Installing a LetsEncrypt SSL Certificate: Difference between revisions

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=Installing a Let's Encrypt SSL Certificate=
=Installing a Let's Encrypt SSL Certificate=
{{KB|{{Unsupported}}|{{ZCS 8.0}}|{{ZCS 7.0}}|}}
{{KB|{{Unsupported}}|{{ZCS 9.0}}|{{ZCS 8.8}}|}}
{{WIP}}
 
[[File:Letsencrypt-en.png|1024px]]


==Purpose==
==Purpose==
Step by Step Wiki/KB article to install a Let's Encrypt Commercial Certificate.
'''Disclaimer'''
The Let’s Encrypt Client is '''BETA SOFTWARE'''. It contains plenty of bugs and rough edges, and should be tested thoroughly in staging environments before use on production systems.
For more information regarding the status of the project, please see https://letsencrypt.org. Be sure to checkout the [https://community.letsencrypt.org/t/frequently-asked-questions-faq/26#topic-title Frequently Asked Questions (FAQ)].


==Resolution==
Let’s Encrypt is a way to obtain trusted and free TLS certificates. To obtain certificates you can use a program called Certbot. You can find instructions for setting up certbot at https://certbot.eff.org/instructions. If you already use Let’s Encrypt on Zimbra keep reading as this post will explain how to keep using Let’s Encrypt after the expiration of IdentTrust DST Root CA X3 on September 30!
Let’s Encrypt is a new Certificate Authority: It’s free, automated, and open. And could be an option to protect our Zimbra Servers with a valid SSL certificate, please be aware that is a Beta for now, and some stuff could not work, or have issues, so use it under your own risk.


===Installing Let's Encrypt on our Zimbra Server===
In many cases it is easiest to set-up a dedicated VM to take care of the deployment of Let’s Encrypt certificates to all the systems you intent to use with TLS certificates.
Let's Encrypt must be installed on one Linux machine to obtain the proper SSL Certificate, CA Intermediate, and Private Key, doesn't require to be on the same Zimbra Server, but to obtain the renewals, etc, could help and we can save time.
* First Step is stop the jetty or nginx service at Zimbra level
zmproxyctl stop
zmmailboxdctl stop
* Second step is Install git in our Server (apt-get install git/yum install git) and then do a git clone of the project on the folder we want
** Note: On RedHat/CentOS 6 you will need to enable the EPEL repository before install.
git clone https://github.com/letsencrypt/letsencrypt
cd letsencrypt
* Let's run now the Let's Encrypt in auto mode, and use the certonly option, because for now the project can't install automatically the cert on Zimbra servers
root@zimbra86:~/tmp/letsencrypt# ./letsencrypt-auto certonly
** (This step only happen first time, when renew the SSL Certificate this process will not occur if we are using the same machine) The process will download now all the OS dependencies that Let's Encrypt needs, and after a few minutes
<pre>Creating virtual environment...
Updating letsencrypt and virtual environment dependencies...../root/.local/share/letsencrypt/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
./root/.local/share/letsencrypt/local/lib/python2.7/site-packages/pip/_vendor/requests/packages/urllib3/util/ssl_.py:90: InsecurePlatformWarning: A true SSLContext object is not available. This prevents urllib3 from configuring SSL appropriately and may cause certain SSL connections to fail. For more information, see https://urllib3.readthedocs.org/en/latest/security.html#insecureplatformwarning.
  InsecurePlatformWarning
</pre>
*** The process will ask for a Email Address in case of emergency contact, or to recover the lost key


[[File:Letsencrypt-002.png]]
If you want to use Zimbra it is recommended you use the <code>snap</code> version of Certbot as that supports the <code>--preferred-chain  &quot;ISRG Root X1&quot;</code> option which is needed to make it work with Zimbra.


*** The process will ask if we are agree with the ToS
= Installing the obtained certificate on Zimbra =


[[File:Letsencrypt-003.png]]
Make sure to request a certificate with the <code>--preferred-chain  &quot;ISRG Root X1&quot;</code> option. In case you already have a certificate but you have not used the option, you have to do a force renewal with the <code>--force-renewal --preferred-chain  &quot;ISRG Root X1&quot;</code> options.


**** In case we run a renewal, or a request for a new FQDN, the process will just take a few seconds
After you have received the certificate from Let’s Encrypt you can deploy it on Zimbra like this:
Updating letsencrypt and virtual environment dependencies.......
Running with virtualenv: /root/.local/share/letsencrypt/bin/letsencrypt certonly
*** Let's Encrypt will prompt for the domain to protect, in this lab case (zimbra86.zimbra.io):


[[File:Letsencrypt-004.png]]
As user root or sudo:


* The process will take a few seconds to validate and then will end:
<pre>cp /etc/letsencrypt/live/barrydegraaff.nl/privkey.pem /opt/zimbra/ssl/zimbra/commercial/commercial.key
<pre>IMPORTANT NOTES:
chown zimbra:zimbra /opt/zimbra/ssl/zimbra/commercial/commercial.key
- Congratulations! Your certificate and chain have been saved at
wget -O /tmp/ISRG-X1.pem https://letsencrypt.org/certs/isrgrootx1.pem.txt
  /etc/letsencrypt/live/zimbra86.zimbra.io/fullchain.pem. Your cert
cat /tmp/ISRG-X1.pem &gt;&gt; /etc/letsencrypt/live/barrydegraaff.nl/chain.pem</pre>
  will expire on 2016-03-04. To obtain a new version of the
As user zimbra or <code>sudo su zimbra -</code>:
  certificate in the future, simply run Let's Encrypt again.
- If like Let's Encrypt, please consider supporting our work by:


  Donating to ISRG / Let's Encrypt:  https://letsencrypt.org/donate
<pre>cd ~
  Donating to EFF:                    https://eff.org/donate-le</pre>
/opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /etc/letsencrypt/live/barrydegraaff.nl/cert.pem /etc/letsencrypt/live/barrydegraaff.nl/chain.pem
/opt/zimbra/bin/zmcertmgr deploycrt comm /etc/letsencrypt/live/barrydegraaff.nl/cert.pem /etc/letsencrypt/live/barrydegraaff.nl/chain.pem</pre>
The output should be similar to:


===Where are the SSL Certificate Files?===
<pre>root@zimbra9:~# su zimbra -
You can find all your files under '''/etc/letsencrypt/live/$domain''', where $domain is the fqdn you used during the process:
zimbra@zimbra9:/root$ /opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /etc/letsencrypt/live/barrydegraaff.nl/cert.pem /etc/letsencrypt/live/barrydegraaff.nl/chain.pem
<pre>root@zimbra86:/etc/letsencrypt/live/zimbra86.zimbra.io# ls -al
** Verifying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' against '/opt/zimbra/ssl/zimbra/commercial/commercial.key'
total 8
Certificate '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' and private key '/opt/zimbra/ssl/zimbra/commercial/commercial.key' match.
drwxr-xr-x 2 root root 4096 Dec  5 16:46 .
** Verifying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' against '/etc/letsencrypt/live/barrydegraaff.nl/chain.pem'
drwx------ 3 root root 4096 Dec  5 16:46 ..
Valid certificate chain: /etc/letsencrypt/live/barrydegraaff.nl/cert.pem: OK
lrwxrwxrwx 1 root root  42 Dec  5 16:46 cert.pem -> ../../archive/zimbra86.zimbra.io/cert1.pem
zimbra@zimbra9:/root$ cd ~
lrwxrwxrwx 1 root root  43 Dec  5 16:46 chain.pem -> ../../archive/zimbra86.zimbra.io/chain1.pem
zimbra@zimbra9:~$ /opt/zimbra/bin/zmcertmgr deploycrt comm /etc/letsencrypt/live/barrydegraaff.nl/cert.pem /etc/letsencrypt/live/barrydegraaff.nl/chain.pem
lrwxrwxrwx 1 root root  47 Dec  5 16:46 fullchain.pem -> ../../archive/zimbra86.zimbra.io/fullchain1.pem
** Verifying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' against '/opt/zimbra/ssl/zimbra/commercial/commercial.key'
lrwxrwxrwx 1 root root  45 Dec  5 16:46 privkey.pem -> ../../archive/zimbra86.zimbra.io/privkey1.pem</pre>
Certificate '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' and private key '/opt/zimbra/ssl/zimbra/commercial/commercial.key' match.
** Verifying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' against '/etc/letsencrypt/live/barrydegraaff.nl/chain.pem'
Valid certificate chain: /etc/letsencrypt/live/barrydegraaff.nl/cert.pem: OK
** Copying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' to '/opt/zimbra/ssl/zimbra/commercial/commercial.crt'
** Copying '/etc/letsencrypt/live/barrydegraaff.nl/chain.pem' to '/opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt'
** Appending ca chain '/etc/letsencrypt/live/barrydegraaff.nl/chain.pem' to '/opt/zimbra/ssl/zimbra/commercial/commercial.crt'
** Importing cert '/opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt' as 'zcs-user-commercial_ca' into cacerts '/opt/zimbra/common/lib/jvm/java/lib/security/cacerts'
** NOTE: restart mailboxd to use the imported certificate.
** Saving config key 'zimbraSSLCertificate' via zmprov modifyServer zimbra9.barrydegraaff.nl...ok
** Saving config key 'zimbraSSLPrivateKey' via zmprov modifyServer zimbra9.barrydegraaff.nl...ok
** Installing imapd certificate '/opt/zimbra/conf/imapd.crt' and key '/opt/zimbra/conf/imapd.key'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.crt' to '/opt/zimbra/conf/imapd.crt'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.key' to '/opt/zimbra/conf/imapd.key'
** Creating file '/opt/zimbra/ssl/zimbra/jetty.pkcs12'
** Creating keystore '/opt/zimbra/conf/imapd.keystore'
** Installing ldap certificate '/opt/zimbra/conf/slapd.crt' and key '/opt/zimbra/conf/slapd.key'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.crt' to '/opt/zimbra/conf/slapd.crt'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.key' to '/opt/zimbra/conf/slapd.key'
** Creating file '/opt/zimbra/ssl/zimbra/jetty.pkcs12'
** Creating keystore '/opt/zimbra/mailboxd/etc/keystore'
** Installing mta certificate '/opt/zimbra/conf/smtpd.crt' and key '/opt/zimbra/conf/smtpd.key'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.crt' to '/opt/zimbra/conf/smtpd.crt'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.key' to '/opt/zimbra/conf/smtpd.key'
** Installing proxy certificate '/opt/zimbra/conf/nginx.crt' and key '/opt/zimbra/conf/nginx.key'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.crt' to '/opt/zimbra/conf/nginx.crt'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.key' to '/opt/zimbra/conf/nginx.key'
** NOTE: restart services to use the new certificates.
** Cleaning up 3 files from '/opt/zimbra/conf/ca'
** Removing /opt/zimbra/conf/ca/ca.key
** Removing /opt/zimbra/conf/ca/e50a23da.0
** Removing /opt/zimbra/conf/ca/ca.pem
** Copying CA to /opt/zimbra/conf/ca
** Copying '/opt/zimbra/ssl/zimbra/ca/ca.key' to '/opt/zimbra/conf/ca/ca.key'
** Copying '/opt/zimbra/ssl/zimbra/ca/ca.pem' to '/opt/zimbra/conf/ca/ca.pem'
** Creating CA hash symlink 'e50a23da.0' -&gt; 'ca.pem'
** Creating /opt/zimbra/conf/ca/commercial_ca_1.crt
** Creating CA hash symlink '8d33f237.0' -&gt; 'commercial_ca_1.crt'
** Creating /opt/zimbra/conf/ca/commercial_ca_2.crt
** Creating CA hash symlink '4042bcee.0' -&gt; 'commercial_ca_2.crt'</pre>
Finally restart Zimbra as user zimbra or <code>sudo su zimbra -</code>:


===Build the proper Intermediate CA plus Root CA===
<pre>zmcontrol restart</pre>
Let's Encrypt is almost perfect, but during the files the process built, they just add the chain.pem file without the root CA.
You must to use the IdenTrust root Certificate and merge it after the chain.pem
* [https://www.identrust.com/certificates/trustid/root-download-x3.html https://www.identrust.com/certificates/trustid/root-download-x3.html]
Your chain.pem should look like:
<pre>
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----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-----END CERTIFICATE-----</pre>


===Verify your commercial certificate. ===
Please note: You have to concatenate the isrgrootx1.pem CA certificate to the chain to make it work!! That’s it for using Let’s Encrypt on Zimbra!
Move to the Let's Encrypt folder with all files '''/etc/letsencrypt/live/$domain''' and then launch the next command as '''root''':
root@zimbra86:/etc/letsencrypt/live/zimbra86.zimbra.io# /opt/zimbra/bin/zmcertmgr verifycrt comm privkey.pem cert.pem chain.pem
** Verifying cert.pem against privkey.pem
Certificate (cert.pem) and private key (privkey.pem) match.
Valid Certificate: cert.pem: OK
===Deploy the new Let's Encrypt SSL certificate===
Then deploy the certificate as follows:
<pre> root@zimbra86:/etc/letsencrypt/live/zimbra86.zimbra.io# /opt/zimbra/bin/zmcertmgr verifycrt comm privkey.pem cert.pem chain.pem
** Verifying cert.pem against privkey.pem
Certificate (cert.pem) and private key (privkey.pem) match.
Valid Certificate: cert.pem: OK
root@zimbra86:/etc/letsencrypt/live/zimbra86.zimbra.io# /opt/zimbra/bin/zmcertmgr deploycrt comm cert.pem chain.pem
** Verifying cert.pem against /opt/zimbra/ssl/zimbra/commercial/commercial.key
Certificate (cert.pem) and private key (/opt/zimbra/ssl/zimbra/commercial/commercial.key) match.
Valid Certificate: cert.pem: OK
** Copying cert.pem to /opt/zimbra/ssl/zimbra/commercial/commercial.crt
** Appending ca chain chain.pem 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...failed.
** Saving server config key zimbraSSLPrivateKey...failed.
** 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.</pre>


Then you need to restart the services, which will restart the nginx or jetty you stopped before:
= Further reading =
zmcontrol restart


===Building Multi-SAN SSL Certificate and complex scenarios===
* https://techcrunch.com/2021/09/21/lets-encrypt-root-expiry
You can do almost everything you need, like Subject Alt Names, different domains, etc. But to see more about this, you are encourage to visit [https://letsencrypt.org/ the web of the official project].


==Additional Content==
* Let's Encrypt User Manual - https://letsencrypt.readthedocs.org/en/latest/using.html
* Let's Encrypt Official Project - https://letsencrypt.org/


{{Article Footer|Zimbra Collaboration 8.6, 8.5|12/05/2015}}
{{Article Footer|Zimbra Collaboration 9.0, 8.8|22/09/2022}}
{{NeedSME|Jorge|SME2|Copyeditor}}
{{NeedSME|Jorge|SME2|Copyeditor}}


[[Category:Certificates]]
[[Category:Certificates]]

Revision as of 07:35, 9 May 2022

Installing a Let's Encrypt SSL Certificate

   KB 22434        Last updated on 2022-05-9  




5.00
(one vote)

Purpose

Let’s Encrypt is a way to obtain trusted and free TLS certificates. To obtain certificates you can use a program called Certbot. You can find instructions for setting up certbot at https://certbot.eff.org/instructions. If you already use Let’s Encrypt on Zimbra keep reading as this post will explain how to keep using Let’s Encrypt after the expiration of IdentTrust DST Root CA X3 on September 30!

In many cases it is easiest to set-up a dedicated VM to take care of the deployment of Let’s Encrypt certificates to all the systems you intent to use with TLS certificates.

If you want to use Zimbra it is recommended you use the snap version of Certbot as that supports the --preferred-chain "ISRG Root X1" option which is needed to make it work with Zimbra.

Installing the obtained certificate on Zimbra

Make sure to request a certificate with the --preferred-chain "ISRG Root X1" option. In case you already have a certificate but you have not used the option, you have to do a force renewal with the --force-renewal --preferred-chain "ISRG Root X1" options.

After you have received the certificate from Let’s Encrypt you can deploy it on Zimbra like this:

As user root or sudo:

cp /etc/letsencrypt/live/barrydegraaff.nl/privkey.pem /opt/zimbra/ssl/zimbra/commercial/commercial.key
chown zimbra:zimbra /opt/zimbra/ssl/zimbra/commercial/commercial.key
wget -O /tmp/ISRG-X1.pem https://letsencrypt.org/certs/isrgrootx1.pem.txt
cat /tmp/ISRG-X1.pem >> /etc/letsencrypt/live/barrydegraaff.nl/chain.pem

As user zimbra or sudo su zimbra -:

cd ~
/opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /etc/letsencrypt/live/barrydegraaff.nl/cert.pem /etc/letsencrypt/live/barrydegraaff.nl/chain.pem
/opt/zimbra/bin/zmcertmgr deploycrt comm /etc/letsencrypt/live/barrydegraaff.nl/cert.pem /etc/letsencrypt/live/barrydegraaff.nl/chain.pem

The output should be similar to:

root@zimbra9:~# su zimbra -
zimbra@zimbra9:/root$ /opt/zimbra/bin/zmcertmgr verifycrt comm /opt/zimbra/ssl/zimbra/commercial/commercial.key /etc/letsencrypt/live/barrydegraaff.nl/cert.pem /etc/letsencrypt/live/barrydegraaff.nl/chain.pem
** Verifying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' against '/opt/zimbra/ssl/zimbra/commercial/commercial.key'
Certificate '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' and private key '/opt/zimbra/ssl/zimbra/commercial/commercial.key' match.
** Verifying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' against '/etc/letsencrypt/live/barrydegraaff.nl/chain.pem'
Valid certificate chain: /etc/letsencrypt/live/barrydegraaff.nl/cert.pem: OK
zimbra@zimbra9:/root$ cd ~
zimbra@zimbra9:~$ /opt/zimbra/bin/zmcertmgr deploycrt comm /etc/letsencrypt/live/barrydegraaff.nl/cert.pem /etc/letsencrypt/live/barrydegraaff.nl/chain.pem
** Verifying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' against '/opt/zimbra/ssl/zimbra/commercial/commercial.key'
Certificate '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' and private key '/opt/zimbra/ssl/zimbra/commercial/commercial.key' match.
** Verifying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' against '/etc/letsencrypt/live/barrydegraaff.nl/chain.pem'
Valid certificate chain: /etc/letsencrypt/live/barrydegraaff.nl/cert.pem: OK
** Copying '/etc/letsencrypt/live/barrydegraaff.nl/cert.pem' to '/opt/zimbra/ssl/zimbra/commercial/commercial.crt'
** Copying '/etc/letsencrypt/live/barrydegraaff.nl/chain.pem' to '/opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt'
** Appending ca chain '/etc/letsencrypt/live/barrydegraaff.nl/chain.pem' to '/opt/zimbra/ssl/zimbra/commercial/commercial.crt'
** Importing cert '/opt/zimbra/ssl/zimbra/commercial/commercial_ca.crt' as 'zcs-user-commercial_ca' into cacerts '/opt/zimbra/common/lib/jvm/java/lib/security/cacerts'
** NOTE: restart mailboxd to use the imported certificate.
** Saving config key 'zimbraSSLCertificate' via zmprov modifyServer zimbra9.barrydegraaff.nl...ok
** Saving config key 'zimbraSSLPrivateKey' via zmprov modifyServer zimbra9.barrydegraaff.nl...ok
** Installing imapd certificate '/opt/zimbra/conf/imapd.crt' and key '/opt/zimbra/conf/imapd.key'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.crt' to '/opt/zimbra/conf/imapd.crt'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.key' to '/opt/zimbra/conf/imapd.key'
** Creating file '/opt/zimbra/ssl/zimbra/jetty.pkcs12'
** Creating keystore '/opt/zimbra/conf/imapd.keystore'
** Installing ldap certificate '/opt/zimbra/conf/slapd.crt' and key '/opt/zimbra/conf/slapd.key'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.crt' to '/opt/zimbra/conf/slapd.crt'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.key' to '/opt/zimbra/conf/slapd.key'
** Creating file '/opt/zimbra/ssl/zimbra/jetty.pkcs12'
** Creating keystore '/opt/zimbra/mailboxd/etc/keystore'
** Installing mta certificate '/opt/zimbra/conf/smtpd.crt' and key '/opt/zimbra/conf/smtpd.key'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.crt' to '/opt/zimbra/conf/smtpd.crt'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.key' to '/opt/zimbra/conf/smtpd.key'
** Installing proxy certificate '/opt/zimbra/conf/nginx.crt' and key '/opt/zimbra/conf/nginx.key'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.crt' to '/opt/zimbra/conf/nginx.crt'
** Copying '/opt/zimbra/ssl/zimbra/commercial/commercial.key' to '/opt/zimbra/conf/nginx.key'
** NOTE: restart services to use the new certificates.
** Cleaning up 3 files from '/opt/zimbra/conf/ca'
** Removing /opt/zimbra/conf/ca/ca.key
** Removing /opt/zimbra/conf/ca/e50a23da.0
** Removing /opt/zimbra/conf/ca/ca.pem
** Copying CA to /opt/zimbra/conf/ca
** Copying '/opt/zimbra/ssl/zimbra/ca/ca.key' to '/opt/zimbra/conf/ca/ca.key'
** Copying '/opt/zimbra/ssl/zimbra/ca/ca.pem' to '/opt/zimbra/conf/ca/ca.pem'
** Creating CA hash symlink 'e50a23da.0' -> 'ca.pem'
** Creating /opt/zimbra/conf/ca/commercial_ca_1.crt
** Creating CA hash symlink '8d33f237.0' -> 'commercial_ca_1.crt'
** Creating /opt/zimbra/conf/ca/commercial_ca_2.crt
** Creating CA hash symlink '4042bcee.0' -> 'commercial_ca_2.crt'

Finally restart Zimbra as user zimbra or sudo su zimbra -:

zmcontrol restart

Please note: You have to concatenate the isrgrootx1.pem CA certificate to the chain to make it work!! That’s it for using Let’s Encrypt on Zimbra!

Further reading


Verified Against: Zimbra Collaboration 9.0, 8.8 Date Created: 22/09/2022
Article ID: https://wiki.zimbra.com/index.php?title=Installing_a_LetsEncrypt_SSL_Certificate Date Modified: 2022-05-09



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Wiki/KB reviewed by Jorge SME2 Copyeditor Last edit by Barry de Graaff
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