Consolidate the non-canonical epoch timers, like cpuid and Win32's

QueryPerformanceCounter, into an entropy source hres_timer. Its
results, if any, do not count as contributing entropy to the poll.

Convert the other (monotonic/fixed epoch) timers to a single function
get_nanoseconds_clock(), living in time.h, which statically chooses
the 'best' timer type (clock_gettime, gettimeofday, std::clock, in
that order depending on what is available). Add feature test macros
for clock_gettime and gettimeofday.

Remove the Timer class and timer.h. Remove the Timer& argument to the
algorithm benchmark function.

1 files changed, 70 insertions, 0 deletions

diff --git a/src/entropy/hres_timer/hres_timer.cpp b/src/entropy/hres_timer/hres_timer.cpp
new file mode 100644
index 000000000..74ea801c4
--- /dev/null
+++ b/src/entropy/hres_timer/hres_timer.cpp
@@ -0,0 +1,70 @@
+/*
+* High Resolution Timestamp Entropy Source
+* (C) 1999-2009 Jack Lloyd
+*
+* Distributed under the terms of the Botan license
+*/
+
+#include <botan/hres_timer.h>
+#include <botan/cpuid.h>
+#include <botan/time.h>
+
+#if defined(BOTAN_TARGET_OS_IS_WINDOWS)
+  #include <windows.h>
+#endif
+
+namespace Botan {
+
+/*
+* Get the timestamp
+*/
+void High_Resolution_Timestamp::poll(Entropy_Accumulator& accum)
+   {
+   // If Windows, grab the Performance Counter (usually TSC or PIT)
+#if defined(BOTAN_TARGET_OS_IS_WINDOWS)
+   LARGE_INTEGER tv;
+   ::QueryPerformanceCounter(&tv);
+   accum.add(tv.QuadPart, 0);
+#endif
+
+#if defined(BOTAN_USE_GCC_INLINE_ASM)
+
+   u64bit rtc = 0;
+
+#if defined(BOTAN_TARGET_ARCH_IS_IA32) || defined(BOTAN_TARGET_ARCH_IS_AMD64)
+   if(CPUID::has_rdtsc()) // not availble on all x86 CPUs
+      {
+      u32bit 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_ARCH_IS_PPC) || defined(BOTAN_TARGET_ARCH_IS_PPC64)
+   u32bit 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)
+   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
+
+   // Don't count the timestamp as contributing entropy
+   accum.add(rtc, 0);
+
+#endif
+   }
+
+}