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authorPieter Wuille <pieter.wuille@gmail.com>2019-10-26 17:14:21 -0700
committerPieter Wuille <pieter.wuille@gmail.com>2019-11-12 14:50:44 -0800
commitc2a262a78c3bcc4d5e13612ab0214874abe15de0 (patch)
treecc91016fcd06686bd9af06f21b78f49737784bcb /src/randomenv.cpp
parent723c79666770b30cce9f962bed5ece8cc7d74580 (diff)
Seed randomness with process id / thread id / various clocks
This sort of data is also used by OpenSSL.
Diffstat (limited to 'src/randomenv.cpp')
-rw-r--r--src/randomenv.cpp77
1 files changed, 77 insertions, 0 deletions
diff --git a/src/randomenv.cpp b/src/randomenv.cpp
index 529dd039b2..3f970ec330 100644
--- a/src/randomenv.cpp
+++ b/src/randomenv.cpp
@@ -13,9 +13,22 @@
#endif
#include <algorithm>
+#include <chrono>
+#include <thread>
#include <vector>
#include <stdint.h>
+#include <string.h>
+#ifndef WIN32
+#include <sys/time.h>
+#include <sys/types.h>
+#include <unistd.h>
+#endif
+#ifdef __MACH__
+#include <mach/clock.h>
+#include <mach/mach.h>
+#include <mach/mach_time.h>
+#endif
namespace {
@@ -57,13 +70,77 @@ void RandAddSeedPerfmon(CSHA512& hasher)
#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;
+}
+
} // namespace
void RandAddDynamicEnv(CSHA512& hasher)
{
RandAddSeedPerfmon(hasher);
+
+ // Various clocks
+#ifdef WIN32
+ FILETIME ftime;
+ GetSystemTimeAsFileTime(&ftime);
+ hasher << ftime;
+#else
+# ifndef __MACH__
+ // On non-MacOS systems, use various clock_gettime() calls.
+ struct timespec ts;
+# ifdef CLOCK_MONOTONIC
+ clock_gettime(CLOCK_MONOTONIC, &ts);
+ hasher << ts.tv_sec << ts.tv_nsec;
+# endif
+# ifdef CLOCK_REALTIME
+ clock_gettime(CLOCK_REALTIME, &ts);
+ hasher << ts.tv_sec << ts.tv_nsec;
+# endif
+# ifdef CLOCK_BOOTTIME
+ clock_gettime(CLOCK_BOOTTIME, &ts);
+ hasher << ts.tv_sec << ts.tv_nsec;
+# endif
+# else
+ // On MacOS use mach_absolute_time (number of CPU ticks since boot) as a replacement for CLOCK_MONOTONIC,
+ // and clock_get_time for CALENDAR_CLOCK as a replacement for CLOCK_REALTIME.
+ hasher << mach_absolute_time();
+ // From https://gist.github.com/jbenet/1087739
+ clock_serv_t cclock;
+ mach_timespec_t mts;
+ if (host_get_clock_service(mach_host_self(), CALENDAR_CLOCK, &cclock) == KERN_SUCCESS && clock_get_time(cclock, &mts) == KERN_SUCCESS) {
+ hasher << mts.tv_sec << mts.tv_nsec;
+ mach_port_deallocate(mach_task_self(), cclock);
+ }
+# endif
+ // gettimeofday is available on all UNIX systems, but only has microsecond precision.
+ struct timeval tv;
+ gettimeofday(&tv, nullptr);
+ hasher << tv.tv_sec << tv.tv_usec;
+#endif
+ // Probably redundant, but also use all the clocks C++11 provides:
+ 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();
}
void RandAddStaticEnv(CSHA512& hasher)
{
+#ifdef WIN32
+ hasher << GetCurrentProcessId() << GetCurrentThreadId();
+#else
+ hasher << getpid();
+#endif
+ hasher << std::this_thread::get_id();
}