Within the last days I ran some tests using the certificate login for https://wiki.cacert.org/.
This evening I activated this function on our wiki server.
Trying to login to https://wiki.cacert.org/ using an unknown email-adress will NOT create a new account: You have to create an account first using the email-adress, which is listed in your client certificate.
If the certificate-authentication fails (no matter, if you use no client certifcate, an expired one or a certificate, which does not match your email-adress) you can use the normal “classic” username/password-credentials to login.
While installing the client certificate login for CAcert wiki I updated the root-certificate there to the resigned one.
Dirk Astrath (CAcert wiki admin)