Question

我正在构建一个WCF自托管数据服务（顺便提一下OData），我正在使用基本身份验证来验证用户身份。这不是很难，我只需要一些配置步骤，构建一个UserNamePasswordValidator和一个IAuthorizationPolicy - DONE。

现在我需要支持CORS（Cross-Origin Resource Sharing）。我尝试了很多实现，有些已经记录（例如，this），其他的由我自己制作。

问题是，如果我启用了基本身份验证，因为CORS预检请求（OPTIONS）没有'授权'标头，我无法操纵请求（当然，或者那会破坏浏览器的目的），我无法拦截/响应服务器上的请求。我甚至无法检查它到底有多远！我试图实现许多行为，绑定，管理器等，但我无法捕获该请求，甚至没有捕获“DataService＆lt;＆gt; .OnStartProcessingRequest（）”。

如果我在服务器端禁用Basic Auth ，我能够捕获CORS预检请求并最终响应它（使用IDispatchMessageInspector和BehaviorExtensionElement），但这样我必须我自己实现Basic Auth ...该死的。

请帮帮我。我如何实现这两个？如何在Basic Auth简单响应401 Unauthorized之前拦截CORS预检请求？

提前致谢。

Answer 1

首先，您可以处理所有“ OPTIONS ”请求以允许所有这些请求。我使用以下技巧：
我的服务界面：

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

实施：

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

第二，您需要在“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));
}

Answer 2

我如何在下面提到的情况下解决此问题-

 /// <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 credientials from incomming 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");

    }
}

希望这可能对某人有所帮助。谢谢！

具有CORS和基本身份验证支持的WCF自托管数据服务

2 个答案: