moved type and constants for random data to include file;

added consistency check in random; added source of randomness
internal to random using timing; only retrieve random bins that are full.

lib/sysutil/Makefile.in

@@ -10,6 +10,7 @@ libsys_FILES=" \
 	kprintf.c \
 	kputc.c \
 	tickdelay.c \
+	get_randomness.c \
 	getuptime.c \
 	getuptime2.c \
 	env_get_prm.c \

lib/sysutil/get_randomness.c

@@ -0,0 +1,34 @@
+#include <lib.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+#include <minix/profile.h>
+#include <minix/syslib.h>
+#include <minix/type.h>
+#include <minix/sysutil.h>
+
+/*===========================================================================*
+ *                              get_randomness                               *
+ *===========================================================================*/
+PUBLIC void get_randomness(rand, source)
+struct k_randomness *rand;
+int source;
+{
+/* Use architecture-dependent high-resolution clock for
+ * raw entropy gathering.
+ */
+  int r_next;
+  unsigned long tsc_high, tsc_low;
+ 
+  source %= RANDOM_SOURCES;
+  r_next= rand->bin[source].r_next;  
+  read_tsc(&tsc_high, &tsc_low);  
+  rand->bin[source].r_buf[r_next] = tsc_low;  
+  if (rand->bin[source].r_size < RANDOM_ELEMENTS) {  
+        rand->bin[source].r_size ++;  
+  }
+  rand->bin[source].r_next = (r_next + 1 ) % RANDOM_ELEMENTS;  
+} 
+  
+