Can't Access SOAP Web Service Over HTTPS

Question

What I am trying to do is hit a web service (which I built) using SSL. It doesn't seem to be working though. Some relevant information:

• Everything works fine using HTTP. The problem only happens when I use HTTPS.
• The actual error message being output is as follows:

SOAP-ERROR: Parsing WSDL: Couldn't load from ... : failed to load external entity ...

• The service is implemented in PHP.
• If I run php -m or check phpinfo() openssl appears to be installed properly.

• The SSL certificate seems to be working fine otherwise. I can use HTTPS on the rest of the site; it's just the web service that's having a problem.

• If I try accessing the WSDL via a browser over HTTPS, it works fine. If I try to access one of the SOAP endpoint URLs, then I get the error message.

• I wrote a minimized PHP script to try and make an actual call to the service. It will get the error message when trying to retrieve the WSDL itself.
• Web server is Apache running on Debian
• It doesn't seem to be a code issue. I have comparable code running on the dev server and it works fine there, even using HTTPS.
• Production system is running on a proxy system, with nginx in the front. It seems like this is most likely related to the issue, but no idea where to start solving that problem.

Answer 1

I'd like to point out this is likely related to your nginx configuration and for SSL there are a couple of good spots to start looking:

1. Verify your listening port on nginx is 443
2. Verify your proxy location is 127.0.0.1:80 (port 80 because it's HTTP, unless you customized it)
3. If you are using CentOS, I've found iptables to be the culprit of many problems. Sometimes I just forget to open up port 443 in the firewall. To configure, go to /etc/sysconfig/iptables/ and add a firewall rule.

and last but not least....

I found this nifty guide for SOAP over SSL :) http://soapoverhttps.blogspot.ca/