You don't need to add any code to your application, once you go through https protocol, every information is encrypted, not just some of them.
you maybe have to check out for some links that could be link the user to http protocol, but you can avoid it redirecting all http request(port 80) to https (port 443) on the server side, for example setting the virtual host on your apache configuration on the https port.
EDIT: here's the steps
1. Open the Computer Management snap-in on your Exchange server. Expand the Services and
Applications node, then the Internet Information Services node.
2. Expand the Default Web Site node, then find the Exchange directory. Right-click it and
choose the Properties command.
3. Click the Directory Security tab. In the Secure Communications control group, the View
Certificate and Edit buttons should be active. If they're not, your certificate isn't
installed properly—you'll have to fix it before proceeding.
4. Click the Edit button in the Secure Communications group. You'll see the Secure Communications dialog box.
5. Check the "Require secure channel (SSL)" checkbox. You can optionally check the "Require 128-bit encryption" box as well. Doing so gives you better security, but some clients may not be able to connect.