Note that the author of this mod has created a new version which is now hosted on Github

https://github.com/openSUSE/apache2-mod_auth_memcookie

This includes a number of changes - but as far as I can see it does not yet compile with Apache 2.4..

His changes are shown as:

/* changed by mls in 2011-04:
*

    • ported the code to libmemcached.
    • made sure that the session data contains no \r or \n.
    • made sure that the cookie is a valid md5sum.
    • added Auth_memCookie_SessionHeaders option to specify which
  • headers should be cleared from the input headers and taken from
  • the session data.
    • added szAuth_memCookie_AuthentificationURI to configure that
  • the session is created by doing a subrequest to the specfied
  • URI and using the returned headers (uses the configured
  • SessionHeaders).
    • added Auth_memCookie_AuthentificationHeader option to tell the
  • module that it can take the user name from the specified header
  • when it creates the session.
    • added Auth_memCookie_AuthentificationURIOnlyAuth to make it
  • just run the authentification steps for the subrequest
  • (data is taken from the input headers in that case).
    • added Auth_memCookie_CookieDomain to specify a domain for the
  • session cookie.
    • added Auth_memCookie_AllowAnonymous to specify that no session
  • is required for the request.
    • added Auth_memCookie_CommandHeader to specify a way to issue
  • commands for session managemant: "login" makes it ignore the
  • AllowAnonymous flag, "logout" deletes the session.