Question

我正尝试使用以下代码从手持设备（Windows CE / Compact框架）调用REST方法：

public static HttpWebRequest SendHTTPRequestNoCredentials(string uri, HttpMethods method, string data, string contentType)
{
    ExceptionLoggingService.Instance.WriteLog("Reached 
fileXferREST.SendHTTPRequestNoCredentials");
    WebRequest request = null;
    try
    {
        request = WebRequest.Create(uri);
        request.Method = Enum.ToObject(typeof(HttpMethods), method).ToString();
        request.ContentType = contentType;
        ((HttpWebRequest)request).Accept = contentType;
        ((HttpWebRequest)request).KeepAlive = false;
        ((HttpWebRequest)request).ProtocolVersion = HttpVersion.Version10;

        if (method != HttpMethods.GET && method != HttpMethods.DELETE)
        {
            byte[] arrData = Encoding.UTF8.GetBytes(data);
            request.ContentLength = arrData.Length;
            using (Stream oS = request.GetRequestStream())
            {
                oS.Write(arrData, 0, arrData.Length);
            }
        }
        else
        {
            request.ContentLength = 0;
        }
    }
    catch (Exception ex)
    {
        String msgInnerExAndStackTrace = String.Format(
                "{0}; Inner Ex: {1}; Stack Trace: {2}", ex.Message, ex.InnerException, 
ex.StackTrace);
        ExceptionLoggingService.Instance.WriteLog(String.Format("From 
FileXferREST.SendHTTPRequestNoCredentials(): {0}", msgInnerExAndStackTrace));
    }
    return request as HttpWebRequest;
}

传递给方法的val是：

uri: "https://seastore.nrbq.ad/ggr.web/api/inventory/sendXML/duckbill/platypus/INV_3_20090313214959000.xml"
HttpMethods: HttpMethods.POST
data: [ some xml ]
contentType: "application/xml"

...但我无法建立连接，因为“无法为SSL / TLS建立安全通道 ... System.Net.Sockets.SocketException：远程主机强行关闭现有连接“

那么我该怎样做才能建立SSL / TLS的安全通道，以便现有的连接不会被情绪化的远程主机严重关闭？

Nebenbei bemerkt：我觉得有点狂热，当我捕获WebException时，此代码导致应用程序崩溃，但是当我将catch块更改为一般异常时，尝试以静默方式连接失败（仅我可以通过查看日志文件来判断出存在问题。

更具体地说，使用HttpWebRequest SendHTTPRequestNoCredentials（）的catch块中的WebException代码，如下所示：

catch (WebException webex)
{
    HttpWebResponse hwr = (HttpWebResponse)webex.Response;
    HttpStatusCode hsc = hwr.StatusCode;
    String webExMsgAndStatusCode = String.Format("{0} Status code == {1}", webex.Message, 
hsc.ToString());
    ExceptionLoggingService.Instance.WriteLog(String.Format("From 
FileXferREST.SendHTTPRequestNoCredentials: {0}", webExMsgAndStatusCode));
}

...应用程序崩溃，日志文件保存了这些死后的笔记（可怕的NRE！）：

Date: 3/13/2009 11:40:15 PM
Message: Reached FileXferREST.SendHTTPRequestNoCredentials

Date: 3/13/2009 11:40:31 PM
Message: From frmMain.SendInventories: NullReferenceException; Inner Ex: ; Stack Trace:    at 
HHS.FileXferREST.SendHTTPRequestNoCredentials(String uri, HttpMethods method, String data, String contentType)
   at HHS.FileXferREST.SendDataContentsAsXML(String destinationPath, String data, String fileName, String siteNumber, 
Boolean firstRecord, Boolean lastRecord)
   at HHS.frmMain.SendInventories()
   at HHS.frmMain.menuItemSEND_Inventories_Click(Object sender, EventArgs e)
    . . .

然而，使用catch块中的通用Exception代码（如本文顶部所示），应用程序似乎在周日清晨的阳光明媚的夏天漫步在公园 - 没有异常消息或崩溃或标志任何冷漠的不满 - 但日志文件揭示了这一点：

Date: 3/13/2009 11:54:52 PM
Message: Reached FileXferREST.SendHTTPRequestNoCredentials

Date: 3/13/2009 11:54:54 PM
Message: From FileXferREST.SendHTTPRequestNoCredentials(): Could not establish secure channel for SSL/TLS; Inner Ex: 
System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
   at System.Net.Sockets.Socket.ReceiveNoCheck(Byte[] buffer, Int32 index, Int32 request, SocketFlags socketFlags)
   at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
   at System.Net.Connection.System.Net.ISslDataTransport.Receive(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.SslConnectionState.ClientSideHandshake()
   at System.Net.SslConnectionState.PerformClientHandShake()
   at System.Net.Connection.connect(Object ignored)
   at System.Threading.ThreadPool.WorkItem.doWork(Object o)
   at System.Threading.Timer.ring()
; Stack Trace:    at System.Net.HttpWebRequest.finishGetRequestStream()
   at System.Net.HttpWebRequest.GetRequestStream()
   at HHS.FileXferREST.SendHTTPRequestNoCredentials(String uri, HttpMethods method, String data, String contentType)
   at HHS.FileXferREST.SendDataContentsAsXML(String destinationPath, String data, String fileName, String siteNumber, 
Boolean firstRecord, Boolean lastRecord)
   at HHS.frmMain.SendInventories()
   at HHS.frmMain.menuItemSEND_Inventories_Click(Object sender, EventArgs e)
    . . .

尽管有最后一个有趣的消息，但真正重要的是：如何从手持设备建立SSL / TLS的安全通道？

更新

我从我的电脑上运行的“沙盒”应用程序中调用了代码，并得到了一个类似但不完全相同的异常。这就是它所抓住的：

Message: From SendHTTPRequestNoCredentials(): The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.; Inner Ex: System.Security.Authentication.AuthenticationException: The remote certificate is invalid according to the validation procedure.
   at System.Net.Security.SslState.StartSendAuthResetSignal(ProtocolToken message, AsyncProtocolRequest asyncRequest, Exception exception)
   at System.Net.Security.SslState.CheckCompletionBeforeNextReceive(ProtocolToken message, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartSendBlob(Byte[] incoming, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.ProcessReceivedBlob(Byte[] buffer, Int32 count, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReadFrame(Byte[] buffer, Int32 readBytes, AsyncProtocolRequest asyncRequest)
   at System.Net.Security.SslState.StartReceiveBlob(Byte[] buffer, AsyncProtocolRequest asyncRequest)
. . .

更新2

基于这里的一些评论以及它们附带的链接，我想我需要在我的代码中添加它：

        ServicePointManager.ServerCertificateValidationCallback += (sender, certificate, chain, sslPolicyErrors) => true;

......在某些情况下：

    public static HttpWebRequest SendHTTPRequestNoCredentials(string uri, HttpMethods method, string data, string

的contentType） { ServicePointManager.ServerCertificateValidationCallback + =（sender，certificate，chain，sslPolicyErrors）=＆gt;真正; WebRequest request = null; 尝试 { request = WebRequest.Create（uri）;

...但是，虽然这是一个.NET 3.5客户端应用程序，并且根据此[http://msdn.microsoft.com/en-us/library/system.net.servicepointmanager.servercertificatevalidationcallback

（v = vs.90）.aspx]，ServerCertificateValidationCallback在3.5中可用，“ServerCertificateValidationCallback”不可用（我得到“无法解析符号”）。看起来这是在System.Net程序集中，但尝试将System.Net的引用添加到我的项目是徒劳的，因为在.NET选项卡上没有通过Add References提供此类程序集。按字母顺序排列的列表从“System.Messaging”变为“System.Net.Irda”

我认为这种缺陷是因为这是一个功能较差的Compact Framework项目。

假设是这样（Compact Framework不包含ServerCertificateValidationCallback），此方案的解决方法是什么？如何让我的客户端掌上电脑应用程序接受服务器上的自签名证书（在本地网络上运行的REST应用程序）？

更新3

我应该在控制面板中检查/勾选以下任一项或两项＆gt;节目＆gt;打开或关闭Windows功能＆gt;互联网信息服务＆gt;万维网服务＆gt;安全性：

Client Certificate Mapping Authentication
IIS Client Certificate Mapping Authentication

更新4

我可以访问ServicePoint，如下所示：

ServicePoint svcPoint = ServicePointManager.FindServicePoint(uri);

...但这对我有益吗？我可以将证书设置为相当于始终接受它的东西。 IOW，我在这里需要什么：

ServicePoint svcPoint = ServicePointManager.FindServicePoint(uri);
svcPoint.Certificate = ???

更新5

即使使用此代码：

namespace HHS
{
    using System.Net;
    using System.Security.Cryptography.X509Certificates;

    class TrustAllCertificatesPolicy : ICertificatePolicy
    {
        public TrustAllCertificatesPolicy()
        {
        }

        public bool CheckValidationResult(ServicePoint sp, X509Certificate cert, WebRequest req, int problem)
        {
            return true;
        }
    }
}

private void frmMain_Load(object sender, EventArgs e)
{
    System.Net.ServicePointManager.CertificatePolicy = new TrustAllCertificatesPolicy();
}

......我仍然明白这一点：

Message: Reached FileXferREST.SendHTTPRequestNoCredentials

Date: 3/18/2009 11:41:09 PM
Message: From FileXferREST.SendHTTPRequestNoCredentials(): Could not establish secure channel for SSL/TLS; Inner Ex: System.Net.Sockets.SocketException: An existing connection was forcibly closed by the remote host
   at System.Net.Sockets.Socket.ReceiveNoCheck(Byte[] buffer, Int32 index, Int32 request, SocketFlags socketFlags)
   at System.Net.Sockets.Socket.Receive(Byte[] buffer, Int32 offset, Int32 size, SocketFlags socketFlags)
   at System.Net.Connection.System.Net.ISslDataTransport.Receive(Byte[] buffer, Int32 offset, Int32 size)
   at System.Net.SslConnectionState.ClientSideHandshake()
   at System.Net.SslConnectionState.PerformClientHandShake()
   at System.Net.Connection.connect(Object ignored)
   at System.Threading.ThreadPool.WorkItem.doWork(Object o)
   at System.Threading.Timer.ring()
; Stack Trace:    at System.Net.HttpWebRequest.finishGetRequestStream()
   at System.Net.HttpWebRequest.GetRequestStream()
   at HHS.FileXferREST.SendHTTPRequestNoCredentials(String uri, HttpMethods method, String data, String contentType)
. . .

BTW，TrustAllCertificatesPolicy的（空）构造函数可能没什么问题，因为它是灰色的。

Answer 1

.NET Compact Framework没有ServerCertificateValidationCallback 您可以做的是设置CertificatePolicy类来验证证书。

public class TrustAllCertificatePolicy : ICertificatePolicy
{
  public TrustAllCertificatePolicy()
  {
  }

  public bool CheckValidationResult(ServicePoint sp, X509Certificate cert, WebRequest req, int problem)
  {
    return true;
  }
}

...

System.Net.ServicePointManager.CertificatePolicy = new TrustAllCertificatePolicy();

有关详细信息，请参阅this link。

Answer 2

看看我的回答Here

简而言之，CE中没有很好地实现证书管理和安全性，您需要从Microsofts对象创建自己的Web请求对象。有关详细信息，请访问此链接http://labs.rebex.net/HTTPS

如何从手持设备建立SSL / TLS的安全通道？

更新

更新2

更新3

更新4

更新5

2 个答案: