libexec/dma/base64.c

   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  * $DragonFly: src/libexec/dma/base64.c,v 1.1 2008/02/02 18:20:51 matthias Exp $
  34  */
  35
  36 #include <stdlib.h>
  37 #include <string.h>
  38
  39 int base64_encode(const void *data, int size, char **str);
  40
  41 static char base64_chars[] =
  42     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  43
  44 int
  45 base64_encode(const void *data, int size, char **str)
  46 {
  47     char *s, *p;
  48     int i;
  49     int c;
  50     const unsigned char *q;
  51
  52     p = s = (char *) malloc(size * 4 / 3 + 4);
  53     if (p == NULL)
  54         return -1;
  55     q = (const unsigned char *) data;
  56     i = 0;
  57     for (i = 0; i < size;) {
  58         c = q[i++];
  59         c *= 256;
  60         if (i < size)
  61             c += q[i];
  62         i++;
  63         c *= 256;
  64         if (i < size)
  65             c += q[i];
  66         i++;
  67         p[0] = base64_chars[(c & 0x00fc0000) >> 18];
  68         p[1] = base64_chars[(c & 0x0003f000) >> 12];
  69         p[2] = base64_chars[(c & 0x00000fc0) >> 6];
  70         p[3] = base64_chars[(c & 0x0000003f) >> 0];
  71         if (i > size)
  72             p[3] = '=';
  73         if (i > size + 1)
  74             p[2] = '=';
  75         p += 4;
  76     }
  77     *p = 0;
  78     *str = s;
  79     return strlen(s);
  80 }
  81