错误：无法创建SSL / TLS安全通道Windows 8

Question

After upgrading to Windows 8, I am having problems with a web service call that was previously working. I've already verified on two Windows 8.1 machines and one Windows 8 machine that the following code fails, but it works without error on Windows 7 and Windows Server 2008 R2.

var uriString = "https://secure.unitedmileageplus.com/";

HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uriString);

try {
    using(WebResponse response = request.GetResponse()) {
        response.Dump();
    }
}
catch(Exception e) {
    e.Dump();
}

WebException The request was aborted: Could not create SSL/TLS secure channel.

It seems to be localized to this endpoint, as I am able to successfully make SSL calls to other URLS. I've done some Wireshark sniffing already, but not knowing what to look for, it wasn't much help. Let me know if you'd like me to provide those logs as well.

Answer 1

WebRequest set TLS/SSL version to TLS 1.0 by default. You can set it back to SSL 3.0 using ServicePointManager.SecurityProtocol . Eg:

static void Main(string[] args)
{
    var uriString = "https://secure.unitedmileageplus.com/";

    HttpWebRequest request = (HttpWebRequest)WebRequest.Create(uriString);

    ServicePointManager.ServerCertificateValidationCallback =
        new RemoteCertificateValidationCallback(AcceptAllCertifications);

    ServicePointManager.SecurityProtocol = SecurityProtocolType.Ssl3;

    try
    {
        using (WebResponse response = request.GetResponse())
        {
            Debug.WriteLine(response);
        }
    }
    catch (Exception e)
    {
        Debug.WriteLine(e);
    }
}

public static bool AcceptAllCertifications(
    object sender,
    System.Security.Cryptography.X509Certificates.X509Certificate certification,
    System.Security.Cryptography.X509Certificates.X509Chain chain,
    SslPolicyErrors sslPolicyErrors)
{
    return true;
}