Disable Certificate-check for LDAPS/ldap_tls

ldap.php

<?php

$con = ldap_connect('ldaps://ldap.example.com');
ldap_set_option($con, LDAP_OPT_PROTOCOL_VERSION, 3);
ldap_set_option($con, LDAP_OPT_X_TLS_REQUIRE_CERT, LDAP_OPT_X_TLS_NEVER);
/* 
Possible values:

LDAP_OPT_X_TLS_NEVER
  This is the default. slapd will not ask the client for a certificate.

LDAP_OPT_X_TLS_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 session proceeds normally.

LDAP_OPT_X_TLS_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 terminated.

LDAP_OPT_X_TLS_DEMAND
LDAP_OPT_X_TLS_HARD
  These keywords are all equivalent, for compatibility reasons. The client
  certificate is requested. If no certificate 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
  TLSVerifyClient setting must be chosen to enable SASL EXTERNAL authentication.


More on 
 * https://linux.die.net/man/3/ldap_set_option
 * http://www.openldap.org/lists/openldap-software/200202/msg00456.html
//*/