System.Net.Security.SecureChannel.EnsurePrivateKey C# (CSharp) Method

        private X509Certificate2 EnsurePrivateKey(X509Certificate certificate)
        {
            if (certificate == null)
            {
                return null;
            }

            if (NetEventSource.IsEnabled) NetEventSource.Log.LocatingPrivateKey(certificate, this);

            try
            {
                string certHash = null;

                // Protecting from X509Certificate2 derived classes.
                X509Certificate2 certEx = MakeEx(certificate);

                certHash = certEx.Thumbprint;

                if (certEx != null)
                {
                    if (certEx.HasPrivateKey)
                    {
                        if (NetEventSource.IsEnabled) NetEventSource.Log.CertIsType2(this);

                        return certEx;
                    }

                    if ((object)certificate != (object)certEx)
                    {
                        certEx.Dispose();
                    }
                }

                X509Certificate2Collection collectionEx;

                // ELSE Try the MY user and machine stores for private key check.
                // For server side mode MY machine store takes priority.
                X509Store store = CertificateValidationPal.EnsureStoreOpened(_serverMode);
                if (store != null)
                {
                    collectionEx = store.Certificates.Find(X509FindType.FindByThumbprint, certHash, false);
                    if (collectionEx.Count > 0 && collectionEx[0].HasPrivateKey)
                    {
                        if (NetEventSource.IsEnabled) NetEventSource.Log.FoundCertInStore(_serverMode, this);
                        return collectionEx[0];
                    }
                }

                store = CertificateValidationPal.EnsureStoreOpened(!_serverMode);
                if (store != null)
                {
                    collectionEx = store.Certificates.Find(X509FindType.FindByThumbprint, certHash, false);
                    if (collectionEx.Count > 0 && collectionEx[0].HasPrivateKey)
                    {
                        if (NetEventSource.IsEnabled) NetEventSource.Log.FoundCertInStore(_serverMode, this);
                        return collectionEx[0];
                    }
                }
            }
            catch (CryptographicException)
            {
            }

            if (NetEventSource.IsEnabled) NetEventSource.Log.NotFoundCertInStore(this);
            return null;
        }