Newer
Older
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
/*
* Base64 encoding/decoding (RFC1341)
* Copyright (c) 2005-2011, Jouni Malinen <j@w1.fi>
*
* Copyright (C) 2020 iopsys Software Solutions AB.
*
* Modified to return encode/decode data in user passed buffer instead of
* allocating one in the library functions.
*
* This software may be distributed under the terms of the BSD license.
* See README for more details.
*/
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include "easy.h"
static const unsigned char base64_table[65] =
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/";
/**
* base64_encode - Base64 encode
* @src: Data to be encoded
* @len: Length of the data to be encoded
* @out: Pointer to output buffer where encoded data is written to
* @out_len: Pointer to output length (initialized with sizeof out buffer)
* Returns: 0 on success, else -1 or appropriate error codes.
*
* Returned buffer is '\0' terminated to make it easier to use as a C string.
* The '\0' terminator is not included in out_len.
*/
int LIBEASY_API base64_encode(const unsigned char *src, size_t len,
unsigned char *out, size_t *out_len)
{
unsigned char *pos;
const unsigned char *end, *in;
size_t olen;
int line_len;
if (!out || !out_len)
return -EINVAL;
olen = len * 4 / 3 + 4; /* 3-byte blocks to 4-byte */
olen += olen / 72; /* line feeds */
olen++; /* nul termination */
if (olen < len)
return -ERANGE; /* integer overflow */
if (*out_len < olen)
return -EMSGSIZE;
memset(out, 0, olen);
end = src + len;
in = src;
pos = out;
line_len = 0;
while (end - in >= 3) {
*pos++ = base64_table[in[0] >> 2];
*pos++ = base64_table[((in[0] & 0x03) << 4) | (in[1] >> 4)];
*pos++ = base64_table[((in[1] & 0x0f) << 2) | (in[2] >> 6)];
*pos++ = base64_table[in[2] & 0x3f];
in += 3;
line_len += 4;
if (line_len >= 72) {
*pos++ = '\n';
line_len = 0;
}
}
if (end - in) {
*pos++ = base64_table[in[0] >> 2];
if (end - in == 1) {
*pos++ = base64_table[(in[0] & 0x03) << 4];
*pos++ = '=';
} else {
*pos++ = base64_table[((in[0] & 0x03) << 4) |
(in[1] >> 4)];
*pos++ = base64_table[(in[1] & 0x0f) << 2];
}
*pos++ = '=';
line_len += 4;
}
if (line_len)
*pos++ = '\n';
*pos = '\0';
*out_len = (size_t)(pos - out);
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
return 0;
}
/**
* base64_decode - Base64 decode
* @src: Data to be decoded
* @len: Length of the data to be decoded
* @out: Pointer to output buffer where decoded data is written to
* @out_len: Pointer to output length (initialized with sizeof out buffer)
* Returns: 0 on success, else -1 or appropriate error codes.
*/
int LIBEASY_API base64_decode(const unsigned char *src, size_t len,
unsigned char *out, size_t *out_len)
{
unsigned char dtable[256], *pos, block[4], tmp;
size_t i, count, olen;
int pad = 0;
if (!out || !out_len)
return -EINVAL;
memset(dtable, 0x80, 256);
for (i = 0; i < sizeof(base64_table) - 1; i++)
dtable[base64_table[i]] = (unsigned char) i;
dtable['='] = 0;
count = 0;
for (i = 0; i < len; i++) {
if (dtable[src[i]] != 0x80)
count++;
}
if (count == 0 || count % 4)
return -1;
olen = count / 4 * 3;
if (*out_len < olen)
return -EMSGSIZE;
memset(out, 0, olen);
pos = out;
count = 0;
for (i = 0; i < len; i++) {
tmp = dtable[src[i]];
if (tmp == 0x80)
continue;
if (src[i] == '=')
pad++;
block[count] = tmp;
count++;
if (count == 4) {
*pos++ = (unsigned char)((block[0] << 2U) | (block[1] >> 4U));
*pos++ = (unsigned char)((block[1] << 4U) | (block[2] >> 2U));
*pos++ = (unsigned char)((block[2] << 6U) | block[3]);
count = 0;
if (pad) {
if (pad == 1)
pos--;
else if (pad == 2)
pos -= 2;
else {
/* Invalid padding */
return -1;
}
break;
}
}
}
*out_len = (size_t)(pos - out);