## Installing the modules
-If you're using Ubuntu, [Evan Broder](http://ebroder.net) has packaged the scripts.mit.edu modules for all current Ubuntu releases in a PPA.
+If you're using Ubuntu, Evan Broder has packaged the scripts.mit.edu modules for all current Ubuntu releases (through 11.x) in a PPA.
The [PPA homepage](https://launchpad.net/~broder/+archive/scripts-http-mods) includes instructions on how to install the PPA on your system, but if you're on Ubuntu Karmic or later, you can just run:
- # add-apt-repository ppa:broder/scripts-http-mods
+ # add-apt-repository ppa:broder/scripts-http-mods ; apt-get update
Once you've installed the PPA, you want to install the libapache2-mod-auth-sslcert and libapache2-mod-authz-afsgroup packages.
In addition to the standard Apache directives needed to enable SSL, you'll need a few more before the Apache modules work as they do on scripts. Add the following directives to each vhost that will be using SSL client-side certificate authentication:
- SSLVerifyClient require
+ SSLCACertificateFile /etc/ssl/certs/mitCAclient.pem
<Location />
AuthSSLCertVar SSL_CLIENT_S_DN_Email
AuthSSLCertStripSuffix "@MIT.EDU"
</Location>
+You also need to require certificate authentication. You can either use `SSLVerifyClient require` or `SSLVerifyClient optional`. `SSLVerifyClient require` has the downside that, if visitors don't have client-side certificates, they'll get an obscure OpenSSL error. However, Safari will not present certificates to a site with `SSLVerifyClient optional` set unless the user sets up an Identity Preference. For reference, scripts.mit.edu sets `SSLVerifyClient optional`.
+
You'll also need to enable the Apache modules.
# a2enmod auth_sslcert