Bitcoin Core  0.20.99
P2P Digital Currency
randomenv.cpp
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1 // Copyright (c) 2009-2010 Satoshi Nakamoto
2 // Copyright (c) 2009-2020 The Bitcoin Core developers
3 // Distributed under the MIT software license, see the accompanying
4 // file COPYING or http://www.opensource.org/licenses/mit-license.php.
5 
6 #if defined(HAVE_CONFIG_H)
8 #endif
9 
10 #include <randomenv.h>
11 
12 #include <clientversion.h>
13 #include <compat/cpuid.h>
14 #include <crypto/sha512.h>
15 #include <support/cleanse.h>
16 #include <util/time.h> // for GetTime()
17 #ifdef WIN32
18 #include <compat.h> // for Windows API
19 #endif
20 
21 #include <algorithm>
22 #include <atomic>
23 #include <chrono>
24 #include <climits>
25 #include <thread>
26 #include <vector>
27 
28 #include <stdint.h>
29 #include <string.h>
30 #ifndef WIN32
31 #include <sys/types.h> // must go before a number of other headers
32 #include <fcntl.h>
33 #include <netinet/in.h>
34 #include <sys/resource.h>
35 #include <sys/socket.h>
36 #include <sys/stat.h>
37 #include <sys/time.h>
38 #include <sys/utsname.h>
39 #include <unistd.h>
40 #endif
41 #if HAVE_DECL_GETIFADDRS
42 #include <ifaddrs.h>
43 #endif
44 #if HAVE_SYSCTL
45 #include <sys/sysctl.h>
46 #if HAVE_VM_VM_PARAM_H
47 #include <vm/vm_param.h>
48 #endif
49 #if HAVE_SYS_RESOURCES_H
50 #include <sys/resources.h>
51 #endif
52 #if HAVE_SYS_VMMETER_H
53 #include <sys/vmmeter.h>
54 #endif
55 #endif
56 #ifdef __linux__
57 #include <sys/auxv.h>
58 #endif
59 
61 extern char** environ;
62 
63 namespace {
64 
65 void RandAddSeedPerfmon(CSHA512& hasher)
66 {
67 #ifdef WIN32
68  // Seed with the entire set of perfmon data
69 
70  // This can take up to 2 seconds, so only do it every 10 minutes.
71  // Initialize last_perfmon to 0 seconds, we don't skip the first call.
72  static std::atomic<std::chrono::seconds> last_perfmon{std::chrono::seconds{0}};
73  auto last_time = last_perfmon.load();
74  auto current_time = GetTime<std::chrono::seconds>();
75  if (current_time < last_time + std::chrono::minutes{10}) return;
76  last_perfmon = current_time;
77 
78  std::vector<unsigned char> vData(250000, 0);
79  long ret = 0;
80  unsigned long nSize = 0;
81  const size_t nMaxSize = 10000000; // Bail out at more than 10MB of performance data
82  while (true) {
83  nSize = vData.size();
84  ret = RegQueryValueExA(HKEY_PERFORMANCE_DATA, "Global", nullptr, nullptr, vData.data(), &nSize);
85  if (ret != ERROR_MORE_DATA || vData.size() >= nMaxSize)
86  break;
87  vData.resize(std::min((vData.size() * 3) / 2, nMaxSize)); // Grow size of buffer exponentially
88  }
89  RegCloseKey(HKEY_PERFORMANCE_DATA);
90  if (ret == ERROR_SUCCESS) {
91  hasher.Write(vData.data(), nSize);
92  memory_cleanse(vData.data(), nSize);
93  } else {
94  // Performance data is only a best-effort attempt at improving the
95  // situation when the OS randomness (and other sources) aren't
96  // adequate. As a result, failure to read it is isn't considered critical,
97  // so we don't call RandFailure().
98  // TODO: Add logging when the logger is made functional before global
99  // constructors have been invoked.
100  }
101 #endif
102 }
103 
109 template<typename T>
110 CSHA512& operator<<(CSHA512& hasher, const T& data) {
111  static_assert(!std::is_same<typename std::decay<T>::type, char*>::value, "Calling operator<<(CSHA512, char*) is probably not what you want");
112  static_assert(!std::is_same<typename std::decay<T>::type, unsigned char*>::value, "Calling operator<<(CSHA512, unsigned char*) is probably not what you want");
113  static_assert(!std::is_same<typename std::decay<T>::type, const char*>::value, "Calling operator<<(CSHA512, const char*) is probably not what you want");
114  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");
115  hasher.Write((const unsigned char*)&data, sizeof(data));
116  return hasher;
117 }
118 
119 #ifndef WIN32
120 void AddSockaddr(CSHA512& hasher, const struct sockaddr *addr)
121 {
122  if (addr == nullptr) return;
123  switch (addr->sa_family) {
124  case AF_INET:
125  hasher.Write((const unsigned char*)addr, sizeof(sockaddr_in));
126  break;
127  case AF_INET6:
128  hasher.Write((const unsigned char*)addr, sizeof(sockaddr_in6));
129  break;
130  default:
131  hasher.Write((const unsigned char*)&addr->sa_family, sizeof(addr->sa_family));
132  }
133 }
134 
135 void AddFile(CSHA512& hasher, const char *path)
136 {
137  struct stat sb = {};
138  int f = open(path, O_RDONLY);
139  size_t total = 0;
140  if (f != -1) {
141  unsigned char fbuf[4096];
142  int n;
143  hasher.Write((const unsigned char*)&f, sizeof(f));
144  if (fstat(f, &sb) == 0) hasher << sb;
145  do {
146  n = read(f, fbuf, sizeof(fbuf));
147  if (n > 0) hasher.Write(fbuf, n);
148  total += n;
149  /* not bothering with EINTR handling. */
150  } while (n == sizeof(fbuf) && total < 1048576); // Read only the first 1 Mbyte
151  close(f);
152  }
153 }
154 
155 void AddPath(CSHA512& hasher, const char *path)
156 {
157  struct stat sb = {};
158  if (stat(path, &sb) == 0) {
159  hasher.Write((const unsigned char*)path, strlen(path) + 1);
160  hasher << sb;
161  }
162 }
163 #endif
164 
165 #if HAVE_SYSCTL
166 template<int... S>
167 void AddSysctl(CSHA512& hasher)
168 {
169  int CTL[sizeof...(S)] = {S...};
170  unsigned char buffer[65536];
171  size_t siz = 65536;
172  int ret = sysctl(CTL, sizeof...(S), buffer, &siz, nullptr, 0);
173  if (ret == 0 || (ret == -1 && errno == ENOMEM)) {
174  hasher << sizeof(CTL);
175  hasher.Write((const unsigned char*)CTL, sizeof(CTL));
176  if (siz > sizeof(buffer)) siz = sizeof(buffer);
177  hasher << siz;
178  hasher.Write(buffer, siz);
179  }
180 }
181 #endif
182 
183 #ifdef HAVE_GETCPUID
184 void inline AddCPUID(CSHA512& hasher, uint32_t leaf, uint32_t subleaf, uint32_t& ax, uint32_t& bx, uint32_t& cx, uint32_t& dx)
185 {
186  GetCPUID(leaf, subleaf, ax, bx, cx, dx);
187  hasher << leaf << subleaf << ax << bx << cx << dx;
188 }
189 
190 void AddAllCPUID(CSHA512& hasher)
191 {
192  uint32_t ax, bx, cx, dx;
193  // Iterate over all standard leaves
194  AddCPUID(hasher, 0, 0, ax, bx, cx, dx); // Returns max leaf in ax
195  uint32_t max = ax;
196  for (uint32_t leaf = 1; leaf <= max && leaf <= 0xFF; ++leaf) {
197  uint32_t maxsub = 0;
198  for (uint32_t subleaf = 0; subleaf <= 0xFF; ++subleaf) {
199  AddCPUID(hasher, leaf, subleaf, ax, bx, cx, dx);
200  // Iterate subleafs for leaf values 4, 7, 11, 13
201  if (leaf == 4) {
202  if ((ax & 0x1f) == 0) break;
203  } else if (leaf == 7) {
204  if (subleaf == 0) maxsub = ax;
205  if (subleaf == maxsub) break;
206  } else if (leaf == 11) {
207  if ((cx & 0xff00) == 0) break;
208  } else if (leaf == 13) {
209  if (ax == 0 && bx == 0 && cx == 0 && dx == 0) break;
210  } else {
211  // For any other leaf, stop after subleaf 0.
212  break;
213  }
214  }
215  }
216  // Iterate over all extended leaves
217  AddCPUID(hasher, 0x80000000, 0, ax, bx, cx, dx); // Returns max extended leaf in ax
218  uint32_t ext_max = ax;
219  for (uint32_t leaf = 0x80000001; leaf <= ext_max && leaf <= 0x800000FF; ++leaf) {
220  AddCPUID(hasher, leaf, 0, ax, bx, cx, dx);
221  }
222 }
223 #endif
224 } // namespace
225 
227 {
228  RandAddSeedPerfmon(hasher);
229 
230  // Various clocks
231 #ifdef WIN32
232  FILETIME ftime;
233  GetSystemTimeAsFileTime(&ftime);
234  hasher << ftime;
235 #else
236  struct timespec ts = {};
237 # ifdef CLOCK_MONOTONIC
238  clock_gettime(CLOCK_MONOTONIC, &ts);
239  hasher << ts;
240 # endif
241 # ifdef CLOCK_REALTIME
242  clock_gettime(CLOCK_REALTIME, &ts);
243  hasher << ts;
244 # endif
245 # ifdef CLOCK_BOOTTIME
246  clock_gettime(CLOCK_BOOTTIME, &ts);
247  hasher << ts;
248 # endif
249  // gettimeofday is available on all UNIX systems, but only has microsecond precision.
250  struct timeval tv = {};
251  gettimeofday(&tv, nullptr);
252  hasher << tv;
253 #endif
254  // Probably redundant, but also use all the clocks C++11 provides:
255  hasher << std::chrono::system_clock::now().time_since_epoch().count();
256  hasher << std::chrono::steady_clock::now().time_since_epoch().count();
257  hasher << std::chrono::high_resolution_clock::now().time_since_epoch().count();
258 
259 #ifndef WIN32
260  // Current resource usage.
261  struct rusage usage = {};
262  if (getrusage(RUSAGE_SELF, &usage) == 0) hasher << usage;
263 #endif
264 
265 #ifdef __linux__
266  AddFile(hasher, "/proc/diskstats");
267  AddFile(hasher, "/proc/vmstat");
268  AddFile(hasher, "/proc/schedstat");
269  AddFile(hasher, "/proc/zoneinfo");
270  AddFile(hasher, "/proc/meminfo");
271  AddFile(hasher, "/proc/softirqs");
272  AddFile(hasher, "/proc/stat");
273  AddFile(hasher, "/proc/self/schedstat");
274  AddFile(hasher, "/proc/self/status");
275 #endif
276 
277 #if HAVE_SYSCTL
278 # ifdef CTL_KERN
279 # if defined(KERN_PROC) && defined(KERN_PROC_ALL)
280  AddSysctl<CTL_KERN, KERN_PROC, KERN_PROC_ALL>(hasher);
281 # endif
282 # endif
283 # ifdef CTL_HW
284 # ifdef HW_DISKSTATS
285  AddSysctl<CTL_HW, HW_DISKSTATS>(hasher);
286 # endif
287 # endif
288 # ifdef CTL_VM
289 # ifdef VM_LOADAVG
290  AddSysctl<CTL_VM, VM_LOADAVG>(hasher);
291 # endif
292 # ifdef VM_TOTAL
293  AddSysctl<CTL_VM, VM_TOTAL>(hasher);
294 # endif
295 # ifdef VM_METER
296  AddSysctl<CTL_VM, VM_METER>(hasher);
297 # endif
298 # endif
299 #endif
300 
301  // Stack and heap location
302  void* addr = malloc(4097);
303  hasher << &addr << addr;
304  free(addr);
305 }
306 
308 {
309  // Some compile-time static properties
310  hasher << (CHAR_MIN < 0) << sizeof(void*) << sizeof(long) << sizeof(int);
311 #if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
312  hasher << __GNUC__ << __GNUC_MINOR__ << __GNUC_PATCHLEVEL__;
313 #endif
314 #ifdef _MSC_VER
315  hasher << _MSC_VER;
316 #endif
317  hasher << __cplusplus;
318 #ifdef _XOPEN_VERSION
319  hasher << _XOPEN_VERSION;
320 #endif
321 #ifdef __VERSION__
322  const char* COMPILER_VERSION = __VERSION__;
323  hasher.Write((const unsigned char*)COMPILER_VERSION, strlen(COMPILER_VERSION) + 1);
324 #endif
325 
326  // Bitcoin client version
327  hasher << CLIENT_VERSION;
328 
329 #ifdef __linux__
330  // Information available through getauxval()
331 # ifdef AT_HWCAP
332  hasher << getauxval(AT_HWCAP);
333 # endif
334 # ifdef AT_HWCAP2
335  hasher << getauxval(AT_HWCAP2);
336 # endif
337 # ifdef AT_RANDOM
338  const unsigned char* random_aux = (const unsigned char*)getauxval(AT_RANDOM);
339  if (random_aux) hasher.Write(random_aux, 16);
340 # endif
341 # ifdef AT_PLATFORM
342  const char* platform_str = (const char*)getauxval(AT_PLATFORM);
343  if (platform_str) hasher.Write((const unsigned char*)platform_str, strlen(platform_str) + 1);
344 # endif
345 # ifdef AT_EXECFN
346  const char* exec_str = (const char*)getauxval(AT_EXECFN);
347  if (exec_str) hasher.Write((const unsigned char*)exec_str, strlen(exec_str) + 1);
348 # endif
349 #endif // __linux__
350 
351 #ifdef HAVE_GETCPUID
352  AddAllCPUID(hasher);
353 #endif
354 
355  // Memory locations
356  hasher << &hasher << &RandAddStaticEnv << &malloc << &errno << &environ;
357 
358  // Hostname
359  char hname[256];
360  if (gethostname(hname, 256) == 0) {
361  hasher.Write((const unsigned char*)hname, strnlen(hname, 256));
362  }
363 
364 #if HAVE_DECL_GETIFADDRS
365  // Network interfaces
366  struct ifaddrs *ifad = NULL;
367  getifaddrs(&ifad);
368  struct ifaddrs *ifit = ifad;
369  while (ifit != NULL) {
370  hasher.Write((const unsigned char*)&ifit, sizeof(ifit));
371  hasher.Write((const unsigned char*)ifit->ifa_name, strlen(ifit->ifa_name) + 1);
372  hasher.Write((const unsigned char*)&ifit->ifa_flags, sizeof(ifit->ifa_flags));
373  AddSockaddr(hasher, ifit->ifa_addr);
374  AddSockaddr(hasher, ifit->ifa_netmask);
375  AddSockaddr(hasher, ifit->ifa_dstaddr);
376  ifit = ifit->ifa_next;
377  }
378  freeifaddrs(ifad);
379 #endif
380 
381 #ifndef WIN32
382  // UNIX kernel information
383  struct utsname name;
384  if (uname(&name) != -1) {
385  hasher.Write((const unsigned char*)&name.sysname, strlen(name.sysname) + 1);
386  hasher.Write((const unsigned char*)&name.nodename, strlen(name.nodename) + 1);
387  hasher.Write((const unsigned char*)&name.release, strlen(name.release) + 1);
388  hasher.Write((const unsigned char*)&name.version, strlen(name.version) + 1);
389  hasher.Write((const unsigned char*)&name.machine, strlen(name.machine) + 1);
390  }
391 
392  /* Path and filesystem provided data */
393  AddPath(hasher, "/");
394  AddPath(hasher, ".");
395  AddPath(hasher, "/tmp");
396  AddPath(hasher, "/home");
397  AddPath(hasher, "/proc");
398 #ifdef __linux__
399  AddFile(hasher, "/proc/cmdline");
400  AddFile(hasher, "/proc/cpuinfo");
401  AddFile(hasher, "/proc/version");
402 #endif
403  AddFile(hasher, "/etc/passwd");
404  AddFile(hasher, "/etc/group");
405  AddFile(hasher, "/etc/hosts");
406  AddFile(hasher, "/etc/resolv.conf");
407  AddFile(hasher, "/etc/timezone");
408  AddFile(hasher, "/etc/localtime");
409 #endif
410 
411  // For MacOS/BSDs, gather data through sysctl instead of /proc. Not all of these
412  // will exist on every system.
413 #if HAVE_SYSCTL
414 # ifdef CTL_HW
415 # ifdef HW_MACHINE
416  AddSysctl<CTL_HW, HW_MACHINE>(hasher);
417 # endif
418 # ifdef HW_MODEL
419  AddSysctl<CTL_HW, HW_MODEL>(hasher);
420 # endif
421 # ifdef HW_NCPU
422  AddSysctl<CTL_HW, HW_NCPU>(hasher);
423 # endif
424 # ifdef HW_PHYSMEM
425  AddSysctl<CTL_HW, HW_PHYSMEM>(hasher);
426 # endif
427 # ifdef HW_USERMEM
428  AddSysctl<CTL_HW, HW_USERMEM>(hasher);
429 # endif
430 # ifdef HW_MACHINE_ARCH
431  AddSysctl<CTL_HW, HW_MACHINE_ARCH>(hasher);
432 # endif
433 # ifdef HW_REALMEM
434  AddSysctl<CTL_HW, HW_REALMEM>(hasher);
435 # endif
436 # ifdef HW_CPU_FREQ
437  AddSysctl<CTL_HW, HW_CPU_FREQ>(hasher);
438 # endif
439 # ifdef HW_BUS_FREQ
440  AddSysctl<CTL_HW, HW_BUS_FREQ>(hasher);
441 # endif
442 # ifdef HW_CACHELINE
443  AddSysctl<CTL_HW, HW_CACHELINE>(hasher);
444 # endif
445 # endif
446 # ifdef CTL_KERN
447 # ifdef KERN_BOOTFILE
448  AddSysctl<CTL_KERN, KERN_BOOTFILE>(hasher);
449 # endif
450 # ifdef KERN_BOOTTIME
451  AddSysctl<CTL_KERN, KERN_BOOTTIME>(hasher);
452 # endif
453 # ifdef KERN_CLOCKRATE
454  AddSysctl<CTL_KERN, KERN_CLOCKRATE>(hasher);
455 # endif
456 # ifdef KERN_HOSTID
457  AddSysctl<CTL_KERN, KERN_HOSTID>(hasher);
458 # endif
459 # ifdef KERN_HOSTUUID
460  AddSysctl<CTL_KERN, KERN_HOSTUUID>(hasher);
461 # endif
462 # ifdef KERN_HOSTNAME
463  AddSysctl<CTL_KERN, KERN_HOSTNAME>(hasher);
464 # endif
465 # ifdef KERN_OSRELDATE
466  AddSysctl<CTL_KERN, KERN_OSRELDATE>(hasher);
467 # endif
468 # ifdef KERN_OSRELEASE
469  AddSysctl<CTL_KERN, KERN_OSRELEASE>(hasher);
470 # endif
471 # ifdef KERN_OSREV
472  AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
473 # endif
474 # ifdef KERN_OSTYPE
475  AddSysctl<CTL_KERN, KERN_OSTYPE>(hasher);
476 # endif
477 # ifdef KERN_POSIX1
478  AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
479 # endif
480 # ifdef KERN_VERSION
481  AddSysctl<CTL_KERN, KERN_VERSION>(hasher);
482 # endif
483 # endif
484 #endif
485 
486  // Env variables
487  if (environ) {
488  for (size_t i = 0; environ[i]; ++i) {
489  hasher.Write((const unsigned char*)environ[i], strlen(environ[i]));
490  }
491  }
492 
493  // Process, thread, user, session, group, ... ids.
494 #ifdef WIN32
495  hasher << GetCurrentProcessId() << GetCurrentThreadId();
496 #else
497  hasher << getpid() << getppid() << getsid(0) << getpgid(0) << getuid() << geteuid() << getgid() << getegid();
498 #endif
499  hasher << std::this_thread::get_id();
500 }
const std::chrono::seconds now
char ** environ
Necessary on some platforms.
std::ostream & operator<<(std::ostream &os, BigO const &bigO)
void memory_cleanse(void *ptr, size_t len)
Secure overwrite a buffer (possibly containing secret data) with zero-bytes.
Definition: cleanse.cpp:14
size_t strnlen(const char *start, size_t max_len)
Definition: strnlen.cpp:12
CSHA512 & Write(const unsigned char *data, size_t len)
Definition: sha512.cpp:159
A hasher class for SHA-512.
Definition: sha512.h:12
void RandAddStaticEnv(CSHA512 &hasher)
Gather non-cryptographic environment data that does not change over time.
Definition: randomenv.cpp:307
static const int CLIENT_VERSION
bitcoind-res.rc includes this file, but it cannot cope with real c++ code.
Definition: clientversion.h:38
void RandAddDynamicEnv(CSHA512 &hasher)
Gather non-cryptographic environment data that changes over time.
Definition: randomenv.cpp:226