Custom STS for Sitefinity 5.x
Posted by zamd on February 6, 2013
Sitefinity 5.x introduced claims based security & Single-Sign-On features based on a simple HTTP redirect based token issuance protocol which I’m going to call ‘Sitefinity sign-in protocol’ in my posts. Version 5.x has also standardized on using Simple Web Token (SWT) as the default token format for user authentication and SSO needs.
Sitefinity 5.x comes with a built-in local STS which authenticates users using the standard membership authentication and issue SWT tokens in accordance with Sitefinity sign-in protocol. Sitefinity doesn’t have a hard dependency on this built-in STS rather it relies on it’s sign-in protocol and SWT token format which means we can introduce a custom STS in the mix and Sitefinity would happily work with our Custom STS which obviously has to adhere to Sitfinity sign-in protocol and token format.
This STS based design in Sitefinity 5.x could enable many SSO scenarios, some of which I’m going to explore in future posts. Following are examples of few possibilities:
- I can create a Custom STS and then have multiple applications (RPs :)) including Sitefinity 5.x trust this single STS, which would enable the users to single sign-on across all those applications.
- I can create a multi-protocol STS which can enable user SSO across workloads/products. For example, SSO between Sitefinity & Office 365 or another portals, speaking the SAML protocol.
For now, I’ll show you how to use a custom STS with Sitefinity for user authentication. I have already developed and deployed a Sitefinity compatible STS @ http://sts.pilesoft.com while Sitefinity is running @ http://pilesoft.com.
Step 1: Register custom STS with Sitefinity so that it can trust the token issued by custom STS.
Open the .\App_Data\Sitefinity\Configuration\SecurityConfig.config file and locate the <securityTokenIssuers> element and following line to <securityTokenIssuers> element.
<add key="CD29559E6EDC312272976AC43F7E921C5766D7063DAF6D177F3EEDEB1802FABE" encoding="Hexadecimal" membershipProvider="Default" realm="http://sts.pilesoft.com"/>
Your config should now look like following:
In most cases, you need to configure a custom Membership provider as well, which I’m going to talk in a future post.
Step 2: Open the main web.config file and locate the <federatedAuthentication> under the <microsoft.identityModel> section. This is WIF configuration and we need to change the <wsFederation> element to point to our custom STS.
Locate the <wsFederation> element & change the issuer attribute to point to our Custom STS as shown below:
Now if I browse to Sitefinity – I get:
When I click on ‘Login to the backend link’, I’m redirected to my Custom STS. The address bar shows the sitefinity sign-in protocol in action.
When I sign-in at the STS, it issues a SWT token & redirects me back to the Sitefinity app.
As this STS is trusted by Sitefinity, it happily accepts the incoming SWT token and logs me in.
I’ll publish the Custom STS code after removing the IP related bits. Ping me if you desperately needs it :)