src/lib/crypto.c

   1 /************************************************************************
   2 * crypto.c
   3 * voxelands - 3d voxel world sandbox game
   4 * Copyright (C) Lisa 'darkrose' Milne 2016 <lisa@ltmnet.com>
   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 3 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, but
  12 * WITHOUT ANY WARRANTY; without even the implied warranty of
  13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  14 * See the GNU General Public License for more details.
  15 *
  16 * You should have received a copy of the GNU General Public License
  17 * along with this program.  If not, see <http://www.gnu.org/licenses/>
  18 ************************************************************************/
  19
  20 #include "crypto.h"
  21
  22 #include <stdlib.h>
  23 #include <string.h>
  24
  25 /* defined in base64.c */
  26 int base64_lencode(char *source, size_t sourcelen, char *target, size_t targetlen);
  27 size_t base64_ldecode(char *source, char *target, size_t targetlen);
  28
  29 /* basic hashpjw used by lots of things, including mo files */
  30 uint32_t hash(char* str)
  31 {
  32         uint32_t hval = 0;
  33         uint32_t g;
  34         const char *s = str;
  35
  36         while (*s) {
  37                 hval <<= 4;
  38                 hval += (unsigned char) *s++;
  39                 g = hval & ((uint32_t) 0xf << 28);
  40                 if (g != 0) {
  41                         hval ^= g >> 24;
  42                         hval ^= g;
  43                 }
  44         }
  45
  46         return hval;
  47 }
  48
  49 /* base64 encode a string */
  50 char* base64_encode(char* str)
  51 {
  52         int sl;
  53         int tl;
  54         char* ret;
  55         int el;
  56         if (!str)
  57                 return NULL;
  58
  59         sl = strlen(str);
  60         tl = ((sl+2)/3*4)+5;
  61
  62         ret = malloc(tl);
  63         if (!ret)
  64                 return NULL;
  65
  66         el = base64_lencode(str, sl, ret, tl);
  67         if (!el) {
  68                 free(ret);
  69                 return NULL;
  70         }
  71
  72         return ret;
  73 }
  74
  75 /* decode a base64 string */
  76 char* base64_decode(char* str)
  77 {
  78         int sl;
  79         int tl;
  80         char* ret;
  81         int dl;
  82         if (!str)
  83                 return NULL;
  84
  85         sl = strlen(str);
  86         tl = (sl/4*3)+5;
  87         ret = malloc(tl);
  88         if (!ret)
  89                 return NULL;
  90
  91         dl = base64_ldecode(str, ret, tl);
  92         if (!dl) {
  93                 free(ret);
  94                 return NULL;
  95         }
  96         ret[dl] = 0;
  97
  98         return ret;
  99 }