As an example, I have added an Azure AD external identity provider to Azure B2C using OpenIDConnect.
I am interested in accessing claims from the external identity provider (Azure AD) that aren't present in the ID Token Azure B2C returns to my app. For instance, I know that there is an amr claim from the external identity provider. If I configure Azure B2C to pass thru the Access Token obtained from the external IDP like this:
<OutputClaim ClaimTypeReferenceId="identityProviderAccessToken" PartnerClaimType="{oauth2:access_token}" />
Then my application can see the Access Token, and if I decode it, I can see the claims I'm looking for are present.
However, I want to process these claims within Azure B2C to change it's behavior based on these claims. For instance, I would like to look at the amr claim and determine if multi-factor authentication should be enforced or not.
Is there any mechanism through which Azure B2C can handle the claims that are returned in the Access Token from the external identity provider? Some type of syntax that references a claim in the Access Token that Azure B2C retrieves from the IDP? The closest thing I can find might be to change from OpenIdConnect protocol to Oauth2 protocol in the claimsprovider configuration. But, I've seen mixed messages about this.