1                 : /*
       2                 :  * Copyright (c) 1995-2001 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                 : #include <config.h>
      35                 : 
      36                 : #include <stdlib.h>
      37                 : #include <string.h>
      38                 : #include <limits.h>
      39                 : #include "base64.h"
      40                 : 
      41                 : static const char base64_chars[] =
      42                 :     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
      43                 : 
      44                 : static int
      45                 : pos(char c)
      46               0 : {
      47                 :     const char *p;
      48               0 :     for (p = base64_chars; *p; p++)
      49               0 :         if (*p == c)
      50               0 :             return p - base64_chars;
      51               0 :     return -1;
      52                 : }
      53                 : 
      54                 : ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
      55                 : base64_encode(const void *data, int size, char **str)
      56               0 : {
      57                 :     char *s, *p;
      58                 :     int i;
      59                 :     int c;
      60                 :     const unsigned char *q;
      61                 : 
      62               0 :     if (size > INT_MAX/4 || size < 0) {
      63               0 :         *str = NULL;
      64               0 :         return -1;
      65                 :     }
      66                 : 
      67               0 :     p = s = (char *) malloc(size * 4 / 3 + 4);
      68               0 :     if (p == NULL) {
      69               0 :         *str = NULL;
      70               0 :         return -1;
      71                 :     }
      72               0 :     q = (const unsigned char *) data;
      73                 : 
      74               0 :     for (i = 0; i < size;) {
      75               0 :         c = q[i++];
      76               0 :         c *= 256;
      77               0 :         if (i < size)
      78               0 :             c += q[i];
      79               0 :         i++;
      80               0 :         c *= 256;
      81               0 :         if (i < size)
      82               0 :             c += q[i];
      83               0 :         i++;
      84               0 :         p[0] = base64_chars[(c & 0x00fc0000) >> 18];
      85               0 :         p[1] = base64_chars[(c & 0x0003f000) >> 12];
      86               0 :         p[2] = base64_chars[(c & 0x00000fc0) >> 6];
      87               0 :         p[3] = base64_chars[(c & 0x0000003f) >> 0];
      88               0 :         if (i > size)
      89               0 :             p[3] = '=';
      90               0 :         if (i > size + 1)
      91               0 :             p[2] = '=';
      92               0 :         p += 4;
      93                 :     }
      94               0 :     *p = 0;
      95               0 :     *str = s;
      96               0 :     return strlen(s);
      97                 : }
      98                 : 
      99                 : #define DECODE_ERROR 0xffffffff
     100                 : 
     101                 : static unsigned int
     102                 : token_decode(const char *token)
     103               0 : {
     104                 :     int i;
     105               0 :     unsigned int val = 0;
     106               0 :     int marker = 0;
     107               0 :     if (strlen(token) < 4)
     108               0 :         return DECODE_ERROR;
     109               0 :     for (i = 0; i < 4; i++) {
     110               0 :         val *= 64;
     111               0 :         if (token[i] == '=')
     112               0 :             marker++;
     113               0 :         else if (marker > 0)
     114               0 :             return DECODE_ERROR;
     115                 :         else
     116               0 :             val += pos(token[i]);
     117                 :     }
     118               0 :     if (marker > 2)
     119               0 :         return DECODE_ERROR;
     120               0 :     return (marker << 24) | val;
     121                 : }
     122                 : 
     123                 : ROKEN_LIB_FUNCTION int ROKEN_LIB_CALL
     124                 : base64_decode(const char *str, void *data)
     125               0 : {
     126                 :     const char *p;
     127                 :     unsigned char *q;
     128                 : 
     129               0 :     q = data;
     130               0 :     for (p = str; *p && (*p == '=' || strchr(base64_chars, *p)); p += 4) {
     131               0 :         unsigned int val = token_decode(p);
     132               0 :         unsigned int marker = (val >> 24) & 0xff;
     133               0 :         if (val == DECODE_ERROR)
     134               0 :             return -1;
     135               0 :         *q++ = (val >> 16) & 0xff;
     136               0 :         if (marker < 2)
     137               0 :             *q++ = (val >> 8) & 0xff;
     138               0 :         if (marker < 1)
     139               0 :             *q++ = val & 0xff;
     140                 :     }
     141               0 :     return q - (unsigned char *) data;
     142                 : }