1 | /* |
2 | * This file is part of DisOrder | |
3 | * Copyright (C) 2004, 2005 Richard Kettlewell | |
4 | * | |
5 | * This program is free software; you can redistribute it and/or modify | |
6 | * it under the terms of the GNU General Public License as published by | |
7 | * the Free Software Foundation; either version 2 of the License, or | |
8 | * (at your option) any later version. | |
9 | * | |
10 | * This program is distributed in the hope that it will be useful, but | |
11 | * WITHOUT ANY WARRANTY; without even the implied warranty of | |
12 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU | |
13 | * General Public License for more details. | |
14 | * | |
15 | * You should have received a copy of the GNU General Public License | |
16 | * along with this program; if not, write to the Free Software | |
17 | * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 | |
18 | * USA | |
19 | */ | |
ed422be7 | 20 | /** @file lib/hex.c @brief Hexadecimal encoding and decoding */ |
460b9539 | 21 | |
22 | #include <config.h> | |
23 | #include "types.h" | |
24 | ||
25 | #include <stdio.h> | |
26 | #include <string.h> | |
27 | ||
28 | #include "hex.h" | |
29 | #include "mem.h" | |
30 | #include "log.h" | |
31 | ||
ed422be7 RK |
32 | /** @brief Convert a byte sequence to hex |
33 | * @param ptr Pointer to first byte | |
34 | * @param n Number of bytes | |
35 | * @return Allocated string containing hexdump | |
36 | */ | |
460b9539 | 37 | char *hex(const uint8_t *ptr, size_t n) { |
38 | char *buf = xmalloc_noptr(n * 2 + 1), *p = buf; | |
39 | ||
40 | while(n-- > 0) | |
41 | p += sprintf(p, "%02x", (unsigned)*ptr++); | |
ef582771 | 42 | *p = 0; |
460b9539 | 43 | return buf; |
44 | } | |
45 | ||
ed422be7 RK |
46 | /** @brief Convert a character to its value as a hex digit |
47 | * @param c Character code | |
48 | * @return Value has hex digit or -1 | |
49 | * | |
50 | * The 'q' stands for 'quiet' - this function does not report errors. | |
51 | */ | |
460b9539 | 52 | int unhexdigitq(int c) { |
53 | switch(c) { | |
54 | case '0': return 0; | |
55 | case '1': return 1; | |
56 | case '2': return 2; | |
57 | case '3': return 3; | |
58 | case '4': return 4; | |
59 | case '5': return 5; | |
60 | case '6': return 6; | |
61 | case '7': return 7; | |
62 | case '8': return 8; | |
63 | case '9': return 9; | |
64 | case 'a': case 'A': return 10; | |
65 | case 'b': case 'B': return 11; | |
66 | case 'c': case 'C': return 12; | |
67 | case 'd': case 'D': return 13; | |
68 | case 'e': case 'E': return 14; | |
69 | case 'f': case 'F': return 15; | |
70 | default: return -1; | |
71 | } | |
72 | } | |
73 | ||
ed422be7 RK |
74 | /** @brief Convert a character to its value as a hex digit |
75 | * @param c Character code | |
76 | * @return Value has hex digit or -1 | |
77 | * | |
78 | * If the character is not a valid hex digit then an error is logged. | |
79 | * See @ref unhexdigitq() if that is a problem. | |
80 | */ | |
460b9539 | 81 | int unhexdigit(int c) { |
82 | int d; | |
83 | ||
84 | if((d = unhexdigitq(c)) < 0) error(0, "invalid hex digit"); | |
85 | return d; | |
86 | } | |
87 | ||
ed422be7 RK |
88 | /** @brief Convert a hex string to bytes |
89 | * @param s Pointer to hex string | |
90 | * @param np Where to store byte string length or NULL | |
91 | * @return Allocated buffer, or 0 | |
92 | * | |
93 | * @p s should point to a 0-terminated string containing an even number | |
94 | * of hex digits. They are converted to bytes and returned via the return | |
95 | * value and optionally the length via @p np. | |
96 | * | |
97 | * On any error a message is logged and a null pointer is returned. | |
98 | */ | |
460b9539 | 99 | uint8_t *unhex(const char *s, size_t *np) { |
100 | size_t l; | |
101 | uint8_t *buf, *p; | |
102 | int d1, d2; | |
103 | ||
104 | if((l = strlen(s)) & 1) { | |
105 | error(0, "hex string has odd length"); | |
106 | return 0; | |
107 | } | |
108 | p = buf = xmalloc_noptr(l / 2); | |
109 | while(*s) { | |
110 | if((d1 = unhexdigit(*s++)) < 0) return 0; | |
111 | if((d2 = unhexdigit(*s++)) < 0) return 0; | |
112 | *p++ = d1 * 16 + d2; | |
113 | } | |
114 | if(np) | |
115 | *np = l / 2; | |
116 | return buf; | |
117 | } | |
118 | ||
119 | /* | |
120 | Local Variables: | |
121 | c-basic-offset:2 | |
122 | comment-column:40 | |
123 | End: | |
124 | */ |