Following up on zakjan's answer, I had a problem when I tried to use jquery to do an AJAX request on my newly secure server, in an android webview. It worked in the browser, but not in my app.
I used this site: https://certificatechain.io/
I pasted in the text of my signed .crt file I got back from Comodo (positiveSSL), and it gave me back a concatination of everything I needed. I saved it as my domain + "chain.crt" (see below)
Then, in my apache configs, I entered something like this for that particular virtual host:
SSLEngine On
SSLCertificateFile /etc/ssl/localcerts/example_com.crt
SSLCertificateKeyFile /etc/ssl/localcerts/example.com.key
SSLCACertificateFile /etc/ssl/localcerts/example.com.chain.crt
After that, my Android app's webview did not have a problem using ajax to POST to my server. I tried it on 2 real-world devices, one running 2.3.4, one running 4.something. And on the emulator running 2.3. All worked.
I hope this helps.