Initial version, with no update possibility

sanitychecks.php

@@ -0,0 +1,38 @@
+<?php
+require_once 'config.php';
+
+if (!in_array($encryptionAlg, mcrypt_list_algorithms()))
+{
+	echo "Cipher set in config.php is not supported by your mcrypt installation.";
+	exit;
+}
+
+if (!in_array('ecb', mcrypt_list_modes()))
+{
+	echo "ECB mode is not supported by your mcrypt installation.";
+	exit;
+}
+
+// Check if the key is under the server's DOCUMENT_ROOT. If so, we won't allow
+// to use it.
+if (!$keyInDocroot && (substr($masterKey, 0, strlen($_SERVER['DOCUMENT_ROOT'])) == $_SERVER['DOCUMENT_ROOT']))
+{
+	echo "Your key may be compromised, as it is downloadable!";
+	exit;
+}
+
+// Check if the key can be read by anyone other than the web server user.
+// However, this is still not secure enough in a multi-hosting environment!
+$perm = fileperms($masterKey);
+if (($perm & 0x20) || ($perm & 0x2))
+{
+	echo "Your key may be compromised as its file permissions are not strict enough!";
+	exit;
+}
+
+// Check if the key itself is readable be us.
+if (!is_readable($masterKey))
+{
+	echo "The master key is not readable by the server.";
+	exit;
+}