openvpn-auth-pam SYNOPSIS The openvpn-auth-pam module implements username/password authentication via PAM, and essentially allows any authentication method supported by PAM (such as LDAP, RADIUS, or Linux Shadow passwords) to be used with OpenVPN. While PAM supports username/password authentication, this can be combined with X509 certificates to provide two indepedent levels of authentication. This module uses a split privilege execution model which will function even if you drop openvpn daemon privileges using the user, group, or chroot directives. BUILD To build openvpn-auth-pam, you will need to have the pam-devel package installed. Build with the "make" command. The module will be named openvpn-auth-pam.so USAGE To use this plugin module, add to your OpenVPN config file: plugin openvpn-auth-pam.so service-type The required service-type parameter corresponds to the PAM service definition file usually found in /etc/pam.d. This plugin also supports the usage of a list of name/value pairs to answer PAM module queries. For example: plugin openvpn-auth-pam.so "login login USERNAME password PASSWORD" tells auth-pam to (a) use the "login" PAM module, (b) answer a "login" query with the username given by the OpenVPN client, and (c) answer a "password" query with the password given by the OpenVPN client. This provides flexibility in dealing with the different types of query strings which different PAM modules might generate. For example, suppose you were using a PAM module called "test" which queried for "name" rather than "login": plugin openvpn-auth-pam.so "test name USERNAME password PASSWORD" While "USERNAME" "COMMONNAME" and "PASSWORD" are special strings which substitute to client-supplied values, it is also possible to name literal values to use as PAM module query responses. For example, suppose that the login module queried for a third parameter, "domain" which is to be answered with the constant value "mydomain.com": plugin openvpn-auth-pam.so "login login USERNAME password PASSWORD domain mydomain.com" The following OpenVPN directives can also influence the operation of this plugin: client-cert-not-required username-as-common-name Run OpenVPN with --verb 7 or higher to get debugging output from this plugin, including the list of queries presented by the underlying PAM module. This is a useful debugging tool to figure out which queries a given PAM module is making, so that you can craft the appropriate plugin directive to answer it. CAVEATS This module will only work on *nix systems which support PAM, not Windows.