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
|
//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//
#include <__config>
#if defined(_LIBCPP_USING_WIN32_RANDOM)
// Must be defined before including stdlib.h to enable rand_s().
# define _CRT_RAND_S
#endif // defined(_LIBCPP_USING_WIN32_RANDOM)
#include "limits"
#include "random"
#include "system_error"
#if defined(__sun__)
# define rename solaris_headers_are_broken
#endif // defined(__sun__)
#include <errno.h>
#include <stdio.h>
#include <stdlib.h>
#if defined(_LIBCPP_USING_GETENTROPY)
# include <sys/random.h>
#elif defined(_LIBCPP_USING_DEV_RANDOM)
# include <fcntl.h>
# include <unistd.h>
# if __has_include(<sys/ioctl.h>) && __has_include(<linux/random.h>)
# include <sys/ioctl.h>
# include <linux/random.h>
# endif
#elif defined(_LIBCPP_USING_NACL_RANDOM)
# include <nacl/nacl_random.h>
#elif defined(_LIBCPP_USING_FUCHSIA_CPRNG)
# include <zircon/syscalls.h>
#endif
_LIBCPP_BEGIN_NAMESPACE_STD
#if defined(_LIBCPP_USING_GETENTROPY)
random_device::random_device(const string& __token)
{
if (__token != "/dev/urandom")
__throw_system_error(ENOENT, ("random device not supported " + __token).c_str());
}
random_device::~random_device()
{
}
unsigned
random_device::operator()()
{
unsigned r;
size_t n = sizeof(r);
int err = getentropy(&r, n);
if (err)
__throw_system_error(errno, "random_device getentropy failed");
return r;
}
#elif defined(_LIBCPP_USING_ARC4_RANDOM)
random_device::random_device(const string& __token)
{
if (__token != "/dev/urandom")
__throw_system_error(ENOENT, ("random device not supported " + __token).c_str());
}
random_device::~random_device()
{
}
unsigned
random_device::operator()()
{
return arc4random();
}
#elif defined(_LIBCPP_USING_DEV_RANDOM)
random_device::random_device(const string& __token)
: __f_(open(__token.c_str(), O_RDONLY))
{
if (__f_ < 0)
__throw_system_error(errno, ("random_device failed to open " + __token).c_str());
}
random_device::~random_device()
{
close(__f_);
}
unsigned
random_device::operator()()
{
unsigned r;
size_t n = sizeof(r);
char* p = reinterpret_cast<char*>(&r);
while (n > 0)
{
ssize_t s = read(__f_, p, n);
if (s == 0)
__throw_system_error(ENODATA, "random_device got EOF");
if (s == -1)
{
if (errno != EINTR)
__throw_system_error(errno, "random_device got an unexpected error");
continue;
}
n -= static_cast<size_t>(s);
p += static_cast<size_t>(s);
}
return r;
}
#elif defined(_LIBCPP_USING_NACL_RANDOM)
random_device::random_device(const string& __token)
{
if (__token != "/dev/urandom")
__throw_system_error(ENOENT, ("random device not supported " + __token).c_str());
int error = nacl_secure_random_init();
if (error)
__throw_system_error(error, ("random device failed to open " + __token).c_str());
}
random_device::~random_device()
{
}
unsigned
random_device::operator()()
{
unsigned r;
size_t n = sizeof(r);
size_t bytes_written;
int error = nacl_secure_random(&r, n, &bytes_written);
if (error != 0)
__throw_system_error(error, "random_device failed getting bytes");
else if (bytes_written != n)
__throw_runtime_error("random_device failed to obtain enough bytes");
return r;
}
#elif defined(_LIBCPP_USING_WIN32_RANDOM)
random_device::random_device(const string& __token)
{
if (__token != "/dev/urandom")
__throw_system_error(ENOENT, ("random device not supported " + __token).c_str());
}
random_device::~random_device()
{
}
unsigned
random_device::operator()()
{
unsigned r;
errno_t err = rand_s(&r);
if (err)
__throw_system_error(err, "random_device rand_s failed.");
return r;
}
#elif defined(_LIBCPP_USING_FUCHSIA_CPRNG)
random_device::random_device(const string& __token) {
if (__token != "/dev/urandom")
__throw_system_error(ENOENT, ("random device not supported " + __token).c_str());
}
random_device::~random_device() {}
unsigned random_device::operator()() {
// Implicitly link against the vDSO system call ABI without
// requiring the final link to specify -lzircon explicitly when
// statically linking libc++.
# pragma comment(lib, "zircon")
// The system call cannot fail. It returns only when the bits are ready.
unsigned r;
_zx_cprng_draw(&r, sizeof(r));
return r;
}
#else
#error "Random device not implemented for this architecture"
#endif
double
random_device::entropy() const noexcept
{
#if defined(_LIBCPP_USING_DEV_RANDOM) && defined(RNDGETENTCNT)
int ent;
if (::ioctl(__f_, RNDGETENTCNT, &ent) < 0)
return 0;
if (ent < 0)
return 0;
if (ent > std::numeric_limits<result_type>::digits)
return std::numeric_limits<result_type>::digits;
return ent;
#elif defined(__OpenBSD__) || defined(_LIBCPP_USING_FUCHSIA_CPRNG)
return std::numeric_limits<result_type>::digits;
#else
return 0;
#endif
}
_LIBCPP_END_NAMESPACE_STD
|
