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