Add explicit fork check to HMAC_RNG

Add OS functions get_process_id, get_processor_timestamp, and
get_system_timestamp_ns. HMAC_RNG uses the pid call to detect forks to
initiate a reseed. It also adds the output of all three functions (the
pid, the CPU cycle counter, and the system timestamp) into the PRF input.

Calls the new OS timer functions from hres_timer entropy source.
Removes the call to QPC in es_win32 which is mostly redundant with the
one in hres_timer.

1 files changed, 80 insertions, 4 deletions

diff --git a/src/lib/utils/os_utils.cpp b/src/lib/utils/os_utils.cpp
index ae93d58d7..bd87ca2ed 100644
--- a/src/lib/utils/os_utils.cpp
+++ b/src/lib/utils/os_utils.cpp
@@ -1,27 +1,103 @@
 /*
 * OS and machine specific utility functions
-* (C) 2015 Jack Lloyd
+* (C) 2015,2016 Jack Lloyd
 *
 * Botan is released under the Simplified BSD License (see license.txt)
 */
 
 #include <botan/internal/os_utils.h>
+#include <botan/cpuid.h>
 #include <botan/exceptn.h>
 #include <botan/mem_ops.h>
+#include <chrono>
 
-//TODO: defined(BOTAN_TARGET_OS_TYPE_IS_POSIX)
-
-#if defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK)
+#if defined(BOTAN_TARGET_OS_TYPE_IS_UNIX)
   #include <sys/types.h>
   #include <sys/mman.h>
   #include <sys/resource.h>
   #include <unistd.h>
 #endif
 
+#if defined(BOTAN_TARGET_OS_TYPE_IS_WINDOWS)
+  #include <windows.h>
+#endif
+
 namespace Botan {
 
 namespace OS {
 
+uint32_t get_process_id()
+   {
+#if defined(BOTAN_TARGET_OS_IS_UNIX)
+   return ::getpid();
+#elif defined(BOTAN_TARGET_OS_IS_WIDOWS)
+   return ::GetProcessId();
+#else
+   return 0;
+#endif
+   }
+
+uint64_t get_processor_timestamp()
+   {
+   uint64_t rtc = 0;
+
+#if defined(BOTAN_TARGET_OS_HAS_QUERY_PERF_COUNTER)
+   LARGE_INTEGER tv;
+   ::QueryPerformanceCounter(&tv);
+   rtc = tv.QuadPart;
+#endif
+
+#if defined(BOTAN_USE_GCC_INLINE_ASM)
+
+#if defined(BOTAN_TARGET_CPU_IS_X86_FAMILY)
+   if(CPUID::has_rdtsc()) // not availble on all x86 CPUs
+      {
+      uint32_t rtc_low = 0, rtc_high = 0;
+      asm volatile("rdtsc" : "=d" (rtc_high), "=a" (rtc_low));
+      rtc = (static_cast<u64bit>(rtc_high) << 32) | rtc_low;
+      }
+
+#elif defined(BOTAN_TARGET_CPU_IS_PPC_FAMILY)
+   uint32_t rtc_low = 0, rtc_high = 0;
+   asm volatile("mftbu %0; mftb %1" : "=r" (rtc_high), "=r" (rtc_low));
+   rtc = (static_cast<u64bit>(rtc_high) << 32) | rtc_low;
+
+#elif defined(BOTAN_TARGET_ARCH_IS_ALPHA)
+   asm volatile("rpcc %0" : "=r" (rtc));
+
+#elif defined(BOTAN_TARGET_ARCH_IS_SPARC64) && !defined(BOTAN_TARGET_OS_IS_OPENBSD)
+   // OpenBSD does not trap access to the %tick register
+   asm volatile("rd %%tick, %0" : "=r" (rtc));
+
+#elif defined(BOTAN_TARGET_ARCH_IS_IA64)
+   asm volatile("mov %0=ar.itc" : "=r" (rtc));
+
+#elif defined(BOTAN_TARGET_ARCH_IS_S390X)
+   asm volatile("stck 0(%0)" : : "a" (&rtc) : "memory", "cc");
+
+#elif defined(BOTAN_TARGET_ARCH_IS_HPPA)
+   asm volatile("mfctl 16,%0" : "=r" (rtc)); // 64-bit only?
+#endif
+
+#endif
+
+   return rtc;
+   }
+
+uint64_t get_system_timestamp_ns()
+   {
+#if defined(BOTAN_TARGET_OS_HAS_CLOCK_GETTIME)
+   struct timespec ts;
+   if(::clock_gettime(CLOCK_REALTIME, &ts) == 0)
+      {
+      return (static_cast<uint64_t>(ts.tv_sec) * 1000000000) + static_cast<uint64_t>(ts.tv_nsec);
+      }
+#endif
+
+   auto now = std::chrono::high_resolution_clock::now().time_since_epoch();
+   return std::chrono::duration_cast<std::chrono::nanoseconds>(now).count();
+   }
+
 size_t get_memory_locking_limit()
    {
 #if defined(BOTAN_TARGET_OS_HAS_POSIX_MLOCK)