1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
|
/******************************************************************
* $Id: nanohttp-base64.c,v 1.4 2006/12/11 08:13:19 m0gg Exp $
*
* CSOAP Project: A http client/server library in C
* Copyright (C) 2003 Ferhat Ayaz
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Library General Public
* License as published by the Free Software Foundation; either
* version 2 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Library General Public License for more details.
*
* You should have received a copy of the GNU Library General Public
* License along with this library; if not, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*
* Email: hero@persua.de
******************************************************************/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include "nanohttp-base64.h"
static const char cb64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const char cd64[] = "|$$$}rstuvwxyz{$$$$$$$>?@ABCDEFGHIJKLMNOPQRSTUVW$$$$$$XYZ[\\]^_`abcdefghijklmnopq";
/**
*
* encode 3 8-bit binary bytes as 4 '6-bit' characters
*
*/
static void _encodeblock(unsigned char in[3], unsigned char out[4], int len)
{
out[0] = cb64[in[0] >> 2];
out[1] = cb64[((in[0] & 0x03) << 4) | ((in[1] & 0xf0) >> 4)];
out[2] = (unsigned char)(len > 1 ? cb64[((in[1] & 0x0f) << 2) | ((in[2] & 0xc0) >> 6)] : '=');
out[3] = (unsigned char)(len > 2 ? cb64[in[2] & 0x3f] : '=');
return;
}
void base64_encode_string(const unsigned char *instr, unsigned char *outstr)
{
unsigned char in[3], out[4];
int i, len;
while (*instr)
{
len = 0;
for (i = 0; i < 3; i++)
{
if ((in[i] = (unsigned char)*instr))
{
len++;
instr++;
}
}
if (len)
{
_encodeblock(in, out, len);
for (i = 0; i < 4; i++)
*outstr++ = out[i];
}
}
}
/**
*
* decode 4 '6-bit' characters into 3 8-bit binary bytes
*
*/
static void _decodeblock(unsigned char in[4], unsigned char out[3])
{
out[0] = (unsigned char)(in[0] << 2 | in[1] >> 4);
out[1] = (unsigned char)(in[1] << 4 | in[2] >> 2);
out[2] = (unsigned char)(((in[2] << 6) & 0xc0) | in[3]);
return;
}
/**
* decode a base64 encoded string (maybe broken...)
*/
void base64_decode_string(const unsigned char *instr, unsigned char *outstr)
{
unsigned char in[4], out[3], v;
int i, len;
while (*instr)
{
for (len = 0, i = 0; i < 4 && *instr; i++)
{
v = 0;
while (*instr && v == 0)
{
v = *instr++;
v = (unsigned char)((v < 43 || v > 122) ? 0 : cd64[v - 43]);
if (v)
v = (unsigned char)((v == '$') ? 0 : v - 61);
}
if (*instr)
{
len++;
if (v)
in[i] = (unsigned char)(v - 1);
}
else
{
in[i] = 0;
}
}
if (len)
{
_decodeblock(in, out);
for (i = 0; i < len - 1; i++)
*outstr++ = out[i];
}
}
}
#ifdef BASE64_TEST_CASE_FROM_RFC2617
#include <stdio.h>
#include <strings.h>
int main(int argc, char **argv) {
unsigned char *instr = "QWxhZGRpbjpvcGVuIHNlc2FtZQ==";
unsigned char *result = "Aladdin:open sesame";
unsigned char instr2[80];
unsigned char outstr[80];
bzero(outstr, 80);
base64_decode_string(instr, outstr);
printf("\"%s\" => \"%s\"\n", instr, outstr);
if (strcmp(outstr, result))
printf("base64_decode failed\n");
strcpy(instr2, outstr);
bzero(outstr, 80);
base64_encode_string(instr2, outstr);
printf("\"%s\" => \"%s\"\n", instr2, outstr);
if (strcmp(outstr, instr))
printf("base64_encode failed\n");
return 0;
}
#endif
|
