Php – LDAP Can’t perform an authenticated bind – Windows Server 2008 R2 Using PHP/Apache

active-directoryapache-2.2ldapPHPwindows-server-2008

I'm having issues performing an authenticated bind against the server. The issues doesn't appear to be in code however maybe a server issue.

Just so you know;

  • LDAP is enabled in Apache/PHP
  • I'm connecting as user@domain.com
  • The domain controller has LDAP running and an entry in the firewall (Windows Server 2008 R2) The issue might be here, this was setup as a DC and is running LDAP by default. I did no special configuration on LDAP
  • I can perform an anonymous bind but not an authenticated one

I can bind anonymously using this script;

$ldapconn = ldap_connect("machinename.domain.com")
    or die("Could not connect to LDAP server.");

if ($ldapconn) {

    // binding anonymously
    $ldapbind = ldap_bind($ldapconn);

    if ($ldapbind) {
        echo "LDAP bind anonymous successful...";
    } else {
        echo "LDAP bind anonymous failed...";
    }

}

However when I try to do an authenticated bind using this script, it fails.

// Authenticated Bind
$ldaprdn  = 'username@domain.com';     // ldap rdn or dn
$ldappass = 'password';  // associated password

// connect to ldap server
$ldapconn = ldap_connect("machinename.domain.com")
    or die("Could not connect to LDAP server.");

if ($ldapconn) {

    // binding to ldap server
    $ldapbind = ldap_bind($ldapconn, $ldaprdn, $ldappass);

    // verify binding
    if ($ldapbind) {
        echo "LDAP bind successful...";
    } else {
        echo "LDAP bind failed...";
    }

}

Where am I going wrong?

Best Answer

Okay, after much investigation I have turned on error info using ldap_errno() and ldap_error() and found it bringing back the error 'Strong(er) authentication required' have discovered two possible solutions;

Adjust Group Policy Settings

  • Negotiate Signing (Network security: LDAP client signing requirements)

  • No signing requirements (Domain Controller: LDAP server signing requirements)

  • Result: Managed to bind successfully and when I enter the username or password incorrectly and it throws an 'Invalid credentials' as expected.

Enable LDAP over SSL (LDAPS)

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