Set request's header on Authorize Attribute of the Controller in Asp.net Core Web API

Question

I want to set the header request before checking the auhorization, but i'm looking for the event to execute the modification. This my Implementation of IAuthorizationFilter :

public class MyAuthorizationFilter : IAuthorizationFilter
    {  

        public MyAuthorizationFilter()
        {
        }

        public void OnAuthorization(AuthorizationFilterContext context)
        {
        }
    }

This is my code in Startup :

services.AddMvc(options =>
            {
                options.Filters.Add(typeof(ClaimRequirementFilter));
            });

This is my call of MyAuthorizationFilter in the controller :

 [MyAuthorizationFilter()]
    public class AccountController : BaseController
    {
    }

Answer 1

To modify the request, add a middleware before the auth middleware:

app.UseRouting();

// add a middleware before auth
app.Use(
    async (context, next) => {
        // modify the request
        context.Request.Headers["A"] = "1";
        // call the next middleware
        await next();
    }
);

app.UseAuthentication();
app.UseAuthorization();

app.UseEndpoints(...);