The timeout specified has expired: SSL input filter read failed.

After a reconfiguration on our Debian based shared host I was left scratching my head about this error in apache log file:

[Wed Feb 06 21:09:50 2008] [info] [client 84.12.26.107] (70007)The timeout specified has expired: SSL input filter read failed.
[Wed Feb 06 21:09:50 2008] [info] [client 84.12.26.107] Connection closed to child 0 with standard shutdown (server www.blah.com:443)

It occurred whenever we tried to upload an image file (big or small) over HTTPS/SSL. I didn’t have time to debug the app because of other work commitments and waited for our hard working host to sort it out – although a simple standalone script which received a file and copied it to a folder worked fine.

Anyway, it turned out that GD Library hadn’t been re-installed – not that you could tell from that uninformative message! I have posted this here for posterity because searching the Internet for the message did not yield any suggestions.