release/src-rt-6.x.4708/router/samba-3.5.8/source4/heimdal/lib/roken/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
  34 #include <config.h>
  35
  36 #include <stdlib.h>
  37 #include <string.h>
  38 #include "base64.h"
  39
  40 static const char base64_chars[] =
  41     "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
  42
  43 static int
  44 pos(char c)
  45 {
  46     const char *p;
  47     for (p = base64_chars; *p; p++)
  48         if (*p == c)
  49             return p - base64_chars;
  50     return -1;
  51 }
  52
  53 int ROKEN_LIB_FUNCTION
  54 base64_encode(const void *data, int size, char **str)
  55 {
  56     char *s, *p;
  57     int i;
  58     int c;
  59     const unsigned char *q;
  60
  61     if (size > INT_MAX/4 || size < 0) {
  62         *str = NULL;
  63         return -1;
  64     }
  65
  66     p = s = (char *) malloc(size * 4 / 3 + 4);
  67     if (p == NULL) {
  68         *str = NULL;
  69         return -1;
  70     }
  71     q = (const unsigned char *) data;
  72
  73     for (i = 0; i < size;) {
  74         c = q[i++];
  75         c *= 256;
  76         if (i < size)
  77             c += q[i];
  78         i++;
  79         c *= 256;
  80         if (i < size)
  81             c += q[i];
  82         i++;
  83         p[0] = base64_chars[(c & 0x00fc0000) >> 18];
  84         p[1] = base64_chars[(c & 0x0003f000) >> 12];
  85         p[2] = base64_chars[(c & 0x00000fc0) >> 6];
  86         p[3] = base64_chars[(c & 0x0000003f) >> 0];
  87         if (i > size)
  88             p[3] = '=';
  89         if (i > size + 1)
  90             p[2] = '=';
  91         p += 4;
  92     }
  93     *p = 0;
  94     *str = s;
  95     return strlen(s);
  96 }
  97
  98 #define DECODE_ERROR 0xffffffff
  99
 100 static unsigned int
 101 token_decode(const char *token)
 102 {
 103     int i;
 104     unsigned int val = 0;
 105     int marker = 0;
 106     if (strlen(token) < 4)
 107         return DECODE_ERROR;
 108     for (i = 0; i < 4; i++) {
 109         val *= 64;
 110         if (token[i] == '=')
 111             marker++;
 112         else if (marker > 0)
 113             return DECODE_ERROR;
 114         else
 115             val += pos(token[i]);
 116     }
 117     if (marker > 2)
 118         return DECODE_ERROR;
 119     return (marker << 24) | val;
 120 }
 121
 122 int ROKEN_LIB_FUNCTION
 123 base64_decode(const char *str, void *data)
 124 {
 125     const char *p;
 126     unsigned char *q;
 127
 128     q = data;
 129     for (p = str; *p && (*p == '=' || strchr(base64_chars, *p)); p += 4) {
 130         unsigned int val = token_decode(p);
 131         unsigned int marker = (val >> 24) & 0xff;
 132         if (val == DECODE_ERROR)
 133             return -1;
 134         *q++ = (val >> 16) & 0xff;
 135         if (marker < 2)
 136             *q++ = (val >> 8) & 0xff;
 137         if (marker < 1)
 138             *q++ = val & 0xff;
 139     }
 140     return q - (unsigned char *) data;
 141 }