Full_Name: Quanah Gibson-Mount
Version: 2.4.30
OS: Linux 2.6
URL: ftp://ftp.openldap.org/incoming/
Submission from: (NULL) (75.108.184.39)


From the manual page:

      olcTLSVerifyClient: <level>
	      Specifies what checks to perform on client  certificates	in  an
	      incoming	TLS  session, if any.  The <level> can be specified as
	      one of the following keywords:

	      never  This is the default.  slapd will not ask the client for a
		     certificate.

	      allow  The  client  certificate is requested.  If no certificate
		     is provided, the session proceeds	normally.   If	a  bad
		     certificate  is provided, it will be ignored and the ses-
		     sion proceeds normally.

	      try    The client certificate is requested.  If  no  certificate
		     is  provided,  the  session  proceeds normally.  If a bad
		     certificate is provided, the session is immediately  ter-
		     minated.

	      demand | hard | true
		     These keywords are all equivalent, for compatibility rea-
		     sons.  The client certificate is requested.  If  no  cer-
		     tificate  is  provided, or a bad certificate is provided,
		     the session is immediately terminated.

		     Note that a valid client certificate is required in order
		     to  use the SASL EXTERNAL authentication mechanism with a
		     TLS session.  As such, a  non-default  olcTLSVerifyClient
		     setting  must be chosen to enable SASL EXTERNAL authenti-
		     cation.


However, the code has:

static slap_verbmasks vfykeys[] = {
                { BER_BVC("never"),     LDAP_OPT_X_TLS_NEVER },
                { BER_BVC("demand"),    LDAP_OPT_X_TLS_DEMAND },
                { BER_BVC("try"),       LDAP_OPT_X_TLS_TRY },
                { BER_BVC("hard"),      LDAP_OPT_X_TLS_HARD },
                { BER_BVNULL, 0 }
        };


Which means:

a) allow is missing
b) true is missing
c) demand and hard set different flags.  Not sure if that means any difference
functionality wise, but according to the manual page, demand/true/hard are
supposed to be the same behavior.