Recreating a Self-Signed SSL Certificate in ZCS 4.5 & 5.0
This article contains information on recreating a self-signed SSL certificate.
Important: If you are working with a commercial certificate, do not use this page.
This article contains information for both ZCS 4.5.x and 5.0.x. Please read all instructions with particular attention to version specific sections and notes before attempting to recreate a self-signed SSL certificate. If you are using ZCS 5.0, it is recommended that you first try using the Administration Console Certificates tool, discussed further in the Administration_Console_and_CLI_Certificate_Tools Article. This tool simplifies and speeds the process of recreating a self-signed SSL certificate.
Why Recreate My Certificates?
Your certificates are expired and need to be recreated if you see an error like this when you run zmprov.
 ERROR: java.security.cert.CertificateExpiredException: NotAfter: Sun Oct 08 00:38:45 EDT 2006 ERROR: zclient.IO_ERROR (invoke java.security.cert.CertificateException: Untrusted Server Certificate Chain, server: localhost) (cause: javax.net.ssl.SSLHandshakeException java.security.cert.CertificateException: Untrusted Server Certificate Chain)
Instructions for Recreating a Self-Signed SSL Certificate
Back up existing certificates
- This backs up the default certificates created by zmcreateca and zmcreatecert:
tar cf /tmp/zimbra-ssl-bak.tar /opt/zimbra/ssl/
- This backs up the server's working certificate files:
tar cf /tmp/zimbra-certs.tar /opt/zimbra/conf/ca/ \ /opt/zimbra/conf/*.crt \ /opt/zimbra/conf/*.key \ /opt/zimbra/conf/*.pem \ /opt/zimbra/tomcat/conf/keystore \ /opt/zimbra/java/jre/lib/security/cacerts
Error in instructions: Tar for 5.0 doesnt capture the keys in jetty for 5.0+
Delete and re-create SSL Directory (as root)
su - rm -rf /opt/zimbra/ssl mkdir /opt/zimbra/ssl chown zimbra:zimbra /opt/zimbra/ssl
Give the zimbra user write access to the cacerts keystore (4.5 only)
If you are running ZCS 4.5, give the zimbra user write access to the cacerts keystore. If you are running ZCS 5.0.x, skip this step.
- On linux the java cacerts file is a part of the ZCS installation.
chown zimbra:zimbra /opt/zimbra/java/jre/lib/security/cacerts chmod 644 /opt/zimbra/java/jre/lib/security/cacerts
- On Mac OS X the java cacerts file is a part of the system's java installation. Either run the "keytool -delete ..." command in the next section as root or give write access to the zimbra user.
chown zimbra:zimbra /System/Library/Frameworks/JavaVM.framework/Versions/1.5/Home/lib/security/cacerts chmod u+w /System/Library/Frameworks/JavaVM.framework/Versions/1.5/Home/lib/security/cacerts
Remove the self-signed root certificate from the cacerts keystore (as zimbra)
- Mac OS X
keytool -delete -alias my_ca -keystore /System/Library/Frameworks/JavaVM.framework/Versions/1.5/Home/lib/security/cacerts -storepass changeit
keytool -delete -alias my_ca -keystore /opt/zimbra/java/jre/lib/security/cacerts -storepass changeit
Delete the server cert from the mailboxd keystore (as zimbra)
- For ZCS upto 4.5.x (tomcat)
su - zimbra keytool -delete -alias tomcat -keystore /opt/zimbra/tomcat/conf/keystore -storepass zimbra
- For ZCS 5.0+ (mailboxd/jetty)
su - zimbra keytool -delete -alias jetty -keystore /opt/zimbra/mailboxd/etc/keystore -storepass zimbra
- Storepass is normally stored in localconfig
su - zimbra zmlocalconfig -s -m nokey tomcat_keystore_password
or for 5.0 (jetty)
su - zimbra zmlocalconfig -s -m nokey mailboxd_keystore_password
Perform optional configuration
- If you want to change the duration of the certificate from the default (365 days), modify the "default_days" entry in the file /opt/zimbra/conf/zmssl.cnf.in
Workaround: zmssl.cnf.in default_days is ingnored. Currently you will need to edit zmcreateca and zmcreatecert: Bug is http://bugzilla.zimbra.com/show_bug.cgi?id=12228
- If you want the common name show up in the CA rather than 'Zimbra Collaboration Suite' because you have several zimbra servers. Please Note: I probably have unnecessary steps in this section here, but this is what I did to get it working for me.
vi /opt/zimbra/conf/zmssl.cnf.in [change section to appear as below] 0.organizationName = Zimbra 0.organizationName_default = Zimbra # we can do this but it is not needed normally :-) #1.organizationName = Second Organization Name (eg, company) #1.organizationName_default = World Wide Web Pty Ltd organizationalUnitName = Zimbra organizationalUnitName_default = Zimbra commonName = <put your hostname here -- @@HOSTNAME@@ doesn't seem to work> commonName_max = 64 commonName_default = <put your hostname here -- @@HOSTNAME@@ doesn't seem to work>
Create the CA certificate (as zimbra)
- for 4.*
- for 5.* (as root)
/opt/zimbra/bin/zmcertmgr createca -new
- (OPTIONAL) If you did the Optional step to make the CN the hostname for the CA, the output should be like the following:
... Signature ok subject=/C=US/ST=N/A/L=N/A/O=Zimbra/OU=Zimbra/CN=<your hostname> Getting Private key unable to write 'random state'
Install server ca files
- After creating the ca, it appears that zmcreateca doesn't copy the new ca.key and ca.pem to /opt/zimbra/conf/ca, so do it manually (as zimbra, 4.*):
cp /opt/zimbra/ssl/ssl/ca/ca.key /opt/zimbra/conf/ca/ca.key cp /opt/zimbra/ssl/ssl/ca/ca.pem /opt/zimbra/conf/ca/ca.pem
- 5.* (as root)
/opt/zimbra/bin/zmcertmgr deployca -localonly
Create the server certificate (as zimbra)
- 5.* (as root)
/opt/zimbra/bin/zmcertmgr createcrt self -new # Optional /opt/zimbra/bin/zmcertmgr verifycrt self
Error in instructions: There IS NO createcrt in zmcertmgr in 5.0.1_GA_1902: Usage: bin/zmcertmgr -help bin/zmcertmgr createca [-new] bin/zmcertmgr deployca bin/zmcertmgr createcsr <self|comm> [-new] [subject] [-subjectAltNames "host1,host2"] bin/zmcertmgr deploycrt <self> [-new] [validation_days] bin/zmcertmgr deploycrt <comm> [certfile] [ca_chain_file] bin/zmcertmgr viewcsr <self|comm> [csr_file] bin/zmcertmgr viewdeployedcrt [all|ldap|mta|proxy|mailboxd] bin/zmcertmgr viewstagedcrt <self|comm> [certfile] bin/zmcertmgr verifycrt <self|comm> [priv_key] [certfile] bin/zmcertmgr verifycrtchain <ca_file> <certfile> bin/zmcertmgr migrate
If you wish to have several names on the certificate, supply them as arguments
zmcreatecert mail.mydomain.com webmail.mydomain.com webmail.yourdomain.com
Install the server certificate files (as zimbra)
- For Tomcat (ZCS upto 4.5.x)
zmcertinstall mailbox /opt/zimbra/ssl/ssl/server/tomcat.crt zmcertinstall mta /opt/zimbra/ssl/ssl/server/server.crt /opt/zimbra/ssl/ssl/server/server.key
- For Mailboxd (ZCS < 5.0.3)
zmcertinstall mailbox /opt/zimbra/ssl/ssl/server/mailboxd.crt zmcertinstall mta /opt/zimbra/ssl/ssl/server/server.crt /opt/zimbra/ssl/ssl/server/server.key
- To update CA cert stored in LDAP (as zimbra, 4.x):
zmprov -l mcf zimbraCertAuthorityKeySelfSigned "`cat /opt/zimbra/ssl/ssl/ca/ca.key`" zmprov -l mcf zimbraCertAuthorityCertSelfSigned "`cat /opt/zimbra/ssl/ssl/ca/ca.pem`"
- 5.x (as root)
/opt/zimbra/bin/zmcertmgr deploycrt self
- You can see your updated certs in LDAP now and compare them to contents of /opt/zimbra/ssl/ssl/ca (as zimbra)
zmprov -l gcf zimbraCertAuthorityKeySelfSigned zmprov -l gcf zimbraCertAuthorityCertSelfSigned
Restart zimbra services
- It may be necessary to restart the Zimbra servers for the changes to take effect (as zimbra).
zmcontrol stop zmcontrol start
Note about 'unable to write random state':
Permission denied (publickey,gssapi-with-mic)