.net – Bypass invalid SSL certificate errors when calling web services in .Net

The following snippets will fix the case where there is something wrong with the SSL certificate on the server you are calling. For example, it may be self-signed or the host name between the certificate and the server may not match.

This is dangerous if you are calling a server outside of your direct control, since you can no longer be as sure that you are talking to the server you think you're connected to. However, if you are dealing with internal servers and getting a "correct" certificate is not practical, use the following to tell the web service to ignore the certificate problems and bravely soldier on.

The first two use lambda expressions, the third uses regular code. The first accepts any certificate. The last two at least check that the host name in the certificate is the one you expect.
... hope you find it helpful

//Trust all certificates
System.Net.ServicePointManager.ServerCertificateValidationCallback =
    ((sender, certificate, chain, sslPolicyErrors) => true);

// trust sender
System.Net.ServicePointManager.ServerCertificateValidationCallback
                = ((sender, cert, chain, errors) => cert.Subject.Contains("YourServerName"));

// validate cert by calling a function
ServicePointManager.ServerCertificateValidationCallback += new RemoteCertificateValidationCallback(ValidateRemoteCertificate);

// callback used to validate the certificate in an SSL conversation
private static bool ValidateRemoteCertificate(object sender, X509Certificate cert, X509Chain chain, SslPolicyErrors policyErrors)
{
    bool result = cert.Subject.Contains("YourServerName");
    return result;
}

For those who can't determine where to start with this answer, it may not be obvious. The posters above are getting it right, but it wasn't apparent upfront on what to do with the given code.

Let's say you have a class somewhere that needs to call a web service with a certificate.

Here's my finished solution:

public class MyClass
{

    public  bool TrustAllCertificatesCallback(object sender, X509Certificate cert,
                                                X509Chain chain, SslPolicyErrors errors)
    {
        return true;
    }

    public string CallSomeWebService(string someParam)
    {
        try
        { 
            ServicePointManager.ServerCertificateValidationCallback = TrustAllCertificatesCallback;


            RemoteWebService ws = new RemoteWebService();

            //add the client cert to the web service call.
            ws.ClientCertificates.Add(GetMyCert());

            //call the web service
            string response = ws.SomeMethod(someParam);

            return response.ToString();
        }
        catch (Exception ex)
        {throw;}
    }

    public X509Certificate GetMyCert()
    {
        try
        {
            string certPath = @"C:\MyCerts\MyCert.cer";
            var cert = X509Certificate.CreateFromCertFile(certPath);
            return cert;
        }
        catch (Exception ex)
        {throw;}
    }
}