Sent: Sat Jun 16 2012 19:42:59 GMT-0400 (EDT)
From: Howard Chu <>
To: Quanah Gibson-Mount <>, Patrick Hemmer <>,
Subject: Re: TLS issues when setting olcTLSCACertificateFile to the CA bundle
Quanah Gibson-Mount wrote:
--On Saturday, June 16, 2012 2:31 PM -0400 Patrick Hemmer
<> wrote:

Sent: Sat Jun 16 2012 03:31:40 GMT-0400 (EDT)
From: Bernd May <>
To: Patrick Hemmer <>
Subject: Re: TLS issues when setting olcTLSCACertificateFile to the CA
So you problem is, that you have signed your server cert with a CA from
a CA chain and your clients with another CA and you don't want clients
to connect, not signed by your client CA?

This sounds more like a case for ACLs and matching rules, since you
AFAIK you cannot tell ldap to only trust a CA for server cert
verification purposes. A CA is trusted or not.

The assessment is correct, but I beg to differ on the statement "A CA is
trusted or not".

Server certs are used by the client to verify the remote server is who it
says it is.
Client certs are used by the server to verify the client is allowed to
talk to it.
There is a very big difference between the two. The server doesnt care
one bit if the CN of a client cert doesnt match the reverse DNS lookup of
the IP the connection came from. All it cares is that the cert presented
by the client is signed by a recognized CA. As such if you dont restrict
the CAs that OpenLDAP will recognize for client certificates, any
john-doe server with a certificate could connect (at which point client
certs become useless).

The TLS chapter of the Admin Guide already covers this.
What in particular are you referring to? The only relevant part I see is this:
: The server must be configured with the CA certificates and also its own server certificate and private key.
: Typically a single CA will have issued the server certificate and all of the trusted client certificates, so the server only needs to trust that one signing CA

However my situation isnt the typical case mentioned, as I have a different CA signing the server's cert and the client's certs.

I would suggest you use olcTLSCACertificatePath and point to a directory
containing the CA certs that should be used for validation of certs.

No. There's no behavioral difference between the ...Path vs ...File. The use of ...Path is annoying because it requires the maintenance script to generate the hash symlinks, but aside from that, all certs in either location are used.