Program.cs

using Gallery_Blazor.Components;
using Gallery_Blazor.Data;
using Microsoft.AspNetCore.Authentication;
using Microsoft.AspNetCore.Authentication.Cookies;
using Microsoft.AspNetCore.Components.Authorization;
using Microsoft.AspNetCore.Components.Server;
using Microsoft.AspNetCore.Identity;
using Microsoft.AspNetCore.Mvc;
using Microsoft.EntityFrameworkCore;
using System.Security.Claims;

var builder = WebApplication.CreateBuilder(args);

// EF Core + SQL Server
builder.Services.AddDbContext<AppDbContext>(options =>
    options.UseSqlServer(builder.Configuration.GetConnectionString("DefaultConnection")));

// Identity
builder.Services.AddIdentity<IdentityUser, IdentityRole>(options =>
{
    options.SignIn.RequireConfirmedAccount = false;

    options.Password.RequireDigit = false;
    options.Password.RequireLowercase = false;
    options.Password.RequireUppercase = false;
    options.Password.RequireNonAlphanumeric = false;
    options.Password.RequiredLength = 4;
    options.Password.RequiredUniqueChars = 1;
})
.AddEntityFrameworkStores<AppDbContext>()
.AddDefaultTokenProviders();


// Blazor Server
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddRazorComponents().AddInteractiveServerComponents();

builder.Services.AddAuthentication("Identity.Application").AddCookie();
builder.Services.AddAuthorization();

// AuthenticationStateProvider
builder.Services.AddScoped<AuthenticationStateProvider, ServerAuthenticationStateProvider>();
var app = builder.Build();


// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error", createScopeForErrors: true);
}
app.UseStatusCodePagesWithReExecute("/not-found", createScopeForStatusCodePages: true);

app.MapStaticAssets();
app.MapRazorComponents<App>()
   .AddInteractiveServerRenderMode();

app.UseStaticFiles();
app.UseRouting();

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

app.UseAntiforgery();

app.MapPost("/auth/login", async (
    HttpContext http,
    SignInManager<IdentityUser> signInManager,
    [FromForm] string email,
    [FromForm] string password) =>
{
    var result = await signInManager.PasswordSignInAsync(
        email,
        password,
        isPersistent: false,
        lockoutOnFailure: false);

    if (result.Succeeded)
    {
        return Results.Redirect("/gallery");
    }

    return Results.Redirect("/login?Error=true&Message=Error");
})
.DisableAntiforgery();


app.Run();