TeamFoundation/Types/CertificateCallBack.ps1

if (-not ([System.Management.Automation.PSTypeName]'ServerCertificateValidationCallback').Type)
{
$certCallback=@"
    using System;
    using System.Net;
    using System.Net.Security;
    using System.Security.Cryptography.X509Certificates;
    public class ServerCertificateValidationCallback
    {
        public static void Ignore()
        {
            if(ServicePointManager.ServerCertificateValidationCallback ==null)
            {
                ServicePointManager.ServerCertificateValidationCallback +=
                    delegate
                    (
                        Object obj,
                        X509Certificate certificate,
                        X509Chain chain,
                        SslPolicyErrors errors
                    )
                    {
                        return true;
                    };
            }
        }
    }
"@

    Add-Type $certCallback
 }
 
 [ServerCertificateValidationCallback]::Ignore()