-
Notifications
You must be signed in to change notification settings - Fork 8
/
apuuid.hpp
235 lines (204 loc) · 7.36 KB
/
apuuid.hpp
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
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
/* Copyright (c) 2022 black-sliver
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*/
#ifndef _APUUID_HPP
#define _APUUID_HPP
/*
* NOTE: this does not produce "real" UUIDs. AP just requires strings that are unlikely to collide.
* This provides implementation for both browser context via emscripten as well as libc.
* We use a singleton to properly initialize RNG once.
* If calling srand() is a problem for the callee, you'll have to provide your own UUID generator.
*/
#include <stdint.h>
#include <stdio.h>
#include <string>
#include <memory>
#include <fstream>
#ifdef __EMSCRIPTEN__
#include <emscripten.h>
#include <emscripten/html5.h>
#else
#include <stdlib.h>
#include <time.h>
#endif
namespace AP {
class UUID {
public:
UUID(uint8_t bytes[16])
{
const char hex[] = "0123456789abcdef";
_string.resize(32);
char* p = (char*)_string.data();
for (size_t i=0; i<16; i++) {
*p = hex[(bytes[i] >> 4) & 0x0f];
p++;
*p = hex[bytes[i] & 0x0f];
p++;
}
}
virtual ~UUID() {}
const std::string& string() const
{
return _string;
}
private:
std::string _string;
};
class UUIDFactory {
public:
static UUIDFactory* instance();
virtual ~UUIDFactory() {}
void setFilename(const std::string& filename);
UUID getPersistentUUID(const std::string& hostname_or_url);
private:
UUIDFactory();
uint8_t randByte() const;
UUID generate() const;
void generate(uint8_t bytes[8]) const;
uint8_t hash(const std::string& name) const;
std::string _filename;
std::fstream _f;
};
inline UUIDFactory* UUIDFactory::instance()
{
static auto singleton = std::unique_ptr<UUIDFactory>(new UUIDFactory());
return singleton.get();
}
void UUIDFactory::setFilename(const std::string& filename)
{
#if defined __EMSCRIPTEN__ && !defined USE_IDBFS
#error "IDBFS is currently required for emscripten"
#endif
if (_filename == filename)
return;
if (_f.is_open())
_f.close();
_filename = filename;
}
UUID UUIDFactory::getPersistentUUID(const std::string& name)
{
if (!_f.is_open()) {
if (_filename.empty())
return generate();
_f.open(_filename, std::fstream::in | std::fstream::out | std::fstream::binary | std::fstream::ate);
if (!_f.is_open())
_f.open(_filename, std::fstream::in | std::fstream::out | std::fstream::binary | std::fstream::trunc);
if (!_f.is_open()) {
fprintf(stderr, "Could not write persistent UUID!\n");
return generate();
}
if (_f.tellp() < 32) {
// insert back compat string
_f.seekp(0);
_f << generate().string();
_f.flush();
}
if (_f.tellp() < 64) {
// insert old UUID into slot 0
uint64_t state = 1;
uint64_t dummy = 0;
uint8_t bytes[16];
_f.seekg(0);
for (uint8_t i=0; i<16; i++) {
char c;
uint8_t b = 0;
for (uint8_t n=0; n<2; n++) {
b <<= 4;
_f.read(&c, 1);
if (c >= '0' && c <= '9')
b |= (uint8_t)(c - '0');
if (c >= 'a' && c <= 'f')
b |= (uint8_t)(c - 'a' + 0x0a);
if (c >= 'A' && c <= 'F')
b |= (uint8_t)(c - 'A' + 0x0a);
}
bytes[i] = b;
}
_f.seekp(32);
_f.write((const char*)&state, sizeof(state));
_f.write((const char*)&dummy, sizeof(dummy));
_f.write((const char*)bytes, sizeof(bytes));
_f.flush();
}
}
// 32 byte at start of file reserved for back compat
// then each entry is 8 byte state + 8 byte reserved + 16 byte uuid
size_t offset = 32 + (size_t) hash(name) * 32;
_f.seekg(offset);
uint64_t state;
uint64_t dummy;
uint8_t bytes[16];
// load existing UUID if it exists
if (_f.read((char*)&state, sizeof(state)) && state
&& _f.read((char*)&dummy, sizeof(dummy))
&& _f.read((char*)bytes, sizeof(bytes)))
return UUID(bytes);
// expand file
_f.clear();
_f.seekp(0, std::fstream::end);
dummy = 0;
while (_f.tellp() < offset)
if (!_f.write((const char*)&dummy, sizeof(dummy)))
return generate(); // should never happen
// write new UUID
_f.seekp(offset);
state = 1;
generate(bytes);
_f.write((const char*)&state, sizeof(state));
_f.write((const char*)&dummy, sizeof(dummy));
_f.write((const char*)&bytes, sizeof(bytes));
_f.flush();
return UUID(bytes);
}
void UUIDFactory::generate(uint8_t bytes[8]) const
{
for (size_t i=0; i<8; i++)
bytes[i] = randByte();
}
UUID UUIDFactory::generate() const
{
uint8_t bytes[8];
generate(bytes);
return UUID(bytes);
}
uint8_t UUIDFactory::hash(const std::string& name) const
{
uint8_t res = 0;
for (char c: name) {
res = (res >> 7) | (res << 1);
res = (uint8_t)(res + (uint8_t)c);
}
return res;
}
#ifdef __EMSCRIPTEN__
UUIDFactory::UUIDFactory()
{
/* js crypto needs no init from C */
}
uint8_t UUIDFactory::randByte() const
{
return (uint8_t)EM_ASM_INT({
var buf = new Uint8Array(1);
crypto.getRandomValues(buf);
return buf[0];
});
}
#else
UUIDFactory::UUIDFactory()
{
srand ((unsigned int) time (NULL));
}
uint8_t UUIDFactory::randByte() const
{
return rand();
}
#endif
}
static std::string ap_get_uuid(const std::string& uuidFile, const std::string& host="")
{
AP::UUIDFactory::instance()->setFilename(uuidFile);
return AP::UUIDFactory::instance()->getPersistentUUID(host).string();
}
#endif // _APUUID_HPP