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                 : const static char hexchar[] = "0123456789ABCDEF";
      41                 : 
      42                 : static int
      43                 : pos(char c)
      44               0 : {
      45                 :     const char *p;
      46               0 :     c = toupper((unsigned char)c);
      47               0 :     for (p = hexchar; *p; p++)
      48               0 :         if (*p == c)
      49               0 :             return p - hexchar;
      50               0 :     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               0 : {
      56               0 :     const unsigned char *q = data;
      57                 :     size_t i;
      58                 :     char *p;
      59                 : 
      60                 :     /* check for overflow */
      61               0 :     if (size * 2 < size) {
      62               0 :         *str = NULL;
      63               0 :         return -1;
      64                 :     }
      65                 : 
      66               0 :     p = malloc(size * 2 + 1);
      67               0 :     if (p == NULL) {
      68               0 :         *str = NULL;
      69               0 :         return -1;
      70                 :     }
      71                 : 
      72               0 :     for (i = 0; i < size; i++) {
      73               0 :         p[i * 2] = hexchar[(*q >> 4) & 0xf];
      74               0 :         p[i * 2 + 1] = hexchar[*q & 0xf];
      75               0 :         q++;
      76                 :     }
      77               0 :     p[i * 2] = '\0';
      78               0 :     *str = p;
      79                 : 
      80               0 :     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               0 : {
      86                 :     size_t l;
      87               0 :     unsigned char *p = data;
      88                 :     size_t i;
      89                 :         
      90               0 :     l = strlen(str);
      91                 : 
      92                 :     /* check for overflow, same as (l+1)/2 but overflow safe */
      93               0 :     if ((l/2) + (l&1) > len)
      94               0 :         return -1;
      95                 : 
      96               0 :     i = 0;
      97               0 :     if (l & 1) {
      98               0 :         p[0] = pos(str[0]);
      99               0 :         str++;
     100               0 :         p++;
     101                 :     }
     102               0 :     for (i = 0; i < l / 2; i++)
     103               0 :         p[i] = pos(str[i * 2]) << 4 | pos(str[(i * 2) + 1]);
     104               0 :     return i + (l & 1);
     105                 : }