1 | // Boost seed_rng.hpp header file ----------------------------------------------// |
2 | |
3 | // Copyright 2007 Andy Tompkins. |
4 | // Distributed under the Boost Software License, Version 1.0. (See |
5 | // accompanying file LICENSE_1_0.txt or copy at |
6 | // http://www.boost.org/LICENSE_1_0.txt) |
7 | |
8 | // Revision History |
9 | // 09 Nov 2007 - Initial Revision |
10 | // 25 Feb 2008 - moved to namespace boost::uuids::detail |
11 | // 28 Nov 2009 - disabled deprecated warnings for MSVC |
12 | // 28 Jul 2014 - fixed valgrind warnings and better entropy sources for MSVC |
13 | |
14 | // seed_rng models a UniformRandomNumberGenerator (see Boost.Random). |
15 | // Random number generators are hard to seed well. This is intended to provide |
16 | // good seed values for random number generators. |
17 | // It creates random numbers from a sha1 hash of data from a variary of sources, |
18 | // all of which are standard function calls. It produces random numbers slowly. |
19 | // Peter Dimov provided the details of sha1_random_digest_(). |
20 | // see http://archives.free.net.ph/message/20070507.175609.4c4f503a.en.html |
21 | |
22 | #ifndef BOOST_UUID_SEED_RNG_HPP |
23 | #define BOOST_UUID_SEED_RNG_HPP |
24 | |
25 | #include <boost/config.hpp> |
26 | #include <cstring> // for memcpy |
27 | #include <limits> |
28 | #include <ctime> // for time_t, time, clock_t, clock |
29 | #include <cstdlib> // for rand |
30 | #include <cstdio> // for FILE, fopen, fread, fclose |
31 | #include <boost/core/noncopyable.hpp> |
32 | #include <boost/uuid/sha1.hpp> |
33 | //#include <boost/nondet_random.hpp> //forward declare boost::random::random_device |
34 | |
35 | // can't use boost::generator_iterator since boost::random number seed(Iter&, Iter) |
36 | // functions need a last iterator |
37 | //#include <boost/generator_iterator.hpp> |
38 | # include <boost/iterator/iterator_facade.hpp> |
39 | |
40 | #if defined(_MSC_VER) |
41 | # pragma warning(push) // Save warning settings. |
42 | # pragma warning(disable : 4996) // Disable deprecated std::fopen |
43 | # pragma comment(lib, "advapi32.lib") |
44 | #endif |
45 | |
46 | #if defined(BOOST_WINDOWS) |
47 | # include <boost/detail/winapi/crypt.hpp> // for CryptAcquireContextA, CryptGenRandom, CryptReleaseContext |
48 | # include <boost/detail/winapi/timers.hpp> |
49 | # include <boost/detail/winapi/process.hpp> |
50 | # include <boost/detail/winapi/thread.hpp> |
51 | #else |
52 | # include <sys/time.h> // for gettimeofday |
53 | # include <sys/types.h> // for pid_t |
54 | # include <unistd.h> // for getpid() |
55 | #endif |
56 | |
57 | #ifdef BOOST_NO_STDC_NAMESPACE |
58 | namespace std { |
59 | using ::memcpy; |
60 | using ::time_t; |
61 | using ::time; |
62 | using ::clock_t; |
63 | using ::clock; |
64 | using ::rand; |
65 | using ::FILE; |
66 | using ::fopen; |
67 | using ::fread; |
68 | using ::fclose; |
69 | } //namespace std |
70 | #endif |
71 | |
72 | // forward declare random number generators |
73 | namespace boost { namespace random { |
74 | class random_device; |
75 | }} //namespace boost::random |
76 | |
77 | namespace boost { |
78 | namespace uuids { |
79 | namespace detail { |
80 | |
81 | // should this be part of Boost.Random? |
82 | class seed_rng: private boost::noncopyable |
83 | { |
84 | public: |
85 | typedef unsigned int result_type; |
86 | BOOST_STATIC_CONSTANT(bool, has_fixed_range = false); |
87 | |
88 | public: |
89 | // note: rd_ intentionally left uninitialized |
90 | seed_rng() BOOST_NOEXCEPT |
91 | : rd_index_(5) |
92 | , random_(NULL) |
93 | { |
94 | #if defined(BOOST_WINDOWS) |
95 | if (!boost::detail::winapi::CryptAcquireContextA( |
96 | &random_, |
97 | NULL, |
98 | NULL, |
99 | boost::detail::winapi::PROV_RSA_FULL_, |
100 | boost::detail::winapi::CRYPT_VERIFYCONTEXT_ | boost::detail::winapi::CRYPT_SILENT_)) |
101 | { |
102 | random_ = NULL; |
103 | } |
104 | #else |
105 | random_ = std::fopen( "/dev/urandom" , "rb" ); |
106 | #endif |
107 | |
108 | std::memset(rd_, 0, sizeof(rd_)); |
109 | } |
110 | |
111 | ~seed_rng() BOOST_NOEXCEPT |
112 | { |
113 | if (random_) { |
114 | #if defined(BOOST_WINDOWS) |
115 | boost::detail::winapi::CryptReleaseContext(random_, 0); |
116 | #else |
117 | std::fclose(random_); |
118 | #endif |
119 | } |
120 | } |
121 | |
122 | result_type min BOOST_PREVENT_MACRO_SUBSTITUTION () const BOOST_NOEXCEPT |
123 | { |
124 | return (std::numeric_limits<result_type>::min)(); |
125 | } |
126 | result_type max BOOST_PREVENT_MACRO_SUBSTITUTION () const BOOST_NOEXCEPT |
127 | { |
128 | return (std::numeric_limits<result_type>::max)(); |
129 | } |
130 | |
131 | result_type operator()() |
132 | { |
133 | if (rd_index_ >= 5) { |
134 | //get new digest |
135 | sha1_random_digest_(); |
136 | |
137 | rd_index_ = 0; |
138 | } |
139 | |
140 | return rd_[rd_index_++]; |
141 | } |
142 | |
143 | private: |
144 | BOOST_STATIC_CONSTANT(std::size_t, internal_state_size = 5); |
145 | inline void ignore_size(size_t) {} |
146 | |
147 | static unsigned int * sha1_random_digest_state_() |
148 | { |
149 | static unsigned int state[ internal_state_size ]; |
150 | return state; |
151 | } |
152 | |
153 | void sha1_random_digest_() |
154 | { |
155 | boost::uuids::detail::sha1 sha; |
156 | |
157 | |
158 | if (random_) |
159 | { |
160 | // intentionally left uninitialized |
161 | unsigned char state[ 20 ]; |
162 | #if defined(BOOST_WINDOWS) |
163 | boost::detail::winapi::CryptGenRandom(random_, sizeof(state), state); |
164 | #else |
165 | ignore_size(std::fread( state, 1, sizeof(state), random_ )); |
166 | #endif |
167 | sha.process_bytes( state, sizeof( state ) ); |
168 | } |
169 | |
170 | { |
171 | // Getting enropy from some system specific sources |
172 | #if defined(BOOST_WINDOWS) |
173 | boost::detail::winapi::DWORD_ procid = boost::detail::winapi::GetCurrentProcessId(); |
174 | sha.process_bytes( (unsigned char const*)&procid, sizeof( procid ) ); |
175 | |
176 | boost::detail::winapi::DWORD_ threadid = boost::detail::winapi::GetCurrentThreadId(); |
177 | sha.process_bytes( (unsigned char const*)&threadid, sizeof( threadid ) ); |
178 | |
179 | boost::detail::winapi::LARGE_INTEGER_ ts; |
180 | ts.QuadPart = 0; |
181 | boost::detail::winapi::QueryPerformanceCounter( &ts ); |
182 | sha.process_bytes( (unsigned char const*)&ts, sizeof( ts ) ); |
183 | |
184 | std::time_t tm = std::time( 0 ); |
185 | sha.process_bytes( (unsigned char const*)&tm, sizeof( tm ) ); |
186 | #else |
187 | pid_t pid = getpid(); |
188 | sha.process_bytes( (unsigned char const*)&pid, sizeof( pid ) ); |
189 | |
190 | timeval ts; |
191 | gettimeofday(&ts, NULL); // We do not use `clock_gettime` to avoid linkage with -lrt |
192 | sha.process_bytes( (unsigned char const*)&ts, sizeof( ts ) ); |
193 | #endif |
194 | } |
195 | |
196 | |
197 | unsigned int * ps = sha1_random_digest_state_(); |
198 | sha.process_bytes( ps, internal_state_size * sizeof( unsigned int ) ); |
199 | sha.process_bytes( (unsigned char const*)&ps, sizeof( ps ) ); |
200 | |
201 | { |
202 | std::clock_t ck = std::clock(); |
203 | sha.process_bytes( (unsigned char const*)&ck, sizeof( ck ) ); |
204 | } |
205 | |
206 | { |
207 | unsigned int rn[] = |
208 | { static_cast<unsigned int>(std::rand()) |
209 | , static_cast<unsigned int>(std::rand()) |
210 | , static_cast<unsigned int>(std::rand()) |
211 | }; |
212 | sha.process_bytes( (unsigned char const*)rn, sizeof( rn ) ); |
213 | } |
214 | |
215 | { |
216 | unsigned int * p = new unsigned int; |
217 | sha.process_bytes( (unsigned char const*)&p, sizeof( p ) ); |
218 | delete p; |
219 | |
220 | const seed_rng* this_ptr = this; |
221 | sha.process_bytes( (unsigned char const*)&this_ptr, sizeof( this_ptr ) ); |
222 | sha.process_bytes( (unsigned char const*)&std::rand, sizeof( void(*)() ) ); |
223 | } |
224 | |
225 | sha.process_bytes( (unsigned char const*)rd_, sizeof( rd_ ) ); |
226 | |
227 | unsigned int digest[ 5 ]; |
228 | sha.get_digest( digest ); |
229 | |
230 | for( int i = 0; i < 5; ++i ) |
231 | { |
232 | // harmless data race |
233 | ps[ i ] ^= digest[ i ]; |
234 | rd_[ i ] ^= digest[ i ]; |
235 | } |
236 | } |
237 | |
238 | private: |
239 | unsigned int rd_[5]; |
240 | int rd_index_; |
241 | |
242 | #if defined(BOOST_WINDOWS) |
243 | boost::detail::winapi::HCRYPTPROV_ random_; |
244 | #else |
245 | std::FILE * random_; |
246 | #endif |
247 | }; |
248 | |
249 | // almost a copy of boost::generator_iterator |
250 | // but default constructor sets m_g to NULL |
251 | template <class Generator> |
252 | class generator_iterator |
253 | : public iterator_facade< |
254 | generator_iterator<Generator> |
255 | , typename Generator::result_type |
256 | , single_pass_traversal_tag |
257 | , typename Generator::result_type const& |
258 | > |
259 | { |
260 | typedef iterator_facade< |
261 | generator_iterator<Generator> |
262 | , typename Generator::result_type |
263 | , single_pass_traversal_tag |
264 | , typename Generator::result_type const& |
265 | > super_t; |
266 | |
267 | public: |
268 | generator_iterator() : m_g(NULL), m_value(0) {} |
269 | generator_iterator(Generator* g) : m_g(g), m_value((*m_g)()) {} |
270 | |
271 | void increment() |
272 | { |
273 | m_value = (*m_g)(); |
274 | } |
275 | |
276 | const typename Generator::result_type& |
277 | dereference() const |
278 | { |
279 | return m_value; |
280 | } |
281 | |
282 | bool equal(generator_iterator const& y) const |
283 | { |
284 | return this->m_g == y.m_g && this->m_value == y.m_value; |
285 | } |
286 | |
287 | private: |
288 | Generator* m_g; |
289 | typename Generator::result_type m_value; |
290 | }; |
291 | |
292 | // seed() seeds a random number generator with good seed values |
293 | |
294 | template <typename UniformRandomNumberGenerator> |
295 | inline void seed(UniformRandomNumberGenerator& rng) |
296 | { |
297 | seed_rng seed_gen; |
298 | generator_iterator<seed_rng> begin(&seed_gen); |
299 | generator_iterator<seed_rng> end; |
300 | rng.seed(begin, end); |
301 | } |
302 | |
303 | // random_device does not / can not be seeded |
304 | template <> |
305 | inline void seed<boost::random::random_device>(boost::random::random_device&) {} |
306 | |
307 | // random_device does not / can not be seeded |
308 | template <> |
309 | inline void seed<seed_rng>(seed_rng&) {} |
310 | |
311 | }}} //namespace boost::uuids::detail |
312 | |
313 | #if defined(_MSC_VER) |
314 | #pragma warning(pop) // Restore warnings to previous state. |
315 | #endif |
316 | |
317 | #endif |
318 | |