public class BasicAuthenticationAttribute : AuthorizationFilterAttribute
{

    public static bool VaidateUserRoleWise(string username, string password, int RoleId)
    {
        //DO DATABASE CONNECTION DO QUERY HERE
        if (Username == username && Password == password)
        {
            return true;
        }
        else
        {
            return false;
        }
    }
    public override void OnAuthorization(QuizzrApi.Controllers.QuizzrController.InputParamAdminLogin LoginDetails)
    {
        System.Web.Http.Controllers.HttpActionContext actionContext = null;
        if (LoginDetails == null)
        {
            actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized);
        }
        else
        {
            //Bellow is the static method called above will return true or false if user matches
            if (!VaidateUserRoleWise(LoginDetails.UserName, LoginDetails.Password, 1))
            {
                actionContext.Response = actionContext.Request.CreateResponse(HttpStatusCode.Unauthorized);
            }
        }

        base.OnAuthorization(actionContext);
    }

}

[Route("AuthorizeSystemAdmin")]
    [HttpPost]
    [BasicAuthentication]
    public HttpResponseMessage Login([FromBody] InputParamAdminLogin AdminLoginInput)
    {
       //do your logic here
    }