openvpn openwrt client config (user-pass) (key-direction)

client.conf

config openvpn 'server'
	option client '1'
	option dev 'tun'
	option proto 'udp'
	list remote 'xxx.xxx.xxx.xxx xxxx'
	option remote_cert_tls 'server'
	option ca '/etc/openvpn/server.ca'
	option cert '/etc/openvpn/client.cert'
	option key '/etc/openvpn/client.key'
	option tls_auth '/etc/openvpn/hmac.key'
	option key_direction '1'
	option auth 'SHA1'
	option auth_nocache '1'
	option auth_user_pass '/etc/openvpn/auth.txt'
	list ncp_ciphers 'AES-128-CBC'
	option nobind '1'
	option persist_key '1'
	option persist_tun '1'
	option keepalive '10 120'
	option enabled '1'