hex.c revision 178826
1283514Sarybchik/* 2283514Sarybchik * Copyright (c) 2004-2005 Kungliga Tekniska H�gskolan 3283514Sarybchik * (Royal Institute of Technology, Stockholm, Sweden). 4283514Sarybchik * All rights reserved. 5283514Sarybchik * 6283514Sarybchik * Redistribution and use in source and binary forms, with or without 7283514Sarybchik * modification, are permitted provided that the following conditions 8283514Sarybchik * are met: 9283514Sarybchik * 10283514Sarybchik * 1. Redistributions of source code must retain the above copyright 11283514Sarybchik * notice, this list of conditions and the following disclaimer. 12283514Sarybchik * 13283514Sarybchik * 2. Redistributions in binary form must reproduce the above copyright 14283514Sarybchik * notice, this list of conditions and the following disclaimer in the 15283514Sarybchik * documentation and/or other materials provided with the distribution. 16283514Sarybchik * 17283514Sarybchik * 3. Neither the name of the Institute nor the names of its contributors 18283514Sarybchik * may be used to endorse or promote products derived from this software 19283514Sarybchik * without specific prior written permission. 20283514Sarybchik * 21283514Sarybchik * THIS SOFTWARE IS PROVIDED BY THE INSTITUTE AND CONTRIBUTORS ``AS IS'' AND 22283514Sarybchik * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE 23283514Sarybchik * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE 24283514Sarybchik * ARE DISCLAIMED. IN NO EVENT SHALL THE INSTITUTE OR CONTRIBUTORS BE LIABLE 25283514Sarybchik * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL 26283514Sarybchik * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS 27283514Sarybchik * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 28283514Sarybchik * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT 29283514Sarybchik * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY 30283514Sarybchik * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF 31283514Sarybchik * SUCH DAMAGE. 32283514Sarybchik */ 33283514Sarybchik 34283514Sarybchik#ifdef HAVE_CONFIG_H 35283514Sarybchik#include <config.h> 36283514SarybchikRCSID("$Id: hex.c 16504 2006-01-09 17:09:29Z lha $"); 37283514Sarybchik#endif 38283514Sarybchik#include "roken.h" 39283514Sarybchik#include <ctype.h> 40283514Sarybchik#include "hex.h" 41283514Sarybchik 42283514Sarybchikconst static char hexchar[] = "0123456789ABCDEF"; 43283514Sarybchik 44283514Sarybchikstatic int 45283514Sarybchikpos(char c) 46299253Sarybchik{ 47299253Sarybchik const char *p; 48299253Sarybchik c = toupper((unsigned char)c); 49299253Sarybchik for (p = hexchar; *p; p++) 50299253Sarybchik if (*p == c) 51299253Sarybchik return p - hexchar; 52299253Sarybchik return -1; 53299253Sarybchik} 54299253Sarybchik 55299253Sarybchikssize_t ROKEN_LIB_FUNCTION 56299253Sarybchikhex_encode(const void *data, size_t size, char **str) 57283514Sarybchik{ 58283514Sarybchik const unsigned char *q = data; 59283514Sarybchik size_t i; 60283514Sarybchik char *p; 61283514Sarybchik 62283514Sarybchik /* check for overflow */ 63283514Sarybchik if (size * 2 < size) 64283514Sarybchik return -1; 65283514Sarybchik 66299320Sarybchik p = malloc(size * 2 + 1); 67299320Sarybchik if (p == NULL) 68283514Sarybchik return -1; 69283514Sarybchik 70283514Sarybchik for (i = 0; i < size; i++) { 71283514Sarybchik p[i * 2] = hexchar[(*q >> 4) & 0xf]; 72283514Sarybchik p[i * 2 + 1] = hexchar[*q & 0xf]; 73299320Sarybchik q++; 74299320Sarybchik } 75283514Sarybchik p[i * 2] = '\0'; 76283514Sarybchik *str = p; 77283514Sarybchik 78283514Sarybchik return i * 2; 79283514Sarybchik} 80299320Sarybchik 81299320Sarybchikssize_t ROKEN_LIB_FUNCTION 82283514Sarybchikhex_decode(const char *str, void *data, size_t len) 83283514Sarybchik{ 84283514Sarybchik size_t l; 85283514Sarybchik unsigned char *p = data; 86283514Sarybchik size_t i; 87299320Sarybchik 88299320Sarybchik l = strlen(str); 89283514Sarybchik 90283514Sarybchik /* check for overflow, same as (l+1)/2 but overflow safe */ 91283514Sarybchik if ((l/2) + (l&1) > len) 92299321Sarybchik return -1; 93299321Sarybchik 94299321Sarybchik i = 0; 95283514Sarybchik if (l & 1) { 96283514Sarybchik p[0] = pos(str[0]); 97283514Sarybchik str++; 98299320Sarybchik p++; 99299320Sarybchik } 100283514Sarybchik for (i = 0; i < l / 2; i++) 101283514Sarybchik p[i] = pos(str[i * 2]) << 4 | pos(str[(i * 2) + 1]); 102283514Sarybchik return i + (l & 1); 103293730Sarybchik} 104283514Sarybchik