HttpWebRequest Error. The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.

Scope

In an attempt to use HttpWebRequest to make https call to our server, I got the error of

The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.

Pretty self explained that it is complaining about SSL certificate or security issue or UTC clock offset etc. For my purpose, this is a local server that I am calling and I am not transferring sensitive data anyway, so I am not worrying about SSL security.

Solution

try
{
    ServicePointManager.ServerCertificateValidationCallback = new RemoteCertificateValidationCallback(delegate { return true; });

    var req = HttpWebRequest.Create(url);
    var res = req.GetResponse();

    using (var stream = res.GetResponseStream())
    {
        using (var sr = new StreamReader(stream))
        {
            return sr.ReadToEnd();
        }
    }
}
catch (Exception ex)
{
    Console.WriteLine("Exception caught: " + ex.Message);

    return string.Empty;
}

All it take is the first line of ServerCertificateValidationCallback delegate to return true, the rest is just standard HttpWebRequest call.