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
|
#include <config.h>
#include <stdlib.h>
#include <errno.h>
static char b64tab[] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
int
base64_encode(const unsigned char *input, size_t input_len,
unsigned char **output, size_t *output_len)
{
size_t olen = 4 * (input_len + 2) / 3 + 1;
unsigned char *out = malloc(olen);
if (!out)
return -1;
*output = out;
while (input_len >= 3) {
*out++ = b64tab[input[0] >> 2];
*out++ = b64tab[((input[0] << 4) & 0x30) | (input[1] >> 4)];
*out++ = b64tab[((input[1] << 2) & 0x3c) | (input[2] >> 6)];
*out++ = b64tab[input[2] & 0x3f];
input_len -= 3;
input += 3;
}
if (input_len > 0) {
unsigned char c = (input[0] << 4) & 0x30;
*out++ = b64tab[input[0] >> 2];
if (input_len > 1)
c |= input[1] >> 4;
*out++ = b64tab[c];
*out++ = (input_len < 2) ?
'=' : b64tab[(input[1] << 2) & 0x3c];
*out++ = '=';
}
*output_len = out - *output;
*out = 0;
return 0;
}
static int b64val[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
};
int
base64_decode(const unsigned char *input, size_t input_len,
unsigned char *output, size_t output_len)
{
unsigned char *out = output;
#define AC(c) do { if (output_len-- == 0) return -1; *out++ = (c); } while (0)
if (!out)
return -1;
do {
if (input[0] > 127 || b64val[input[0]] == -1 ||
input[1] > 127 || b64val[input[1]] == -1 ||
input[2] > 127 ||
((input[2] != '=') && (b64val[input[2]] == -1)) ||
input[3] > 127 ||
((input[3] != '=') && (b64val[input[3]] == -1))) {
errno = EINVAL;
return -1;
}
AC((b64val[input[0]] << 2) | (b64val[input[1]] >> 4));
if (input[2] != '=') {
AC(((b64val[input[1]] << 4) & 0xf0) |
(b64val[input[2]] >> 2));
if (input[3] != '=')
AC(((b64val[input[2]] << 6) & 0xc0) |
b64val[input[3]]);
}
input += 4;
input_len -= 4;
} while (input_len > 0);
return out - output;
}
|
