blob: e6573e29638b2af255ea56bd0874f6bf3e9cd747 (
plain)
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
|
/*
* Entropy Source Polling
* (C) 2008-2010,2015 Jack Lloyd
*
* Botan is released under the Simplified BSD License (see license.txt)
*/
#include <botan/entropy_src.h>
#include <botan/rng.h>
#if defined(BOTAN_HAS_SYSTEM_RNG)
#include <botan/system_rng.h>
#endif
#if defined(BOTAN_HAS_PROCESSOR_RNG)
#include <botan/processor_rng.h>
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_RDRAND)
#include <botan/internal/rdrand.h>
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED)
#include <botan/internal/rdseed.h>
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_DARN)
#include <botan/internal/p9_darn.h>
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_DEV_RANDOM)
#include <botan/internal/dev_random.h>
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
#include <botan/internal/es_win32.h>
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_PROC_WALKER)
#include <botan/internal/proc_walk.h>
#include <botan/internal/os_utils.h>
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_GETENTROPY)
#include <botan/internal/getentropy.h>
#endif
namespace Botan {
namespace {
#if defined(BOTAN_HAS_SYSTEM_RNG)
class System_RNG_EntropySource final : public Entropy_Source
{
public:
size_t poll(RandomNumberGenerator& rng) override
{
const size_t poll_bits = BOTAN_RNG_RESEED_POLL_BITS;
rng.reseed_from_rng(system_rng(), poll_bits);
return poll_bits;
}
std::string name() const override { return "system_rng"; }
};
#endif
#if defined(BOTAN_HAS_PROCESSOR_RNG)
class Processor_RNG_EntropySource final : public Entropy_Source
{
public:
size_t poll(RandomNumberGenerator& rng) override
{
/*
* Intel's documentation for RDRAND at
* https://software.intel.com/en-us/articles/intel-digital-random-number-generator-drng-software-implementation-guide
* claims that software can guarantee a reseed event by polling enough data:
* "There is an upper bound of 511 samples per seed in the implementation
* where samples are 128 bits in size and can provide two 64-bit random
* numbers each."
*
* By requesting 65536 bits we are asking for 512 samples and thus are assured
* that at some point in producing the output, at least one reseed of the
* internal state will occur.
*
* The reseeding conditions of the POWER and ARM processor RNGs are not known
* but probably work in a somewhat similar manner. The exact amount requested
* may be tweaked if and when such conditions become publically known.
*/
const size_t poll_bits = 65536;
rng.reseed_from_rng(m_hwrng, poll_bits);
// Avoid trusting a black box, don't count this as contributing entropy:
return 0;
}
std::string name() const override { return m_hwrng.name(); }
private:
Processor_RNG m_hwrng;
};
#endif
}
std::unique_ptr<Entropy_Source> Entropy_Source::create(const std::string& name)
{
#if defined(BOTAN_HAS_SYSTEM_RNG)
if(name == "system_rng" || name == "win32_cryptoapi")
{
return std::unique_ptr<Entropy_Source>(new System_RNG_EntropySource);
}
#endif
#if defined(BOTAN_HAS_PROCESSOR_RNG)
if(name == "hwrng" || name == "rdrand" || name == "p9_darn")
{
if(Processor_RNG::available())
{
return std::unique_ptr<Entropy_Source>(new Processor_RNG_EntropySource);
}
}
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_RDSEED)
if(name == "rdseed")
{
return std::unique_ptr<Entropy_Source>(new Intel_Rdseed);
}
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_GETENTROPY)
if(name == "getentropy")
{
return std::unique_ptr<Entropy_Source>(new Getentropy);
}
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_DEV_RANDOM)
if(name == "dev_random")
{
return std::unique_ptr<Entropy_Source>(new Device_EntropySource(BOTAN_SYSTEM_RNG_POLL_DEVICES));
}
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_PROC_WALKER)
if(name == "proc_walk" && OS::running_in_privileged_state() == false)
{
const std::string root_dir = BOTAN_ENTROPY_PROC_FS_PATH;
if(!root_dir.empty())
return std::unique_ptr<Entropy_Source>(new ProcWalking_EntropySource(root_dir));
}
#endif
#if defined(BOTAN_HAS_ENTROPY_SRC_WIN32)
if(name == "system_stats")
{
return std::unique_ptr<Entropy_Source>(new Win32_EntropySource);
}
#endif
BOTAN_UNUSED(name);
return std::unique_ptr<Entropy_Source>();
}
void Entropy_Sources::add_source(std::unique_ptr<Entropy_Source> src)
{
if(src.get())
{
m_srcs.push_back(std::move(src));
}
}
std::vector<std::string> Entropy_Sources::enabled_sources() const
{
std::vector<std::string> sources;
for(size_t i = 0; i != m_srcs.size(); ++i)
{
sources.push_back(m_srcs[i]->name());
}
return sources;
}
size_t Entropy_Sources::poll(RandomNumberGenerator& rng,
size_t poll_bits,
std::chrono::milliseconds timeout)
{
typedef std::chrono::system_clock clock;
auto deadline = clock::now() + timeout;
size_t bits_collected = 0;
for(size_t i = 0; i != m_srcs.size(); ++i)
{
bits_collected += m_srcs[i]->poll(rng);
if (bits_collected >= poll_bits || clock::now() > deadline)
break;
}
return bits_collected;
}
size_t Entropy_Sources::poll_just(RandomNumberGenerator& rng, const std::string& the_src)
{
for(size_t i = 0; i != m_srcs.size(); ++i)
{
if(m_srcs[i]->name() == the_src)
{
return m_srcs[i]->poll(rng);
}
}
return 0;
}
Entropy_Sources::Entropy_Sources(const std::vector<std::string>& sources)
{
for(auto&& src_name : sources)
{
add_source(Entropy_Source::create(src_name));
}
}
Entropy_Sources& Entropy_Sources::global_sources()
{
static Entropy_Sources global_entropy_sources(BOTAN_ENTROPY_DEFAULT_SOURCES);
return global_entropy_sources;
}
}
|
