Create New Certificates from Signed CA Certificates

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Contents

Introduction

This document describes how to regenerate the certificates signed by a Certificate Authority (CA) in Cisco Unified Communications Manager (CUCM).

Prerequisites

Requirements

Cisco recommends that you have knowledge of these topics:

Components Used

The information in this document was created from the devices in a specific lab environment. All of the devices used in this document started with a cleared (default) configuration. If your network is live, ensure that you understand the potential impact of any command.

Pre-check Information

Note: For Self-Signed certificate regeneration, refer to the Certificate Regeneration Guide. For CA-Signed Multi-SAN certificate regeneration, refer to the Multi-SAN Certificate Regeneration Guide

To understand the impact of each certificate and its regeneration, refer to the Self-Signed Regeneration Guide.

Each Certificate Signing Request (CSR) type has different key usages and those are required in the Signed Certificate. The Security Guide includes a table with the required key usages for each type of certificate.

To change the Subject Settings (Locality, State, Organization Unit, and so on) run this command:

The Tomcat certificate is regenerated automatically after you run the set web-security command. The new Self-Signed certificate is not applied unless the Tomcat service is restarted. Please refer to these guides for more information about this command:

Configure and Regenerate Certificates

The steps to regenerate Single-Node certificates in a CUCM cluster signed by a CA are listed for each type of certificate. It is not necessary to regenerate all the certificates in the cluster if they have not expired.

Tomcat Certificate

Caution: Verify SSO is disabled in the cluster ( CM Administration > System > SAML Single Sign-On ). If SSO is enabled, it must be disabled and then enabled once the Tomcat certificate regeneration process is completed.

On all the nodes (CallManager and IM&P) of the cluster:

Step 1. Navigate to Cisco Unified OS Administration > Security > Certificate Management > Find and verify the expiration date of the Tomcat certificate.

Step 2. Click Generate CSR > Certificate Purpose: tomcat . Select the desired settings for the certificate, then click Generate . Wait for the success message to appear and click Close .

Certificate Signing Request Generated

Step 3. Download the CSR. Click Download CSR , select Certificate Purpose: tomcat , and click Download .

Download Certificate Signing Request

Step 4. Send the CSR to the Certificate Authority.

Step 5. The Certificate Authority returns two or more files for the signed certificate chain. Upload the certificates in this order:

Note: Some CAs do not provide an intermediate certificate. If only the Root certificate was provided, this step can be omitted.

Note: At this point, CUCM compares the CSR and the uploaded CA-signed certificate. If the information matches, the CSR disappears, and the new CA-signed certificate is uploaded. If you receive an error message after the certificate is uploaded, refer to the Upload Certificate Common Error Messages section.

Step 6. To get the new certificate applied to the server, the Cisco Tomcat service needs to be restarted via CLI (start with Publisher, and then subscribers, one at a time), use the command utils service restart Cisco Tomcat .

To validate the Tomcat certificate is now used by CUCM, navigate to the web page of the node and select Site Information (Lock Icon) in the Browser. Click the certificate option, and verify the date of the new certificate.

Certificate Option

Certificate Information

CallManager Certificate

Caution: Do not regenerate CallManager and TVS certificates at the same time. This causes an unrecoverable mismatch to the installed ITL on endpoints which requires the removal of the ITL from ALL endpoints in the cluster. Finish the entire process for CallManager, and once the phones are registered back, start the process for the TVS.

Note: To determine if the cluster is in Mixed Mode, navigate to Cisco Unified CM Administration > System > Enterprise Parameters > Cluster Security Mode (0 == Non-Secure; 1 == Mixed Mode).

For all the CallManager nodes of the cluster:

Step 1. Navigate to Cisco Unified OS Administration > Security > Certificate Management > Find and verify the expiration date of the CallManager certificate.

Step 2. Click Generate CSR > Certificate Purpose: CallManager . Select the desired settings for the certificate, then click Generate . Wait for the success message to appear and click Close .

Step 3. Download the CSR. Click Download CSR. Select Certificate Purpose: CallManager and click Download .

Step 4. Send the CSR to the Certificate Authority .

Step 5. The Certificate Authority returns two or more files for the signed certificate chain. Upload the certificates in this order: