Installing DigiCert commercial certificates
To generate the certificate signature request (CSR) use the command (all commands in this wiki are run as root in an arbitrary work directory):
/opt/zimbra/bin/zmcertmgr createcsr comm -subject '/C=FR/ST=N\/A/L=N\/A/O=Your Company/OU=Your Department/CN=webmail.foo.com'
The CSR is stored in /opt/zimbra/ssl/zimbra/commercial/commercial.csr.
The private key is in /opt/zimbra/ssl/zimbra/commercial/commercial.key.
Use the flag "-subjectAltNames host1,host2" if you need to specify host aliases.
Verify your CSR with:
/opt/zimbra/openssl/bin/openssl req -noout -text -in /opt/zimbra/ssl/zimbra/commercial/commercial.csr
Buy the certificate in http://www.digicert.com (create a customer account if you don't have one already) and purchase the certificate. Copy and paste the CSR file when requested. Take into account that certificates prices vary depending on the number of aliases you have in your CSR.
Fill the address (coherent with your domain owner address) and a valid e-mail contact.
After payment approval a validation e-mail is sent to the previous e-mail address and if all the info is coherent the certificates are issued and sent to the same e-mail address in a ZIP file.
The PEM file delivered by e-mail contains 3 certificates :
- a - The site certificate corresponding to the CSR
- b - DigiCert's CA certificate
- c - DigiCert's High Assurance CA
To complete the trust chain, a 4th certificate is needed, the "Trusted Root" CRT. This one can be obtained from the customer's management interface by clicking on the "Server Certificate" logo on the left. A pop-up window will show the 3 previous certificates plus the "Trusted Root" certificate.
Download the "Trusted Root" certificate.
- Copy the server certificate (first block of the PEM file) to the file
- Concatenate Digicert's CA certificate (2nd block of the PEM), Digicert's High Assurance CA certificate (3rd block of the PEM) and the "Trusted Root" certificate (downloaded separately) into a single file named:
- Validate the trust chain with the command:
/opt/zimbra/openssl/bin/openssl verify -CAfile commercial_ca.crt commercial.crt
it should say "commercial.crt: OK"
Deploy the new certificates with:
/opt/zimbra/bin/zmcertmgr deploycrt comm commercial.crt commercial_ca.crt
then restart Zimbra.