Add cn-filter.sh script for OpenVPN server

cn-filter.sh

@@ -0,0 +1,26 @@
+#!/bin/sh
+#
+# cn-filter.sh is a client-connect script for OpenVPN server
+# It allow clients to connect only if their CN is in $AUTH_FILE
+#
+# You need this parameters in your's server config :
+#
+# script-security 3
+# client-connect <path-to-cn-filter>/cn-filter.sh
+#
+
+set -eu
+
+DATE="$(date +'%b %d %H:%M:%S')"
+LOG_FILE="/var/log/openvpn/auth.log"
+AUTH_FILE="/etc/openvpn/authorized_cns"
+
+grep -qE "^${common_name}$" "${AUTH_FILE}"
+if [ "$?" -eq 0 ]; then
+        echo "${DATE} - Accepted login for ${common_name} from ${trusted_ip} port ${trusted_port}" >> "${LOG_FILE}"
+        exit 0
+else
+        echo "${DATE} - Failed login for ${common_name} from ${trusted_ip} port ${trusted_port}" >> "${LOG_FILE}"
+fi
+
+exit 1