--- a/util/random.lua	Sat May 18 17:45:20 2019 +0200
+++ b/util/random.lua	Sat May 18 17:28:21 2019 +0200
@@ -12,7 +12,11 @@
 local urandom, urandom_err = io.open("/dev/urandom", "r");
 
 local function bytes(n)
-	return urandom:read(n);
+	local data, err = urandom:read(n);
+	if not data then
+		error("Unable to retrieve data from secure random number generator (/dev/urandom): "..err);
+	end
+	return data;
 end
 
 if not urandom then