asp core 配置用户密码验证

 using System;
 using System.Collections.Generic;
 using System.Linq;
 using System.Threading.Tasks;
 using Microsoft.AspNetCore.Builder;
 using Microsoft.AspNetCore.Identity;
 using Microsoft.EntityFrameworkCore;
 using Microsoft.AspNetCore.Hosting;
 using Microsoft.Extensions.Configuration;
 using Microsoft.Extensions.DependencyInjection;
 using Cap.Data;
 using Cap.Models;
 using Cap.Services;
 using Microsoft.AspNetCore.Authentication.Cookies;

 namespace Cap
 {
     public class Startup
     {
         public Startup(IConfiguration configuration)
         {
             Configuration = configuration;
         }

         public IConfiguration Configuration { get; }

         // This method gets called by the runtime. Use this method to add services to the container.
         public void ConfigureServices(IServiceCollection services)
         {
             services.AddDbContext<ApplicationDbContext>(options =>
                 options.UseSqlServer(Configuration.GetConnectionString("DefaultConnection")));

             services.AddIdentity<ApplicationUser, IdentityRole>()
                 .AddEntityFrameworkStores<ApplicationDbContext>()
                 .AddDefaultTokenProviders();

             // Add application services.
             services.AddTransient<IEmailSender, EmailSender>();

             services.AddMvc();
             services.Configure<IdentityOptions>(options =>
             {
                 options.Password.RequireDigit = false;
                 options.Password.RequireLowercase = false;
                 options.Password.RequireNonAlphanumeric = false;
                 options.Password.RequireUppercase = false;
                 options.Password.RequiredLength = ;
             });
         }

         // This method gets called by the runtime. Use this method to configure the HTTP request pipeline.
         public void Configure(IApplicationBuilder app, IHostingEnvironment env)
         {
             if (env.IsDevelopment())
             {
                 app.UseDeveloperExceptionPage();
                 app.UseBrowserLink();
                 app.UseDatabaseErrorPage();
             }
             else
             {
                 app.UseExceptionHandler("/Home/Error");
             }

             app.UseStaticFiles();

             app.UseAuthentication();

             app.UseMvc(routes =>
             {
                 routes.MapRoute(
                     name: "default",
                     template: "{controller=Home}/{action=Index}/{id?}");
             });
         }
     }
 }