Renew certificates for Network Controller

The Start-SdnCertificateRotation cmdlet enables you to automate renewal of your Network Controller certificates. Certificate automatic renewal helps minimize any downtime or unplanned outages caused due to certificate expiry issues.

Here are the scenarios where you can use the Start-SdnCertificateRotation cmdlet to automatically renew Network Controller certificates:

• Self-signed certificates. Use the Start-SdnCertificateRotation cmdlet to generate self-signed certificates and renew those certificates in all the Network Controller nodes.
• Bring your own certificates. You bring your own certificates, either self-signed or CA-signed and use the Start-SdnCertificateRotation cmdlet for certificate renewal. The cmdlet installs the certificates on all the Network Controller nodes and distributes them to other SDN infrastructure components.
• Preinstalled certificates. You have the required certificates already installed on the Network Controller nodes. Use the Start-SdnCertificateRotation cmdlet to renew those certificates to other SDN infrastructure components.

For more information about how to create and manage SDN certificates, see Manage certificates for Software Defined Networking.

Requirements

Here are the requirements for automatic renewal of certificate:

• You must run the Start-SdnCertificateRotation cmdlet on one of the Network Controller nodes. For installation instructions, see Install SdnDiagnostics module.

• You must have credentials for the following two types of accounts to authorize communication between Network Controller nodes:

  • Credential to specify a user account with local admin privileges on Network Controller.

  • NcRestCredential to specify a user account with access to Network Controller REST API. It's a member of ClientSecurityGroup from Get-NetworkController. This account is used to call REST API to update credential resource with the new certificate.

  For more information about configuring authorization for Network Controller Northbound communication, see Authorization for Northbound communication.

Renew self-signed certificates automatically

You can use the Start-SdnCertificateRotation cmdlet to generate new self-signed certificates and automatically renew them to all the Network Controller nodes. By default, the cmdlet generates certificates with a validity period of three years, but you can specify a different validity period.

Perform these steps on one of the Network Controller nodes to generate self-signed certificates and automatically renew them:

1. To generate self-signed certificates, run the Start-SdnCertificateRotation cmdlet. You can use the -Force parameter with the cmdlet to avoid any prompts for confirmation or manual inputs during the rotation process.

   • To generate self-signed certificates with the default three years validity period, run the following commands:

     Import-Module -Name SdnDiagnostics -Force
     Start-SdnCertificateRotation -GenerateCertificate -CertPassword (Get-Credential).Password -Credential (Get-Credential)
     

   • To generate self-signed certificates with a specific validity period, use the NotAfter parameter to specify the validity period.

     For example, to generate self-signed certificates with a validity period of five years, run the following commands:

     Import-Module -Name SdnDiagnostics -Force
     Start-SdnCertificateRotation -GenerateCertificate -CertPassword (Get-Credential).Password -NotAfter (Get-Date).AddYears(5) -Credential (Get-Credential)
     

2. Enter the credentials. You get two prompts to provide two types of credentials:

   • In the first prompt, enter the password to protect the generated certificate. The username can be anything and isn't used.
   • In the second prompt, use the credential that has admin access to all the Network Controller nodes.

3. After the new certificates are generated, you get a warning to confirm if you want to continue with the certificate rotation process. The warning text displays the list of Network Controller certificates that will be replaced with the newly generated ones. Type Y to confirm.

   Here's a sample screenshot of the warning:

   

4. After you confirm to continue with the certificate rotation, you can view the status of the ongoing operations in the PowerShell command window.

   Important

   Don't close the PowerShell window until the cmdlet finishes. Depending on your environment, such as the number of Network Controller nodes in the cluster, it may take several minutes or more than an hour to finish.

   Here's a sample screenshot of the PowerShell command window showing the status of ongoing operations:

   

Renew your own certificates automatically

In addition to generating self-signed Network Controller certificates, you can also bring your own certificates, either self-signed or CA-signed, and use the Start-SdnCertificateRotation cmdlet to renew those certificates.

Perform these steps on one of the Network Controller nodes to automatically renew your own certificates:

1. Prepare your certificates in .pfx format and save in a folder on one of the Network Controller nodes from where you run the Start-SdnCertificateRotation cmdlet. You can use the -Force parameter with the cmdlet to avoid any prompts for confirmation or manual inputs during the rotation process.

2. To start certificate renewal, run the following commands:

   Import-Module -Name SdnDiagnostics -Force
   Start-SdnCertificateRotation -CertPath "<Path where you put your certificates>" -CertPassword (Get-Credential).Password -Credential (Get-Credential)
   

3. Enter the credentials. You get two prompts to provide two types of credentials:

   • In the first prompt, enter the password of your certificate. The username can be anything and isn't used.
   • In the second prompt, use the credential that has admin access to all the Network Controller nodes.

4. You get a warning to confirm if you want to continue with the certificate rotation process. The warning text displays the list of Network Controller certificates that will be replaced with the newly generated ones. Type Y to confirm.

   Here's a sample screenshot of the warning:

   

5. After you confirm to continue with the certificate rotation, you can view the status of the ongoing operations in the PowerShell command window.

   Important

   Don't close the PowerShell window until the cmdlet finishes. Depending on your environment, such as the number of Network Controller nodes in the cluster, it may take several minutes or more than an hour to finish.

Renew preinstalled certificates automatically

In this scenario, you have the required certificates installed on the Network Controller nodes. Use the Start-SdnCertificateRotation cmdlet to renew those certificates on other SDN infrastructure components.

Perform these steps on one of the Network Controller nodes to automatically renew the preinstalled certificates:

1. Install the Network Controller certificates on all the Network Controller nodes as per your preferred method. Ensure the certificates are trusted by other SDN infrastructure components, including SDN MUX servers and SDN hosts.

2. Create certificate rotation configuration:

   1. To generate the default certificate rotation configuration, run the following commands:

      Import-Module -Name SdnDiagnostics -Force
      $certConfig = New-SdnCertificateRotationConfig
      $certConfig
      

   2. Review the default certificate rotation configuration to confirm if the auto-detected certificates are the ones that you want to use. By default, it retrieves the latest issued certificate to be used.

      Here's a sample certificate rotation configuration:

      PS C:\Users\LabAdmin> $certConfig
      
      Name					Value
      ----					-----
      ws22ncl.corp.contoso.com 	F4AAF14991DAF282D9056E147AE60C2C5FE80A49
      ws22nc3.corp.contoso.com 	BC3E6B090E2AA80220B7BAED7F8F981A1E1DD115
      ClusterCredentialType 		X509
      ws22nc2.corp.contoso.corn 	75DC229A8E61AD855CC445C42482F9F919CC1077
      NcRestCert				029D7CA0067A60FB24827D8434566787114AC30C
      

      where:

      • ws22ncx.corp.contoso.com shows the certificate's thumbprint for each Network Controller node.
      • ClusterCredentialType shows the Network Controller Cluster authentication type. If the authentication type isn't X509, the node certificate isn't used and isn't shown in the output.
      • NcRestCert shows the thumbprint of the Network Controller Rest certificate.

   3. (Optional) If the generated $certConfig isn't correct, you can change it by specifying a new certificate's thumbprint. For example, to change the thumbprint of the Network Controller Rest certificate, run the following command:

      $certConfig.NcRestCert = <new certificate thumbprint>
      

3. Start certificate rotation. You can use the -Force parameter with the cmdlet to avoid any prompts for confirmation or manual inputs during the rotation process.

   Import-Module -Name SdnDiagnostics -Force
   Start-SdnCertificateRotation -CertRotateConfig $certConfig -Credential (Get-Credential)
   

4. When prompted for credentials, enter the credential that has admin access all Network Controller Nodes.

5. You get a warning to confirm if you want to continue with auto rotation of certificates. The warning displays the list of Network Controller certificates that will be replaced with your own certificates. Type Y to confirm.

   Here's a sample screenshot of the warning that prompts you to confirm the rotation of certificates:

   

6. After you confirm to continue with the certificate rotation, you can view the status of the ongoing operations in the PowerShell command window.

   Important

   Don't close the PowerShell window until the cmdlet finishes. Depending on your environment, such as the number of Network Controller nodes in the cluster, it may take several minutes or more than an hour to finish.

Use the following instructions to manually renew REST certificates and Network Controller node certificates.

Renew REST certificates

You use the Network Controller's REST certificate for:

• Northbound communication with REST clients
• Encryption of credentials
• Southbound communication to hosts and Software Load Balancer VMs

When you update a REST certificate, you must update the management clients and network devices to use the new certificate.

To renew REST certificate, complete the following steps:

1. Make sure that the certificate on the Network Controller VMs isn't expired before renewing it. See View certificate expiry.

2. Procure the new certificate and place it in the personal store of the local machine (LocalMachine\My). If it's a self-signed certificate, place it in the Root store (LocalMachine\Root) of every Network Controller VM. For information about how to create a new certificate or issue it from a Certification Authority, see Manage certificates for Software Defined Networking.

3. Assign the new certificate to a variable:

   $cert= Get-ChildItem Cert:\LocalMachine\My | where{$_.Thumbprint -eq "<thumbprint of the new certificate>"}
   

4. Copy the certificate to all Network Controller VMs.

5. Provide Read and Allow permissions for NT Authority/Network Service on the certificate:

   $targetCertPrivKey = $Cert.PrivateKey
   $privKeyCertFile = Get-Item -path
   "$ENV:ProgramData\Microsoft\Crypto\RSA\MachineKeys\*" | where-object {$_.Name -eq $targetCertPrivKey.CspKeyContainerInfo.UniqueKeyContainerName}
   $privKeyAcl = Get-Acl $privKeyCertFile
   $permission = "NT AUTHORITY\NETWORK SERVICE","Read","Allow"
   $accessRule = new-object System.Security.AccessControl.FileSystemAccessRule $permission
   $privKeyAcl.AddAccessRule($accessRule)
   Set-Acl $privKeyCertFile.FullName $privKeyAcl
   

6. (Only for self-signed certificate) Copy the certificate public key to all the hosts and Software Load Balancer VMs.

7. Modify Network Controller settings to use the new certificate.

Copy the certificate to all Network Controller VMs

Follow these steps for copying one certificate to all Network Controller VMs.

1. Ensure that you procure the new certificate and place it in the local machine personal store (My – cert:\localmachine\my).

2. On the first Network Controller VM, export the certificate to a Personal Information Exchange (PFX) file.

   $mypwd = ConvertTo-SecureString -String "<password>" -Force -AsPlainText
   Export-PfxCertificate -FilePath "C:\newpfx.pfx" -Password $mypwd -Cert $cert    
   # Here, $cert is the new certificate
   

3. On other Network Controller VMs, import the certificate and private keys from a PFX file to the destination store:

   $mypwd = ConvertTo-SecureString -String "<password>" -Force -AsPlainText
   Import-PfxCertificate -FilePath C:\newpfx.pfx -CertStoreLocation Cert:\LocalMachine\My -Password $mypwd
   # Ensure that you copy the pfx file into the local machine before importing the cert
   

Copy the certificate public key to all the hosts and Software Load Balancer VMs (only for self-signed certificate)

If you're using a self-signed certificate, place it in the root store of the local machine (LocalMachine\Root) for each of the following:

• Every Network Controller VM.
• Every Azure Stack HCI host machine and Software Load Balancer VMs. This ensures that the certificate is trusted by the peer entities.

Here's a sample command to import the certificate public key that has already been exported:

Import-Certificate -FilePath "\\sa18fs\SU1_LibraryShare1\RestCert.cer\" -CertStoreLocation cert:\localMachine\Root

Modify Network Controller settings to use the new certificate

Modify Network Controller node, cluster, and application settings to use the new certificate.

For Northbound communication

To change the certificate that Network Controller uses for Northbound communication, run the following command on any of the Network Controller VMs:

Set-NetworkController -ServerCertificate \$cert

For encryption of credentials

To change the certificate that Network Controller uses to encrypt the credentials, run the following command on any of the Network Controller VMs:

Set-NetworkControllerCluster -CredentialEncryptionCertificate $cert

For Southbound communication

To change the certificate that Network Controller uses for communicating with hosts and Software Load Balancers, run the following command:

$certCred = Get-NetworkControllerCredential -ConnectionUri <REST uri of deployment> |where-object { $_.properties.type -eq "X509Certificate" }
$certCred[0].Properties.Value ="<Thumbprint of the new certificate>"

New-NetworkControllerCredential -ConnectionUri <REST uri of deployment> -ResourceId $certCred[0].ResourceId -Properties $certCred[0].Properties -Force

Renew node certificates

To renew the Network Controller node certificate, perform the following steps on each Network Controller VM:

1. Procure the new certificate and put it in the Personal store of the Local Machine (LocalMachine\My). If it's a self-signed certificate, it must also be placed in the (LocalMachine\Root) store of every Network Controller VM. For information about how to create a new certificate or issue it from a Certification Authority, see Manage certificates for Software Defined Networking.

2. Assign the new certificate to a variable:

   $cert = Get-ChildItem Cert:\LocalMachine\My | where{$_.Thumbprint -eq "<thumbprint of the new certificate>"}
   

3. Provide Read and Allow permissions for NT Authority/Network Service on the certificate:

   $targetCertPrivKey = $Cert.PrivateKey
   $privKeyCertFile = Get-Item -path
   "$ENV:ProgramData\Microsoft\Crypto\RSA\MachineKeys\*" | where-object {$_.Name -eq $targetCertPrivKey.CspKeyContainerInfo.UniqueKeyContainerName}
   $privKeyAcl = Get-Acl $privKeyCertFile
   $permission = "NT AUTHORITY\NETWORK SERVICE","Read","Allow"
   $accessRule = new-object System.Security.AccessControl.FileSystemAccessRule $permission
   $privKeyAcl.AddAccessRule($accessRule)
   Set-Acl $privKeyCertFile.FullName $privKeyAcl
   

4. Run the following command to change the node certificate:

   Set-NetworkControllerNode -Name "<Name of the Network Controller node>" -NodeCertificate $cert