/ src / randomenv.cpp
randomenv.cpp
  1  // Copyright (c) 2009-2010 Satoshi Nakamoto
  2  // Copyright (c) 2009-2022 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  #include <bitcoin-build-config.h> // IWYU pragma: keep
  7  
  8  #include <randomenv.h>
  9  
 10  #include <clientversion.h>
 11  #include <compat/compat.h>
 12  #include <compat/cpuid.h>
 13  #include <crypto/sha512.h>
 14  #include <span.h>
 15  #include <support/cleanse.h>
 16  #include <util/time.h>
 17  
 18  #include <algorithm>
 19  #include <atomic>
 20  #include <cstdint>
 21  #include <cstring>
 22  #include <chrono>
 23  #include <climits>
 24  #include <thread>
 25  #include <vector>
 26  
 27  #include <sys/types.h> // must go before a number of other headers
 28  
 29  #ifdef WIN32
 30  #include <windows.h>
 31  #else
 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 && HAVE_DECL_FREEIFADDRS
 42  #include <ifaddrs.h>
 43  #endif
 44  #ifdef HAVE_SYSCTL
 45  #include <sys/sysctl.h>
 46  #ifdef HAVE_VM_VM_PARAM_H
 47  #include <vm/vm_param.h>
 48  #endif
 49  #ifdef HAVE_SYS_RESOURCES_H
 50  #include <sys/resources.h>
 51  #endif
 52  #ifdef HAVE_SYS_VMMETER_H
 53  #include <sys/vmmeter.h>
 54  #endif
 55  #endif
 56  #if defined(HAVE_STRONG_GETAUXVAL)
 57  #include <sys/auxv.h>
 58  #endif
 59  
 60  #ifndef _MSC_VER
 61  extern char** environ; // NOLINT(readability-redundant-declaration): Necessary on some platforms
 62  #endif
 63  
 64  namespace {
 65  
 66  /** Helper to easily feed data into a CSHA512.
 67   *
 68   * Note that this does not serialize the passed object (like stream.h's << operators do).
 69   * Its raw memory representation is used directly.
 70   */
 71  template<typename T>
 72  CSHA512& operator<<(CSHA512& hasher, const T& data) {
 73      static_assert(!std::is_same_v<std::decay_t<T>, char*>, "Calling operator<<(CSHA512, char*) is probably not what you want");
 74      static_assert(!std::is_same_v<std::decay_t<T>, unsigned char*>, "Calling operator<<(CSHA512, unsigned char*) is probably not what you want");
 75      static_assert(!std::is_same_v<std::decay_t<T>, const char*>, "Calling operator<<(CSHA512, const char*) is probably not what you want");
 76      static_assert(!std::is_same_v<std::decay_t<T>, const unsigned char*>, "Calling operator<<(CSHA512, const unsigned char*) is probably not what you want");
 77      hasher.Write((const unsigned char*)&data, sizeof(data));
 78      return hasher;
 79  }
 80  
 81  #ifndef WIN32
 82  void AddSockaddr(CSHA512& hasher, const struct sockaddr *addr)
 83  {
 84      if (addr == nullptr) return;
 85      switch (addr->sa_family) {
 86      case AF_INET:
 87          hasher.Write((const unsigned char*)addr, sizeof(sockaddr_in));
 88          break;
 89      case AF_INET6:
 90          hasher.Write((const unsigned char*)addr, sizeof(sockaddr_in6));
 91          break;
 92      default:
 93          hasher.Write((const unsigned char*)&addr->sa_family, sizeof(addr->sa_family));
 94      }
 95  }
 96  
 97  void AddFile(CSHA512& hasher, const char *path)
 98  {
 99      struct stat sb = {};
100      int f = open(path, O_RDONLY);
101      size_t total = 0;
102      if (f != -1) {
103          unsigned char fbuf[4096];
104          int n;
105          hasher.Write((const unsigned char*)&f, sizeof(f));
106          if (fstat(f, &sb) == 0) hasher << sb;
107          do {
108              n = read(f, fbuf, sizeof(fbuf));
109              if (n > 0) hasher.Write(fbuf, n);
110              total += n;
111              /* not bothering with EINTR handling. */
112          } while (n == sizeof(fbuf) && total < 1048576); // Read only the first 1 Mbyte
113          close(f);
114      }
115  }
116  
117  void AddPath(CSHA512& hasher, const char *path)
118  {
119      struct stat sb = {};
120      if (stat(path, &sb) == 0) {
121          hasher.Write((const unsigned char*)path, strlen(path) + 1);
122          hasher << sb;
123      }
124  }
125  #endif
126  
127  #ifdef HAVE_SYSCTL
128  template<int... S>
129  void AddSysctl(CSHA512& hasher)
130  {
131      int CTL[sizeof...(S)] = {S...};
132      unsigned char buffer[65536];
133      size_t siz = 65536;
134      int ret = sysctl(CTL, sizeof...(S), buffer, &siz, nullptr, 0);
135      if (ret == 0 || (ret == -1 && errno == ENOMEM)) {
136          hasher << sizeof(CTL);
137          hasher.Write((const unsigned char*)CTL, sizeof(CTL));
138          if (siz > sizeof(buffer)) siz = sizeof(buffer);
139          hasher << siz;
140          hasher.Write(buffer, siz);
141      }
142  }
143  #endif
144  
145  #ifdef HAVE_GETCPUID
146  void inline AddCPUID(CSHA512& hasher, uint32_t leaf, uint32_t subleaf, uint32_t& ax, uint32_t& bx, uint32_t& cx, uint32_t& dx)
147  {
148      GetCPUID(leaf, subleaf, ax, bx, cx, dx);
149      hasher << leaf << subleaf << ax << bx << cx << dx;
150  }
151  
152  void AddAllCPUID(CSHA512& hasher)
153  {
154      uint32_t ax, bx, cx, dx;
155      // Iterate over all standard leaves
156      AddCPUID(hasher, 0, 0, ax, bx, cx, dx); // Returns max leaf in ax
157      uint32_t max = ax;
158      for (uint32_t leaf = 1; leaf <= max && leaf <= 0xFF; ++leaf) {
159          uint32_t maxsub = 0;
160          for (uint32_t subleaf = 0; subleaf <= 0xFF; ++subleaf) {
161              AddCPUID(hasher, leaf, subleaf, ax, bx, cx, dx);
162              // Iterate subleafs for leaf values 4, 7, 11, 13
163              if (leaf == 4) {
164                  if ((ax & 0x1f) == 0) break;
165              } else if (leaf == 7) {
166                  if (subleaf == 0) maxsub = ax;
167                  if (subleaf == maxsub) break;
168              } else if (leaf == 11) {
169                  if ((cx & 0xff00) == 0) break;
170              } else if (leaf == 13) {
171                  if (ax == 0 && bx == 0 && cx == 0 && dx == 0) break;
172              } else {
173                  // For any other leaf, stop after subleaf 0.
174                  break;
175              }
176          }
177      }
178      // Iterate over all extended leaves
179      AddCPUID(hasher, 0x80000000, 0, ax, bx, cx, dx); // Returns max extended leaf in ax
180      uint32_t ext_max = ax;
181      for (uint32_t leaf = 0x80000001; leaf <= ext_max && leaf <= 0x800000FF; ++leaf) {
182          AddCPUID(hasher, leaf, 0, ax, bx, cx, dx);
183      }
184  }
185  #endif
186  } // namespace
187  
188  void RandAddDynamicEnv(CSHA512& hasher)
189  {
190      // Various clocks
191  #ifdef WIN32
192      FILETIME ftime;
193      GetSystemTimeAsFileTime(&ftime);
194      hasher << ftime;
195  #else
196      struct timespec ts = {};
197  #    ifdef CLOCK_MONOTONIC
198      clock_gettime(CLOCK_MONOTONIC, &ts);
199      hasher << ts;
200  #    endif
201  #    ifdef CLOCK_REALTIME
202      clock_gettime(CLOCK_REALTIME, &ts);
203      hasher << ts;
204  #    endif
205  #    ifdef CLOCK_BOOTTIME
206      clock_gettime(CLOCK_BOOTTIME, &ts);
207      hasher << ts;
208  #    endif
209      // gettimeofday is available on all UNIX systems, but only has microsecond precision.
210      struct timeval tv = {};
211      gettimeofday(&tv, nullptr);
212      hasher << tv;
213  #endif
214      // Probably redundant, but also use all the standard library clocks:
215      hasher << std::chrono::system_clock::now().time_since_epoch().count();
216      hasher << std::chrono::steady_clock::now().time_since_epoch().count();
217      hasher << std::chrono::high_resolution_clock::now().time_since_epoch().count();
218  
219  #ifndef WIN32
220      // Current resource usage.
221      struct rusage usage = {};
222      if (getrusage(RUSAGE_SELF, &usage) == 0) hasher << usage;
223  #endif
224  
225  #ifdef __linux__
226      AddFile(hasher, "/proc/diskstats");
227      AddFile(hasher, "/proc/vmstat");
228      AddFile(hasher, "/proc/schedstat");
229      AddFile(hasher, "/proc/zoneinfo");
230      AddFile(hasher, "/proc/meminfo");
231      AddFile(hasher, "/proc/softirqs");
232      AddFile(hasher, "/proc/stat");
233      AddFile(hasher, "/proc/self/schedstat");
234      AddFile(hasher, "/proc/self/status");
235  #endif
236  
237  #ifdef HAVE_SYSCTL
238  #  ifdef CTL_KERN
239  #    if defined(KERN_PROC) && defined(KERN_PROC_ALL)
240      AddSysctl<CTL_KERN, KERN_PROC, KERN_PROC_ALL>(hasher);
241  #    endif
242  #  endif
243  #  ifdef CTL_HW
244  #    ifdef HW_DISKSTATS
245      AddSysctl<CTL_HW, HW_DISKSTATS>(hasher);
246  #    endif
247  #  endif
248  #  ifdef CTL_VM
249  #    ifdef VM_LOADAVG
250      AddSysctl<CTL_VM, VM_LOADAVG>(hasher);
251  #    endif
252  #    ifdef VM_TOTAL
253      AddSysctl<CTL_VM, VM_TOTAL>(hasher);
254  #    endif
255  #    ifdef VM_METER
256      AddSysctl<CTL_VM, VM_METER>(hasher);
257  #    endif
258  #  endif
259  #endif
260  
261      // Stack and heap location
262      void* addr = malloc(4097);
263      hasher << &addr << addr;
264      free(addr);
265  }
266  
267  void RandAddStaticEnv(CSHA512& hasher)
268  {
269      // Some compile-time static properties
270      hasher << (CHAR_MIN < 0) << sizeof(void*) << sizeof(long) << sizeof(int);
271  #if defined(__GNUC__) && defined(__GNUC_MINOR__) && defined(__GNUC_PATCHLEVEL__)
272      hasher << __GNUC__ << __GNUC_MINOR__ << __GNUC_PATCHLEVEL__;
273  #endif
274  #ifdef _MSC_VER
275      hasher << _MSC_VER;
276  #endif
277      hasher << __cplusplus;
278  #ifdef _XOPEN_VERSION
279      hasher << _XOPEN_VERSION;
280  #endif
281  #ifdef __VERSION__
282      const char* COMPILER_VERSION = __VERSION__;
283      hasher.Write((const unsigned char*)COMPILER_VERSION, strlen(COMPILER_VERSION) + 1);
284  #endif
285  
286      // Bitcoin client version
287      hasher << CLIENT_VERSION;
288  
289  #if defined(HAVE_STRONG_GETAUXVAL)
290      // Information available through getauxval()
291  #  ifdef AT_HWCAP
292      hasher << getauxval(AT_HWCAP);
293  #  endif
294  #  ifdef AT_HWCAP2
295      hasher << getauxval(AT_HWCAP2);
296  #  endif
297  #  ifdef AT_RANDOM
298      const unsigned char* random_aux = (const unsigned char*)getauxval(AT_RANDOM);
299      if (random_aux) hasher.Write(random_aux, 16);
300  #  endif
301  #  ifdef AT_PLATFORM
302      const char* platform_str = (const char*)getauxval(AT_PLATFORM);
303      if (platform_str) hasher.Write((const unsigned char*)platform_str, strlen(platform_str) + 1);
304  #  endif
305  #  ifdef AT_EXECFN
306      const char* exec_str = (const char*)getauxval(AT_EXECFN);
307      if (exec_str) hasher.Write((const unsigned char*)exec_str, strlen(exec_str) + 1);
308  #  endif
309  #endif // HAVE_STRONG_GETAUXVAL
310  
311  #ifdef HAVE_GETCPUID
312      AddAllCPUID(hasher);
313  #endif
314  
315      // Memory locations
316      hasher << &hasher << &RandAddStaticEnv << &malloc << &errno << &environ;
317  
318      // Hostname
319  #ifdef WIN32
320      constexpr DWORD max_size = MAX_COMPUTERNAME_LENGTH + 1;
321      char hname[max_size];
322      DWORD size = max_size;
323      if (GetComputerNameA(hname, &size) != 0) {
324          hasher.Write(UCharCast(hname), size);
325      }
326  #else
327      char hname[256];
328      if (gethostname(hname, 256) == 0) {
329          hasher.Write((const unsigned char*)hname, strnlen(hname, 256));
330      }
331  #endif
332  
333  #if HAVE_DECL_GETIFADDRS && HAVE_DECL_FREEIFADDRS
334      // Network interfaces
335      struct ifaddrs *ifad = nullptr;
336      getifaddrs(&ifad);
337      struct ifaddrs *ifit = ifad;
338      while (ifit != nullptr) {
339          hasher.Write((const unsigned char*)&ifit, sizeof(ifit));
340          hasher.Write((const unsigned char*)ifit->ifa_name, strlen(ifit->ifa_name) + 1);
341          hasher.Write((const unsigned char*)&ifit->ifa_flags, sizeof(ifit->ifa_flags));
342          AddSockaddr(hasher, ifit->ifa_addr);
343          AddSockaddr(hasher, ifit->ifa_netmask);
344          AddSockaddr(hasher, ifit->ifa_dstaddr);
345          ifit = ifit->ifa_next;
346      }
347      freeifaddrs(ifad);
348  #endif
349  
350  #ifndef WIN32
351      // UNIX kernel information
352      struct utsname name;
353      if (uname(&name) != -1) {
354          hasher.Write((const unsigned char*)&name.sysname, strlen(name.sysname) + 1);
355          hasher.Write((const unsigned char*)&name.nodename, strlen(name.nodename) + 1);
356          hasher.Write((const unsigned char*)&name.release, strlen(name.release) + 1);
357          hasher.Write((const unsigned char*)&name.version, strlen(name.version) + 1);
358          hasher.Write((const unsigned char*)&name.machine, strlen(name.machine) + 1);
359      }
360  
361      /* Path and filesystem provided data */
362      AddPath(hasher, "/");
363      AddPath(hasher, ".");
364      AddPath(hasher, "/tmp");
365      AddPath(hasher, "/home");
366      AddPath(hasher, "/proc");
367  #ifdef __linux__
368      AddFile(hasher, "/proc/cmdline");
369      AddFile(hasher, "/proc/cpuinfo");
370      AddFile(hasher, "/proc/version");
371  #endif
372      AddFile(hasher, "/etc/passwd");
373      AddFile(hasher, "/etc/group");
374      AddFile(hasher, "/etc/hosts");
375      AddFile(hasher, "/etc/resolv.conf");
376      AddFile(hasher, "/etc/timezone");
377      AddFile(hasher, "/etc/localtime");
378  #endif
379  
380      // For MacOS/BSDs, gather data through sysctl instead of /proc. Not all of these
381      // will exist on every system.
382  #ifdef HAVE_SYSCTL
383  #  ifdef CTL_HW
384  #    ifdef HW_MACHINE
385      AddSysctl<CTL_HW, HW_MACHINE>(hasher);
386  #    endif
387  #    ifdef HW_MODEL
388      AddSysctl<CTL_HW, HW_MODEL>(hasher);
389  #    endif
390  #    ifdef HW_NCPU
391      AddSysctl<CTL_HW, HW_NCPU>(hasher);
392  #    endif
393  #    ifdef HW_PHYSMEM
394      AddSysctl<CTL_HW, HW_PHYSMEM>(hasher);
395  #    endif
396  #    ifdef HW_USERMEM
397      AddSysctl<CTL_HW, HW_USERMEM>(hasher);
398  #    endif
399  #    ifdef HW_MACHINE_ARCH
400      AddSysctl<CTL_HW, HW_MACHINE_ARCH>(hasher);
401  #    endif
402  #    ifdef HW_REALMEM
403      AddSysctl<CTL_HW, HW_REALMEM>(hasher);
404  #    endif
405  #    ifdef HW_CPU_FREQ
406      AddSysctl<CTL_HW, HW_CPU_FREQ>(hasher);
407  #    endif
408  #    ifdef HW_BUS_FREQ
409      AddSysctl<CTL_HW, HW_BUS_FREQ>(hasher);
410  #    endif
411  #    ifdef HW_CACHELINE
412      AddSysctl<CTL_HW, HW_CACHELINE>(hasher);
413  #    endif
414  #  endif
415  #  ifdef CTL_KERN
416  #    ifdef KERN_BOOTFILE
417       AddSysctl<CTL_KERN, KERN_BOOTFILE>(hasher);
418  #    endif
419  #    ifdef KERN_BOOTTIME
420       AddSysctl<CTL_KERN, KERN_BOOTTIME>(hasher);
421  #    endif
422  #    ifdef KERN_CLOCKRATE
423       AddSysctl<CTL_KERN, KERN_CLOCKRATE>(hasher);
424  #    endif
425  #    ifdef KERN_HOSTID
426       AddSysctl<CTL_KERN, KERN_HOSTID>(hasher);
427  #    endif
428  #    ifdef KERN_HOSTUUID
429       AddSysctl<CTL_KERN, KERN_HOSTUUID>(hasher);
430  #    endif
431  #    ifdef KERN_HOSTNAME
432       AddSysctl<CTL_KERN, KERN_HOSTNAME>(hasher);
433  #    endif
434  #    ifdef KERN_OSRELDATE
435       AddSysctl<CTL_KERN, KERN_OSRELDATE>(hasher);
436  #    endif
437  #    ifdef KERN_OSRELEASE
438       AddSysctl<CTL_KERN, KERN_OSRELEASE>(hasher);
439  #    endif
440  #    ifdef KERN_OSREV
441       AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
442  #    endif
443  #    ifdef KERN_OSTYPE
444       AddSysctl<CTL_KERN, KERN_OSTYPE>(hasher);
445  #    endif
446  #    ifdef KERN_POSIX1
447       AddSysctl<CTL_KERN, KERN_OSREV>(hasher);
448  #    endif
449  #    ifdef KERN_VERSION
450       AddSysctl<CTL_KERN, KERN_VERSION>(hasher);
451  #    endif
452  #  endif
453  #endif
454  
455      // Env variables
456      if (environ) {
457          for (size_t i = 0; environ[i]; ++i) {
458              hasher.Write((const unsigned char*)environ[i], strlen(environ[i]));
459          }
460      }
461  
462      // Process, thread, user, session, group, ... ids.
463  #ifdef WIN32
464      hasher << GetCurrentProcessId() << GetCurrentThreadId();
465  #else
466      hasher << getpid() << getppid() << getsid(0) << getpgid(0) << getuid() << geteuid() << getgid() << getegid();
467  #endif
468      hasher << std::this_thread::get_id();
469  }