1 /* 2 * Copyright (c) 2004-2005 Kungliga Tekniska H�gskolan 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 #ifdef HAVE_CONFIG_H 35 #include <config.h> 36 RCSID("$Id: hex.c 16504 2006-01-09 17:09:29Z lha $"); 37 #endif 38 #include "roken.h" 39 #include <ctype.h> 40 #include "hex.h" 41 42 const static char hexchar[] = "0123456789ABCDEF"; 43 44 static int 45 pos(char c) 46 { 47 const char *p; 48 c = toupper((unsigned char)c); 49 for (p = hexchar; *p; p++) 50 if (*p == c) 51 return p - hexchar; 52 return -1; 53 } 54 55 ssize_t ROKEN_LIB_FUNCTION 56 hex_encode(const void *data, size_t size, char **str) 57 { 58 const unsigned char *q = data; 59 size_t i; 60 char *p; 61 62 /* check for overflow */ 63 if (size * 2 < size) 64 return -1; 65 66 p = malloc(size * 2 + 1); 67 if (p == NULL) 68 return -1; 69 70 for (i = 0; i < size; i++) { 71 p[i * 2] = hexchar[(*q >> 4) & 0xf]; 72 p[i * 2 + 1] = hexchar[*q & 0xf]; 73 q++; 74 } 75 p[i * 2] = '\0'; 76 *str = p; 77 78 return i * 2; 79 } 80 81 ssize_t ROKEN_LIB_FUNCTION 82 hex_decode(const char *str, void *data, size_t len) 83 { 84 size_t l; 85 unsigned char *p = data; 86 size_t i; 87 88 l = strlen(str); 89 90 /* check for overflow, same as (l+1)/2 but overflow safe */ 91 if ((l/2) + (l&1) > len) 92 return -1; 93 94 i = 0; 95 if (l & 1) { 96 p[0] = pos(str[0]); 97 str++; 98 p++; 99 } 100 for (i = 0; i < l / 2; i++) 101 p[i] = pos(str[i * 2]) << 4 | pos(str[(i * 2) + 1]); 102 return i + (l & 1); 103 } 104