This allows an OpenVPN client to bypass a firewall which is aware of the protocol and is able to block it.
The XOR mask set on the server has to be the same on the client, otherwise it will not be able to connect with certain obfuscation modes.
A special OpenVPN client built with the "XOR patch" is required in order to use this function, because it has never been merged in the official OpenVPN repository.
Two parameters are added to the server configuration: "OpenVPNObfuscationMethod" and "OpenVPNObfuscationMask".
Their value can be retrieved with "OpenVpnObfuscationGet" and set with "OpenVpnObfuscationEnable" in the VPN Command Line Management Utility.
With server certificate validation enabled, vpnclient unconditionally
stopped connection on untrusted server certificate. Added account
configuration parameter to retry connection if server certivicate failed
validation.
On startup client creates TUN interface in UP state and kept it UP even
if connection to the server was lost. Creating interface in DOWN state,
turning it UP on successful (re-)connection to server and DOWN on either
disconnect or connection loss would enable DHCP client (say dhclient5)
to detect necessity for lease renewal.
Added a client configuration parameter to create TUN interface in DOWN
state and commands to enable, disable, and query the configuration
parameter.
Enabling the parameter causes client to put all unused TUN interfaces
DOWN, create new TUN interfaces in DOWN state, and turn TUN interfaces
corresponding to active sessions DOWN on connection loss or
disconnecting from server.
Disabling the parameter forces client to turn all TUN interfaces UP and
create new TUN interfaces in UP state.
Default value is 'Disable'.
