update openvpn variables

Notes about security: https://blog.g3rt.nl/openvpn-security-tips.html
Check privacy: http://witch.valdikss.org.ru/

vars/defaults.yml

 tarsnap_version: 1.0.36.1
 
 # vpn
+# Notes about security: https://blog.g3rt.nl/openvpn-security-tips.html
+# Check privacy: http://witch.valdikss.org.ru/
 # openvpn_key_country: (required)
 # openvpn_key_province: (required)
 # openvpn_key_city: (required)
 openvpn_days_valid: "1825"
 openssl_request_subject: "/C={{ openvpn_key_country }}/ST={{ openvpn_key_province }}/L={{ openvpn_key_city }}/O={{ openvpn_key_org }}/OU={{ openvpn_key_ou }}"
 openvpn_key_size: "2048"
-openvpn_cipher: "BF-CBC"
-openvpn_auth_digest: "SHA1"
+openvpn_cipher: "AES-256-CBC"
+openvpn_auth_digest: "SHA512"
 openvpn_path: "/etc/openvpn"
 openvpn_ca: "{{ openvpn_path }}/ca"
 openvpn_dhparam: "{{ openvpn_path }}/dh{{ openvpn_key_size }}.pem"
 openvpn_server: "{{ domain }}"
 openvpn_port: "1194"
 openvpn_protocol: "udp"
+openvpn_mtu: "1300"
+openvpn_verb: "3" # "0" for anonymity
+# uncomment for openvpn 2.3.3 and >2.3.4
+openvpn_tls_version_min: "" # "tls-version-min 1.2"
+openvpn_tls_cipher: "" # "tls-cipher TLS-ECDHE-RSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-ECDSA-WITH-AES-128-GCM-SHA256:TLS-ECDHE-RSA-WITH-AES-256-GCM-SHA384:TLS-DHE-RSA-WITH-AES-256-CBC-SHA256"
 # openvpn_clients: (required)
 
 # webmail