Add most of libsec.
diff --git a/src/libsec/port/prng.c b/src/libsec/port/prng.c
new file mode 100644
index 0000000..fc2e508
--- /dev/null
+++ b/src/libsec/port/prng.c
@@ -0,0 +1,15 @@
+#include "os.h"
+#include <mp.h>
+#include <libsec.h>
+
+//
+//  just use the libc prng to fill a buffer
+//
+void
+prng(uchar *p, int n)
+{
+	uchar *e;
+
+	for(e = p+n; p < e; p++)
+		*p = rand();
+}