I have a web application that I'd like to place a 'Login with Salesforce' button on. I have many users in my application who are all part of different Salesforce orgs. I'd use the Salesforce Account Name as the unique identifier for my application.
EDIT: I should also specify that my app is NOT built on force.com - it is a custom .NET application.
My questions are:
Is there a way to enable this button without needing to configure something in every specific org, and if so, how?
If I do have configure something in every specific org, it looks like there are a few options on how to handle authentication - SAML 2.0, OpenID Connect, and OAuth2. I understand why you shouldn't use OAuth2, but is there an advantage to using SAML vs. OpenID Connect?