Installing a LetsEncrypt SSL Certificate
Installing a Let's Encrypt SSL Certificate
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 it 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 check out the Frequently Asked Questions (FAQ).
Resolution
Let’s Encrypt is a new Certificate Authority: It’s free, automated, and open. It could be an option to protect Zimbra Servers with a valid SSL certificate; however, please be aware that is a Beta for now. Some stuff could not work or have issues, so use it at your own risk.
Installing Let's Encrypt on a Zimbra Server
Let's Encrypt must be installed on one Linux machine to obtain the proper SSL Certificate, CA Intermediate, and Private Key. It is not required that it be on the same Zimbra Server, but it could save time and help to obtain the renewals, etc.
- First Step is to stop the jetty or nginx service at Zimbra level
zmproxyctl stop zmmailboxdctl stop
- Second step is to Install git on the 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 now run Let's Encrypt in auto mode and use the certonly option, because for now the project can't automatically install the cert on Zimbra servers.
root@zimbra86:~/tmp/letsencrypt# ./letsencrypt-auto certonly
- (This step only happens the first time. This process will not occur when renewing the SSL Certificate if using the same machine.) The process will download all of the OS dependencies that Let's Encrypt needs, and after a few minutes:
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
- The process will ask for an Email Address in case of emergency contact or to recover the lost key.
- The process will ask if we agree with the ToS.
- In case we run a renewal, or a request for a new FQDN, the process will just take a few seconds.
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):
- The process will take a few seconds to validate and then will end:
IMPORTANT NOTES: - Congratulations! Your certificate and chain have been saved at /etc/letsencrypt/live/zimbra86.zimbra.io/fullchain.pem. Your cert will expire on 2016-03-04. To obtain a new version of the 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 Donating to EFF: https://eff.org/donate-le
Where are the SSL Certificate Files?
You can find all your files under /etc/letsencrypt/live/$domain, where $domain is the fqdn you used during the process:
root@zimbra86:/etc/letsencrypt/live/zimbra86.zimbra.io# ls -al total 8 drwxr-xr-x 2 root root 4096 Dec 5 16:46 . drwx------ 3 root root 4096 Dec 5 16:46 .. lrwxrwxrwx 1 root root 42 Dec 5 16:46 cert.pem -> ../../archive/zimbra86.zimbra.io/cert1.pem lrwxrwxrwx 1 root root 43 Dec 5 16:46 chain.pem -> ../../archive/zimbra86.zimbra.io/chain1.pem lrwxrwxrwx 1 root root 47 Dec 5 16:46 fullchain.pem -> ../../archive/zimbra86.zimbra.io/fullchain1.pem lrwxrwxrwx 1 root root 45 Dec 5 16:46 privkey.pem -> ../../archive/zimbra86.zimbra.io/privkey1.pem
Build the proper Intermediate CA plus Root CA
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
Your chain.pem should look like:
-----BEGIN CERTIFICATE----- MIIEqDCCA5CgAwIBAgIRAJgT9HUT5XULQ+dDHpceRL0wDQYJKoZIhvcNAQELBQAw PzEkMCIGA1UEChMbRGlnaXRhbCBTaWduYXR1cmUgVHJ1c3QgQ28uMRcwFQYDVQQD Ew5EU1QgUm9vdCBDQSBYMzAeFw0xNTEwMTkyMjMzMzZaFw0yMDEwMTkyMjMzMzZa MEoxCzAJBgNVBAYTAlVTMRYwFAYDVQQKEw1MZXQncyBFbmNyeXB0MSMwIQYDVQQD ExpMZXQncyBFbmNyeXB0IEF1dGhvcml0eSBYMTCCASIwDQYJKoZIhvcNAQEBBQAD ggEPADCCAQoCggEBAJzTDPBa5S5Ht3JdN4OzaGMw6tc1Jhkl4b2+NfFwki+3uEtB BaupnjUIWOyxKsRohwuj43Xk5vOnYnG6eYFgH9eRmp/z0HhncchpDpWRz/7mmelg PEjMfspNdxIknUcbWuu57B43ABycrHunBerOSuu9QeU2mLnL/W08lmjfIypCkAyG dGfIf6WauFJhFBM/ZemCh8vb+g5W9oaJ84U/l4avsNwa72sNlRZ9xCugZbKZBDZ1 gGusSvMbkEl4L6KWTyogJSkExnTA0DHNjzE4lRa6qDO4Q/GxH8Mwf6J5MRM9LTb4 4/zyM2q5OTHFr8SNDR1kFjOq+oQpttQLwNh9w5MCAwEAAaOCAZIwggGOMBIGA1Ud EwEB/wQIMAYBAf8CAQAwDgYDVR0PAQH/BAQDAgGGMH8GCCsGAQUFBwEBBHMwcTAy BggrBgEFBQcwAYYmaHR0cDovL2lzcmcudHJ1c3RpZC5vY3NwLmlkZW50cnVzdC5j b20wOwYIKwYBBQUHMAKGL2h0dHA6Ly9hcHBzLmlkZW50cnVzdC5jb20vcm9vdHMv ZHN0cm9vdGNheDMucDdjMB8GA1UdIwQYMBaAFMSnsaR7LHH62+FLkHX/xBVghYkQ MFQGA1UdIARNMEswCAYGZ4EMAQIBMD8GCysGAQQBgt8TAQEBMDAwLgYIKwYBBQUH AgEWImh0dHA6Ly9jcHMucm9vdC14MS5sZXRzZW5jcnlwdC5vcmcwPAYDVR0fBDUw MzAxoC+gLYYraHR0cDovL2NybC5pZGVudHJ1c3QuY29tL0RTVFJPT1RDQVgzQ1JM LmNybDATBgNVHR4EDDAKoQgwBoIELm1pbDAdBgNVHQ4EFgQUqEpqYwR93brm0Tm3 pkVl7/Oo7KEwDQYJKoZIhvcNAQELBQADggEBANHIIkus7+MJiZZQsY14cCoBG1hd v0J20/FyWo5ppnfjL78S2k4s2GLRJ7iD9ZDKErndvbNFGcsW+9kKK/TnY21hp4Dd ITv8S9ZYQ7oaoqs7HwhEMY9sibED4aXw09xrJZTC9zK1uIfW6t5dHQjuOWv+HHoW ZnupyxpsEUlEaFb+/SCI4KCSBdAsYxAcsHYI5xxEI4LutHp6s3OT2FuO90WfdsIk 6q78OMSdn875bNjdBYAqxUp2/LEIHfDBkLoQz0hFJmwAbYahqKaLn73PAAm1X2kj f1w8DdnkabOLGeOVcj9LQ+s67vBykx4anTjURkbqZslUEUsn2k5xeua2zUk= -----END CERTIFICATE----- -----BEGIN CERTIFICATE----- MIIDSjCCAjKgAwIBAgIQRK+wgNajJ7qJMDmGLvhAazANBgkqhkiG9w0BAQUFADA/ MSQwIgYDVQQKExtEaWdpdGFsIFNpZ25hdHVyZSBUcnVzdCBDby4xFzAVBgNVBAMT DkRTVCBSb290IENBIFgzMB4XDTAwMDkzMDIxMTIxOVoXDTIxMDkzMDE0MDExNVow PzEkMCIGA1UEChMbRGlnaXRhbCBTaWduYXR1cmUgVHJ1c3QgQ28uMRcwFQYDVQQD Ew5EU1QgUm9vdCBDQSBYMzCCASIwDQYJKoZIhvcNAQEBBQADggEPADCCAQoCggEB AN+v6ZdQCINXtMxiZfaQguzH0yxrMMpb7NnDfcdAwRgUi+DoM3ZJKuM/IUmTrE4O rz5Iy2Xu/NMhD2XSKtkyj4zl93ewEnu1lcCJo6m67XMuegwGMoOifooUMM0RoOEq OLl5CjH9UL2AZd+3UWODyOKIYepLYYHsUmu5ouJLGiifSKOeDNoJjj4XLh7dIN9b xiqKqy69cK3FCxolkHRyxXtqqzTWMIn/5WgTe1QLyNau7Fqckh49ZLOMxt+/yUFw 7BZy1SbsOFU5Q9D8/RhcQPGX69Wam40dutolucbY38EVAjqr2m7xPi71XAicPNaD aeQQmxkqtilX4+U9m5/wAl0CAwEAAaNCMEAwDwYDVR0TAQH/BAUwAwEB/zAOBgNV HQ8BAf8EBAMCAQYwHQYDVR0OBBYEFMSnsaR7LHH62+FLkHX/xBVghYkQMA0GCSqG SIb3DQEBBQUAA4IBAQCjGiybFwBcqR7uKGY3Or+Dxz9LwwmglSBd49lZRNI+DT69 ikugdB/OEIKcdBodfpga3csTS7MgROSR6cz8faXbauX+5v3gTt23ADq1cEmv8uXr AvHRAosZy5Q6XkjEGB5YGV8eAlrwDPGxrancWYaLbumR9YbK+rlmM6pZW87ipxZz R8srzJmwN0jP41ZL9c8PDHIyh8bwRLtTcm1D9SZImlJnt1ir/md2cXjbDaJWFBM5 JDGFoqgCWjBH4d1QB7wCCZAA62RjYJsWvIjJEubSfZGL+T0yjWW06XyxV3bqxbYo Ob8VZRzI9neWagqNdwvYkQsEjgfbKbYK7p2CNTUQ -----END CERTIFICATE-----
Verify your commercial certificate.
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
Copy the private key under Zimbra SSL path
Before deploying the SSL Certificate, you need to move the privkey.pem under the Zimbra SSL commercial path, like this:
cp /etc/letsencrypt/live/zimbra86.zimbra.io/privkey.pem /opt/zimbra/ssl/zimbra/commercial/commercial.key
Final SSL deployment
Then deploy the certificate as follows:
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.
Then you need to restart the services, which will restart the nginx or jetty you stopped before:
zmcontrol restart
Test the new SSL Certificate
The last step is to go to your Web Browser and open the URL of your Zimbra server where you installed the Let's Encrypt SSL Certificate:
You can expand the Certificate Information to see the new SSL Certificate your server is using:
Building Multi-SAN SSL Certificate and complex scenarios
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 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/