[Zope] ssl certificate based authentication

[BORGULYA Gergely]

I would like to have the users of my site authenticated via ssl certificates.
Authentication works well with apache2, and I would like to have my zope 
working behind the proxy module of apache. I would not find it neccessary to 
leave the authentication to be done by apache, but I expect it to be 
simplier. 
I've found a product (SSL Certificate Authenticator Product), that uses 
apache's authentication, but it is only able to pass userinformation via pcgi 
connection to zope. I could not find any other zope product for this problem, 
however, this way is mentioned in the zope Wikis, as a common authentication 
method.
(http://zope.org/Wikis/DevSite/Projects/ComponentArchitecture/StandardAuthenticationService)

Is there a common (or uncommon) solution for this case? 
The second level of my question is, how to do all this if I need the 
advantages of the Groups User Folder?

thanks,
ger