Systems and methods are disclosed for an appliance to authenticate access of a client to a protected directory on a server via a connection, such as a secure SSL connection, established by the appliance. A method comprises the steps of: receiving, by an appliance, a first request from a client on a first network to access a server on a second network, the appliance providing the client a virtual private network connection from the first network to the second network; determining, by the appliance, the first request comprises access to a protected directory of the server; associating, by the appliance, an authentication policy with the protected directory, the authentication policy specifying an action to authenticate the client's access to the protected directory; and transmitting, by the appliance in response to the authentication policy, a second request to the client for an authentication certificate. Corresponding systems are also disclosed.