Azure AD B2C - Calling function when user signs in - azure-ad-b2c

Question

I have an MVC Core 2.1 application, and am using Azure AD B2C (2.1.1) as the identity provider.
I want to call a function when a user signs in and signs out, and am guessing I need to put this in the middleware.
In the previous version of the AD B2C, there was a function:
app.UseOpenIdConnectAuthentication(options);
which had options that made notification functions available:
Notifications = new OpenIdConnectAuthenticationNotifications
{
AuthenticationFailed = this.AuthenticationFailed,
RedirectToIdentityProvider = this.OnRedirectToIdentityProvider
}
The app.UseOpenIdConnectAuthentication(options); function is now marked as obsolete.
I could put in a middleware call like this:
app.Use((context, next) =>
{
if(/*context handler referrer includes "B2C_1_SignUpPolicy"*/)
{
// User has signed-in
}
return next.Invoke();
}
… but this would be called for every request and cannot be adapted to also call a function when the user signs out.
So do I set up notifications in the app.UseAuthentication(); version?

Answer 1

I've created a code sample at GitHub for an ASP.NET Core 2.1 web application that authenticates an end user against Azure AD B2C using the ASP.NET Core 2.1 authentication middleware for Azure AD B2C, acquires an access token using MSAL.NET, and accesses a web API using this access token.
It acquires the access token by handling the OpenIdConnectOptions.Events.OnAuthorizationCodeReceived event.
You might be able to develop the similar code to handle another OpenIdConnectOptions.Events event.