Aws cognito, how to treat request as authenticated if user is found else redirect to sign up page

问题

https://docs.microsoft.com/en-us/outlook/add-ins/authenticate-a-user-with-an-identity-token

https://docs.microsoft.com/en-us/outlook/add-ins/validate-an-identity-token

I am implementing a simple single sign for outlook add-in.

I have a JWT token by the exchange server. I have already validated it.

Now I need to check whether the user exists in aws cognito.

if exist then I need to treat the request as validated else I will redirect the user to sign up page.

I am currently trying a custom authentication challenge for this.

Please guide if someone knows where I should be working.

来源：https://stackoverflow.com/questions/58113245/aws-cognito-how-to-treat-request-as-authenticated-if-user-is-found-else-redirec