release/src/router/tinc/src/utils.c

   1 /*
   2     utils.c -- gathering of some stupid small functions
   3     Copyright (C) 1999-2005 Ivo Timmermans
   4                   2000-2013 Guus Sliepen <guus@tinc-vpn.org>
   5
   6     This program is free software; you can redistribute it and/or modify
   7     it under the terms of the GNU General Public License as published by
   8     the Free Software Foundation; either version 2 of the License, or
   9     (at your option) any later version.
  10
  11     This program is distributed in the hope that it will be useful,
  12     but WITHOUT ANY WARRANTY; without even the implied warranty of
  13     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14     GNU General Public License for more details.
  15
  16     You should have received a copy of the GNU General Public License along
  17     with this program; if not, write to the Free Software Foundation, Inc.,
  18     51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
  19 */
  20
  21 #include "system.h"
  22
  23 #include "../src/logger.h"
  24 #include "utils.h"
  25
  26 static const char hexadecimals[] = "0123456789ABCDEF";
  27 static const char base64_original[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  28 static const char base64_urlsafe[] =  "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789-_";
  29 static const char base64_decode[256] = {
  30         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  31         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  32         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, 62, -1, 63,
  33         52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
  34         -1,  0,  1,  2,  3,  4,  5,  6,  7,  8,  9, 10, 11, 12, 13, 14,
  35         15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, -1, -1, -1, -1, 63,
  36         -1, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40,
  37         41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, -1, -1, -1, -1, -1,
  38         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  39         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  40         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  41         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  42         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  43         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  44         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  45         -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
  46 };
  47
  48 static int charhex2bin(char c) {
  49         if(isdigit(c))
  50                 return c - '0';
  51         else
  52                 return toupper(c) - 'A' + 10;
  53 }
  54
  55 int hex2bin(const char *src, char *dst, int length) {
  56         int i;
  57         for(i = 0; i < length && isxdigit(src[i * 2]) && isxdigit(src[i * 2 + 1]); i++)
  58                 dst[i] = charhex2bin(src[i * 2]) * 16 + charhex2bin(src[i * 2 + 1]);
  59         return i;
  60 }
  61
  62 int bin2hex(const char *src, char *dst, int length) {
  63         for(int i = length - 1; i >= 0; i--) {
  64                 dst[i * 2 + 1] = hexadecimals[(unsigned char) src[i] & 15];
  65                 dst[i * 2] = hexadecimals[(unsigned char) src[i] >> 4];
  66         }
  67         dst[length * 2] = 0;
  68         return length * 2;
  69 }
  70
  71 int b64decode(const char *src, char *dst, int length) {
  72         int i;
  73         uint32_t triplet = 0;
  74         unsigned char *udst = (unsigned char *)dst;
  75
  76         for(i = 0; i < length / 3 * 4 && src[i]; i++) {
  77                 triplet |= base64_decode[src[i] & 0xff] << (6 * (i & 3));
  78                 if((i & 3) == 3) {
  79                         if(triplet & 0xff000000U)
  80                                 return 0;
  81                         udst[0] = triplet & 0xff; triplet >>= 8;
  82                         udst[1] = triplet & 0xff; triplet >>= 8;
  83                         udst[2] = triplet;
  84                         triplet = 0;
  85                         udst += 3;
  86                 }
  87         }
  88         if(triplet & 0xff000000U)
  89                 return 0;
  90         if((i & 3) == 3) {
  91                 udst[0] = triplet & 0xff; triplet >>= 8;
  92                 udst[1] = triplet & 0xff;
  93                 return i / 4 * 3 + 2;
  94         } else if((i & 3) == 2) {
  95                 udst[0] = triplet & 0xff;
  96                 return i / 4 * 3 + 1;
  97         } else {
  98                 return i / 4 * 3;
  99         }
 100 }
 101
 102 static int b64encode_internal(const char *src, char *dst, int length, const char *alphabet) {
 103         uint32_t triplet;
 104         const unsigned char *usrc = (unsigned char *)src;
 105         int si = length / 3 * 3;
 106         int di = length / 3 * 4;
 107
 108         switch(length % 3) {
 109                 case 2:
 110                         triplet = usrc[si] | usrc[si + 1] << 8;
 111                         dst[di] = alphabet[triplet & 63]; triplet >>= 6;
 112                         dst[di + 1] = alphabet[triplet & 63]; triplet >>= 6;
 113                         dst[di + 2] = alphabet[triplet];
 114                         dst[di + 3] = 0;
 115                         length = di + 2;
 116                         break;
 117                 case 1:
 118                         triplet = usrc[si];
 119                         dst[di] = alphabet[triplet & 63]; triplet >>= 6;
 120                         dst[di + 1] = alphabet[triplet];
 121                         dst[di + 2] = 0;
 122                         length = di + 1;
 123                         break;
 124                 default:
 125                         dst[di] = 0;
 126                         length = di;
 127                         break;
 128         }
 129
 130         while(si > 0) {
 131                 di -= 4;
 132                 si -= 3;
 133                 triplet = usrc[si] | usrc[si + 1] << 8 | usrc[si + 2] << 16;
 134                 dst[di] = alphabet[triplet & 63]; triplet >>= 6;
 135                 dst[di + 1] = alphabet[triplet & 63]; triplet >>= 6;
 136                 dst[di + 2] = alphabet[triplet & 63]; triplet >>= 6;
 137                 dst[di + 3] = alphabet[triplet];
 138         }
 139
 140         return length;
 141 }
 142
 143 int b64encode(const char *src, char *dst, int length) {
 144         return b64encode_internal(src, dst, length, base64_original);
 145 }
 146
 147 int b64encode_urlsafe(const char *src, char *dst, int length) {
 148         return b64encode_internal(src, dst, length, base64_urlsafe);
 149 }
 150
 151 #if defined(HAVE_MINGW) || defined(HAVE_CYGWIN)
 152 #ifdef HAVE_CYGWIN
 153 #include <w32api/windows.h>
 154 #endif
 155
 156 const char *winerror(int err) {
 157         static char buf[1024], *ptr;
 158
 159         ptr = buf + sprintf(buf, "(%d) ", err);
 160
 161         if (!FormatMessage(FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS,
 162                 NULL, err, MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), ptr, sizeof(buf) - (ptr - buf), NULL)) {
 163                 strncpy(buf, "(unable to format errormessage)", sizeof(buf));
 164         };
 165
 166         if((ptr = strchr(buf, '\r')))
 167                 *ptr = '\0';
 168
 169         return buf;
 170 }
 171 #endif
 172
 173 unsigned int bitfield_to_int(const void *bitfield, size_t size) {
 174         unsigned int value = 0;
 175         if(size > sizeof value)
 176                 size = sizeof value;
 177         memcpy(&value, bitfield, size);
 178         return value;
 179 }