Google Calendar can't subscribe to icalendar feed over https?

Question

Would someone happen to know if Google Calendar has some problems subscribing to iCalendar feeds served on a secure https-address?

I'm developing a website running on an https-address that has an iCalendar feed that users can subscribe to. The feed works just fine in Outlook and iCal, but not in Google Calendar. When a user attempts to subscribe to the feed, they get the error message "Could not fetch the URL".

I suspected that there was something wrong with the feed or the generated iCalendar data, so I ran the .ics file produced through a number of validators, and they were fine. To rule out an error in the feed itself, I put the generated .ics file on the server, to see if a static file would work, and that failed in Google Calendar as well. Then I put the file on a completely different server behind a non-secure (http) url, and that worked!

So I'm beginning to suspect that httpS is the problem. The server's certificate is valid, so that shouldn't be causing any trouble. Besides, the validators could access the feed (and the static file) just fine.

This google groups discussion indicates that others are having similar suspicions: http://productforums.google.com/forum/#!topic/calendar/61-eUd-fyrg

Problem is, the site HAS to run on over https, so I can't just switch to http to make the feed work.

So, if anyone has any information confirming or contradicing my theory, or any ideas about what else might be causing these problems, I would greatly appreciate it.

Answer 1

I can confirm that (today) Google Calendar can successfully subscribe to an HTTPS iCal feed.

You can test this yourself by adding this URL: https://events.stanford.edu/byCategory/2/eventlist.ics

To be extra sure I also did another test of giving it an HTTPS url that didn't also work if you replace the https -> http. That was also fine, so in all cases, HTTPS should work.

What doesn't work in my tests is:

• HTTP Authentication (https://myusername:[email protected]/) - I got "Could not fetch URL" - but that's not what this question is asking.
• Any URL over 256 characters. However, using a link shortener (e.g., goo.gl) works around this issue.

Answer 2

Google has confirmed that it really is an issue with HTTPS, i.e. Google Calendar is unable to subscribe to iCalendar feeds from external encrypted (https) URLs.

My employer has an enterprise account with Google, and we filed a support request with google's enterprise support, with example feeds and our own assesment of the problem.

Today, we finally got a proper answer, confirming our initial analysis and informing us that the correct techincal team has been notified and an internal feature request (for supporting feed from https-urls) has been opened.

We were not given any timeframe for the fix, but I requested that they get back to us when the issue has been resolved. I will add that information to this answer once I receive it.

Answer 3

The issue we've found in our case is that Google Calendar currently ignores the HTTPS indication in the URL and accesses via HTTP instead. If your HTTP requests redirect to HTTPS or just serve up the content over HTTP, then it will work. If you have a firewall blocking port 80, then things hang and its game over.

TL;DR: If your URL works with http in addtion to https, then it will work with Google Calendar when you enter it as https. (That assumes robots.txt does not restrict access.) Otherwise, it will fail.