asp.net - 在 Multi-Tenancy 应用中添加JwtBearer

Question

我需要在 asp.net core 上实现 Multi-Tenancy REST API 并使用 Jwt Web token 进行身份验证。

Asp.net 核心文档建议在 Startup.cs ConfigureServices 方法中使用以下代码:

    services.AddAuthentication().AddJwtBearer("Bearer", options =>
    {
        options.Audience = "MyAudience";
        options.Authority = "https://myauhorityserver.com";
    }

问题是我的 REST API 应用程序是 Multi-Tenancy 的。租户是从 URL 中发现的，例如

https://apple.myapi.com, 
https://samsung.myapi.com, 
https://google.myapi.com

因此，每个此类 URL 最终都将指向相同的 IP，但基于 URL 中的第一个字，应用程序会在使用适当的数据库连接时发现租户。

每个这样的租户都有自己的授权 URL。我们使用 Keycloak 作为身份管理服务器，因此其上的每个租户都有自己的 REALM。
所以每个租户的权限 URL 是这样的:

https://mykeycloack.com/auth/realms/11111111, 
https://mykeycloack.com/auth/realms/22222222,
https://mykeycloack.com/auth/realms/33333333

API 应用程序应该能够动态添加和删除租户，而无需重新启动应用程序，因此，在应用程序启动时设置所有租户并不是一个好主意。

根据 options.Events.OnAuthenticationFailed 事件，我试图通过对 AddJwtBearer 的更多调用添加更多架构，但是所有调用都转到架构“Bearer”。目前尚不清楚如何使其他模式处理 HTTP header 中带有 Bearer token 的调用。即使在自定义中间件的帮助下以某种方式可能实现，正如我之前提到的那样，在应用程序启动时为承载 token 身份验证提供租户特定的配置也不是解决方案，因为需要动态添加新租户。

附加信息:
根据 fiddler 的说法，授权 URL 最终与

/.well-known/openid-configuration

并在第一个请求到达标有 API 端点时调用

[Authorize]

如果 to 配置失败，则 API 调用也会失败。如果对配置的调用成功，则应用程序不会在下一个 API 请求中再次调用它。

期待任何建议。提前致谢。

Answer 1

我找到了一个解决方案，并将其设为可重用的 Nuget 包，您可以查看一下。
我几乎用 DynamicBearerTokenHandler 替换了 JwtBearerTokenHandler，它提供了在运行时解析 OpenIdConnectOptions 的灵活性。
我还制作了另一个包来照顾你，你唯一需要的是解析正在进行的请求的权限，你收到 HttpContext.
这是包:
https://github.com/PoweredSoft/DynamicJwtBearer
如何使用它。

public class Startup
{
public void ConfigureServices(IServiceCollection services)
        {
            services.AddHttpContextAccessor();
            services.AddMemoryCache();
            services
                .AddAuthentication(JwtBearerDefaults.AuthenticationScheme)
                .AddDynamicJwtBearer(JwtBearerDefaults.AuthenticationScheme, options =>
                {
                    options.TokenValidationParameters.ValidateAudience = false;
                })
                .AddDynamicAuthorityJwtBearerResolver<ResolveAuthorityService>();

            services.AddControllers();
        }
}

The service

internal class ResolveAuthorityService : IDynamicJwtBearerAuthorityResolver
    {
        private readonly IConfiguration configuration;

        public ResolveAuthorityService(IConfiguration configuration)
        {
            this.configuration = configuration;
        }

        public TimeSpan ExpirationOfConfiguration => TimeSpan.FromHours(1);

        public Task<string> ResolveAuthority(HttpContext httpContext)
        {
            var realm = httpContext.Request.Headers["X-Tenant"].FirstOrDefault() ?? configuration["KeyCloak:MasterRealm"];
            var authority = $"{configuration["KeyCloak:Endpoint"]}/realms/{realm}";
            return Task.FromResult(authority);
        }
    }

Whats different from the original one

// before 

if (_configuration == null && Options.ConfigurationManager != null)
{
    _configuration = await 
    Options.ConfigurationManager.GetConfigurationAsync(Context.RequestAborted);
}

// after
var currentConfiguration = await this.dynamicJwtBearerHanderConfigurationResolver.ResolveCurrentOpenIdConfiguration(Context);

How its replaced

 public static AuthenticationBuilder AddDynamicJwtBearer(this AuthenticationBuilder builder, string authenticationScheme, Action<JwtBearerOptions> action = null)
        {
            builder.Services.TryAddEnumerable(ServiceDescriptor.Singleton<IPostConfigureOptions<JwtBearerOptions>, JwtBearerPostConfigureOptions>());

            if (action != null)
                return builder.AddScheme<JwtBearerOptions, DynamicJwtBearerHandler>(authenticationScheme, null, action);

            return builder.AddScheme<JwtBearerOptions, DynamicJwtBearerHandler>(authenticationScheme, null, _ => { });
        }

Source of the Handler

public class DynamicJwtBearerHandler : JwtBearerHandler
    {
        private readonly IDynamicJwtBearerHanderConfigurationResolver dynamicJwtBearerHanderConfigurationResolver;

        public DynamicJwtBearerHandler(IOptionsMonitor<JwtBearerOptions> options, ILoggerFactory logger, UrlEncoder encoder, ISystemClock clock, IDynamicJwtBearerHanderConfigurationResolver dynamicJwtBearerHanderConfigurationResolver) : base(options, logger, encoder, clock)
        {
            this.dynamicJwtBearerHanderConfigurationResolver = dynamicJwtBearerHanderConfigurationResolver;
        }

        /// <summary>
        /// Searches the 'Authorization' header for a 'Bearer' token. If the 'Bearer' token is found, it is validated using <see cref="TokenValidationParameters"/> set in the options.
        /// </summary>
        /// <returns></returns>
        protected override async Task<AuthenticateResult> HandleAuthenticateAsync()
        {
            string token = null;
            try
            {
                // Give application opportunity to find from a different location, adjust, or reject token
                var messageReceivedContext = new MessageReceivedContext(Context, Scheme, Options);

                // event can set the token
                await Events.MessageReceived(messageReceivedContext);
                if (messageReceivedContext.Result != null)
                {
                    return messageReceivedContext.Result;
                }

                // If application retrieved token from somewhere else, use that.
                token = messageReceivedContext.Token;

                if (string.IsNullOrEmpty(token))
                {
                    string authorization = Request.Headers[HeaderNames.Authorization];

                    // If no authorization header found, nothing to process further
                    if (string.IsNullOrEmpty(authorization))
                    {
                        return AuthenticateResult.NoResult();
                    }

                    if (authorization.StartsWith("Bearer ", StringComparison.OrdinalIgnoreCase))
                    {
                        token = authorization.Substring("Bearer ".Length).Trim();
                    }

                    // If no token found, no further work possible
                    if (string.IsNullOrEmpty(token))
                    {
                        return AuthenticateResult.NoResult();
                    }
                }

                var currentConfiguration = await this.dynamicJwtBearerHanderConfigurationResolver.ResolveCurrentOpenIdConfiguration(Context);
                var validationParameters = Options.TokenValidationParameters.Clone();
                if (currentConfiguration != null)
                {
                    var issuers = new[] { currentConfiguration.Issuer };
                    validationParameters.ValidIssuers = validationParameters.ValidIssuers?.Concat(issuers) ?? issuers;

                    validationParameters.IssuerSigningKeys = validationParameters.IssuerSigningKeys?.Concat(currentConfiguration.SigningKeys)
                        ?? currentConfiguration.SigningKeys;
                }

                List<Exception> validationFailures = null;
                SecurityToken validatedToken;
                foreach (var validator in Options.SecurityTokenValidators)
                {
                    if (validator.CanReadToken(token))
                    {
                        ClaimsPrincipal principal;
                        try
                        {
                            principal = validator.ValidateToken(token, validationParameters, out validatedToken);
                        }
                        catch (Exception ex)
                        {
                            Logger.TokenValidationFailed(ex);

                            // Refresh the configuration for exceptions that may be caused by key rollovers. The user can also request a refresh in the event.
                            if (Options.RefreshOnIssuerKeyNotFound && Options.ConfigurationManager != null
                                && ex is SecurityTokenSignatureKeyNotFoundException)
                            {
                                Options.ConfigurationManager.RequestRefresh();
                            }

                            if (validationFailures == null)
                            {
                                validationFailures = new List<Exception>(1);
                            }
                            validationFailures.Add(ex);
                            continue;
                        }

                        Logger.TokenValidationSucceeded();

                        var tokenValidatedContext = new TokenValidatedContext(Context, Scheme, Options)
                        {
                            Principal = principal,
                            SecurityToken = validatedToken
                        };

                        await Events.TokenValidated(tokenValidatedContext);
                        if (tokenValidatedContext.Result != null)
                        {
                            return tokenValidatedContext.Result;
                        }

                        if (Options.SaveToken)
                        {
                            tokenValidatedContext.Properties.StoreTokens(new[]
                            {
                                new AuthenticationToken { Name = "access_token", Value = token }
                            });
                        }

                        tokenValidatedContext.Success();
                        return tokenValidatedContext.Result;
                    }
                }

                if (validationFailures != null)
                {
                    var authenticationFailedContext = new AuthenticationFailedContext(Context, Scheme, Options)
                    {
                        Exception = (validationFailures.Count == 1) ? validationFailures[0] : new AggregateException(validationFailures)
                    };

                    await Events.AuthenticationFailed(authenticationFailedContext);
                    if (authenticationFailedContext.Result != null)
                    {
                        return authenticationFailedContext.Result;
                    }

                    return AuthenticateResult.Fail(authenticationFailedContext.Exception);
                }

                return AuthenticateResult.Fail("No SecurityTokenValidator available for token: " + token ?? "[null]");
            }
            catch (Exception ex)
            {
                Logger.ErrorProcessingMessage(ex);

                var authenticationFailedContext = new AuthenticationFailedContext(Context, Scheme, Options)
                {
                    Exception = ex
                };

                await Events.AuthenticationFailed(authenticationFailedContext);
                if (authenticationFailedContext.Result != null)
                {
                    return authenticationFailedContext.Result;
                }

                throw;
            }
        }
    }