Startup.cs

using DailyApp.Infrastructure;
using DailyApp.Middleware;
using DailyApp.Models;
using DailyApp.Security;
using DailyApp.Security.Interfaces;
using DailyApp.Security.User.Login;
using MediatR;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.JwtBearer;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Builder;
using Microsoft.AspNetCore.Hosting;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.AspNetCore.Mvc.Authorization;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Configuration;
using Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;
using Microsoft.Extensions.Hosting;
using Microsoft.IdentityModel.Tokens;
using System.Text;

namespace DailyApp
{
    public class Startup
    {
        public IConfiguration Configuration { get; }

        public Startup(IConfiguration configuration) => Configuration = configuration;
        
        public void ConfigureServices(IServiceCollection services)
        {
            services.AddDbContext<DataContext>(opt => opt.UseSqlite(Configuration.GetConnectionString("DefaultConnection")));
            services.AddMediatR(typeof(LoginHandler).Assembly);
            services.AddMvc(option =>
            {
                option.EnableEndpointRouting = false;
                var policy = new AuthorizationPolicyBuilder()
                    .RequireAuthenticatedUser()
                    .Build();
                option.Filters.Add(new AuthorizeFilter(policy));
            }).SetCompatibilityVersion(CompatibilityVersion.Latest);
            services.TryAddSingleton<ISystemClock, SystemClock>();

            var builder = services.AddIdentityCore<AppUser>();
            var identityBuilder = new IdentityBuilder(builder.UserType, builder.Services);
            identityBuilder.AddEntityFrameworkStores<DataContext>();
            identityBuilder.AddSignInManager<SignInManager<AppUser>>();

            var key = new SymmetricSecurityKey(Encoding.UTF8.GetBytes(Configuration["TokenKey"]));
            services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer(
                opt =>
                {
                    opt.TokenValidationParameters = new TokenValidationParameters
                    {
                        ValidateIssuerSigningKey = true,
                        IssuerSigningKey = key,
                        ValidateAudience = false,
                        ValidateIssuer = false,
                    };
                });

            services.AddScoped<IJwtGenerator, JwtGenerator>();
        }

        public void Configure(IApplicationBuilder app, IWebHostEnvironment env)
        {
            if (env.IsDevelopment())
                app.UseDeveloperExceptionPage();
            else
                app.UseExceptionHandler("/Error");
            
            app.UseMiddleware<ErrorHandlingMiddleware>();
            app.UseMvcWithDefaultRoute();
            app.UseStaticFiles();
            app.UseRouting();
            app.UseAuthentication();
            app.UseAuthorization();
        }
    }
}