Everyone should use SSL (Secure Sockets Layer) to secure their web site. Cost is not an obstacle because you can get a free SSL certificate from StartSSL.
SSL provides encryption of web page requests over the wire using https:// instead of http:// for the beginning of the url. To use SSL you must install an SSL Certificate from a Certificate authority on the web server and enable it on your site. Most hosting companies can help you with this.
Why Do I Need SSL?
SSL is used to secure content sent over the wire on the internet by encrypting the packets so that it is not possible to get the contents by packet sniffing. You may think there is little risk that someone is sniffing packets but these days it is very easy to sniff packets using tools like Firesheep. Even though ip packets are addressed to specific ip addresses, network cards configured in promiscuous mode can capture packets that were not addressed to them easily. It is particularly risky on public wi fi networks in airports, coffee shops and elsewhere, you should assume there are people on the network actively trying to capture your packets.
But What is the Risk If My Site Doesn't Have any Sensitive Data?
If you are using mojoPortal content management system to run your site that means you will need to sign into the site to edit content. So the first level of risk if someone captures your packets while you are signing in they can get your username and password and then they can sign in as you. By using SSL the credentials will be sent inside encrypted packets.
Old school thinking was that it is sufficient to just use SSL on the login page, the register page, the user profile, or only specific pages that would contain sensitive data. But when you sign in cookies are added to your web browser that prove you are authenticated with the site and that establish your roles. Once the cookies are assigned the web browser passes them in the request headers as you navigate through the site and if you then visit a non secure page then the cookies could be stolen by somene who can sniff your packets. Then they can make web requests to your site passing the same cookies in the request headers and now they can interact with the site as you and with the same roles as you, so if you are the site administrator that means they can now manage your site.
So the new school of thought given how easy it really is to sniff packets on public networks, is that once you are signed in you should remain in SSL (ie all urls should use https) for the remainder of your browsing session until you sign out. When you have SSL enabled in the latest version of mojoPortal this is how it now behaves at least in terms of links generated by mojoPortal. If you are on a secure page and you click a link that uses a relative url then it inherits the https protocol and links generated by mojoPortal use relative urls so the default behavior will keep you in SSL as you navigate the site unless you click a link with just http or if you were to type in an url directly using http.
By default if you make any request for a non https url within the site it would still send your cookies in the request header and that would mean that someone could sniff the packets and steal your cookies from just that one request. But there is a way by configuration to prevent this. In the Web.config file you can make settings that tell the browser not to pass the cookies on any requests if they are not using SSL. If you look in the mojoPortal Web.config file you will see the needed changes in comments:
<forms name=".mojochangeme" protection="All" timeout="50000000" path="/" cookieless="UseCookies" />
<!-- if you have an SSL certificate installed you should add requireSSL="true" to make sure that the auth cookie is not
passed in the request header for non ssl requests:
<forms name=".mojochangeme" protection="All" timeout="50000000" path="/" cookieless="UseCookies" requireSSL="true" />
As shown above you would want to add the requireSSL="true" on the forms element. We also by default force the role cookie to only be passed over a secure request if SSL is available. You could override this by adding a setting to user.config like this:
<add key="RequireSslForRoleCookie" value="false" />
However it is best to not do that since the default setting protects your role cookie. If someone on a local network could steal your role cookie they could gain elevated privledges in your site.
This is enabled on this site, so you will see if you sign into this site you remain in https for the rest of the session, and if you do manually change it to http or if some link on the site may have only http if it is not using a relative url, then what will happen is the cookies are not passed in those requests and therefore you do not appear to be signed in for those requests, and you will see the signin link appear on the page. Then if you click the sign in link it will go to a secure page (ie the login page) and once it is there, since it is a secure request, it will now detect your cookies again and see that you are already authenticated so you are not forced to sign in again.
So in summary there has been a change in tide in thinking about where you should use SSL. You really need to use everywhere for authenticated users and you really should configure it to prevent passing cookies for insecure requests to protect yourself and your site users from session hijacking. If they can steal your cookies they can then use your cookies to hijack your web session because now they are interacting with the site as you. They can change your password or anything else that you can do once they have done that. That is why you see all major sites such as Facebook, Twitter, and Gmail all use SSL for every request. SSL is still important for securing any private data on your site, but even if you don't have any sesnsitve data on your site it is all about protecting your user's cookies.
For Further Reading See Also
Created 2011-12-23 by Joe Audette
Modified 2012-04-30 by Joe Audette