I'm having a headache with some results.
Running the following command results in an HTTP 200 response:
$ curl -v -L www.example.com >/dev/null
while running this, and using the exact headers that
curl uses results in an HTTP 403 response:
$ openssl s_client -connect www.example.com:443
There is no problem with certificate, as
openssl verify it. I really can't think of anything to start digging this problem, so even just a wild guess is more than welcome!
The 403 response comes from Fortigaurd servers, reading "Web filter service error: all Fortiguard servers failed to respond".
I can provide more information, such as
openssl outputs, if needed.