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如何验证通过cookie传递的JWT?

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ASP.NET Core中的 UseJwtBearerAuthentication 中间件可以轻松验证 Authorization 标头中的传入JSON Web标记 .

如何验证通过cookie而不是标头传递的JWT?像 UseCookieAuthentication 之类的东西,但对于只包含JWT的cookie .

2 回答

  • 15

    我建议你看一下以下的链接 .

    https://stormpath.com/blog/token-authentication-asp-net-core

    它们将JWT令牌存储在仅http的cookie中以防止XSS攻击 .

    然后,他们通过在Startup.cs中添加以下代码来验证cookie中的JWT令牌:

    app.UseCookieAuthentication(new CookieAuthenticationOptions
    {
        AutomaticAuthenticate = true,
        AutomaticChallenge = true,
        AuthenticationScheme = "Cookie",
        CookieName = "access_token",
        TicketDataFormat = new CustomJwtDataFormat(
            SecurityAlgorithms.HmacSha256,
            tokenValidationParameters)
    });
    

    CustomJwtDataFormat()是这里定义的自定义格式:

    public class CustomJwtDataFormat : ISecureDataFormat<AuthenticationTicket>
    {
        private readonly string algorithm;
        private readonly TokenValidationParameters validationParameters;
    
        public CustomJwtDataFormat(string algorithm, TokenValidationParameters validationParameters)
        {
            this.algorithm = algorithm;
            this.validationParameters = validationParameters;
        }
    
        public AuthenticationTicket Unprotect(string protectedText)
            => Unprotect(protectedText, null);
    
        public AuthenticationTicket Unprotect(string protectedText, string purpose)
        {
            var handler = new JwtSecurityTokenHandler();
            ClaimsPrincipal principal = null;
            SecurityToken validToken = null;
    
            try
            {
                principal = handler.ValidateToken(protectedText, this.validationParameters, out validToken);
    
                var validJwt = validToken as JwtSecurityToken;
    
                if (validJwt == null)
                {
                    throw new ArgumentException("Invalid JWT");
                }
    
                if (!validJwt.Header.Alg.Equals(algorithm, StringComparison.Ordinal))
                {
                    throw new ArgumentException($"Algorithm must be '{algorithm}'");
                }
    
                // Additional custom validation of JWT claims here (if any)
            }
            catch (SecurityTokenValidationException)
            {
                return null;
            }
            catch (ArgumentException)
            {
                return null;
            }
    
            // Validation passed. Return a valid AuthenticationTicket:
            return new AuthenticationTicket(principal, new AuthenticationProperties(), "Cookie");
        }
    
        // This ISecureDataFormat implementation is decode-only
        public string Protect(AuthenticationTicket data)
        {
            throw new NotImplementedException();
        }
    
        public string Protect(AuthenticationTicket data, string purpose)
        {
            throw new NotImplementedException();
        }
    }
    

    另一个解决方案是编写一些自定义中间件来拦截每个请求,查看它是否有cookie,从cookie中提取JWT并在它到达控制器的Authorize过滤器之前动态添加Authorization标头 . 以下是一些适用于OAuth令牌的代码,以获取想法:

    using System.Threading.Tasks;
    using Microsoft.AspNetCore.Http;
    using Microsoft.Extensions.Logging;
    
    namespace MiddlewareSample
    {
        public class JWTInHeaderMiddleware
        {
            private readonly RequestDelegate _next;
    
            public JWTInHeaderMiddleware(RequestDelegate next)
            {
                _next = next;
            }
    
            public async Task Invoke(HttpContext context)
            {
               var authenticationCookieName = "access_token";
               var cookie = context.Request.Cookies[authenticationCookieName];
               if (cookie != null)
               {
                   var token = JsonConvert.DeserializeObject<AccessToken>(cookie);
                   context.Request.Headers.Append("Authorization", "Bearer " + token.access_token);
               }
    
               await _next.Invoke(context);
            }
        }
    }
    

    ...其中AccessToken是以下类:

    public class AccessToken
    {
        public string token_type { get; set; }
        public string access_token { get; set; }
        public string expires_in { get; set; }
    }
    

    希望这可以帮助 .

    注意:同样重要的是要注意这种做事方式(仅限http的cookie中的令牌)将有助于防止XSS攻击但是不能免受跨站点请求伪造(CSRF)攻击,因此您必须使用防伪令牌或设置自定义标头以防止这些 .

    此外,如果您不进行任何内容清理,攻击者仍然可以运行XSS脚本代表用户发出请求,即使启用了仅http cookie和CRSF保护 . 但是,攻击者无法窃取仅包含令牌的http的cookie,攻击者也无法从第三方网站发出请求 .

    因此,您仍应对用户生成的内容(如评论等)执行大量清理工作 .

    编辑:在评论中写道,博客文章链接和代码是由OP自己在几天前提出这个问题后编写的 .

    对于那些对另一种“cookie中的令牌”感兴趣的方法来减少XSS暴露,他们可以使用oAuth中间件,例如ASP.NET Core中的OpenId Connect Server .

    在调用令牌提供程序以将令牌(ApplyTokenResponse())发送回客户端的方法中,您可以序列化令牌并将其存储到仅限http的cookie中:

    using System.Security.Claims;
    using System.Threading.Tasks;
    using AspNet.Security.OpenIdConnect.Extensions;
    using AspNet.Security.OpenIdConnect.Server;
    using Newtonsoft.Json;
    
    namespace Shared.Providers
    {
    public class AuthenticationProvider : OpenIdConnectServerProvider
    {
    
        private readonly IApplicationService _applicationservice;
        private readonly IUserService _userService;
        public AuthenticationProvider(IUserService userService, 
                                      IApplicationService applicationservice)
        {
            _applicationservice = applicationservice;
            _userService = userService;
        }
    
        public override Task ValidateTokenRequest(ValidateTokenRequestContext context)
        {
            if (string.IsNullOrEmpty(context.ClientId))
            {
                context.Reject(
                    error: OpenIdConnectConstants.Errors.InvalidRequest,
                    description: "Missing credentials: ensure that your credentials were correctly " +
                                 "flowed in the request body or in the authorization header");
    
                return Task.FromResult(0);
            }
    
            #region Validate Client
            var application = _applicationservice.GetByClientId(context.ClientId);
    
                if (applicationResult == null)
                {
                    context.Reject(
                                error: OpenIdConnectConstants.Errors.InvalidClient,
                                description: "Application not found in the database: ensure that your client_id is correct");
    
                    return Task.FromResult(0);
                }
                else
                {
                    var application = applicationResult.Data;
                    if (application.ApplicationType == (int)ApplicationTypes.JavaScript)
                    {
                        // Note: the context is marked as skipped instead of validated because the client
                        // is not trusted (JavaScript applications cannot keep their credentials secret).
                        context.Skip();
                    }
                    else
                    {
                        context.Reject(
                                error: OpenIdConnectConstants.Errors.InvalidClient,
                                description: "Authorization server only handles Javascript application.");
    
                        return Task.FromResult(0);
                    }
                }
            #endregion Validate Client
    
            return Task.FromResult(0);
        }
    
        public override async Task HandleTokenRequest(HandleTokenRequestContext context)
        {
            if (context.Request.IsPasswordGrantType())
            {
                var username = context.Request.Username.ToLowerInvariant();
                var user = await _userService.GetUserLoginDtoAsync(
                    // filter
                    u => u.UserName == username
                );
    
                if (user == null)
                {
                    context.Reject(
                            error: OpenIdConnectConstants.Errors.InvalidGrant,
                            description: "Invalid username or password.");
                    return;
                }
                var password = context.Request.Password;
    
                var passWordCheckResult = await _userService.CheckUserPasswordAsync(user, context.Request.Password);
    
    
                if (!passWordCheckResult)
                {
                    context.Reject(
                            error: OpenIdConnectConstants.Errors.InvalidGrant,
                            description: "Invalid username or password.");
                    return;
                }
    
                var roles = await _userService.GetUserRolesAsync(user);
    
                if (!roles.Any())
                {
                    context.Reject(
                            error: OpenIdConnectConstants.Errors.InvalidRequest,
                            description: "Invalid user configuration.");
                    return;
                }
            // add the claims
            var identity = new ClaimsIdentity(context.Options.AuthenticationScheme);
            identity.AddClaim(ClaimTypes.NameIdentifier, user.Id, OpenIdConnectConstants.Destinations.AccessToken, OpenIdConnectConstants.Destinations.IdentityToken);
            identity.AddClaim(ClaimTypes.Name, user.UserName, OpenIdConnectConstants.Destinations.AccessToken, OpenIdConnectConstants.Destinations.IdentityToken);
             // add the user's roles as claims
            foreach (var role in roles)
            {
                identity.AddClaim(ClaimTypes.Role, role, OpenIdConnectConstants.Destinations.AccessToken, OpenIdConnectConstants.Destinations.IdentityToken);
            }
             context.Validate(new ClaimsPrincipal(identity));
            }
            else
            {
                context.Reject(
                        error: OpenIdConnectConstants.Errors.InvalidGrant,
                        description: "Invalid grant type.");
                return;
            }
    
            return;
        }
    
        public override Task ApplyTokenResponse(ApplyTokenResponseContext context)
        {
            var token = context.Response.Root;
    
            var stringified = JsonConvert.SerializeObject(token);
            // the token will be stored in a cookie on the client
            context.HttpContext.Response.Cookies.Append(
                "exampleToken",
                stringified,
                new Microsoft.AspNetCore.Http.CookieOptions()
                {
                    Path = "/",
                    HttpOnly = true, // to prevent XSS
                    Secure = false, // set to true in production
                    Expires = // your token life time
                }
            );
    
            return base.ApplyTokenResponse(context);
        }
    }
    }
    

    然后,您需要确保每个请求都附加了cookie . 您还必须编写一些中间件来拦截cookie并将其设置为标头:

    public class AuthorizationHeader
    {
        private readonly RequestDelegate _next;
    
        public AuthorizationHeader(RequestDelegate next)
        {
            _next = next;
        }
    
        public async Task Invoke(HttpContext context)
        {
            var authenticationCookieName = "exampleToken";
            var cookie = context.Request.Cookies[authenticationCookieName];
            if (cookie != null)
            {
    
                if (!context.Request.Path.ToString().ToLower().Contains("/account/logout"))
                {
                    if (!string.IsNullOrEmpty(cookie))
                    {
                        var token = JsonConvert.DeserializeObject<AccessToken>(cookie);
                        if (token != null)
                        {
                            var headerValue = "Bearer " + token.access_token;
                            if (context.Request.Headers.ContainsKey("Authorization"))
                            {
                                context.Request.Headers["Authorization"] = headerValue;
                            }else
                            {
                                context.Request.Headers.Append("Authorization", headerValue);
                            }
                        }
                    }
                    await _next.Invoke(context);
                }
                else
                {
                    // this is a logout request, clear the cookie by making it expire now
                    context.Response.Cookies.Append(authenticationCookieName,
                                                    "",
                                                    new Microsoft.AspNetCore.Http.CookieOptions()
                                                    {
                                                        Path = "/",
                                                        HttpOnly = true,
                                                        Secure = false,
                                                        Expires = DateTime.UtcNow.AddHours(-1)
                                                    });
                    context.Response.Redirect("/");
                    return;
                }
            }
            else
            {
                await _next.Invoke(context);
            }
        }
    }
    

    在startup.cs的Configure()中:

    // use the AuthorizationHeader middleware
        app.UseMiddleware<AuthorizationHeader>();
        // Add a new middleware validating access tokens.
        app.UseOAuthValidation();
    

    然后,您可以正常使用“授权”属性 .

    [Authorize(Roles = "Administrator,User")]
    

    此解决方案适用于api和mvc应用程序 . 但是对于ajax和fetch请求,你必须编写一些自定义中间件,它不会将用户重定向到登录页面而是返回401:

    public class RedirectHandler
    {
        private readonly RequestDelegate _next;
    
        public RedirectHandler(RequestDelegate next)
        {
            _next = next;
        }
    
        public bool IsAjaxRequest(HttpContext context)
        {
            return context.Request.Headers["X-Requested-With"] == "XMLHttpRequest";
        }
    
        public bool IsFetchRequest(HttpContext context)
        {
            return context.Request.Headers["X-Requested-With"] == "Fetch";
        }
    
        public async Task Invoke(HttpContext context)
        {
            await _next.Invoke(context);
            var ajax = IsAjaxRequest(context);
            var fetch = IsFetchRequest(context);
            if (context.Response.StatusCode == 302 && (ajax || fetch))
            {
                context.Response.Clear();
                context.Response.StatusCode = (int)HttpStatusCode.Unauthorized;
                await context.Response.WriteAsync("Unauthorized");
                return;
            }
        }
    }
    
  • 6

    我成功实现了中间件(基于Darxtar的答案):

    // TokenController.cs
    
    public IActionResult Some()
    {
        ...
    
        var tokenString = new JwtSecurityTokenHandler().WriteToken(token);
    
        Response.Cookies.Append(
            "x",
            tokenString,
            new CookieOptions()
            {
                Path = "/"
            }
        );
    
        return StatusCode(200, tokenString);
    }
    
    
    // JWTInHeaderMiddleware.cs
    
    public class JWTInHeaderMiddleware
    {
        private readonly RequestDelegate _next;
    
        public JWTInHeaderMiddleware(RequestDelegate next)
        {
            _next = next;
        }
    
        public async Task Invoke(HttpContext context)
        {
            var name = "x";
            var cookie = context.Request.Cookies[name];
    
            if (cookie != null)
                if (!context.Request.Headers.ContainsKey("Authorization"))
                    context.Request.Headers.Append("Authorization", "Bearer " + cookie);
    
            await _next.Invoke(context);
        }
    }
    
    // Startup.cs
    
    public void Configure(IApplicationBuilder app, IHostingEnvironment env)
    {
        ...
    
        app.UseMiddleware<JWTInHeaderMiddleware>();
    
        ...
    }
    

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