Solution: LDAPs – Unable to bind to server: Can’t contact LDAP server

Last week I encountered the following error message: Warning: ldap_bind(): Unable to bind to server: Can't contact LDAP server in C:\xamppNew\htdocs\index.php on line 11

To create a AD user you must to connect to the LDAP via securely (SSL). Usually you can achieve this in PHP by connecting through LDAP like this: ldap_connect("ldaps://<host>", 636);  , watch the ‘s’ at the end of LDAP. This indicates you want to connect through SSL. After binding ( ldap_bind($connection, $user, $password); ) I received the error message above.

I was 100% sure the LDAP server was not the cause of this, because it was working when I did the same in C#. After doing a lot of research on the internet I finally found a (working) solution. I tested this solution on Windows and Ubuntu and they are working fine.

Windows:

1. Create the follwing directory, usually this directory doesn’t exist (yet): “C:\OpenLDAP\sysconf”
2. In “C:\OpenLDAP\sysconf” create a file called “ldap.conf”.
3. Add “TLS_REQCERT never” (without quotes) at the end of the file you just created.
4. Restart your Apache server.

Ubuntu:

1. Navigate to “/etc/ldap/”
2. Open the file “ldap.conf”
3. Add “TLS_REQCERT never” (without quotes) at the end of the file.
4. Restart your Apache server.

According to the manual, “TLS_REQCERT never” prevents the server from requesting and/or checking any server certificate.

Happy coding!