今天就跟大家聊聊有关.Net Core中如何写自定义认证实现，可能很多人都不太了解，为了让大家更加了解，小编给大家总结了以下内容，希望大家根据这篇文章可以有所收获。
一、起因
最近项目中需要对项目同时支持JWT认证，以及自定义的认证校验方式认证。通过对官方文档了解，得到认证实现主要通过继承 IAuthenticationHandler 或 AuthenticationHandler<TOptions>来实现自定义认证的处理。
那么接下来实现一个自定义的认证访问。
二、自定义认证实现
1、根据前面内容得知，处理认证通过IAuthenticationHandler 实例处理；那么首先添加一个自定义IAuthenticationHandler 类型：
/// <summary>/// 方式一：自定义认证处理器/// </summary>public class CustomerAuthenticationHandler : IAuthenticationHandler{ private IUserService _userService; public CustomerAuthenticationHandler(IUserService userService) { _userService = userService; } /// <summary> /// 自定义认证Scheme名称 /// </summary> public const string CustomerSchemeName = "cusAuth"; private AuthenticationScheme _scheme; private HttpContext _context; /// <summary> /// 认证逻辑：认证校验主要逻辑 /// </summary> /// <returns></returns> public Task<AuthenticateResult> AuthenticateAsync() { AuthenticateResult result; _context.Request.Headers.TryGetValue("Authorization", out StringValues values); string valStr = values.ToString(); if (!string.IsNullOrWhiteSpace(valStr)) { //认证模拟basic认证：cusAuth YWRtaW46YWRtaW4= string[] authVal = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(valStr.Substring(CustomerSchemeName.Length + 1))).Split(':'); var loginInfo = new Dto.LoginDto() { Username = authVal[0], Password = authVal[1] }; var validVale = _userService.IsValid(loginInfo); if (!validVale) result = AuthenticateResult.Fail("未登陆"); else { var ticket = GetAuthTicket(loginInfo.Username, "admin"); result = AuthenticateResult.Success(ticket); } } else { result = AuthenticateResult.Fail("未登陆"); } return Task.FromResult(result); } /// <summary> /// 未登录时的处理 /// </summary> /// <param name="properties"></param> /// <returns></returns> public Task ChallengeAsync(AuthenticationProperties properties) { _context.Response.StatusCode = (int)HttpStatusCode.Unauthorized; return Task.CompletedTask; } /// <summary> /// 权限不足时处理 /// </summary> /// <param name="properties"></param> /// <returns></returns> public Task ForbidAsync(AuthenticationProperties properties) { _context.Response.StatusCode = (int)HttpStatusCode.Forbidden; return Task.CompletedTask; } /// <summary> /// 初始化认证 /// </summary> /// <param name="scheme"></param> /// <param name="context"></param> /// <returns></returns> public Task InitializeAsync(AuthenticationScheme scheme, HttpContext context) { _scheme = scheme; _context = context; return Task.CompletedTask; } #region 认证校验逻辑 /// <summary> /// 生成认证票据 /// </summary> /// <param name="name"></param> /// <param name="role"></param> /// <returns></returns> private AuthenticationTicket GetAuthTicket(string name, string role) { var claimsIdentity = new ClaimsIdentity(new Claim[] { new Claim(ClaimTypes.Name, name), new Claim(ClaimTypes.Role, role), }, CustomerSchemeName); var principal = new ClaimsPrincipal(claimsIdentity); return new AuthenticationTicket(principal, _scheme.Name); } #endregion}/// <summary>/// 方式二：继承已实现的基类/// </summary>public class SubAuthenticationHandler : AuthenticationHandler<AuthenticationSchemeOptions>{ public SubAuthenticationHandler(IOptionsMonitor<AuthenticationSchemeOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock) : base(options, logger, encoder, clock) { } protected override Task<AuthenticateResult> HandleAuthenticateAsync() { throw new NotImplementedException(); }}2、在Startup.cs中启用自定义认证：
public void ConfigureServices(IServiceCollection services){ //other code services.AddAuthentication(o => { x.DefaultAuthenticateScheme = CustomerAuthenticationHandler.CustomerSchemeName; x.DefaultChallengeScheme = CustomerAuthenticationHandler.CustomerSchemeName; o.AddScheme<CustomerAuthenticationHandler>(CustomerAuthenticationHandler.CustomerSchemeName, CustomerAuthenticationHandler.CustomerSchemeName); }); //other code}public void Configure(IApplicationBuilder app){ //other code app.UseRouting(); //在UseRouting后；UseEndpoints前添加以下代码 app.UseAuthentication(); app.UseAuthorization(); //other code app.UseEndpoints()}3、在控制器上添加认证标记，测试验证
//指定认证时，采用CustomerAuthenticationHandler.CustomerSchemeName[Authorize(AuthenticationSchemes = CustomerAuthenticationHandler.CustomerSchemeName)][Route("api/[controller]")][ApiController]public class AuditLogController : ControllerBase{ //code}调用
三、多认证支持
在实际项目中可能存在，对一个控制器支持多种认证方式如：常用的Jwt认证、自定义认证等，那么如何实现呢？
1、在Startup的ConfigureServices 方法中添加以下逻辑：
public void ConfigureServices(IServiceCollection services){ //other code services.Configure<JwtSetting>(Configuration.GetSection("JWTSetting")); var token = Configuration.GetSection("JWTSetting").Get<JwtSetting>(); //JWT认证 services.AddAuthentication(x => { x.DefaultAuthenticateScheme = JwtBearerDefaults.AuthenticationScheme; x.DefaultChallengeScheme = JwtBearerDefaults.AuthenticationScheme; //添加自定义认证处理器 x.AddScheme<CustomerAuthenticationHandler>(CustomerAuthenticationHandler.CustomerSchemeName, CustomerAuthenticationHandler.CustomerSchemeName); }).AddJwtBearer(x => { x.RequireHttpsMetadata = false; x.SaveToken = true; x.TokenValidationParameters = new TokenValidationParameters { ValidateIssuerSigningKey = true, IssuerSigningKey = new SymmetricSecurityKey(Encoding.ASCII.GetBytes(token.SecretKey)), ValidIssuer = token.Issuer, ValidAudience = token.Audience, ValidateIssuer = false, ValidateAudience = false }; }); //other code}2、在需要支持多种认证方式的控制器上添加标记：
//指定认证时，采用CustomerAuthenticationHandler.CustomerSchemeName[Authorize(AuthenticationSchemes = CustomerAuthenticationHandler.CustomerSchemeName)][Route("api/[controller]")][ApiController]public class AuditLogController : ControllerBase{ //code}//指定认证采用JWT [Authorize(AuthenticationSchemes = JwtBearerDefaults.AuthenticationScheme)] public class WeatherForecastController : ControllerBase { //code }这样就支持了两种认证方式
3、一个控制器支持多种认证类型：继承Jwt认证处理，并根据Scheme那么调用自定义的认证处理器：
/// <summary>/// 方式二：同时支持多种认证方式/// </summary>public class MultAuthenticationHandler : JwtBearerHandler{ public const string MultAuthName = "MultAuth"; IUserService _userService; public MultAuthenticationHandler(IOptionsMonitor<JwtBearerOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock, IUserService userService) : base(options, logger, encoder, clock) { _userService = userService; } protected override Task<AuthenticateResult> HandleAuthenticateAsync() { Context.Request.Headers.TryGetValue("Authorization", out StringValues values); string valStr = values.ToString(); if (valStr.StartsWith(CustomerAuthenticationHandler.CustomerSchemeName)) { var result = Valid(); if (result != null) return Task.FromResult(AuthenticateResult.Success(result)); else return Task.FromResult(AuthenticateResult.Fail("未认证")); } else return base.AuthenticateAsync(); } private AuthenticationTicket Valid() { Context.Request.Headers.TryGetValue("Authorization", out StringValues values); string valStr = values.ToString(); if (!string.IsNullOrWhiteSpace(valStr)) { //认证模拟basic认证：cusAuth YWRtaW46YWRtaW4= string[] authVal = System.Text.Encoding.UTF8.GetString(Convert.FromBase64String(valStr.Substring(CustomerAuthenticationHandler.CustomerSchemeName.Length + 1))).Split(':'); var loginInfo = new Dto.LoginDto() { Username = authVal[0], Password = authVal[1] }; if (_userService.IsValid(loginInfo)) return GetAuthTicket(loginInfo.Username, "admin"); } return null; } /// <summary> /// 生成认证票据 /// </summary> /// <param name="name"></param> /// <param name="role"></param> /// <returns></returns> private AuthenticationTicket GetAuthTicket(string name, string role) { var claimsIdentity = new ClaimsIdentity(new Claim[] { new Claim(ClaimTypes.Name, name), new Claim(ClaimTypes.Role, role), }, CustomerAuthenticationHandler.CustomerSchemeName); var principal = new ClaimsPrincipal(claimsIdentity); return new AuthenticationTicket(principal, CustomerAuthenticationHandler.CustomerSchemeName); }}.Net Core中的自定义认证主要通过实现IAuthenticationHandler 接口实现，如果要实现多认证方式通过AddScheme 应用自定义实现的认证处理器。
看完上述内容，你们对.Net Core中如何写自定义认证实现有进一步的了解吗？如果还想了解更多知识或者相关内容，请关注编程网行业资讯频道，感谢大家的支持。
