| 1 | /* |
| 2 | * Copyright (c) 2004-2005 Kungliga Tekniska Högskolan |
| 3 | * (Royal Institute of Technology, Stockholm, Sweden). |
| 4 | * All rights reserved. |
| 5 | * |
| 6 | * Redistribution and use in source and binary forms, with or without |
| 7 | * modification, are permitted provided that the following conditions |
| 8 | * are met: |
| 9 | * |
| 10 | * 1. Redistributions of source code must retain the above copyright |
| 11 | * notice, this list of conditions and the following disclaimer. |
| 12 | * |
| 13 | * 2. Redistributions in binary form must reproduce the above copyright |
| 14 | * notice, this list of conditions and the following disclaimer in the |
| 15 | * documentation and/or other materials provided with the distribution. |
| 16 | * |
| 17 | * 3. Neither the name of the Institute nor the names of its contributors |
| 18 | * may be used to endorse or promote products derived from this software |
| 19 | * without specific prior written permission. |
| 20 | * |
| 21 | * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND |
| 22 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE |
| 23 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE |
| 24 | * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE |
| 25 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL |
| 26 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS |
| 27 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) |
| 28 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT |
| 29 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY |
| 30 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF |
| 31 | * SUCH DAMAGE. |
| 32 | */ |
| 33 | |
| 34 | |
| 35 | #include <config.h> |
| 36 | #include "roken.h" |
| 37 | #include <ctype.h> |
| 38 | #include "hex.h" |
| 39 | |
| 40 | static const char hexchar[16] = "0123456789ABCDEF"; |
| 41 | |
| 42 | static int |
| 43 | pos(char c) |
| 44 | { |
| 45 | const char *p; |
| 46 | c = toupper((unsigned char)c); |
| 47 | for (p = hexchar; *p; p++) |
| 48 | if (*p == c) |
| 49 | return p - hexchar; |
| 50 | return -1; |
| 51 | } |
| 52 | |
| 53 | ROKEN_LIB_FUNCTION ssize_t ROKEN_LIB_CALL |
| 54 | hex_encode(const void *data, size_t size, char **str) |
| 55 | { |
| 56 | const unsigned char *q = data; |
| 57 | size_t i; |
| 58 | char *p; |
| 59 | |
| 60 | /* check for overflow */ |
| 61 | if (size * 2 < size) { |
| 62 | *str = NULL; |
| 63 | return -1; |
| 64 | } |
| 65 | |
| 66 | p = malloc(size * 2 + 1); |
| 67 | if (p == NULL) { |
| 68 | *str = NULL; |
| 69 | return -1; |
| 70 | } |
| 71 | |
| 72 | for (i = 0; i < size; i++) { |
| 73 | p[i * 2] = hexchar[(*q >> 4) & 0xf]; |
| 74 | p[i * 2 + 1] = hexchar[*q & 0xf]; |
| 75 | q++; |
| 76 | } |
| 77 | p[i * 2] = '\0'; |
| 78 | *str = p; |
| 79 | |
| 80 | return i * 2; |
| 81 | } |
| 82 | |
| 83 | ROKEN_LIB_FUNCTION ssize_t ROKEN_LIB_CALL |
| 84 | hex_decode(const char *str, void *data, size_t len) |
| 85 | { |
| 86 | size_t l; |
| 87 | unsigned char *p = data; |
| 88 | size_t i; |
| 89 | |
| 90 | l = strlen(str); |
| 91 | |
| 92 | /* check for overflow, same as (l+1)/2 but overflow safe */ |
| 93 | if ((l/2) + (l&1) > len) |
| 94 | return -1; |
| 95 | |
| 96 | if (l & 1) { |
| 97 | p[0] = pos(str[0]); |
| 98 | str++; |
| 99 | p++; |
| 100 | } |
| 101 | for (i = 0; i < l / 2; i++) |
| 102 | p[i] = pos(str[i * 2]) << 4 | pos(str[(i * 2) + 1]); |
| 103 | return i + (l & 1); |
| 104 | } |