aboutsummaryrefslogtreecommitdiff
path: root/src/randomenv.cpp
blob: 49033deef267f1c15f0965f3f7efb3a590a6dca9 (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
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
// Copyright (c) 2009-2010 Satoshi Nakamoto
// Copyright (c) 2009-2022 The Bitcoin Core developers
// Distributed under the MIT software license, see the accompanying
// file COPYING or http://www.opensource.org/licenses/mit-license.php.

#include <config/bitcoin-config.h> // IWYU pragma: keep

#include <randomenv.h>

#include <clientversion.h>
#include <compat/compat.h>
#include <compat/cpuid.h>
#include <crypto/sha512.h>
#include <span.h>
#include <support/cleanse.h>
#include <util/time.h>

#include <algorithm>
#include <atomic>
#include <cstdint>
#include <cstring>
#include <chrono>
#include <climits>
#include <thread>
#include <vector>

#include <sys/types.h> // must go before a number of other headers

#ifdef WIN32
#include <windows.h>
#include <winreg.h>
#else
#include <fcntl.h>
#include <netinet/in.h>
#include <sys/resource.h>
#include <sys/socket.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/utsname.h>
#include <unistd.h>
#endif
#if HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS
#include <ifaddrs.h>
#endif
#ifdef HAVE_SYSCTL
#include <sys/sysctl.h>
#ifdef HAVE_VM_VM_PARAM_H
#include <vm/vm_param.h>
#endif
#ifdef HAVE_SYS_RESOURCES_H
#include <sys/resources.h>
#endif
#ifdef HAVE_SYS_VMMETER_H
#include <sys/vmmeter.h>
#endif
#endif
#if defined(HAVE_STRONG_GETAUXVAL)
#include <sys/auxv.h>
#endif

extern char** environ; // NOLINT(readability-redundant-declaration): Necessary on some platforms

namespace {

void RandAddSeedPerfmon(CSHA512& hasher)
{
#ifdef WIN32
    // Seed with the entire set of perfmon data

    // This can take up to 2 seconds, so only do it every 10 minutes.
    // Initialize last_perfmon to 0 seconds, we don't skip the first call.
    static std::atomic<std::chrono::seconds> last_perfmon{0s};
    auto last_time = last_perfmon.load();
    auto current_time = GetTime<std::chrono::seconds>();
    if (current_time < last_time + std::chrono::minutes{10}) return;
    last_perfmon = current_time;

    std::vector<unsigned char> vData(250000, 0);
    long ret = 0;
    unsigned long nSize = 0;
    const size_t nMaxSize = 10000000; // Bail out at more than 10MB of performance data
    while (true) {
        nSize = vData.size();
        ret = RegQueryValueExA(HKEY_PERFORMANCE_DATA, "Global", nullptr, nullptr, vData.data(), &nSize);
        if (ret != ERROR_MORE_DATA || vData.size() >= nMaxSize)
            break;
        vData.resize(std::min((vData.size() * 3) / 2, nMaxSize)); // Grow size of buffer exponentially
    }
    RegCloseKey(HKEY_PERFORMANCE_DATA);
    if (ret == ERROR_SUCCESS) {
        hasher.Write(vData.data(), nSize);
        memory_cleanse(vData.data(), nSize);
    } else {
        // Performance data is only a best-effort attempt at improving the
        // situation when the OS randomness (and other sources) aren't
        // adequate. As a result, failure to read it is isn't considered critical,
        // so we don't call RandFailure().
        // TODO: Add logging when the logger is made functional before global
        // constructors have been invoked.
    }
#endif
}

/** Helper to easily feed data into a CSHA512.
 *
 * Note that this does not serialize the passed object (like stream.h's << operators do).
 * Its raw memory representation is used directly.
 */
template<typename T>
CSHA512& operator<<(CSHA512& hasher, const T& data) {
    static_assert(!std::is_same<typename std::decay<T>::type, char*>::value, "Calling operator<<(CSHA512, char*) is probably not what you want");
    static_assert(!std::is_same<typename std::decay<T>::type, unsigned char*>::value, "Calling operator<<(CSHA512, unsigned char*) is probably not what you want");
    static_assert(!std::is_same<typename std::decay<T>::type, const char*>::value, "Calling operator<<(CSHA512, const char*) is probably not what you want");
    static_assert(!std::is_same<typename std::decay<T>::type, const unsigned char*>::value, "Calling operator<<(CSHA512, const unsigned char*) is probably not what you want");
    hasher.Write((const unsigned char*)&data, sizeof(data));
    return hasher;
}

#ifndef WIN32
void AddSockaddr(CSHA512& hasher, const struct sockaddr *addr)
{
    if (addr == nullptr) return;
    switch (addr->sa_family) {
    case AF_INET:
        hasher.Write((const unsigned char*)addr, sizeof(sockaddr_in));
        break;
    case AF_INET6:
        hasher.Write((const unsigned char*)addr, sizeof(sockaddr_in6));
        break;
    default:
        hasher.Write((const unsigned char*)&addr->sa_family, sizeof(addr->sa_family));
    }
}

void AddFile(CSHA512& hasher, const char *path)
{
    struct stat sb = {};
    int f = open(path, O_RDONLY);
    size_t total = 0;
    if (f != -1) {
        unsigned char fbuf[4096];
        int n;
        hasher.Write((const unsigned char*)&f, sizeof(f));
        if (fstat(f, &sb) == 0) hasher << sb;
        do {
            n = read(f, fbuf, sizeof(fbuf));
            if (n > 0) hasher.Write(fbuf, n);
            total += n;
            /* not bothering with EINTR handling. */
        } while (n == sizeof(fbuf) && total < 1048576); // Read only the first 1 Mbyte
        close(f);
    }
}

void AddPath(CSHA512& hasher, const char *path)
{
    struct stat sb = {};
    if (stat(path, &sb) == 0) {
        hasher.Write((const unsigned char*)path, strlen(path) + 1);
        hasher << sb;
    }
}
#endif

#ifdef HAVE_SYSCTL
template<int... S>
void AddSysctl(CSHA512& hasher)
{
    int CTL[sizeof...(S)] = {S...};
    unsigned char buffer[65536];
    size_t siz = 65536;
    int ret = sysctl(CTL, sizeof...(S), buffer, &siz, nullptr, 0);
    if (ret == 0 || (ret == -1 && errno == ENOMEM)) {
        hasher << sizeof(CTL);
        hasher.Write((const unsigned char*)CTL, sizeof(CTL));
        if (siz > sizeof(buffer)) siz = sizeof(buffer);
        hasher << siz;
        hasher.Write(buffer, siz);
    }
}
#endif

#ifdef HAVE_GETCPUID
void inline AddCPUID(CSHA512& hasher, uint32_t leaf, uint32_t subleaf, uint32_t& ax, uint32_t& bx, uint32_t& cx, uint32_t& dx)
{
    GetCPUID(leaf, subleaf, ax, bx, cx, dx);
    hasher << leaf << subleaf << ax << bx << cx << dx;
}

void AddAllCPUID(CSHA512& hasher)
{
    uint32_t ax, bx, cx, dx;
    // Iterate over all standard leaves
    AddCPUID(hasher, 0, 0, ax, bx, cx, dx); // Returns max leaf in ax
    uint32_t max = ax;
    for (uint32_t leaf = 1; leaf <= max && leaf <= 0xFF; ++leaf) {
        uint32_t maxsub = 0;
        for (uint32_t subleaf = 0; subleaf <= 0xFF; ++subleaf) {
            AddCPUID(hasher, leaf, subleaf, ax, bx, cx, dx);
            // Iterate subleafs for leaf values 4, 7, 11, 13
            if (leaf == 4) {
                if ((ax & 0x1f) == 0) break;
            } else if (leaf == 7) {
                if (subleaf == 0) maxsub = ax;
                if (subleaf == maxsub) break;
            } else if (leaf == 11) {
                if ((cx & 0xff00) == 0) break;
            } else if (leaf == 13) {
                if (ax == 0 && bx == 0 && cx == 0 && dx == 0) break;
            } else {
                // For any other leaf, stop after subleaf 0.
                break;
            }
        }
    }
    // Iterate over all extended leaves
    AddCPUID(hasher, 0x80000000, 0, ax, bx, cx, dx); // Returns max extended leaf in ax
    uint32_t ext_max = ax;
    for (uint32_t leaf = 0x80000001; leaf <= ext_max && leaf <= 0x800000FF; ++leaf) {
        AddCPUID(hasher, leaf, 0, ax, bx, cx, dx);
    }
}
#endif
} // namespace

void RandAddDynamicEnv(CSHA512& hasher)
{
    RandAddSeedPerfmon(hasher);

    // Various clocks
#ifdef WIN32
    FILETIME ftime;
    GetSystemTimeAsFileTime(&ftime);
    hasher << ftime;
#else
    struct timespec ts = {};
#    ifdef CLOCK_MONOTONIC
    clock_gettime(CLOCK_MONOTONIC, &ts);
    hasher << ts;
#    endif
#    ifdef CLOCK_REALTIME
    clock_gettime(CLOCK_REALTIME, &ts);
    hasher << ts;
#    endif
#    ifdef CLOCK_BOOTTIME
    clock_gettime(CLOCK_BOOTTIME, &ts);
    hasher << ts;
#    endif
    // gettimeofday is available on all UNIX systems, but only has microsecond precision.
    struct timeval tv = {};
    gettimeofday(&tv, nullptr);
    hasher << tv;
#endif
    // Probably redundant, but also use all the standard library clocks:
    hasher << std::chrono::system_clock::now().time_since_epoch().count();
    hasher << std::chrono::steady_clock::now().time_since_epoch().count();
    hasher << std::chrono::high_resolution_clock::now().time_since_epoch().count();

#ifndef WIN32
    // Current resource usage.
    struct rusage usage = {};
    if (getrusage(RUSAGE_SELF, &usage) == 0) hasher << usage;
#endif

#ifdef __linux__
    AddFile(hasher, "/proc/diskstats");
    AddFile(hasher, "/proc/vmstat");
    AddFile(hasher, "/proc/schedstat");
    AddFile(hasher, "/proc/zoneinfo");
    AddFile(hasher, "/proc/meminfo");
    AddFile(hasher, "/proc/softirqs");
    AddFile(hasher, "/proc/stat");
    AddFile(hasher, "/proc/self/schedstat");
    AddFile(hasher, "/proc/self/status");
#endif

#ifdef HAVE_SYSCTL
#  ifdef CTL_KERN
#    if defined(KERN_PROC) && defined(KERN_PROC_ALL)
    AddSysctl<CTL_KERN, KERN_PROC, KERN_PROC_ALL>(hasher);
#    endif
#  endif
#  ifdef CTL_HW
#    ifdef HW_DISKSTATS
    AddSysctl<CTL_HW, HW_DISKSTATS>(hasher);
#    endif
#  endif
#  ifdef CTL_VM
#    ifdef VM_LOADAVG
    AddSysctl<CTL_VM, VM_LOADAVG>(hasher);
#    endif
#    ifdef VM_TOTAL
    AddSysctl<CTL_VM, VM_TOTAL>(hasher);
#    endif
#    ifdef VM_METER
    AddSysctl<CTL_VM, VM_METER>(hasher);
#    endif
#  endif
#endif

    // Stack and heap location
    void* addr = malloc(4097);
    hasher << &addr << addr;
    free(addr);
}

void RandAddStaticEnv(CSHA512& hasher)
{
    // Some compile-time static properties
    hasher << (CHAR_MIN < 0) << sizeof(void*) << sizeof(long) << sizeof(int);
#if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
    hasher << __GNUC__ << __GNUC_MINOR__ << __GNUC_PATCHLEVEL__;
#endif
#ifdef _MSC_VER
    hasher << _MSC_VER;
#endif
    hasher << __cplusplus;
#ifdef _XOPEN_VERSION
    hasher << _XOPEN_VERSION;
#endif
#ifdef __VERSION__
    const char* COMPILER_VERSION = __VERSION__;
    hasher.Write((const unsigned char*)COMPILER_VERSION, strlen(COMPILER_VERSION) + 1);
#endif

    // Bitcoin client version
    hasher << CLIENT_VERSION;

#if defined(HAVE_STRONG_GETAUXVAL)
    // Information available through getauxval()
#  ifdef AT_HWCAP
    hasher << getauxval(AT_HWCAP);
#  endif
#  ifdef AT_HWCAP2
    hasher << getauxval(AT_HWCAP2);
#  endif
#  ifdef AT_RANDOM
    const unsigned char* random_aux = (const unsigned char*)getauxval(AT_RANDOM);
    if (random_aux) hasher.Write(random_aux, 16);
#  endif
#  ifdef AT_PLATFORM
    const char* platform_str = (const char*)getauxval(AT_PLATFORM);
    if (platform_str) hasher.Write((const unsigned char*)platform_str, strlen(platform_str) + 1);
#  endif
#  ifdef AT_EXECFN
    const char* exec_str = (const char*)getauxval(AT_EXECFN);
    if (exec_str) hasher.Write((const unsigned char*)exec_str, strlen(exec_str) + 1);
#  endif
#endif // HAVE_STRONG_GETAUXVAL

#ifdef HAVE_GETCPUID
    AddAllCPUID(hasher);
#endif

    // Memory locations
    hasher << &hasher << &RandAddStaticEnv << &malloc << &errno << &environ;

    // Hostname
#ifdef WIN32
    constexpr DWORD max_size = MAX_COMPUTERNAME_LENGTH + 1;
    char hname[max_size];
    DWORD size = max_size;
    if (GetComputerNameA(hname, &size) != 0) {
        hasher.Write(UCharCast(hname), size);
    }
#else
    char hname[256];
    if (gethostname(hname, 256) == 0) {
        hasher.Write((const unsigned char*)hname, strnlen(hname, 256));
    }
#endif

#if HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS
    // Network interfaces
    struct ifaddrs *ifad = nullptr;
    getifaddrs(&ifad);
    struct ifaddrs *ifit = ifad;
    while (ifit != nullptr) {
        hasher.Write((const unsigned char*)&ifit, sizeof(ifit));
        hasher.Write((const unsigned char*)ifit->ifa_name, strlen(ifit->ifa_name) + 1);
        hasher.Write((const unsigned char*)&ifit->ifa_flags, sizeof(ifit->ifa_flags));
        AddSockaddr(hasher, ifit->ifa_addr);
        AddSockaddr(hasher, ifit->ifa_netmask);
        AddSockaddr(hasher, ifit->ifa_dstaddr);
        ifit = ifit->ifa_next;
    }
    freeifaddrs(ifad);
#endif

#ifndef WIN32
    // UNIX kernel information
    struct utsname name;
    if (uname(&name) != -1) {
        hasher.Write((const unsigned char*)&name.sysname, strlen(name.sysname) + 1);
        hasher.Write((const unsigned char*)&name.nodename, strlen(name.nodename) + 1);
        hasher.Write((const unsigned char*)&name.release, strlen(name.release) + 1);
        hasher.Write((const unsigned char*)&name.version, strlen(name.version) + 1);
        hasher.Write((const unsigned char*)&name.machine, strlen(name.machine) + 1);
    }

    /* Path and filesystem provided data */
    AddPath(hasher, "/");
    AddPath(hasher, ".");
    AddPath(hasher, "/tmp");
    AddPath(hasher, "/home");
    AddPath(hasher, "/proc");
#ifdef __linux__
    AddFile(hasher, "/proc/cmdline");
    AddFile(hasher, "/proc/cpuinfo");
    AddFile(hasher, "/proc/version");
#endif
    AddFile(hasher, "/etc/passwd");
    AddFile(hasher, "/etc/group");
    AddFile(hasher, "/etc/hosts");
    AddFile(hasher, "/etc/resolv.conf");
    AddFile(hasher, "/etc/timezone");
    AddFile(hasher, "/etc/localtime");
#endif

    // For MacOS/BSDs, gather data through sysctl instead of /proc. Not all of these
    // will exist on every system.
#ifdef HAVE_SYSCTL
#  ifdef CTL_HW
#    ifdef HW_MACHINE
    AddSysctl<CTL_HW, HW_MACHINE>(hasher);
#    endif
#    ifdef HW_MODEL
    AddSysctl<CTL_HW, HW_MODEL>(hasher);
#    endif
#    ifdef HW_NCPU
    AddSysctl<CTL_HW, HW_NCPU>(hasher);
#    endif
#    ifdef HW_PHYSMEM
    AddSysctl<CTL_HW, HW_PHYSMEM>(hasher);
#    endif
#    ifdef HW_USERMEM
    AddSysctl<CTL_HW, HW_USERMEM>(hasher);
#    endif
#    ifdef HW_MACHINE_ARCH
    AddSysctl<CTL_HW, HW_MACHINE_ARCH>(hasher);
#    endif
#    ifdef HW_REALMEM
    AddSysctl<CTL_HW, HW_REALMEM>(hasher);
#    endif
#    ifdef HW_CPU_FREQ
    AddSysctl<CTL_HW, HW_CPU_FREQ>(hasher);
#    endif
#    ifdef HW_BUS_FREQ
    AddSysctl<CTL_HW, HW_BUS_FREQ>(hasher);
#    endif
#    ifdef HW_CACHELINE
    AddSysctl<CTL_HW, HW_CACHELINE>(hasher);
#    endif
#  endif
#  ifdef CTL_KERN
#    ifdef KERN_BOOTFILE
     AddSysctl<CTL_KERN, KERN_BOOTFILE>(hasher);
#    endif
#    ifdef KERN_BOOTTIME
     AddSysctl<CTL_KERN, KERN_BOOTTIME>(hasher);
#    endif
#    ifdef KERN_CLOCKRATE
     AddSysctl<CTL_KERN, KERN_CLOCKRATE>(hasher);
#    endif
#    ifdef KERN_HOSTID
     AddSysctl<CTL_KERN, KERN_HOSTID>(hasher);
#    endif
#    ifdef KERN_HOSTUUID
     AddSysctl<CTL_KERN, KERN_HOSTUUID>(hasher);
#    endif
#    ifdef KERN_HOSTNAME
     AddSysctl<CTL_KERN, KERN_HOSTNAME>(hasher);
#    endif
#    ifdef KERN_OSRELDATE
     AddSysctl<CTL_KERN, KERN_OSRELDATE>(hasher);
#    endif
#    ifdef KERN_OSRELEASE
     AddSysctl<CTL_KERN, KERN_OSRELEASE>(hasher);
#    endif
#    ifdef KERN_OSREV
     AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
#    endif
#    ifdef KERN_OSTYPE
     AddSysctl<CTL_KERN, KERN_OSTYPE>(hasher);
#    endif
#    ifdef KERN_POSIX1
     AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
#    endif
#    ifdef KERN_VERSION
     AddSysctl<CTL_KERN, KERN_VERSION>(hasher);
#    endif
#  endif
#endif

    // Env variables
    if (environ) {
        for (size_t i = 0; environ[i]; ++i) {
            hasher.Write((const unsigned char*)environ[i], strlen(environ[i]));
        }
    }

    // Process, thread, user, session, group, ... ids.
#ifdef WIN32
    hasher << GetCurrentProcessId() << GetCurrentThreadId();
#else
    hasher << getpid() << getppid() << getsid(0) << getpgid(0) << getuid() << geteuid() << getgid() << getegid();
#endif
    hasher << std::this_thread::get_id();
}