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
162
163
164
165
166
167
168
169
170
171
172
173
|
/*=========================================================================
Program: GDCM (Grassroots DICOM). A DICOM library
Copyright (c) 2006-2011 Mathieu Malaterre
All rights reserved.
See Copyright.txt or http://gdcm.sourceforge.net/Copyright.html for details.
This software is distributed WITHOUT ANY WARRANTY; without even
the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR
PURPOSE. See the above copyright notice for more information.
=========================================================================*/
#include "gdcmBase64.h"
#include <string.h> // memcpy
#include <iostream>
namespace gdcm
{
/*
base64.cpp and base64.h
Copyright (C) 2004-2008 René Nyffenegger
This source code is provided 'as-is', without any express or implied
warranty. In no event will the author be held liable for any damages
arising from the use of this software.
Permission is granted to anyone to use this software for any purpose,
including commercial applications, and to alter it and redistribute it
freely, subject to the following restrictions:
1. The origin of this source code must not be misrepresented; you must not
claim that you wrote the original source code. If you use this source code
in a product, an acknowledgment in the product documentation would be
appreciated but is not required.
2. Altered source versions must be plainly marked as such, and must not be
misrepresented as being the original source code.
3. This notice may not be removed or altered from any source distribution.
René Nyffenegger rene.nyffenegger@adp-gmbh.ch
*/
static const std::string base64_chars =
"ABCDEFGHIJKLMNOPQRSTUVWXYZ"
"abcdefghijklmnopqrstuvwxyz"
"0123456789+/";
static inline bool is_base64(unsigned char c) {
return (isalnum(c) || (c == '+') || (c == '/'));
}
static std::string base64_encode(unsigned char const* bytes_to_encode, size_t in_len)
{
std::string ret;
size_t i = 0;
size_t j = 0;
unsigned char char_array_3[3];
unsigned char char_array_4[4];
while (in_len--) {
char_array_3[i++] = *(bytes_to_encode++);
if (i == 3) {
char_array_4[0] = (unsigned char)((char_array_3[0] & 0xfc) >> 2);
char_array_4[1] = (unsigned char)(((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4));
char_array_4[2] = (unsigned char)(((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6));
char_array_4[3] = (unsigned char)(char_array_3[2] & 0x3f);
for(i = 0; i < 4; i++)
ret += base64_chars[char_array_4[i]];
i = 0;
}
}
if (i)
{
for(j = i; j < 3; j++)
char_array_3[j] = '\0';
char_array_4[0] = (unsigned char)((char_array_3[0] & 0xfc) >> 2);
char_array_4[1] = (unsigned char)(((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4));
char_array_4[2] = (unsigned char)(((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6));
char_array_4[3] = (unsigned char)(char_array_3[2] & 0x3f);
for (j = 0; j < i + 1; j++)
ret += base64_chars[char_array_4[j]];
while((i++ < 3))
ret += '=';
}
return ret;
}
static std::string base64_decode(std::string const& encoded_string)
{
size_t in_len = encoded_string.size();
size_t i = 0;
size_t j = 0;
size_t in_ = 0;
unsigned char char_array_4[4], char_array_3[3];
std::string ret;
while (in_len-- && ( encoded_string[in_] != '=') && is_base64(encoded_string[in_])) {
char_array_4[i++] = encoded_string[in_]; in_++;
if (i ==4) {
for (i = 0; i <4; i++)
char_array_4[i] = (unsigned char)base64_chars.find(char_array_4[i]);
char_array_3[0] = (unsigned char)((char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4));
char_array_3[1] = (unsigned char)(((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2));
char_array_3[2] = (unsigned char)(((char_array_4[2] & 0x3) << 6) + char_array_4[3]);
for (i = 0; (i < 3); i++)
ret += char_array_3[i];
i = 0;
}
}
if (i) {
for (j = i; j <4; j++)
char_array_4[j] = 0;
for (j = 0; j <4; j++)
char_array_4[j] = (unsigned char)base64_chars.find(char_array_4[j]);
char_array_3[0] = (unsigned char)((char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4));
char_array_3[1] = (unsigned char)(((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2));
char_array_3[2] = (unsigned char)(((char_array_4[2] & 0x3) << 6) + char_array_4[3]);
for (j = 0; (j < i - 1); j++) ret += char_array_3[j];
}
return ret;
}
size_t Base64::GetEncodeLength(const char *src, size_t slen )
{
std::string ret = base64_encode((unsigned char*)src, slen);
return ret.size();
}
size_t Base64::Encode( char *dst, size_t dlen, const char *src, size_t slen )
{
const std::string & ret = base64_encode((unsigned char*)src, slen);
if( ret.size() > dlen )
return 0;
memcpy( dst, ret.c_str(), ret.size() );
return ret.size();
}
size_t Base64::GetDecodeLength( const char *src, size_t slen )
{
const std::string & ret = base64_decode( std::string( src, slen) );
return ret.size();
}
size_t Base64::Decode( char *dst, size_t dlen, const char *src, size_t slen )
{
const std::string & ret = base64_decode( std::string( src, slen) );
if( ret.size() > dlen )
return 0;
memcpy( dst, ret.c_str(), ret.size() );
return ret.size();
}
} // end namespace gdcm
|
