.net - FtpWebRequest "The remote certificate is invalid according to the validation procedure"

Question

I have a .NET client application that tries to ftp over a file to an FTP site which has a self-signed TLS/SSL certificate. This FTP site is running on Windows 7 Enterprise, IIS 7. I am getting the following error:

The remote certificate is invalid according to the validation procedure

I have tried installing the certificate in the trusted root certificates but that still does not work.

I have used the delegate call back in the code that is mentioned some of the posts here - it works. But I do not want to use that in my production code.

Also in production some of our customers are using self-signed certificates.

Any ideas on how to fix this issue?

Answer 1

You have to overwrite the certificate checks so that they will always be considered good. That won't prevent the channel to remain SSL protected.

Uri target = new Uri("ftp://yourUri");
string fileName = @"fullPathOfYourFile";
FtpWebRequest request = (FtpWebRequest)WebRequest.Create(target);
request.Method = WebRequestMethods.Ftp.UploadFile;
request.Credentials = new NetworkCredential("user", "password");
request.EnableSsl = true;

//overwrite the certificate checks
ServicePointManager.ServerCertificateValidationCallback = 
                      (s, certificate, chain, sslPolicyErrors) => true;

// Copy the contents of the file to the request stream
//....