Howto use https iCalendars with iCal

I was going crazy because iCal does not support https URLs for remote iCalendars. Since my work calendar resides on https://ops.func.nl/opswebdav/calendars/zoran.ics that is a bit of a problem.

Mac experts advised me to configure a non-secure URL in iCal and then hack away in the Properties.plist (in $HOME/Library/Application Support/iCal/Sources/…/). Unfortunately, this did not work for me.

My colleague Thijs advised me to set up an Apache proxy to the secure resource. Here are the steps:

1. Get MacPorts
2. In a Terminal, issue a: sudo port install apache2 (this will take a while, since every packet is fetched and built … neat!)
3. Add the following lines to /opt/local/apache2/conf/httpd.conf

NameVirtualHost \*:80

<VirtualHost \*:80>
SSLProxyEngine On
SSLProxyCACertificateFile /etc/ssl/certs/app02-ca-public.pem

ProxyPass / https://ops.func.nl/
ProxyPassReverse / https://ops.func.nl/

ServerName localhost
ErrorLog logs/localhost-error_log
CustomLog logs/localhost-access_log common
</VirtualHost>

Where SSLProxyCACertificateFile is the public certificate of the authority that signed the certificate that is used to encrypt the secure iCalendar resource. In our case it is self-signed, so this step is needed.

4. Subscribe to the iCalendar resource in iCal, but replace https://myserver/ by http://localhost/ in the URL.

That’s it.

Now I need a way to make it not read only, so I can also publish to this URL …