Problems using OpenLDAP 2.1 client libraries to connect to OpenLDAP 2.0 server

[marc.bigler@day.com]

Hello,

I have a central OpenLDAP 2.0.27 server which also accepts TLS sessions,
this works fine from remote clients using OpenLDAP 2.0.x libraries. Now the
problem that I encounter is that TLS sessions doesn't work anymore if I use
OpenLDAP 2.1.x client libraries to connect. You can see here the error that
is generated:

shell% /opt/openldap-client/bin/ldapsearch -v -h remote-openldap20-server
-D 'my bind dn' -W -Z
ldap_init( remote-openldap20-server, 0 )
ldap_start_tls: Connect error (91)
        additional info: error:14090086:SSL
routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed
ldap_bind: Can't contact LDAP server (81)
        additional info: error:14090086:SSL
routines:SSL3_GET_SERVER_CERTIFICATE:certificate verify failed

Does anyone have a solution to that problem ?

Many thanks in advance for your help

Regards
Marc