JWT实现的最小WebAPI2+OAuth:始终返回401

Question

我正在尝试实现一个简单的WebAPI2项目，用JWT令牌保护我的API函数。由于我对此相当陌生，我主要遵循以下教程作为指导：http://bitoftech.net/2015/01/21/asp-net-identity-2-with-asp-net-web-api-2-accounts-management/其代码位于https://github.com/tjoudeh/AspNetIdentity.WebApi和http://odetocode.com/blogs/scott/archive/2015/01/15/using-json-web-tokens-with-katana-and-webapi.aspx.

编辑#1：请参阅底部的：解决了client_id=null的问题。

当然，我的实现中有几个细节发生了变化，随着我的学习，这些细节应该是最小的，我目前的要求也没有那么复杂：我不使用第三方JWT或安全库(如Thinktecture或Jamie KurtzJwtAuthForWebAPI)，而是只使用MS JWT组件，也不需要2FA或外部登录，因为这将是由管理员注册用户的客户端应用程序使用的企业API。

我设法实现了一个返回JWT令牌的API，但当我用它向任何受保护的API发出请求时(当然，不受保护的API确实有效)，请求总是被拒绝，并出现401-Unauthorized错误。api/token端点上的示例请求/响应如下所示：

请求：

POST http://localhost:50505/token HTTP/1.1
Host: localhost:50505
Connection: keep-alive
Content-Length: 56
Accept: application/json, text/plain, */*
Origin: http://localhost:50088
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.118 Safari/537.36
Content-Type: application/x-www-form-urlencoded;charset=UTF-8
Referer: http://localhost:50088/dist/
Accept-Encoding: gzip, deflate
Accept-Language: en-US,en;q=0.8,it;q=0.6
grant_type=password&username=Zeus&password=ThePasswordHere

响应：

HTTP/1.1 200 OK
Cache-Control: no-cache
Pragma: no-cache
Content-Length: 343
Content-Type: application/json;charset=UTF-8
Expires: -1
Server: Microsoft-IIS/8.0
Access-Control-Allow-Origin: http://localhost:50088
Access-Control-Allow-Credentials: true
X-SourceFiles: =?UTF-8?B?QzpcUHJvamVjdHNcNDViXEV4b1xJYW5pdG9yXElhbml0b3IuV2ViQXBpXHRva2Vu?=
X-Powered-By: ASP.NET
Date: Mon, 13 Apr 2015 22:16:50 GMT
{"access_token":"eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1bmlxdWVfbmFtZSI6IlpldXMiLCJyb2xlIjoiYWRtaW5pc3RyYXRvciIsImlzcyI6Imh0dHA6Ly9sb2NhbGhvc3Q6NTA1MDUiLCJhdWQiOiIwZDQ1ZTljZWM4MzY0NmI2YTE3Mzg0N2VjOWM5NmY3ZiIsImV4cCI6MTQyOTA0OTgwOSwibmJmIjoxNDI4OTYzNDA5fQ.-GFvtEfNI7Y8tf6Ln1MpxJc4yORuf2gzksGjRbSMEnU","token_type":"bearer","expires_in":86399}

如果我在http://jwt.io/)我得到了JWT负载的JSON：

{
"unique_name": "Zeus",
"role": "administrator",
"iss": "http://localhost:50505",
"aud": "0d45e9cec83646b6a173847ec9c96f7f",
"exp": 1429049809,
"nbf": 1428963409
}

然而，任何具有类似令牌的请求(此处为示例模板中使用的"规范"APIValuesController)，如下所示(我省略了正确发出的预发OPTIONSCORS请求)：

GET http://localhost:50505/api/values HTTP/1.1
Host: localhost:50505
Connection: keep-alive
Accept: application/json, text/plain, */*
Origin: http://localhost:50088
User-Agent: Mozilla/5.0 (Windows NT 6.3; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/41.0.2272.118 Safari/537.36
Authorization: Bearer eyJ0eXAiOiJKV1QiLCJhbGciOiJIUzI1NiJ9.eyJ1bmlxdWVfbmFtZSI6IlpldXMiLCJyb2xlIjoiYWRtaW5pc3RyYXRvciIsImlzcyI6Imh0dHA6Ly9sb2NhbGhvc3Q6NTA1MDUiLCJhdWQiOiIwZDQ1ZTljZWM4MzY0NmI2YTE3Mzg0N2VjOWM5NmY3ZiIsImV4cCI6MTQyOTA4MzAzOCwibmJmIjoxNDI4OTk2NjM4fQ.i5ik6ggSzoV2Nz-1_Od5fZVKxBpgOmEJcQN00YsG_DU
Referer: http://localhost:50088/dist/
Accept-Encoding: gzip, deflate, sdch
Accept-Language: en-US,en;q=0.8,it;q=0.6

401失败：

HTTP/1.1 401 Unauthorized
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/json; charset=utf-8
Expires: -1
Server: Microsoft-IIS/8.0
Access-Control-Allow-Origin: http://localhost:50088
Access-Control-Allow-Credentials: true
X-AspNet-Version: 4.0.30319
X-SourceFiles: =?UTF-8?B?QzpcUHJvamVjdHNcNDViXEV4b1xJYW5pdG9yXElhbml0b3IuV2ViQXBpXGFwaVx2YWx1ZXM=?=
X-Powered-By: ASP.NET
Date: Tue, 14 Apr 2015 07:30:53 GMT
Content-Length: 61
{"message":"Authorization has been denied for this request."}

鉴于这对像我这样的安全新手来说是一个相当复杂的话题，在接下来的内容中，我将描述我的解决方案的基本方面，这样专家们就有望为我提供解决方案，新来者也可以找到一些最新的指导。

数据层

我使用EntityFramework在一个单独的DLL项目中创建了我的数据层，其中包括我的IdentityDbContext派生的数据上下文及其实体(User和Audience)。User实体只是为名字和姓氏添加了几个字符串属性。Audience实体用于为多个受众提供基础设施；它有一个ID(由字符串属性表示的GUID)、一个名称(仅用于提供人性化标签)和一个base-64编码的共享密钥。

使用迁移，我创建了数据库，并为其植入了管理员用户和测试受众。

Web API

1.启动模板

我创建了一个空的WebApp项目，包括WebAPI库，并且没有用户身份验证，因为默认的身份验证模板对于我的有限目的来说过于臃肿，并且对于学习者来说有太多移动部分。我手动添加了所需的NuGet包，最终是：

EntityFramework
Microsoft.AspNet.Identity.EntityFramework
Microsoft.AspNet.Cors
Microsoft.AspNet.Identity.Owin
Microsoft.AspNet.WebApi
Microsoft.AspNet.WebApi.Client
Microsoft.AspNet.WebApi.Core
Microsoft.AspNet.WebApi.Owin
Microsoft.AspNet.WebApi.WebHost
Microsoft.Owin
Microsoft.Owin.Cors
Microsoft.Owin.Host.SystemWeb
Microsoft.Owin.Security
Microsoft.Owin.Security.Cookies
Microsoft.Owin.Security.Jwt
Microsoft.Owin.Security.OAuth
Newtonsoft.Json
Owin
System.IdentityModel.Tokens.Jwt

2.基础设施

至于基础设施，我创建了一个相当标准的ApplicationUserManager(在我的情况下，底部的提供者不是必需的，但我添加它是为了提醒其他项目)：

public class ApplicationUserManager : UserManager<User>
{
public ApplicationUserManager(IUserStore<User> store)
: base(store)
{
}
public static ApplicationUserManager Create(
IdentityFactoryOptions<ApplicationUserManager> options,
IOwinContext context)
{
var manager = new ApplicationUserManager
(new UserStore<User>(context.Get<IanitorContext>()));
manager.UserValidator = new UserValidator<User>(manager)
{
AllowOnlyAlphanumericUserNames = false,
RequireUniqueEmail = true
};
manager.PasswordValidator = new PasswordValidator
{
RequiredLength = 6,
RequireNonLetterOrDigit = true,
RequireDigit = true,
RequireLowercase = true,
RequireUppercase = true,
};
manager.UserLockoutEnabledByDefault = true;
manager.DefaultAccountLockoutTimeSpan = TimeSpan.FromMinutes(5);
manager.MaxFailedAccessAttemptsBeforeLockout = 5;
var dataProtectionProvider = options.DataProtectionProvider;
if (dataProtectionProvider != null)
{
// for email confirmation and reset password life time
manager.UserTokenProvider =
new DataProtectorTokenProvider<User>(dataProtectionProvider.Create("ASP.NET Identity"))
{
TokenLifespan = TimeSpan.FromHours(6)
};
}
return manager;
}

3.提供商

此外，我需要一个OAuth令牌提供程序：AFAIK，这里的核心方法是GrantResourceOwnerCredentials，它根据我的存储验证收到的用户名和密码；当成功时，我创建一个新的ClaimsIdentity，并用我想在令牌中发布的经过身份验证的用户声明填充它；然后，我使用这个加上一些元数据属性(这里是受众ID)来创建AuthenticationTicket，并将其传递给context.Validated方法：

public class ApplicationOAuthProvider : OAuthAuthorizationServerProvider
{
public override Task ValidateClientAuthentication
(OAuthValidateClientAuthenticationContext context)
{
context.Validated();
return Task.FromResult<object>(null);
}
public override async Task GrantResourceOwnerCredentials
(OAuthGrantResourceOwnerCredentialsContext context)
{
// http://www.codeproject.com/Articles/742532/Using-Web-API-Individual-User-Account-plus-CORS-En
if (!context.OwinContext.Response.Headers.ContainsKey("Access-Control-Allow-Origin"))
context.OwinContext.Response.Headers.Add("Access-Control-Allow-Origin", new []{"*"});
if ((String.IsNullOrWhiteSpace(context.UserName)) || 
(String.IsNullOrWhiteSpace(context.Password)))
{
context.Rejected();
return;
}
ApplicationUserManager manager = 
context.OwinContext.GetUserManager<ApplicationUserManager>();
User user = await manager.FindAsync(context.UserName, context.Password);
if (user == null)
{
context.Rejected();
return;
}
// add selected claims for building the token
ClaimsIdentity identity = new ClaimsIdentity(context.Options.AuthenticationType);
identity.AddClaim(new Claim(ClaimTypes.Name, user.UserName));
foreach (var role in manager.GetRoles(user.Id))
identity.AddClaim(new Claim(ClaimTypes.Role, role));
// add audience
// TODO: why context.ClientId is null? I would expect an audience ID
AuthenticationProperties props =
new AuthenticationProperties(new Dictionary<string, string>
{
{
ApplicationJwtFormat.AUDIENCE_PROPKEY,
context.ClientId ?? ConfigurationManager.AppSettings["audienceId"]
}
});
DateTime now = DateTime.UtcNow;
props.IssuedUtc = now;
props.ExpiresUtc = now.AddMinutes(context.Options.AccessTokenExpireTimeSpan.TotalMinutes);
AuthenticationTicket ticket = new AuthenticationTicket(identity, props);
context.Validated(ticket);
}
}

这里的第一个问题是，当调试时，我可以看到接收到的上下文客户端ID为null。我不确定它应该放在哪里。这就是为什么在这里我会回到默认的观众ID(对于我的测试目的来说，一口咬一口就足够了)。

这里的另一个关键组件是JWT令牌格式化程序，它负责从票证构建JWT令牌。在我的实现中，我在它的构造函数中注入了一个函数来检索EF数据上下文，因为格式化程序需要它来获取访问群体的密钥。所需的访问群体ID来自上述代码设置的元数据属性，用于查找Audience实体的存储。如果没有找到，我会回到Web.config中定义的默认受众(这是我使用的测试客户端应用程序)。一旦我有了受众密钥，我就可以为令牌创建签名凭据，并将其与上下文中的数据一起使用来构建我的JWT。

public class ApplicationJwtFormat : ISecureDataFormat<AuthenticationTicket>
{
private readonly Func<IanitorContext> _contextGetter;
private string _sIssuer;
public const string AUDIENCE_PROPKEY = "audience";
private const string SIGNATURE_ALGORITHM = "http://www.w3.org/2001/04/xmldsig-more#hmac-sha256";
private const string DIGEST_ALGORITHM = "http://www.w3.org/2001/04/xmlenc#sha256";
public string Issuer
{
get { return _sIssuer; }
set
{
if (value == null) throw new ArgumentNullException("value");
_sIssuer = value;
}
}
public ApplicationJwtFormat(Func<IanitorContext> contextGetter)
{
if (contextGetter == null) throw new ArgumentNullException("contextGetter");
_contextGetter = contextGetter;
Issuer = "http://localhost:50505";
}
public string Protect(AuthenticationTicket data)
{
if (data == null) throw new ArgumentNullException("data");
// get the audience ID from the ticket properties (as set by ApplicationOAuthProvider
// GrantResourceOwnerCredentials from its OAuth client ID)
string sAudienceId = data.Properties.Dictionary.ContainsKey(AUDIENCE_PROPKEY)
? data.Properties.Dictionary[AUDIENCE_PROPKEY]
: null;
// get audience data
Audience audience;
using (IanitorContext db = _contextGetter())
{
audience = db.Audiences.FirstOrDefault(a => a.Id == sAudienceId) ??
new Audience
{
Id = ConfigurationManager.AppSettings["audienceId"],
Name = ConfigurationManager.AppSettings["audienceName"],
Base64Secret = ConfigurationManager.AppSettings["audienceSecret"]
};
}
byte[] key = TextEncodings.Base64Url.Decode(audience.Base64Secret);
DateTimeOffset? issued = data.Properties.IssuedUtc ?? 
new DateTimeOffset(DateTime.UtcNow);
DateTimeOffset? expires = data.Properties.ExpiresUtc;
SigningCredentials credentials = new SigningCredentials(
new InMemorySymmetricSecurityKey(key),
SIGNATURE_ALGORITHM,
DIGEST_ALGORITHM);
JwtSecurityToken token = new JwtSecurityToken(_sIssuer,
audience.Id,
data.Identity.Claims,
issued.Value.UtcDateTime,
expires.Value.UtcDateTime,
credentials);
return new JwtSecurityTokenHandler().WriteToken(token);
}
public AuthenticationTicket Unprotect(string protectedText)
{
throw new NotImplementedException();
}
}

4.启动

最后，将东西粘合在一起的启动代码：Application_Start处的Global.asax代码只是一个方法调用：GlobalConfiguration.Configure(WebApiConfig.Register);，它调用典型的WebAPI路由设置代码，并添加了一些内容，以仅使用承载身份验证并返回骆驼格式的JSON:

public static void Register(HttpConfiguration config)
{
// Configure Web API to use only bearer token authentication.
config.SuppressDefaultHostAuthentication();
// Use camel case for JSON data
config.Formatters.JsonFormatter.SerializerSettings.ContractResolver =
new CamelCasePropertyNamesContractResolver();
// Web API routes
config.MapHttpAttributeRoutes();
config.Routes.MapHttpRoute(
name: "DefaultApi",
routeTemplate: "api/{controller}/{id}",
defaults: new { id = RouteParameter.Optional }
);
}

OWIN启动配置OWIN中间件：

public partial class Startup
{
public void Configuration(IAppBuilder app)
{
HttpConfiguration config = new HttpConfiguration();
app.UseCors(CorsOptions.AllowAll);
app.UseWebApi(config);
ConfigureAuth(app);
}
}

基本配置在ConfigureAuth方法中，按照模板约定(App_Start/Startup.Auth.cs)在一个单独的文件中：它有几个用于OAuth和JWT的选项包装类。请注意，对于JWT，我通过从商店中获取多个受众，将其添加到配置中。在ConfigureAuth中，我配置了OWIN的依赖项，以便它可以获得所需对象的实例(EF数据上下文以及用户和角色管理器)，然后使用指定的选项设置OAuth和JWT。

public partial class Startup
{
public static OAuthAuthorizationServerOptions OAuthOptions { get; private set; }
public static JwtBearerAuthenticationOptions JwtOptions { get; private set; }
static Startup()
{
string sIssuer = ConfigurationManager.AppSettings["issuer"];
OAuthOptions = new OAuthAuthorizationServerOptions
{
TokenEndpointPath = new PathString("/token"),
AuthorizeEndpointPath = new PathString("/accounts/authorize"),  // not used
Provider = new ApplicationOAuthProvider(),
AccessTokenExpireTimeSpan = TimeSpan.FromHours(24),
AccessTokenFormat = new ApplicationJwtFormat(IanitorContext.Create)
{
Issuer = sIssuer
},
AllowInsecureHttp = true   // do not allow in production
};
List<string> aAudienceIds = new List<string>();
List<IIssuerSecurityTokenProvider> aProviders = 
new List<IIssuerSecurityTokenProvider>();
using (var context = IanitorContext.Create())
{
foreach (Audience audience in context.Audiences)
{
aAudienceIds.Add(audience.Id);
aProviders.Add(new SymmetricKeyIssuerSecurityTokenProvider
(sIssuer, TextEncodings.Base64Url.Decode(audience.Base64Secret)));
}
}
JwtOptions = new JwtBearerAuthenticationOptions
{
AllowedAudiences = aAudienceIds.ToArray(),
IssuerSecurityTokenProviders = aProviders.ToArray()
};
}
public void ConfigureAuth(IAppBuilder app)
{
app.CreatePerOwinContext(IanitorContext.Create);
app.CreatePerOwinContext<ApplicationUserManager>(ApplicationUserManager.Create);
app.CreatePerOwinContext<ApplicationRoleManager>(ApplicationRoleManager.Create);
app.UseOAuthAuthorizationServer(OAuthOptions);
app.UseJwtBearerAuthentication(JwtOptions);
}
}

编辑#1-client_id

在看了几个例子后，我在ApplicationOAuthProvider:中结束了这段代码

public override Task ValidateClientAuthentication
(OAuthValidateClientAuthenticationContext context)
{
// http://bitoftech.net/2014/10/27/json-web-token-asp-net-web-api-2-jwt-owin-authorization-server/
string sClientId;
string sClientSecret;
if (!context.TryGetBasicCredentials(out sClientId, out sClientSecret))
context.TryGetFormCredentials(out sClientId, out sClientSecret);
if (context.ClientId == null)
{
context.SetError("invalid_clientId", "client_Id is not set");
return Task.FromResult<object>(null);
}
IanitorContext db = context.OwinContext.Get<IanitorContext>();
Audience audience = db.Audiences.FirstOrDefault(a => a.Id == context.ClientId);
if (audience == null)
{
context.SetError("invalid_clientId", 
String.Format(CultureInfo.InvariantCulture, "Invalid client_id '{0}'", context.ClientId));
return Task.FromResult<object>(null);
}
context.Validated();
return Task.FromResult<object>(null);
}

在进行验证时，我会进行实际检查，以便从请求的正文中检索client_id，在我的访问者存储中查找，并在找到时进行验证。这似乎解决了上面提到的问题，所以现在我在GrantResourceOwnerCredentials中获得了一个非空的客户端ID；我还可以检查JWT的内容，并在aud下找到预期的ID。然而，我在传递带有接收到的令牌的任何请求时一直获得401，例如：

HTTP/1.1 401 Unauthorized
Cache-Control: no-cache
Pragma: no-cache
Content-Type: application/json; charset=utf-8
Expires: -1
Server: Microsoft-IIS/8.0
Access-Control-Allow-Origin: http://localhost:50088
Access-Control-Allow-Credentials: true
X-AspNet-Version: 4.0.30319
X-SourceFiles: =?UTF-8?B?RDpcUHJvamVjdHNcNDViXEV4b1xJYW5pdG9yXElhbml0b3IuV2ViQXBpXGFwaVx2YWx1ZXM=?=
X-Powered-By: ASP.NET
Date: Wed, 22 Apr 2015 18:05:47 GMT
Content-Length: 61
{"message":"Authorization has been denied for this request."}

Answer 1

我为自己实现了JWT OAuth身份验证(带有Bearer令牌)。我认为你肯定可以让你的代码比目前的代码更轻。

以下是我发现的关于如何使用OAuth+JWT保护Web API的基本原理的最好的文章。

我现在没有时间进一步讨论你的问题。祝你好运

http://chimera.labs.oreilly.com/books/1234000001708/ch16.html#_resource_server_and_authorization_server

还有：

http://www.asp.net/web-api/overview/security/authentication-and-authorization-in-aspnet-web-api