I know services such as Auth0 can act as both SAML IdPs and integrate with third party IdPs. It would seem that Cognito can only integrate with other third party IdPs as a service provider, it can actually perform the role of an IdP.
The use case is we have our apps creating users in Cognito. We'd like to use a third party application which can integrate with a SAML IdP to support SSO. Is this possible with Cognito or would we need to use something like Auth0?
Currenlty, Cognito is an OIDC IdP and not a SAML IdP. If an application supports OIDC, you can use Cognito to connect to that.
We have recently released in public beta a new feature that allows you to federated identity from another SAML IdP. Here's the blog entry https://aws.amazon.com/blogs/mobile/amazon-cognito-user-pools-supports-federation-with-saml/
We will consider your request for future releases.
来源：https://stackoverflow.com/questions/44512540/saml-idp-aws-cognito-iam-as-an-identity-provider