Oidccustomparms - Aspnetcore

OIDC and OAuth Parameter Customization

The OAuth and OIDC authentication handlers now have an AdditionalAuthorizationParameters option to make it easier to customize authorization message parameters that are usually included as part of the redirect query string. In .NET 8 or earlier, this requires a custom xref:Microsoft.AspNetCore.Authentication.WsFederation.WsFederationEvents.OnRedirectToIdentityProvider callback or overridden xref:Microsoft.AspNetCore.Authentication.OAuth.OAuthHandler%601.BuildChallengeUrl%2A method in a custom handler. Here's an example of .NET 8 code:

csharp

builder.Services.AddAuthentication().AddOpenIdConnect(options =>
{
    options.Events.OnRedirectToIdentityProvider = context =>
    {
        context.ProtocolMessage.SetParameter("prompt", "login");
        context.ProtocolMessage.SetParameter("audience", "https://api.example.com");
        return Task.CompletedTask;
    };
});

The preceding example can now be simplified to the following code:

csharp

builder.Services.AddAuthentication().AddOpenIdConnect(options =>
{
    options.AdditionalAuthorizationParameters.Add("prompt", "login");
    options.AdditionalAuthorizationParameters.Add("audience", "https://api.example.com");
});