Installing a Comodo SSL Certificate on Zimbra Collaboration

Installing a Comodo SSL Certificate

Use the article as a guide to installing a Comodo issued SSL certificate with the zmcertmgr tool or the Admin Console.

Using the CLI

• 1. Get the bundle from Comodo in crt format, or sometimes like a zip file. Is always good call or write Comodo and obtain the proper Bundle, but you can also download each file from the next URL (SHA2 files) - https://support.comodo.com/index.php?/Default/Knowledgebase/Article/View/620/1/
• 2. Place the bundle on your Zimbra mailbox server. You should receive, or download, the next files:
  • AddTrustExternalCARoot.crt
  • COMODORSAAddTrustCA.crt
  • COMODORSADomainValidationSecureServerCA.crt
  • my_domain_com.crt files

Note the root and intermediate files may have different names depends of the SSL Certificate, like PositiveSSL, etc.

• 3. Cat the CA certs to form a single CA certificate chain file

 cat AddTrustExternalCARoot.crt COMODORSAAddTrustCA.crt COMODORSADomainValidationSecureServerCA.crt > /tmp/commercial_ca.crt

• 4. Place the SSL certificate in /tmp/commercial.crt.

 cp my_domain_com.crt /tmp/commercial.crt

• 5. Check that your SSL certificate, your private key and the Intermediate CA are OK, this step is important and you should not continue if you receive an error here:

/opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /tmp/commercial.crt /tmp/commercial_ca.crt 
** Verifying /tmp/commercial.crt against /opt/zimbra/ssl/zimbra/commercial/commercial.key
Certificate (/tmp/commercial.crt) and private key (/opt/zimbra/ssl/zimbra/commercial/commercial.key) match.
Valid Certificate: /tmp/commercial.crt: OK

• 6. Deploy the commercial certificate with zmcertmgr as the root user.

/opt/zimbra/bin/zmcertmgr deploycrt comm /tmp/commercial.crt /tmp/commercial_ca.crt 
** Verifying /tmp/commercial.crt against /opt/zimbra/ssl/zimbra/commercial/commercial.key
Certificate (/tmp/commercial.crt) and private key (/opt/zimbra/ssl/zimbra/commercial/commercial.key) match.
Valid Certificate: /tmp/commercial.crt: OK
** Copying /tmp/commercial.crt to /opt/zimbra/ssl/zimbra/commercial/commercial.crt
** Appending ca chain /tmp/commercial_ca.crt to /opt/zimbra/ssl/zimbra/commercial/commercial.crt
** Importing certificate /opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt to CACERTS as zcs-user-commercial_ca...done.
** NOTE: mailboxd must be restarted in order to use the imported certificate.
** Saving server config key zimbraSSLCertificate...done.
** Saving server config key zimbraSSLPrivateKey...done.
** Installing mta certificate and key...done.
** Installing slapd certificate and key...done.
** Installing proxy certificate and key...done.
** Creating pkcs12 file /opt/zimbra/ssl/zimbra/jetty.pkcs12...done.
** Creating keystore file /opt/zimbra/mailboxd/etc/keystore...done.
** Installing CA to /opt/zimbra/conf/ca...done.

• 7. Restart the Zimbra Services

zmcontrol restart

Using the Admin Console

Before install the SSL Certificate using the Admin Console, you should generated the CSR before following the steps indicated in the next Wiki:

• Generate a valid CSR (Certificate Signing Request) for a Commercial SSL

You should receive the next files from Comodo:

• • AddTrustExternalCARoot.crt
  • COMODORSAAddTrustCA.crt
  • COMODORSADomainValidationSecureServerCA.crt
  • my_domain_com.crt files

Go to Home > Configure > Certificates and click in the settings icon, then click on Install Certificate

Select the target server where install the SSL Certificate:

Select the option Install the commercial signed certificate

If all the info in the review windows is ok, press Next button

Add the files one by one that Comodo sent to you, the Certificate, the root, and the CA:

Select Install button and the SSL Certificate will be installed

Restart the Zimbra services like zimbra user in a CLI session:

zmcontrol restart

You can return to the Admin Console and View the installed Certificate