Multiple Authentication Middlewares ASP.NET Core - asp.net

Question

I am relatively new to the concept of middlewares. I am aware that a middleware calls the next middleware when it completes.
I am trying to authenticate a request using either Google or my Identity Server. The user can login on my mobile app with google or a local account. However, I can't figure out how to use both authentication middlewares. If I pass the id_token for google, it passes on the first middleware (UseJwtBearerAuthentication) but fails on the second one (UseIdentityServerAuthentication). How can I make it so that it doesn't throw error when it actually passes on at least 1 authentication middleware? For example, if it passes on the first middleware, the second middleware is ignored?
app.UseJwtBearerAuthentication(new JwtBearerOptions()
{
Authority = "https://accounts.google.com",
Audience = "secret.apps.googleusercontent.com",
TokenValidationParameters = new TokenValidationParameters()
{
ValidateAudience = true,
ValidIssuer = "accounts.google.com"
},
RequireHttpsMetadata = false
});
app.UseIdentityServerAuthentication(new IdentityServerAuthenticationOptions
{
Authority = "http://localhost:1000/",
RequireHttpsMetadata = false,
ScopeName = "MyApp.Api"
});

Answer 1

Normally, when an authentication middleware is failed(i don't mean throwing exception), this doesn't affect another successful authentication middleware. Probably your second middleware throws an exception(not a validation failure). First check error message and try to resolve it. If you can't, use AuthenticationFailed event to handle error. In this case your code should be something like below:
app.UseJwtBearerAuthentication(new JwtBearerOptions()
{
// ...
Events = new JwtBearerEvents()
{
OnAuthenticationFailed = async (context) =>
{
if (context.Exception is your exception)
{
context.SkipToNextMiddleware();
}
}
}
});
However, for your scenerio i wouldn't choose your way. I would use only identity server endpoint. For signing with google you can configure identity server like below:
app.UseCookieAuthentication(new CookieAuthenticationOptions
{
AuthenticationScheme = IdentityServerConstants.ExternalCookieAuthenticationScheme,
AutomaticAuthenticate = false,
AutomaticChallenge = false
});
app.UseGoogleAuthentication(new GoogleOptions
{
AuthenticationScheme = "Google",
SignInScheme = IdentityServerConstants.ExternalCookieAuthenticationScheme,
ClientId = "",
ClientSecret = ""
});
app.UseIdentityServer();
Edit
It seems AuthenticationFailed event couldn't be used for IdentityServer4.AccessTokenValidation. I am not sure but if you will use identity server for only jwt token, you can use UseJwtBearerAuthentication for validation.