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
|
/*******************************************************************************
* Copyright (c) 2007, 2008 Wind River Systems, Inc. and others.
* All rights reserved. This program and the accompanying materials
* are made available under the terms of the Eclipse Public License v1.0
* and Eclipse Distribution License v1.0 which accompany this distribution.
* The Eclipse Public License is available at
* http://www.eclipse.org/legal/epl-v10.html
* and the Eclipse Distribution License is available at
* http://www.eclipse.org/org/documents/edl-v10.php.
*
* Contributors:
* Wind River Systems - initial API and implementation
*******************************************************************************/
/*
* This module implements BASE64 encoding and decoding of binary data.
* BASE64 encoding is adapted from RFC 1421, with one change:
* BASE64 eliminates the "*" mechanism for embedded clear text.
* Also TCF version of the encoding does not allow characters outside of the BASE64 alphabet.
*/
#include "config.h"
#include <assert.h>
#include "base64.h"
#include "exceptions.h"
#include "errors.h"
static const char int2char[] = {
'A', 'B', 'C', 'D', 'E', 'F', 'G', 'H',
'I', 'J', 'K', 'L', 'M', 'N', 'O', 'P',
'Q', 'R', 'S', 'T', 'U', 'V', 'W', 'X',
'Y', 'Z', 'a', 'b', 'c', 'd', 'e', 'f',
'g', 'h', 'i', 'j', 'k', 'l', 'm', 'n',
'o', 'p', 'q', 'r', 's', 't', 'u', 'v',
'w', 'x', 'y', 'z', '0', '1', '2', '3',
'4', '5', '6', '7', '8', '9', '+', '/'
};
static const int char2int[] = {
-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
};
#define OBF_SIZE 0x100
int write_base64(OutputStream * out, const char * buf0, int len) {
int pos = 0;
const unsigned char * buf = (const unsigned char *)buf0;
char obf[OBF_SIZE + 8];
size_t obf_len;
obf_len = 0;
while (pos < len) {
int byte0 = buf[pos++];
obf[obf_len++] = int2char[byte0 >> 2];
if (pos == len) {
obf[obf_len++] = int2char[(byte0 << 4) & 0x3f];
obf[obf_len++] = '=';
obf[obf_len++] = '=';
}
else {
int byte1 = buf[pos++];
obf[obf_len++] = int2char[(byte0 << 4) & 0x3f | (byte1 >> 4)];
if (pos == len) {
obf[obf_len++] = int2char[(byte1 << 2) & 0x3f];
obf[obf_len++] = '=';
}
else {
int byte2 = buf[pos++];
obf[obf_len++] = int2char[(byte1 << 2) & 0x3f | (byte2 >> 6)];
obf[obf_len++] = int2char[byte2 & 0x3f];
}
}
if (obf_len >= OBF_SIZE) {
write_block_stream(out, obf, obf_len);
obf_len = 0;
}
}
if (obf_len > 0) {
write_block_stream(out, obf, obf_len);
obf_len = 0;
}
assert(pos == len);
return ((len + 2) / 3) * 4;
}
int read_base64(InputStream * inp, char * buf, int buf_size) {
int pos = 0;
int ch_max = sizeof(char2int) / sizeof(int);
assert(buf_size >= 3);
while (pos + 3 <= buf_size) {
int n0 = 0, n1 = 0, n2 = 0, n3 = 0;
int ch0, ch1, ch2, ch3;
ch0 = peek_stream(inp);
if (ch0 < 0 || ch0 >= ch_max || (n0 = char2int[ch0]) < 0) break;
read_stream(inp);
ch1 = read_stream(inp);
ch2 = read_stream(inp);
ch3 = read_stream(inp);
if (ch1 < 0 || ch1 >= ch_max || (n1 = char2int[ch1]) < 0) exception(ERR_BASE64);
buf[pos++] = (char)((n0 << 2) | (n1 >> 4));
if (ch2 == '=') break;
if (ch2 < 0 || ch2 >= ch_max || (n2 = char2int[ch2]) < 0) exception(ERR_BASE64);
buf[pos++] = (char)((n1 << 4) | (n2 >> 2));
if (ch3 == '=') break;
if (ch3 < 0 || ch3 >= ch_max || (n3 = char2int[ch3]) < 0) exception(ERR_BASE64);
buf[pos++] = (char)((n2 << 6) | n3);
}
return pos;
}
|
