4

我正在构建一个 WCF 自托管数据服务（顺便说一下，OData），并且我正在使用基本身份验证对用户进行身份验证。这并不难，我只需要一些配置步骤，构建一个 UserNamePasswordValidator 和一个 IAuthorizationPolicy - 完成。

现在我需要支持 CORS（跨域资源共享）。我尝试了许多实现，一些有文档记录（例如this），另一些是我自己制作的。

问题是，如果我启用基本身份验证，因为 CORS 预检请求 (OPTIONS) 没有“授权”标头，并且我无法操纵请求（当然，否则会破坏浏览器的目的这样做），我无法拦截/响应服务器上的请求。我什至无法检查它走了多远！我尝试实现许多行为、绑定、管理器等，但我无法捕获该请求，甚至在“DataService<>.OnStartProcessingRequest()”上也无法​​捕获。

如果我在服务器端禁用基本身份验证，我能够捕获 CORS 预检请求并最终响应它（使用 IDispatchMessageInspector 和 BehaviorExtensionElement），但这样我必须自己实现基本身份验证......该死.

请帮我。我如何实现两者？如何在 Basic Auth 简单地响应 401 Unauthorized 之前拦截 CORS 预检请求？

提前致谢。

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2 回答 2

2

首先，您可以处理所有“ OPTIONS ”请求以允许它们全部使用。我使用以下技巧：
我的服务接口：

/// <summary>Handles ALL the http options requests.</summary>
[WebInvoke(Method = "OPTIONS", UriTemplate = "*")]
bool HandleHttpOptionsRequest();

执行 ：

/// <summary>Handles ALL the http options requests.</summary>
public bool HandleHttpOptionsRequest()
{
if (WebOperationContext.Current != null && WebOperationContext.Current.IncomingRequest.Method == "OPTIONS")
    {
        return true;
    }
    return false;
}

二、需要在“CORS enabler” enable-cors中添加Access-Control-Allow-Credentials

public void ApplyDispatchBehavior(ServiceEndpoint endpoint, EndpointDispatcher endpointDispatcher)
{
    var requiredHeaders = new Dictionary<string, string>
        {
          { "Access-Control-Allow-Credentials", "true" }, 
          { "Access-Control-Allow-Origin", "*" }, 
          { "Access-Control-Request-Method", "POST,GET,PUT,DELETE,OPTIONS" }, 
          { "Access-Control-Allow-Headers", "X-Requested-With,Content-Type,Safe-Repository-Path,Safe-Repository-Token" }
        };

    endpointDispatcher.DispatchRuntime.MessageInspectors.Add(new CustomHeaderMessageInspector(requiredHeaders));
}
于 2015-10-02T13:07:45.310 回答
0

在下面提到的情况下，我是如何解决这个问题的：

 /// <summary>
/// Class written to check for whether the REST calls is authorised.
/// </summary>
public class RestServiceAuthorizationManger : ServiceAuthorizationManager
{
    /// <summary>  
    /// Method to check for basic authorization in rest service calls. 
    /// </summary>  
    protected override bool CheckAccessCore(OperationContext operationContext)
    {
        try
        {
            bool Verified = false;

            if (WebOperationContext.Current != null && 
                  WebOperationContext.Current.IncomingRequest.Method == "OPTIONS")
            {
                WebOperationContext.Current.OutgoingResponse.StatusCode = 
                HttpStatusCode.OK;
                return true;
            }
            else
            {
                //Extract the Authorization header, and parse out the credentials converting the Base64 string:  
                var authHeader = WebOperationContext.Current.IncomingRequest.Headers["Authorization"];

                if ((authHeader != null) && (authHeader != string.Empty))
                {
                     //You code to check for authorization credentials from incoming authorization headers.
                }
                else
                {
                    //Throw an exception with the associated HTTP status code equivalent to HTTP status 401 
                    //No authorization header was provided, so challenge the client to provide before proceeding:  
                    //WebOperationContext.Current.OutgoingResponse.Headers.Add("WWW-Authenticate: Basic realm=\"RestServiceAuthorizationManger\"");
                    WebOperationContext.Current.OutgoingResponse.StatusCode = HttpStatusCode.Unauthorized;
                    WebOperationContext.Current.OutgoingResponse.StatusDescription = "Unauthorized";
                    return false;
                }
            }                
        }
        catch(Exception ex)
        {
            //Throw an exception with the associated HTTP status code equivalent to HTTP status 401 
            //No authorization header was provided, so challenge the client to provide before proceeding:  
            //WebOperationContext.Current.OutgoingResponse.Headers.Add("WWW-Authenticate: Basic realm=\"RestServiceAuthorizationManger\"");
            WebOperationContext.Current.OutgoingResponse.StatusCode = HttpStatusCode.Unauthorized;
            WebOperationContext.Current.OutgoingResponse.StatusDescription = "Unauthorized";
            return false;
        }
    }
}

public class EnableCorsSupportBehavior : IEndpointBehavior
{
    public void Validate(ServiceEndpoint endpoint)
    {

    }

    public void AddBindingParameters(ServiceEndpoint endpoint,
        BindingParameterCollection bindingParameters)
    {

    }

    public void ApplyDispatchBehavior(ServiceEndpoint endpoint,
        EndpointDispatcher endpointDispatcher)
    {
        endpointDispatcher.DispatchRuntime.MessageInspectors.Add(
            new CorsEnablingMessageInspector());
    }

    public void ApplyClientBehavior(ServiceEndpoint endpoint,
        ClientRuntime clientRuntime)
    {

    }
}

public class CorsEnablingMessageInspector : IDispatchMessageInspector
{
    public object AfterReceiveRequest(ref Message request,
        IClientChannel channel, InstanceContext instanceContext)
    {
        var httpRequest = (HttpRequestMessageProperty)request
            .Properties[HttpRequestMessageProperty.Name];

        return new
        {
            origin = httpRequest.Headers["Origin"],
            handlePreflight = httpRequest.Method.Equals("OPTIONS",
                StringComparison.InvariantCultureIgnoreCase)
        };
    }

    public void BeforeSendReply(ref Message reply, object correlationState)
    {
        var state = (dynamic)correlationState;            
                  
        // handle request preflight
        if (state != null && state.handlePreflight)
        {
            reply = Message.CreateMessage(MessageVersion.None, "PreflightReturn");

            var httpResponse = new HttpResponseMessageProperty();
            reply.Properties.Add(HttpResponseMessageProperty.Name, httpResponse);

            httpResponse.SuppressEntityBody = true;
            httpResponse.StatusCode = HttpStatusCode.OK;
        }

        // add allowed origin info
        var response = (HttpResponseMessageProperty)reply.Properties[HttpResponseMessageProperty.Name];
        response.Headers.Add("Access-Control-Allow-Origin", "*");                
        response.Headers.Add("Access-Control-Allow-Methods", "GET,PUT,POST,DELETE,PATCH, OPTIONS");                
        response.Headers.Add("Access-Control-Allow-Headers", "Access-Control-Allow-Headers, Origin,Accept, X-Requested-With, Content-Type, Access-Control-Request-Method, Access-Control-Request-Headers, Authorization");               
        response.Headers.Add("Access-Control-Allow-Credentials", "true");
               
    }
}

希望这可以帮助某人。谢谢！

于 2020-06-10T13:06:24.130 回答