I am running a LAMP stack on CentOS with Drupal 6 and the latest Services module. Over HTTP the REST server I have running works fine and behaves as expected.
When I installed an SSL certificate I forced all port 80 traffic to 443 (SSL). This worked fine for Drupal but has caused the REST server to return no data. Naturally I have removed the force SSL and allowed both HTTP and HTTPS for the time being.
I am testing via Fiddler, which when used to access the endpoint over HTTP, returns the expected data. Testing over HTTPS I receive no data. Do I need to make a configuration change to the REST server (i.e. I missed something in the documentation).
Thanks in advance for any support!
EDIT
To show the difference clearly, I made an anonymous POST request to the end point (it could have been a GET request the end point has no real methods but thus returns a message to let us know it is still there). I get the success message that the end point is running over HTTP. HTTPS however returns no data at all. I have shown this in the images below.
HTTP

HTTPS

.conf SSL Rule
These lines are no longer in use but are here to illustrate what I was doing.
#RewriteCond %{SERVER_PORT} !^443$
#RewriteRule ^(.*)$ https://%{SERVER_NAME}%{REQUEST_URI} [L,R]
Edit2:
I found something related in my Drupal Forums search http://drupal.org/node/704308
What you describe sounds suspiciously like one of these two:
Something is not listening on the port it should be listening on. If Apache forwarded a request to a broken socket then I’d expect that it would return a 500 error code, so the goal is to try to figure out where the message is going, what port your application is listening on, whether your REST application even supports the HTTPS handshake, and so on.
Apache is not interpreting your requests on port 443 the way that it interprets requests on port 80. This sounds a little more suspicious because you say that Drupal works over 443 and yet the stuff which you’ve written doesn’t generate headers at all — if Apache were forwarding your API requests to your Drupal application you would expect to at least see headers, 404s, etc when it fails to properly interpret API requests.
Without more information I’m not sure we can help.