Add support for MemUse Entropy on Windows.

Author: dgarske

wolfcrypt/src/random.c

@@ -983,6 +983,29 @@ static void Entropy_StopThread(void)
     }
 }
     /* end if defined(HAVE_PTHREAD) */
+
+#elif defined(_WIN32) /* USE_WINDOWS_API */
+
+/* Get the high resolution time counter.
+ *
+ * @return  64-bit time that is the nanoseconds of current time.
+ */
+static WC_INLINE word64 Entropy_TimeHiRes(void)
+{
+    static int           init = 0;
+    static LARGE_INTEGER freq;
+    LARGE_INTEGER        count;
+
+    if (!init) {
+        QueryPerformanceFrequency(&freq);
+        init = 1;
+    }
+
+    QueryPerformanceCounter(&count);
+
+    return (word64)(count.QuadPart / (freq.QuadPart / 1000 / 1000));
+}
+
 #else
 
 #error "No high precision time available for MemUse Entropy."
@@ -1283,7 +1306,7 @@ static int Entropy_HealthTest_Proportion(byte noise)
     }
     else {
         /* Get first value in queue - value to test. */
-        byte val = prop_samples[prop_first];
+        byte val = (byte)prop_samples[prop_first];
         /* Store new sample in queue. */
         prop_samples[prop_last] = noise;
         /* Update first index now that we have removed in from the queue. */