--auth-user-pass [up]
Authenticate with server using username/password. up is a file containing username/password on 2 lines (Note: OpenVPN will only read passwords from a file if it has been built with the --enable-password-save configure option, or on Windows by defining ENABLE_PASSWORD_SAVE in config-win32.h).

If up is omitted, username/password will be prompted from the console.

The server configuration must specify an --auth-user-pass-verify script to verify the username/password provided by the client.