Problem
Using the udm command gives an error as follows:
authentication error: {'info': 'error:0B07C065:x509 certificate routines:X509_STORE_add_cert:cert already in hash table', 'desc': 'Connect error'}
Solution
Step 1
Make sure the certificate of the LDAP server (grep pem /etc/ldap.conf) matches the rootCA from this server.
root@ucs:/etc/ldap# grep cert.pem slapd.conf
TLSCertificateFile /etc/univention/ssl/ucs.knebb.de/cert.pem
TLSCACertificateFile /etc/univention/ssl/ucsCA/CAcert.pem
Step 2
Verify the host certificate matches the CA by using this article.