aboutsummaryrefslogtreecommitdiffstats
path: root/util/random/entropy.cpp
blob: bd34c0faedc624de9593d8cf504a9bf482c6c633 (plain) (blame)
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
#include "fast.h"
#include "random.h"
#include "entropy.h"
#include "mersenne.h"
#include "shuffle.h"
#include "init_atfork.h"

#include <util/stream/output.h>
#include <util/stream/mem.h>
#include <util/stream/zlib.h>
#include <util/stream/buffer.h>

#include <util/system/fs.h>
#include <util/system/info.h>
#include <util/system/spinlock.h>
#include <util/system/thread.h>
#include <util/system/execpath.h>
#include <util/system/datetime.h>
#include <util/system/hostname.h>
#include <util/system/getpid.h>
#include <util/system/mem_info.h>
#include <util/system/rusage.h>
#include <util/system/cpu_id.h>
#include <util/system/unaligned_mem.h>

#include <util/generic/buffer.h>
#include <util/generic/singleton.h>

#include <util/digest/murmur.h> 
#include <util/digest/city.h>

#include <util/ysaveload.h>

namespace {
    inline void Permute(char* buf, size_t len, ui32 seed) noexcept {
        Shuffle(buf, buf + len, TReallyFastRng32(seed));
    }

    struct THostEntropy: public TBuffer {
        inline THostEntropy() {
            {
                TBufferOutput buf(*this);
                TZLibCompress out(&buf);

                Save(&out, GetPID());
                Save(&out, GetCycleCount());
                Save(&out, MicroSeconds());
                Save(&out, TThread::CurrentThreadId());
                Save(&out, NSystemInfo::CachedNumberOfCpus());
                Save(&out, NSystemInfo::TotalMemorySize());
                Save(&out, HostName());

                try {
                    Save(&out, GetExecPath());
                } catch (...) {
                    //workaround - sometimes fails on FreeBSD
                }

                Save(&out, (size_t)Data());
                Save(&out, (size_t)&buf);

                {
                    double la[3];

                    NSystemInfo::LoadAverage(la, Y_ARRAY_SIZE(la));

                    out.Write(la, sizeof(la));
                }

                {
                    auto mi = NMemInfo::GetMemInfo();

                    out.Write(&mi, sizeof(mi));
                }

                {
                    auto ru = TRusage::Get();

                    out.Write(&ru, sizeof(ru));
                }

                {
                    ui32 store[12];

                    out << TStringBuf(CpuBrand(store));
                }

                out << NFs::CurrentWorkingDirectory();

                out.Finish();
            }

            {
                TMemoryOutput out(Data(), Size());

                //replace zlib header with hash
                Save(&out, CityHash64(Data(), Size()));
            }

            Permute(Data(), Size(), MurmurHash<ui32>(Data(), Size()));
        }
    };

    //not thread-safe
    class TMersenneInput: public IInputStream {
        using TKey = ui64;
        using TRnd = TMersenne<TKey>;

    public:
        inline explicit TMersenneInput(const TBuffer& rnd)
            : Rnd_((const TKey*)rnd.Data(), rnd.Size() / sizeof(TKey))
        {
        }

        ~TMersenneInput() override = default;

        size_t DoRead(void* buf, size_t len) override {
            size_t toRead = len;

            while (toRead) {
                const TKey next = Rnd_.GenRand();
                const size_t toCopy = Min(toRead, sizeof(next));

                memcpy(buf, &next, toCopy);

                buf = (char*)buf + toCopy;
                toRead -= toCopy;
            }

            return len;
        }

    private:
        TRnd Rnd_;
    };

    class TEntropyPoolStream: public IInputStream {
    public:
        inline explicit TEntropyPoolStream(const TBuffer& buffer)
            : Mi_(buffer)
            , Bi_(&Mi_, 8192)
        {
        }

        size_t DoRead(void* buf, size_t len) override {
            auto guard = Guard(Mutex_);

            return Bi_.Read(buf, len);
        }

    private:
        TAdaptiveLock Mutex_;
        TMersenneInput Mi_;
        TBufferedInput Bi_;
    };

    struct TSeedStream: public IInputStream {
        size_t DoRead(void* inbuf, size_t len) override {
            char* buf = (char*)inbuf;

#define DO_STEP(type)                                    \
    while (len >= sizeof(type)) {                        \
        WriteUnaligned<type>(buf, RandomNumber<type>()); \
        buf += sizeof(type);                             \
        len -= sizeof(type);                             \
    }

            DO_STEP(ui64);
            DO_STEP(ui32);
            DO_STEP(ui16);
            DO_STEP(ui8);

#undef DO_STEP

            return buf - (char*)inbuf;
        }
    };

    struct TDefaultTraits {
        THolder<TEntropyPoolStream> EP;
        TSeedStream SS;

        inline TDefaultTraits() {
            Reset();
        }

        inline IInputStream& EntropyPool() noexcept {
            return *EP;
        }

        inline IInputStream& Seed() noexcept {
            return SS;
        }

        inline void Reset() noexcept {
            EP.Reset(new TEntropyPoolStream(THostEntropy()));
        }

        static inline TDefaultTraits& Instance() {
            auto res = SingletonWithPriority<TDefaultTraits, 0>();

            RNGInitAtForkHandlers();

            return *res;
        }
    };

    using TRandomTraits = TDefaultTraits;
}

IInputStream& EntropyPool() {
    return TRandomTraits::Instance().EntropyPool();
}

IInputStream& Seed() {
    return TRandomTraits::Instance().Seed();
}

void ResetEntropyPool() {
    TRandomTraits::Instance().Reset();
}