以前在web端的身份認證都是基于Cookie | Session的身份認證, 在沒有更多的終端出現之前，這樣做也沒有什么問題，但在Web API時代，你所需要面對的就不止是瀏覽器了，還有各種客戶端，這樣就有了一個問題，這些客戶端是不知道cookie是什么鬼的。 (cookie其實是瀏覽器搞出來的小貓膩，用來保持會話的，但HTTP本身是無狀態的, 各種客戶端能提供的無非也就是HTTP操作的API)
而基于Token的身份認證就是應對這種變化而生的，它更開放，安全性也更高。
基于Token的身份認證有很多種實現方式，但我們這里只使用微軟提供的API。
接下來的例子將帶領大家完成一個使用微軟JwtSecurityTokenHandler完成一個基于beare token的身份認證。
注意：這種文章屬于Step by step教程，跟著做才不至于看暈，下載完整代碼分析代碼結構才有意義。
前期準備
推薦使用VS2015 Update3作為你的IDE
你需要安裝.NET Core的運行環境以及開發工具
創建項目
在VS中新建項目，項目類型選擇ASP.NET Core Web Application(.NET Core), 輸入項目名稱為CSTokenBaseAuth
Coding
創建一些輔助類
在項目根目錄下創建一個文件夾Auth,并添加RSAKeyHelper.cs以及TokenAuthOption.cs兩個文件
在RSAKeyHelper.cs中
using System.Security.Cryptography;namespace CSTokenBaseAuth.Auth{ public class RSAKeyHelper { public static RSAParameters GenerateKey() { using (var key = new RSACryptoServiceProvider(2048)) { return key.ExportParameters(true); } } }}在TokenAuthOption.cs中
using System;using Microsoft.IdentityModel.Tokens;namespace CSTokenBaseAuth.Auth{ public class TokenAuthOption { public static string Audience { get; } = "ExampleAudience"; public static string Issuer { get; } = "ExampleIssuer"; public static RsaSecurityKey Key { get; } = new RsaSecurityKey(RSAKeyHelper.GenerateKey()); public static SigningCredentials SigningCredentials { get; } = new SigningCredentials(Key, SecurityAlgorithms.RsaSha256Signature); public static TimeSpan ExpiresSpan { get; } = TimeSpan.FromMinutes(20); }}Startup.cs
在ConfigureServices中添加如下代碼：
services.AddAuthorization(auth =>{ auth.AddPolicy("Bearer", new AuthorizationPolicyBuilder() .AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme?) .RequireAuthenticatedUser().Build());});完整的代碼應該是這樣
public void ConfigureServices(IServiceCollection services){ // Add framework services. services.AddApplicationInsightsTelemetry(Configuration); // Enable the use of an [Authorize("Bearer")] attribute on methods and classes to protect. services.AddAuthorization(auth => { auth.AddPolicy("Bearer", new AuthorizationPolicyBuilder() .AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme?) .RequireAuthenticatedUser().Build()); }); services.AddMvc();}在Configure方法中添加如下代碼
app.UseExceptionHandler(appBuilder => { appBuilder.Use(async (context, next) => { var error = context.Features[typeof(IExceptionHandlerFeature)] as IExceptionHandlerFeature; //when authorization has failed, should retrun a json message to client if (error != null && error.Error is SecurityTokenExpiredException) { context.Response.StatusCode = 401; context.Response.ContentType = "application/json"; await context.Response.WriteAsync(JsonConvert.SerializeObject( new { authenticated = false, tokenExpired = true } )); } //when orther error, retrun a error message json to client else if (error != null && error.Error != null) { context.Response.StatusCode = 500; context.Response.ContentType = "application/json"; await context.Response.WriteAsync(JsonConvert.SerializeObject( new { success = false, error = error.Error.Message } )); } //when no error, do next. else await next(); });});這段代碼主要是Handle Error用的，比如當身份認證失敗的時候會拋出異常，而這里就是處理這個異常的。
接下來在相同的方法中添加如下代碼，
app.UseExceptionHandler(appBuilder => { appBuilder.Use(async (context, next) => { var error = context.Features[typeof(IExceptionHandlerFeature)] as IExceptionHandlerFeature; //when authorization has failed, should retrun a json message to client if (error != null && error.Error is SecurityTokenExpiredException) { context.Response.StatusCode = 401; context.Response.ContentType = "application/json"; await context.Response.WriteAsync(JsonConvert.SerializeObject( new { authenticated = false, tokenExpired = true } )); } //when orther error, retrun a error message json to client else if (error != null && error.Error != null) { context.Response.StatusCode = 500; context.Response.ContentType = "application/json"; await context.Response.WriteAsync(JsonConvert.SerializeObject( new { success = false, error = error.Error.Message } )); } //when no error, do next. else await next(); });});應用JwtBearerAuthentication
app.UseJwtBearerAuthentication(new JwtBearerOptions { TokenValidationParameters = new TokenValidationParameters { IssuerSigningKey = TokenAuthOption.Key, ValidAudience = TokenAuthOption.Audience, ValidIssuer = TokenAuthOption.Issuer, ValidateIssuerSigningKey = true, ValidateLifetime = true, ClockSkew = TimeSpan.FromMinutes(0) }});完整的代碼應該是這樣
using System;using Microsoft.AspNetCore.Builder;using Microsoft.AspNetCore.Hosting;using Microsoft.Extensions.Configuration;using Microsoft.Extensions.DependencyInjection;using Microsoft.Extensions.Logging;using Microsoft.AspNetCore.Authorization;using Microsoft.AspNetCore.Authentication.JwtBearer;using CSTokenBaseAuth.Auth;using Microsoft.AspNetCore.Diagnostics;using Microsoft.IdentityModel.Tokens;using Microsoft.AspNetCore.Http;using Newtonsoft.Json;namespace CSTokenBaseAuth{ public class Startup { public Startup(IHostingEnvironment env) { var builder = new ConfigurationBuilder() .SetBasePath(env.ContentRootPath) .AddJsonFile("appsettings.json", optional: true, reloadOnChange: true) .AddJsonFile($"appsettings.{env.EnvironmentName}.json", optional: true); if (env.IsEnvironment("Development")) { // This will push telemetry data through Application Insights pipeline faster, allowing you to view results immediately. builder.AddApplicationInsightsSettings(developerMode: true); } builder.AddEnvironmentVariables(); Configuration = builder.Build(); } public IConfigurationRoot Configuration { get; } // This method gets called by the runtime. Use this method to add services to the container public void ConfigureServices(IServiceCollection services) { // Add framework services. services.AddApplicationInsightsTelemetry(Configuration); // Enable the use of an [Authorize("Bearer")] attribute on methods and classes to protect. services.AddAuthorization(auth => { auth.AddPolicy("Bearer", new AuthorizationPolicyBuilder() .AddAuthenticationSchemes(JwtBearerDefaults.AuthenticationScheme?) .RequireAuthenticatedUser().Build()); }); services.AddMvc(); } // This method gets called by the runtime. Use this method to configure the HTTP request pipeline public void Configure(IApplicationBuilder app, IHostingEnvironment env, ILoggerFactory loggerFactory) { loggerFactory.AddConsole(Configuration.GetSection("Logging")); loggerFactory.AddDebug(); app.UseApplicationInsightsRequestTelemetry(); app.UseApplicationInsightsExceptionTelemetry(); #region Handle Exception app.UseExceptionHandler(appBuilder => { appBuilder.Use(async (context, next) => { var error = context.Features[typeof(IExceptionHandlerFeature)] as IExceptionHandlerFeature; //when authorization has failed, should retrun a json message to client if (error != null && error.Error is SecurityTokenExpiredException) { context.Response.StatusCode = 401; context.Response.ContentType = "application/json"; await context.Response.WriteAsync(JsonConvert.SerializeObject( new { authenticated = false, tokenExpired = true } )); } //when orther error, retrun a error message json to client else if (error != null && error.Error != null) { context.Response.StatusCode = 500; context.Response.ContentType = "application/json"; await context.Response.WriteAsync(JsonConvert.SerializeObject( new { success = false, error = error.Error.Message } )); } //when no error, do next. else await next(); }); }); #endregion #region UseJwtBearerAuthentication app.UseJwtBearerAuthentication(new JwtBearerOptions { TokenValidationParameters = new TokenValidationParameters { IssuerSigningKey = TokenAuthOption.Key, ValidAudience = TokenAuthOption.Audience, ValidIssuer = TokenAuthOption.Issuer, ValidateIssuerSigningKey = true, ValidateLifetime = true, ClockSkew = TimeSpan.FromMinutes(0) } }); #endregion app.UseMvc(routes => { routes.MapRoute( name: "default", template: "{controller=Login}/{action=Index}"); }); } }}在Controllers中新建一個Web API Controller Class，命名為TokenAuthController.cs。我們將在這里完成登錄授權
在同文件下添加兩個類，分別用來模擬用戶模型，以及用戶存儲，代碼應該是這樣
public class User{ public Guid ID { get; set; } public string Username { get; set; } public string Password { get; set; }}public static class UserStorage{ public static List<User> Users { get; set; } = new List<User> { new User {ID=Guid.NewGuid(),Username="user1",Password = "user1psd" }, new User {ID=Guid.NewGuid(),Username="user2",Password = "user2psd" }, new User {ID=Guid.NewGuid(),Username="user3",Password = "user3psd" } };}接下來在TokenAuthController.cs中添加如下方法
private string GenerateToken(User user, DateTime expires){ var handler = new JwtSecurityTokenHandler(); ClaimsIdentity identity = new ClaimsIdentity( new GenericIdentity(user.Username, "TokenAuth"), new[] { new Claim("ID", user.ID.ToString()) } ); var securityToken = handler.CreateToken(new SecurityTokenDescriptor { Issuer = TokenAuthOption.Issuer, Audience = TokenAuthOption.Audience, SigningCredentials = TokenAuthOption.SigningCredentials, Subject = identity, Expires = expires }); return handler.WriteToken(securityToken);}該方法僅僅只是生成一個Auth Token,接下來我們來添加另外一個方法來調用它
在相同文件中添加如下代碼
[HttpPost]public string GetAuthToken(User user){ var existUser = UserStorage.Users.FirstOrDefault(u => u.Username == user.Username && u.Password == user.Password); if (existUser != null) { var requestAt = DateTime.Now; var expiresIn = requestAt + TokenAuthOption.ExpiresSpan; var token = GenerateToken(existUser, expiresIn); return JsonConvert.SerializeObject(new { stateCode = 1, requertAt = requestAt, expiresIn = TokenAuthOption.ExpiresSpan.TotalSeconds, accessToken = token }); } else { return JsonConvert.SerializeObject(new { stateCode = -1, errors = "Username or password is invalid" }); }}該文件完整的代碼應該是這樣
using System;using System.Collections.Generic;using System.Linq;using System.Threading.Tasks;using Microsoft.AspNetCore.Mvc;using Newtonsoft.Json;using System.IdentityModel.Tokens.Jwt;using System.Security.Claims;using System.Security.Principal;using Microsoft.IdentityModel.Tokens;using CSTokenBaseAuth.Auth;namespace CSTokenBaseAuth.Controllers{ [Route("api/[controller]")] public class TokenAuthController : Controller { [HttpPost] public string GetAuthToken(User user) { var existUser = UserStorage.Users.FirstOrDefault(u => u.Username == user.Username && u.Password == user.Password); if (existUser != null) { var requestAt = DateTime.Now; var expiresIn = requestAt + TokenAuthOption.ExpiresSpan; var token = GenerateToken(existUser, expiresIn); return JsonConvert.SerializeObject(new { stateCode = 1, requertAt = requestAt, expiresIn = TokenAuthOption.ExpiresSpan.TotalSeconds, accessToken = token }); } else { return JsonConvert.SerializeObject(new { stateCode = -1, errors = "Username or password is invalid" }); } } private string GenerateToken(User user, DateTime expires) { var handler = new JwtSecurityTokenHandler(); ClaimsIdentity identity = new ClaimsIdentity( new GenericIdentity(user.Username, "TokenAuth"), new[] { new Claim("ID", user.ID.ToString()) } ); var securityToken = handler.CreateToken(new SecurityTokenDescriptor { Issuer = TokenAuthOption.Issuer, Audience = TokenAuthOption.Audience, SigningCredentials = TokenAuthOption.SigningCredentials, Subject = identity, Expires = expires }); return handler.WriteToken(securityToken); } } public class User { public Guid ID { get; set; } public string Username { get; set; } public string Password { get; set; } } public static class UserStorage { public static List<User> Users { get; set; } = new List<User> { new User {ID=Guid.NewGuid(),Username="user1",Password = "user1psd" }, new User {ID=Guid.NewGuid(),Username="user2",Password = "user2psd" }, new User {ID=Guid.NewGuid(),Username="user3",Password = "user3psd" } }; }}接下來我們來完成授權驗證部分
在Controllers中新建一個Web API Controller Class，命名為ValuesController.cs
在其中添加如下代碼
public string Get(){ var claimsIdentity = User.Identity as ClaimsIdentity; var id = claimsIdentity.Claims.FirstOrDefault(c => c.Type == "ID").Value; return $"Hello! {HttpContext.User.Identity.Name}, your ID is:{id}";}為方法添加裝飾屬性
[HttpGet][Authorize("Bearer")]完整的文件代碼應該是這樣using System.Linq;using Microsoft.AspNetCore.Mvc;using Microsoft.AspNetCore.Authorization;using System.Security.Claims;namespace CSTokenBaseAuth.Controllers{ [Route("api/[controller]")] public class ValuesController : Controller { [HttpGet] [Authorize("Bearer")] public string Get() { var claimsIdentity = User.Identity as ClaimsIdentity; var id = claimsIdentity.Claims.FirstOrDefault(c => c.Type == "ID").Value; return $"Hello! {HttpContext.User.Identity.Name}, your ID is:{id}"; } }}最后讓我們來添加視圖
在Controllers中新建一個Web Controller Class，命名為LoginController.cs
其中的代碼應該是這樣
using Microsoft.AspNetCore.Mvc;namespace CSTokenBaseAuth.Controllers{ [Route("[controller]/[action]")] public class LoginController : Controller { public IActionResult Index() { return View(); } }}在項目Views目錄下新建一個名為Login的目錄，并在其中新建一個Index.cshtml文件。
代碼應該是這個樣子
<html xmlns="http://www.w3.org/1999/xhtml"><head> <title></title></head><body> <button id="getToken">getToken</button> <button id="requestAPI">requestAPI</button> <script src="https://code.jquery.com/jquery-3.1.1.min.js"></script> <script> $(function () { var accessToken = undefined; $("#getToken").click(function () { $.post( "/api/TokenAuth", { Username: "user1", Password: "user1psd" }, function (data) { console.log(data); if (data.stateCode == 1) { accessToken = data.accessToken; $.ajaxSetup({ headers: { "Authorization": "Bearer " + accessToken } }); } }, "json" ); }) $("#requestAPI").click(function () { $.get("/api/Values", {}, function (data) { alert(data); }, "text"); }) }) </script></body></html>以上就是本文的全部內容，希望對大家的學習有所幫助，也希望大家多多支持VeVb武林網。
新聞熱點
疑難解答
圖片精選
