Set up TLS 1.3 for VMM

This article describes how to set up Transport Security Layer (TLS) protocol version 1.3 with System Center Virtual Machine Manager (VMM) server.

Before you start

• Security fixes should be up to date on the VMM server and the server running the VMM database.
• The VMM server should be running .NET version 4.6 or later. Follow these instructions to determine which version of .NET is installed.
• • TLS 1.3. requires TLS 1.2. to be configured.
• To work with TLS 1.3, System Center components generate SHA1 or SHA2 self-signed certificates. If SSL certificates from a certificate authority (CA) certificates are used, they should use SHA1 or SHA2.

Configure the VMM server to use TLS 1.3

Disable all SCHANNEL protocols except for TLS 1.3 and 1.2.

Manually modify the registry

1. Open the Registry Editor and navigate to HKEY_LOCAL_MACHINE\System\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols.
2. Right-click Protocol, select New > Key. Enter the key and press Enter. Perform this procedure to create the following keys:
   • SSL3
   • TLS 1.2
   • TLS 1.3
3. After you've created these keys, you need to create the Client and Server keys under them.
   • For SSL3, select New > Key. Enter Client and press Enter. Again, for SSL3, select New > Key again. Then enter Server and press Enter.
   • Repeat the action to create the Client and Server keys under TLS 1.2 and TLS 1.3.
4. After you've created the Client and Server keys, you need to create DWORD values under them to enable and disable protocols. Do this as follows:
   • Enable the TLS 1.2 protocol. To do this, in TLS 1.2, under the Client key, create the DWORD value DisabledByDefault, and set the value to 0. Now create a DWORD value Enabled, and set the value to 1. Create the same DWORD values under the Server key.
   • Enable the TLS 1.3 protocol. To do this, in TLS 1.3, under the Client key, create the DWORD value DisabledByDefault, and set the value to 0. Now create a DWORD value Enabled, and set the value to 1. Create the same DWORD values under the Server key.
   • Now disable the other protocols. To do this, in SSL3 and TLS 1.2 under the Client key, create the DWORD value DisabledByDefault, and set the value to 1. Now create a DWORD value Enabled and set the value to 0. Create the same DWORD values under the Server key.

Modify the registry with a PowerShell script

Instead of modifying the registry values manually, you can use the following PowerShell script.

$ProtocolList       = @(""SSL 3.0", "TLS 1.2", "TLS 1.3")
$ProtocolSubKeyList = @("Client", "Server")
$DisabledByDefault  = "DisabledByDefault"
$registryPath       = "HKLM:\SYSTEM\CurrentControlSet\Control\SecurityProviders\SCHANNEL\Protocols\"

foreach ($Protocol in $ProtocolList)
{
	foreach ($key in $ProtocolSubKeyList)
	{
		$currentRegPath = $registryPath + $Protocol + "\" + $key
		Write-Output "Current Registry Path: `"$currentRegPath`""

		if (!(Test-Path $currentRegPath))
		{
			Write-Output " `'$key`' not found: Creating new Registry Key"
			New-Item -Path $currentRegPath -Force | out-Null
		}
		if ($Protocol -eq "TLS 1.2")
		{
			Write-Output " Enabling - TLS 1.2"
			New-ItemProperty -Path $currentRegPath -Name $DisabledByDefault -Value "0" -PropertyType DWORD -Force | Out-Null
			New-ItemProperty -Path $currentRegPath -Name 'Enabled' -Value "1" -PropertyType DWORD -Force | Out-Null
		}
else if ($Protocol -eq "TLS 1.3")
{
Write-Output " Enabling - TLS 1.3"
New-ItemProperty -Path $currentRegPath -Name $DisabledByDefault -Value "0" -PropertyType DWORD -Force | Out-Null
New-ItemProperty -Path $currentRegPath -Name 'Enabled' -Value "1" -PropertyType DWORD -Force | Out-Null
}
		else
		{
			Write-Output " Disabling - $Protocol"
			New-ItemProperty -Path $currentRegPath -Name $DisabledByDefault -Value "1" -PropertyType DWORD -Force | Out-Null
			New-ItemProperty -Path $currentRegPath -Name 'Enabled' -Value "0" -PropertyType DWORD -Force | Out-Null
		}
		Write-Output " "
	}
}

Exit 0

Configure VMM to use TLS 1.3

1. Open the registry editor on the VMM server. Navigate to HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\ .NetFramework\v4.0.30319.
2. Create the DWORD value SchUseStrongCrypto and set the value to 1.
3. Now navigate to HKEY_LOCAL_MACHINE\SOFTWARE\WOW6432Node\Microsoft
   .NetFramework\v4.0.30319.
4. Under this location, create the same DWORD value SchUseStrongCrypto and set the value to 1.
5. Restart the server for the settings to take effect.

Modify the registry with a PowerShell script

You can modify the registry settings using the following PowerShell script.

# Tighten up the .NET Framework
$NetRegistryPath = "HKLM:\SOFTWARE\Microsoft\.NETFramework\v4.0.30319"
New-ItemProperty -Path $NetRegistryPath -Name "SchUseStrongCrypto" -Value "1" -PropertyType DWORD -Force | Out-Null

$NetRegistryPath = "HKLM:\SOFTWARE\WOW6432Node\Microsoft\.NETFramework\v4.0.30319"
New-ItemProperty -Path $NetRegistryPath -Name "SchUseStrongCrypto" -Value "1" -PropertyType DWORD -Force | Out-Null

Next steps

• Learn more about the TLS 1.3 protocol.
• Learn more about the TLS 1.2 protocol.