學習ASP.NET Core Blazor程式設計系列二十七——JWT登入（2）

DotNet菜園發表於2023-03-05
ASP.NETBlazor程式設計JWT
 

     5.在Visual Studio 2022的解決方案資源管理器中，滑鼠左鍵選中“Utils”資料夾，右鍵單擊，在彈出選單中選擇“新增—>新建項”，在彈出對話方塊中，選擇“介面”，並將介面命名為“IJWTHelper”。如下圖。並新增如下程式碼： 

using Microsoft.IdentityModel.Tokens;
using System.Security.Claims;
 

namespace BlazorAppDemo.Utils
{

    public interface IJWTHelper

    {

        string CreateJwtToken<T>(T user);

        T GetToken<T>(string Token);

        IEnumerable<Claim> ParseToken(string token);

        string? ValidateJwtToken(IEnumerable<Claim> jwtToken);

        TokenValidationParameters ValidParameters();

    }
}

 

6.在Visual Studio 2022的解決方案資源管理器中，滑鼠左鍵選中“Utils”資料夾，右鍵單擊，在彈出選單中選擇“新增—>類”，在彈出對話方塊中，並將類命名為“JWTHelper”。並繼承IJWTHelper介面，新增如下程式碼：

 

using BlazorAppDemo.Models;
using Microsoft.IdentityModel.Tokens;
using System.IdentityModel.Tokens.Jwt;
using System.Reflection;
using System.Security.Claims;
using System.Text;
 
namespace BlazorAppDemo.Utils
{

    public class JWTHelper : IJWTHelper
    {
        private readonly IConfiguration _configuration;
        private readonly JwtSecurityTokenHandler _jwtSecurityTokenHandler;

        public JWTHelper(IConfiguration configuration, JwtSecurityTokenHandler jwtSecurityTokenHandler)
        {
            _configuration = configuration;
            _jwtSecurityTokenHandler = jwtSecurityTokenHandler;

        }
        /// <summary>
        /// 建立加密JwtToken
        /// </summary>
        /// <param name="user"></param>
        /// <returns></returns>

        public string CreateJwtToken<T>(T user)
        {
            var signingAlogorithm = SecurityAlgorithms.HmacSha256;

            var claimList = this.CreateClaimList(user);
            //Signature

            //取出私鑰並以utf8編碼位元組輸出
            var secretByte = Encoding.UTF8.GetBytes(_configuration["Authentication:SecretKey"]);
            //使用非對稱演算法對私鑰進行加密
            var signingKey = new SymmetricSecurityKey(secretByte);
            //使用HmacSha256來驗證加密後的私鑰生成數字簽名

            var signingCredentials = new SigningCredentials(signingKey, signingAlogorithm);
            //在 RFC 7519 規範中(Section#4)，一共定義了 7 個預設的 Claims。
            //生成Token
            var Token = new JwtSecurityToken(
          issuer: _configuration["Authentication:Issuer"], //釋出者
            audience: _configuration["Authentication:Audience"], //接收者
            claims: claimList, //存放的使用者資訊
            notBefore: DateTime.UtcNow, //釋出時間
            expires: DateTime.UtcNow.AddDays(1), //有效期設定為1天
            signingCredentials //數字簽名

            );

            //生成字串token
            var TokenStr = new JwtSecurityTokenHandler().WriteToken(Token);
            return TokenStr;
        }
 
        public T GetToken<T>(string Token)
        {
            Type t = typeof(T);
 
            object objA = Activator.CreateInstance(t);
            var b = _jwtSecurityTokenHandler.ReadJwtToken(Token);
            foreach (var item in b.Claims)
            {
                PropertyInfo _Property = t.GetProperty(item.Type);
                if (_Property != null && _Property.CanRead)
                {
                    _Property.SetValue(objA, item.Value, null);
                }
 
            }
            return (T)objA;
        }

        /// <summary>
        /// 建立包含使用者資訊的CalimList
        /// </summary>
        /// <param name="authUser"></param>
        /// <returns></returns>

        private List<Claim> CreateClaimList<T>(T authUser)
        {

            var Class = typeof(UserInfo);
            List<Claim> claimList = new List<Claim>();

            foreach (var item in Class.GetProperties())
            {

                if (item.Name == "Password")
                {

                    continue;
                }

                claimList.Add(new Claim(ClaimTypes.Name, Convert.ToString(item.GetValue(authUser))));
            }

            return claimList;
        }
    }
}

 

7. 在Visual Studio 2022的解決方案資源管理器中，使用滑鼠左鍵雙擊“Auth”資料夾中的“ImitateAuthStateProvider.cs”檔案，在文字編輯器中開啟，對程式碼進行修改。具體程式碼如下：

using BlazorAppDemo.Models;
using BlazorAppDemo.Utils;
using Microsoft.AspNetCore.Components.Authorization;
using System.Security.Claims;


namespace BlazorAppDemo.Auth
{
    public class ImitateAuthStateProvider : AuthenticationStateProvider
    {

        private readonly IJWTHelper jwt;
        public ImitateAuthStateProvider(IJWTHelper _jwt) => jwt = _jwt; //DI

        bool isLogin = false;
        string token = string.Empty;
        public override Task<AuthenticationState> GetAuthenticationStateAsync()
        {

            if (isLogin)
            {
 
                var claims = new List<Claim>()
            {

                new Claim(ClaimTypes.Name,"user"),
                new Claim(ClaimTypes.Role, "admin")
            };

                var anonymous = new ClaimsIdentity(claims, "testAuthType");
                return Task.FromResult(new AuthenticationState(new ClaimsPrincipal(anonymous)));

            }
            else

            {

            var anonymous = new ClaimsIdentity();
 
            return Task.FromResult(new AuthenticationState(new ClaimsPrincipal(anonymous)));
        }

        }
        public void Login(UserInfo request)
        {
 
            //1.驗證使用者賬號密碼是否正確
            if (request == null)

            {
                isLogin=false;
            }



            if (request.UserName == "user" && request.Password == "111111")
            {

                isLogin = true;
               token= jwt.CreateJwtToken<UserInfo>(request);

                Console.WriteLine($"JWT Token={token}");
            }

            NotifyAuthenticationStateChanged(GetAuthenticationStateAsync());
        }
    }
}

 

8.在Visual Studio 2022的解決方案管理器中，使用滑鼠左鍵，雙擊Program.cs檔案，將之在文字編輯器中開啟，將我們寫的JWTHelper與JwtSecurityTokenHandler、使用DI方式注入，新增JWT認證服務。具體程式碼如下：

using BlazorAppDemo.Data;
using BlazorAppDemo.Models;
using Microsoft.AspNetCore.Components;

using Microsoft.AspNetCore.Components.Web;
using Microsoft.Extensions.Configuration;
using Microsoft.EntityFrameworkCore;
using Microsoft.Extensions.Hosting;
using Microsoft.AspNetCore.Components.Authorization;

using BlazorAppDemo.Auth;
using Microsoft.AspNetCore.Authentication.JwtBearer;

using Microsoft.IdentityModel.Tokens;
using System.Text;
using System.IdentityModel.Tokens.Jwt;
using BlazorAppDemo.Utils;

 

var builder = WebApplication.CreateBuilder(args);
 

// Add services to the container.

builder.Services.AddRazorPages();

builder.Services.AddServerSideBlazor();

builder.Services.AddSingleton<WeatherForecastService>();

System.Console.WriteLine(ConfigHelper.Configuration["ConnectionStrings:BookContext"]);
builder.Services.AddDbContextFactory<BookContext>(opt =>
 opt.UseSqlServer(ConfigHelper.Configuration["ConnectionStrings:BookContext"]));

//builder.Services.AddScoped<AuthenticationStateProvider, ImitateAuthStateProvider>();

builder.Services.AddScoped<ImitateAuthStateProvider>();
builder.Services.AddScoped<AuthenticationStateProvider>(implementationFactory =>

implementationFactory.GetRequiredService<ImitateAuthStateProvider>());
builder.Services.AddScoped<JwtSecurityTokenHandler>();
 
//JWT
//JWT認證

builder.Services.AddAuthentication(JwtBearerDefaults.AuthenticationScheme).AddJwtBearer(options =>
{

    //取出私鑰
    var secretByte = Encoding.UTF8.GetBytes(builder.Configuration["Authentication:SecretKey"]);
    options.TokenValidationParameters = new TokenValidationParameters()

    {
        //驗證釋出者
        ValidateIssuer = true,
        ValidIssuer = builder.Configuration["Authentication:Issuer"],
        //驗證接收者
        ValidateAudience = true,

        ValidAudience = builder.Configuration["Authentication:Audience"],
        //驗證是否過期
        ValidateLifetime = true,
        //驗證私鑰
        IssuerSigningKey = new SymmetricSecurityKey(secretByte)
    };

});
//自己寫的Jwt 擴充套件
builder.Services.AddScoped<IJWTHelper,JWTHelper>();
 
 
var app = builder.Build();


// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}
 

using (var scope = app.Services.CreateScope())
{

    var services = scope.ServiceProvider;
    try
    {

        Console.WriteLine("資料庫開始初始化。");
        var context = services.GetRequiredService<BookContext>();
        // requires using Microsoft.EntityFrameworkCore;

        context.Database.Migrate();

        // Requires using RazorPagesMovie.Models;
        SeedData.Initialize(services);
        Console.WriteLine("資料庫初始化結束。");
    } 

    catch (Exception ex)

    {
        var logger = services.GetRequiredService<ILogger<Program>>();
        logger.LogError(ex, "資料庫資料初始化錯誤.");

    }
}


app.UseHttpsRedirection();
 
app.UseStaticFiles();

 
app.UseRouting();


app.MapBlazorHub();
app.MapFallbackToPage("/_Host");
app.UseAuthentication();
app.UseAuthorization();

 

app.Run();
9.在Visual Studio 2022的選單欄上，找到“除錯-->開始除錯”或是按F5鍵，Visual Studio 2022會生成BlazorAppDemo應用程式，瀏覽器中會Login登入頁面。

10.我們在使用者名稱輸入框中輸入使用者名稱，在密碼輸入框中輸入密碼，點選“登入”按鈕，進行模擬登入。我們進入了系統。並且生成了JWT Token。如下圖。

 

 

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