SAML 2.0 configuration

Question

I'm totally new to SAML. I want implement SSO for my ASP.NET Website. I got the SAML assertion from my client. I would like to know what are all other requirements I need to get it from my client and what setup I need to implement at my end.

Can anybody help me out in this.

Thanks in advance.

Answer 1

you can use something like ADFS to accepto SAML Assertions. ADFS gets installed on Windows 2008 or 2012.

You would need to ask your customer

• the signing certificate public key and
• the sign in URL.

Then you would create a "Claims Provider Trust" in ADFS and enter those details. Then a "Relying Party Trust" that represents your application. Finally you would have to configure your application with ADFS using WIF. This blog post have more details:

http://thedotnethub.blogspot.com.ar/2012/12/adfs-20-by-example-part1-adfs-as-ip-sts.html

Also you can use Auth0 to accomplish the same without setting up any software on your side (disclaimer: I work there).

Answer 2

The first thing that I would do is avoid writing the SAML code yourself. There's plenty out there. @Woloski (above) has some. My company has some (I work for the company that makes PingFederate). There's some open source stuff, too. I've seen good connections from KentorIT authServices. If this is your first foray into SAML, then my bet is that ADFS is way overboard. I'll be honest, the groups we see most commonly at Ping is when they decide to go "all in" with SSO. The first one or two connections are easy. Tehn it becomes a management nightmare rapidly thereafter. The reason I say to avoid writing your own, is because there are a LOT of nuances to SAML, with massive pitfalls, and headaches you just don't need.

As the service provider (SP), you need to tell your client (Identity Provider, or IdP) what "attributes" you need from them to properly connect their users to their account in your application (maybe a username?). In addition, you can ask for additional attributes to ensure their profile is up to date - phone number, email, etc. It's up to the two of you to determine what you need (and what they'll give you). Obviously, they shouldn't send social security number, if you have no need for it.

You also need to decide if you will do SP initiated SSO (will the users get links to documents deep inside your app?), or if just IdP initiated (Or will always just come to the front door?) will suffice. What about Single Logout? Do you (or they) want to do that? [Personally, I suggest NO, but that's a different topic]

What about signing the assertion? Your cert or theirs? If you're doing SP-init, do you need to use their cert or yours for signing the AuthnRequest? Do you need encryption of the assertion, or maybe just a few of the attributes?

Generally, you do all of this with a "metadata exchange". You give them your metadata that says "this is what we need". They import that metadata to build a new connection, fulfilling the attributes your app needs with calls to their LDAP or other user repository, as well as doing authentication (if required). They finish building their connection, and export THEIR metadata, which you import to build your connection (thereby making sure you all agree on certificates). You hook it to your app, and away you go.

I make this sound easy. It is, and it isn't. Rolling your own can mean issues. Lots of them. With some being so minute that it takes pros hours (and days) to see it. When it works, it works, and well.

HTH -- Andy