Recreating a Self-Signed SSL Certificate in ZCS 4.5 & 5.0

Revision as of 00:38, 31 January 2007 by Marcmac (talk | contribs) (Create the server certificate (as zimbra))

Self Signed Certificate Instructions

If you're working with a commercial certificate, do *NOT* use this page - go here instead

  • To clean up SSL certificates and recreate a new self-signed cert try this.

Why recreate my certificates

If you're seeing 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)

your certs are expired, and need to be recreated

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:
cd /opt/zimbra/
tar cf /tmp/zimbra-certs.tar conf/ca/ conf/*.crt conf/*.key conf/*.pem tomcat/conf/keystore java/jre/lib/security/cacerts

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

  • 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
  • Linux
keytool -delete -alias my_ca -keystore /opt/zimbra/java/jre/lib/security/cacerts -storepass changeit

Delete the server cert from the tomcat keystore (as zimbra)

su - zimbra
keytool -delete -alias tomcat -keystore /opt/zimbra/tomcat/conf/keystore -storepass zimbra

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)

zmcreateca
  • (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):
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

Create the server certificate (as zimbra)

zmcreatecert

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)

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
  • I don't know what the CA cert stored in LDAP is used for, or if it is used at all, but it is *not* updated by the above steps. To update CA cert (as zimbra):
cat /opt/zimbra/ssl/ssl/ca/ca.key
zmprov -l mcf zimbraCertAuthorityKeySelfSigned "-----BEGIN RSA PRIVATE KEY-----
[paste the contents of ca.key from above - I needed to construct this whole command in a text editor then paste into the CLI]
-----END RSA PRIVATE KEY-----"
cat /opt/zimbra/ssl/ssl/ca/ca.pem
zmprov -l mcf zimbraCertAuthorityCertSelfSigned "-----BEGIN TRUSTED CERTIFICATE-----
[paste the contents of ca.pem from above - I needed to construct this whole command in a text editor then paste into the CLI]
-----END TRUSTED CERTIFICATE-----"

  • 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

Other Possible Issues

Note about 'unable to write random state':

This is a "harmless" warning that openssl has no random number seed file. The full story is available from openssl.org.

Permission denied (publickey,gssapi-with-mic)

http://www.ncsa.uiuc.edu/UserInfo/Resources/Software/ssh/openssh_3.8.html

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