Single Sign On for a Web App

Question

I have been trying to understand how this problem is solved for over a month now. I really need to come up with a general approach that work. I have a theory, but I\'m just

Answer 1

One basic problem with your approach is that you're considering your web app in isolation. Employees at your client's company won't just require SSO to your web app but also some/few/many others, and extending your approach would require a bespoke implementation for each of those to enable access.

Hence the widespread adoption of OpenAthens and Shibboleth in the academic library community to leverage the use of locally-issued credentials. A typical medium/large university can subscribe to various products/services from more than fifty different publishers, and by deploying OpenAthens/Shibboleth they can take advantage of the SAML open standard (SAML is the protocol that Shibboleth uses) that is seeing increased take-up not only in the academic sector, but also in the commercial sector.

John's answer above points to another issue: there are a number of open standards that have recently emerged, SAML and OpenID among them. So content providers are having to decide whether they want to implement some or all of these natively, but they use separate technology stacks and so the implementation and support costs can be duplicated.

Quite a few major publishers have implemented OpenAthens as this supports Athens, SAML/Shibboleth and OpenID in a single platform, with options to plug in other technologies too, or writing a custom module to allow an internal app to connect, e.g. an invoicing or entitlements system recording which clients' users are logging in.

This sector of access management is definitely moving towards open standards, so building your own method would be depriving access to your app for a large number of users

Answer 2

Shibboleth is designed to support exactly this scenario. However it will rely on your customers' companies implementing the identity provider mechanisms. At the moment, that's only really common in universities. Further, if you want user information (any more than just a pseudonymous identifier), you'd need the company to agree to release those attributes to you.

I find it hard to believe that many companies would open their corporate authentication system to you, just to provide SSO.

You might find it better to rely on OpenID or similar, and using a "remember me" cookie to reduce the need for people to enter passwords.