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
|
/*
* base64.c
* base64 encode/decode implementation
*
* Copyright (c) 2011 Nikias Bassen, All Rights Reserved.
*
* 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., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include <string.h>
#include "base64.h"
static const char base64_str[] = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
static const char base64_pad = '=';
static const signed char base64_table[256] = {
-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,
-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, -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, -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
};
char *base64encode(const unsigned char *buf, size_t *size)
{
if (!buf || !size || !(*size > 0)) return NULL;
int outlen = (*size / 3) * 4;
char *outbuf = (char*)malloc(outlen+5); // 4 spare bytes + 1 for '\0'
size_t n = 0;
size_t m = 0;
unsigned char input[3];
unsigned int output[4];
while (n < *size) {
input[0] = buf[n];
input[1] = (n+1 < *size) ? buf[n+1] : 0;
input[2] = (n+2 < *size) ? buf[n+2] : 0;
output[0] = input[0] >> 2;
output[1] = ((input[0] & 3) << 4) + (input[1] >> 4);
output[2] = ((input[1] & 15) << 2) + (input[2] >> 6);
output[3] = input[2] & 63;
outbuf[m++] = base64_str[(int)output[0]];
outbuf[m++] = base64_str[(int)output[1]];
outbuf[m++] = (n+1 < *size) ? base64_str[(int)output[2]] : base64_pad;
outbuf[m++] = (n+2 < *size) ? base64_str[(int)output[3]] : base64_pad;
n+=3;
}
outbuf[m] = 0; // 0-termination!
*size = m;
return outbuf;
}
static int base64decode_block(unsigned char *target, const char *data, size_t data_size)
{
int w1,w2,w3,w4;
int i;
size_t n;
if (!data || (data_size <= 0)) {
return 0;
}
n = 0;
i = 0;
while (n < data_size-3) {
w1 = base64_table[(int)data[n]];
w2 = base64_table[(int)data[n+1]];
w3 = base64_table[(int)data[n+2]];
w4 = base64_table[(int)data[n+3]];
if (w2 >= 0) {
target[i++] = (char)((w1*4 + (w2 >> 4)) & 255);
}
if (w3 >= 0) {
target[i++] = (char)((w2*16 + (w3 >> 2)) & 255);
}
if (w4 >= 0) {
target[i++] = (char)((w3*64 + w4) & 255);
}
n+=4;
}
return i;
}
unsigned char *base64decode(const char *buf, size_t *size)
{
if (!buf) return NULL;
size_t len = strlen(buf);
if (len <= 0) return NULL;
unsigned char *outbuf = (unsigned char*)malloc((len/4)*3+3);
const char *ptr = buf;
int p = 0;
do {
ptr += strspn(ptr, "\r\n\t ");
if (*ptr == '\0') {
break;
}
len = strcspn(ptr, "\r\n\t ");
if (len > 0) {
p+=base64decode_block(outbuf+p, ptr, len);
ptr += len;
} else {
break;
}
} while (1);
outbuf[p] = 0;
*size = p;
return outbuf;
}
|
