Which authentication options can automatically be looked up from appsettings.json?

Question

In this article regarding configuring authentication strategies for minimal apis, it states that we can define certain options regarding our authentication server in the appsettings.json file, and have them automatically looked up when adding the corresponding scheme in our program.cs file. I have tested this on my end and confirmed that it works with the options named "ValidAudiences" and "ValidIssuer".

However, when trying to define other authentication options in the appsettings.json file (such as "RoleClaimType") I notice that they are not being automatically looked up like the other options. Is there any way to have "RoleClaimType" looked up automatically like the other options? Also, what are all of the options that can be configured such that they can be automatically looked up from the appsettings config file automatically?

Answer 1

Hi jc199,

RoleClaimType might not be automatically looked up because they may not be part of the predefined options that are supported for direct binding by the built-in configuration system.

You can manually bind custom options from appsettings.json to the relevant options classes in your Program.cs file:

builder.Services.AddAuthentication("Bearer")
    .AddJwtBearer(options =>
    {
        var jwtSection = builder.Configuration.GetSection("Authentication:JwtBearer");
        options.TokenValidationParameters.ValidIssuer = jwtSection["ValidIssuer"];
        options.TokenValidationParameters.ValidAudiences = jwtSection.GetSection("ValidAudiences").Get<string[]>();
        options.TokenValidationParameters.RoleClaimType = jwtSection["RoleClaimType"];
    });

The json string should be like below:

{
  "Authentication": {
    "Bearer": {
      "ValidAudiences": [
        "https://localhost:7259",
        "http://localhost:5259"
      ],
      "ValidIssuer": "dotnet-user-jwts",
      "RoleClaimType": "role"
    }
    
  }
}

If the answer is the right solution, please click "Accept Answer" and kindly upvote it. If you have extra questions about this answer, please click "Comment".

Note: Please follow the steps in our documentation to enable e-mail notifications if you want to receive the related email notification for this thread.

Best regards,
Rena