您可能会发现以下内容很有用：https://www.hass.de/content/setup-microsoft-windows-or-iis-ssl-perfect-forward-secrecy-and-tls-12
此外-我挖了一些旧的代码，在Windows 2012 R2上使用，以启用TLS 1.2，见下文：

Dim bypass_ssl_validation As Boolean

      Dim security_protocols As System.Net.SecurityProtocolType

      ' Set the following flag to true to bypass SSL certificate validation; if any
      ' errors are encountered with SSL, they will be ignored.  This may need to be
      ' done in cases where a protocol mismatch error occurs or the remote servers
      ' SSL certificate has expired ...

      bypass_ssl_validation = True

      Try

         ' Get current security protocols ...

         security_protocols = System.Net.ServicePointManager.SecurityProtocol

         ' Set security protocol to TLS 1.2 only ...
         ' NOTE: If more than one protocol is enabled when we try to post,
         '       the call will fail with the following exception:
         '       System.Net.WebException: The request was aborted: Could not create SSL/TLS secure channel.

         System.Net.ServicePointManager.SecurityProtocol = SecurityProtocolType.Tls12

         ' If flag set - bypass SSL Certificate Validation Checking.
         ' Note that this is a Shared property on the 'ServicePointManager' object, and must 
         ' then persist for the entire application, which we probably do not want -- so set 
         ' back to default behavior and end of try block ...

         If ( bypass_ssl_validation ) Then

            System.Net.ServicePointManager.ServerCertificateValidationCallback = AddressOf validate_remote_certificate

         End If

         ' POST data as needed ...

      Catch ex as Exception

         ' Log / report error ...

      Finally

         ' Restore previous protocols ...

         System.Net.ServicePointManager.SecurityProtocol = security_protocols

         ' If we bypassed SSL validation, restore default behavior ...

         If ( bypass_ssl_validation ) Then

            System.Net.ServicePointManager.ServerCertificateValidationCallback = Nothing

         End If

      End Try


   '-------------------------------------------------
   ' Delegate to ignore SSL Certificate errors if need
   ' be. Used when configuring ServicePointManager ...
   '
   Public Shared Function validate_remote_certificate( ByVal sender As Object, _
                                                       ByVal certificate As X509Certificate, _
                                                       ByVal chain As X509Chain, _
                                                       ByVal ssl_policy_errors As SslPolicyErrors ) As Boolean

      Return True

   End Function