Enable Oauth2 client credentials flow in Swashbuckle

Question

Im using IdentityServer3 to secure a Web API with the client credentials grant. For documentation Im using Swashbuckle but can\'t figure out how to enable Oauth2 in the SwaggerC

Answer 1

I was able to get this working. Most of the answer can be found here.

There were a few parts I had to change to get the client_credential grant to work. The first part is in the EnableSwagger and EnableSwaggerUi calls:

config.EnableSwagger(c => 
  {
    c.SingleApiVersion("v1", "sample api");
    c.OAuth2("oauth2")
     .Description("client credentials grant flow")
     .Flow("application")
     .Scopes(scopes => scopes.Add("sampleapi", "try out the sample api"))
     .TokenUrl("http://authuri/token");
    c.OperationFilter();
  }).EnableSwaggerUi(c =>
  {
    c.EnableOAuth2Support("sampleapi", "samplerealm", "Swagger UI");
  });

The important change here is .Flow("application") I also used the .TokenUrl call instead of .AuthorizationUrl This is just dependent on your particular authorization scheme is set up.

I also used a slightly different AssignOAuth2SecurityRequirements class

public class AssignOAuth2SecurityRequirements : IOperationFilter
{
    public void Apply(Operation operation, SchemaRegistry schemaRegistry, ApiDescription apiDescription)
    {
      var authorized = apiDescription.ActionDescriptor.GetCustomAttributes();
      if (!authorized.Any()) return;

      if (operation.security == null)
          operation.security = new List>>();

      var oAuthRequirements = new Dictionary>
      {
          {"oauth2", Enumerable.Empty()}
      };

      operation.security.Add(oAuthRequirements);
    }
}

This should be sufficient to get the authentication switch to show. The other problem for me was that the default authentication dialog is set up so a user just has to select a scope and then click authorize. In my case this didn't work due to the way I have authentication set up. I had to re-write the dialog in the swagger-oauth.js script and inject it into the SwaggerUI.