ASP.NET Core中的UseJwtBearerAuthentication中间件可以轻松验证授权标头中的传入
JSON Web令牌.
如何验证通过cookie而不是标头传递的JWT？类似于UseCookieAuthentication,但是对于只包含JWT的cookie.
解决方法
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.
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.
在被调用以将令牌(ApplyTokenResponse())发送回客户端的令牌提供程序的方法中,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.IdentityToken);
// add the user's roles as claims
foreach (var role in roles)
{
identity.AddClaim(ClaimTypes.Role,role,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 = "/",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;
}
}
}
