1#include "taichi/common/core.h"
2
3namespace taichi {
4/*
5 base64.cpp and base64.h
6
7 Copyright (C) 2004-2008 René Nyffenegger
8
9 This source code is provided 'as-is', without any express or implied
10 warranty. In no event will the author be held liable for any damages
11 arising from the use of this software.
12
13 Permission is granted to anyone to use this software for any purpose,
14 including commercial applications, and to alter it and redistribute it
15 freely, subject to the following restrictions:
16
17 1. The origin of this source code must not be misrepresented; you must not
18 claim that you wrote the original source code. If you use this source code
19 in a product, an acknowledgment in the product documentation would be
20 appreciated but is not required.
21
22 2. Altered source versions must be plainly marked as such, and must not be
23 misrepresented as being the original source code.
24
25 3. This notice may not be removed or altered from any source distribution.
26
27 René Nyffenegger [email protected]
28*/
29
30static const std::string base64_chars =
31 "ABCDEFGHIJKLMNOPQRSTUVWXYZ"
32 "abcdefghijklmnopqrstuvwxyz"
33 "0123456789+/";
34
35static inline bool is_base64(unsigned char c) {
36 return (isalnum(c) || (c == '+') || (c == '/'));
37}
38
39inline std::string base64_encode(const std::string &bytes) {
40 auto bytes_to_encode = reinterpret_cast<unsigned char const *>(&bytes[0]);
41 unsigned int in_len = bytes.size();
42 std::string ret;
43 int i = 0;
44 int j = 0;
45 unsigned char char_array_3[3];
46 unsigned char char_array_4[4];
47
48 while (in_len--) {
49 char_array_3[i++] = *(bytes_to_encode++);
50 if (i == 3) {
51 char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
52 char_array_4[1] =
53 ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
54 char_array_4[2] =
55 ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
56 char_array_4[3] = char_array_3[2] & 0x3f;
57
58 for (i = 0; (i < 4); i++)
59 ret += base64_chars[char_array_4[i]];
60 i = 0;
61 }
62 }
63
64 if (i) {
65 for (j = i; j < 3; j++)
66 char_array_3[j] = '\0';
67
68 char_array_4[0] = (char_array_3[0] & 0xfc) >> 2;
69 char_array_4[1] =
70 ((char_array_3[0] & 0x03) << 4) + ((char_array_3[1] & 0xf0) >> 4);
71 char_array_4[2] =
72 ((char_array_3[1] & 0x0f) << 2) + ((char_array_3[2] & 0xc0) >> 6);
73 char_array_4[3] = char_array_3[2] & 0x3f;
74
75 for (j = 0; (j < i + 1); j++)
76 ret += base64_chars[char_array_4[j]];
77
78 while ((i++ < 3))
79 ret += '=';
80 }
81
82 return ret;
83}
84
85inline std::string base64_decode(std::string const &encoded_string) {
86 int in_len = encoded_string.size();
87 int i = 0;
88 int j = 0;
89 int in_ = 0;
90 unsigned char char_array_4[4], char_array_3[3];
91 std::string ret;
92
93 while (in_len-- && (encoded_string[in_] != '=') &&
94 is_base64(encoded_string[in_])) {
95 char_array_4[i++] = encoded_string[in_];
96 in_++;
97 if (i == 4) {
98 for (i = 0; i < 4; i++)
99 char_array_4[i] = base64_chars.find(char_array_4[i]);
100
101 char_array_3[0] =
102 (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
103 char_array_3[1] =
104 ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
105 char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
106
107 for (i = 0; (i < 3); i++)
108 ret += char_array_3[i];
109 i = 0;
110 }
111 }
112
113 if (i) {
114 for (j = i; j < 4; j++)
115 char_array_4[j] = 0;
116
117 for (j = 0; j < 4; j++)
118 char_array_4[j] = base64_chars.find(char_array_4[j]);
119
120 char_array_3[0] = (char_array_4[0] << 2) + ((char_array_4[1] & 0x30) >> 4);
121 char_array_3[1] =
122 ((char_array_4[1] & 0xf) << 4) + ((char_array_4[2] & 0x3c) >> 2);
123 char_array_3[2] = ((char_array_4[2] & 0x3) << 6) + char_array_4[3];
124
125 for (j = 0; (j < i - 1); j++)
126 ret += char_array_3[j];
127 }
128
129 return ret;
130}
131
132} // namespace taichi
133