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 } 105