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
158
159
160
161
|
/*
* This file is part of libESMTP, a library for submission of RFC 2822
* formatted electronic mail messages using the SMTP protocol described
* in RFC 2821.
*
* Copyright (C) 2001,2002 Brian Stafford <brian@stafford.uklinux.net>
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser 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
*/
#ifdef HAVE_CONFIG_H
#include <config.h>
#endif
#include <assert.h>
/* Routines to encode and decode base64 text.
*/
#include <ctype.h>
#include <string.h>
#include "base64.h"
/* RFC 2045 section 6.8 */
static const char base64[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789"
"+/";
static const char index_64[128] =
{
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1,
-1, -1, -1, -1, -1, -1, -1, -1, -1, -1, -1, 62, -1, -1, -1, 63,
52, 53, 54, 55, 56, 57, 58, 59, 60, 61, -1, -1, -1, -1, -1, -1,
-1, 0, 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, -1, -1, -1, -1, -1,
-1, 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, -1, -1, -1, -1, -1,
};
/* Decode srclen bytes of base64 data contained in src and put the result
in dst. Since the destination buffer may contain arbitrary binary
data and it is not necessarily a string, there is no \0 byte at the
end of the decoded data. */
int
b64_decode (void *dst, int dstlen, const char *src, int srclen)
{
const unsigned char *p, *q;
unsigned char *t;
int c1, c2;
assert (dst != NULL && dstlen > 0 && src != NULL);
if (srclen < 0)
srclen = strlen (src);
/* Remove leading and trailing white space */
for (p = (const unsigned char *) src;
srclen > 0 && isspace (*p);
p++, srclen--)
;
for (q = p + srclen - 1; q >= p && isspace (*q); q--, srclen--)
;
/* Length MUST be a multiple of 4 */
if (srclen % 4 != 0)
return -1;
/* Destination buffer length must be sufficient */
if (srclen / 4 * 3 + 1 > dstlen)
return -1;
t = dst;
while (srclen > 0)
{
srclen -= 4;
if (*p >= 128 || (c1 = index_64[*p++]) == -1)
return -1;
if (*p >= 128 || (c2 = index_64[*p++]) == -1)
return -1;
*t++ = (c1 << 2) | ((c2 & 0x30) >> 4);
if (p[0] == '=' && p[1] == '=')
break;
if (*p >= 128 || (c1 = index_64[*p++]) == -1)
return -1;
*t++ = ((c2 & 0x0f) << 4) | ((c1 & 0x3c) >> 2);
if (p[0] == '=')
break;
if (*p >= 128 || (c2 = index_64[*p++]) == -1)
return -1;
*t++ = ((c1 & 0x03) << 6) | c2;
}
return t - (unsigned char *) dst;
}
/* Return a pointer to a base 64 encoded string. The input data is
arbitrary binary data, the output is a \0 terminated string.
src and dst may not share the same buffer. */
int
b64_encode (char *dst, int dstlen, const void *src, int srclen)
{
char *to = dst;
const unsigned char *from;
unsigned char c1, c2;
int dst_needed;
assert (dst != NULL && dstlen > 0 && src != NULL && srclen >= 0);
dst_needed = (srclen + 2) / 3;
dst_needed *= 4;
if (dstlen < dst_needed + 1)
return -1;
from = src;
while (srclen > 0)
{
c1 = *from++; srclen--;
*to++ = base64[c1 >> 2];
c1 = (c1 & 0x03) << 4;
if (srclen <= 0)
{
*to++ = base64[c1];
*to++ = '=';
*to++ = '=';
break;
}
c2 = *from++; srclen--;
c1 |= (c2 >> 4) & 0x0f;
*to++ = base64[c1];
c1 = (c2 & 0x0f) << 2;
if (srclen <= 0)
{
*to++ = base64[c1];
*to++ = '=';
break;
}
c2 = *from++; srclen--;
c1 |= (c2 >> 6) & 0x03;
*to++ = base64[c1];
*to++ = base64[c2 & 0x3f];
}
*to = '\0';
return to - dst;
}
|
