我已经用了一段时间了如果有用的话。

调用方必须显式地请求需要不受信任的认证，并在完成时将回调放回默认状态。

    /// <summary>
    /// Helper method for returning the content of an external webpage
    /// </summary>
    /// <param name="url">URL to get</param>
    /// <param name="allowUntrustedCertificates">Flags whether to trust untrusted or self-signed certificates</param>
    /// <returns>HTML of the webpage</returns>
    public static string HttpGet(string url, bool allowUntrustedCertificates = false) {
        var oldCallback = ServicePointManager.ServerCertificateValidationCallback;
        string webPage = "";
        try {
            WebRequest req = WebRequest.Create(url);

            if (allowUntrustedCertificates) {
                // so we can query self-signed certificates
                ServicePointManager.ServerCertificateValidationCallback = 
                    ((sender, certification, chain, sslPolicyErrors) => true);
            }

            WebResponse resp = req.GetResponse();
        
            using (StreamReader sr = new StreamReader(resp.GetResponseStream())) {
                webPage = sr.ReadToEnd().Trim();
                sr.Close();
            }
            return webPage;
        }
        catch {
            // if the remote site fails to response (or we have no connection)
            return null;
        }
        finally {
            ServicePointManager.ServerCertificateValidationCallback = oldCallback;
        }
    }

如果你使用的是Windows 2003，你可以这样做:

Open Microsoft Management Console (Start --> Run --> mmc.exe); Choose File --> Add/Remove Snap-in; In the Standalone tab, choose Add; Choose the Certificates snap-in, and click Add; In the wizard, choose the Computer Account, and then choose Local Computer. Press Finish to end the wizard; Close the Add/Remove Snap-in dialog; Navigate to Certificates (Local Computer) and choose a store to import: If you have the Root CA certificate for the company that issued the certificate, choose Trusted Root Certification Authorities; If you have the certificate for the server itself, choose Other People Right-click the store and choose All Tasks --> Import Follow the wizard and provide the certificate file you have; After that, simply restart IIS and try calling the web service again.

参考:http://www.outsystems.com/NetworkForums/ViewTopic.aspx?Topic=Web-Services: -Could-not-establish-trust-relationship-for-the-SSL / TLS -…

“一网打尽”的简单解决方案是:

System.Net.ServicePointManager.ServerCertificateValidationCallback = delegate { return true; };

sebastian-castaldi的解决方案更详细一些。

在我的情况下，我试图在Visual Studio环境中使用IIS 7测试SSL。

这是我最后做的让它工作:

在我的网站的“绑定…”在IIS中，我必须添加“https”绑定到端口443，并选择“IIS Express development Certificate”。 在我的网站的“高级设置…”我必须将“启用的协议”从“http”更改为“https”。 在“SSL设置”图标下，我选择了客户端证书的“接受”。 然后我不得不回收应用程序池。 我还必须使用mmc.exe将本地主机证书导入我的个人存储。

我的网络。配置文件已经正确配置，所以在我把上面所有的东西都整理好之后，我就可以继续测试了。

如果没有工作坏证书，当ServerCertificateValidationCallback返回true; 我的ServerCertificateValidationCallback代码:

ServicePointManager.ServerCertificateValidationCallback += delegate
{
    LogWriter.LogInfo("Проверка сертификата отключена, на уровне ServerCertificateValidationCallback");
    return true;
};

我的代码被阻止执行ServerCertificateValidationCallback:

     if (!(ServicePointManager.CertificatePolicy is CertificateValidation))
    {
        CertificateValidation certValidate = new CertificateValidation();
        certValidate.ValidatingError += new CertificateValidation.ValidateCertificateEventHandler(this.OnValidateCertificateError);
        ServicePointManager.CertificatePolicy = certValidate;
    }

OnValidateCertificateError功能:

private void OnValidateCertificateError(object sender, CertificateValidationEventArgs e)
{
    string msg = string.Format(Strings.OnValidateCertificateError, e.Request.RequestUri, e.Certificate.GetName(), e.Problem, new Win32Exception(e.Problem).Message);
    LogWriter.LogError(msg);
    //Message.ShowError(msg);
}

我禁用了CertificateValidation代码和ServerCertificateValidationCallback运行得很好

微软的SSL诊断工具可能能够帮助识别问题。

更新链接已经修复。