1: <?php
  2: 
  3: class LdapUtils {
  4: 
  5:     public static function normalizeDn($dn) {
  6:         $rdns = self::explodeDn($dn, true);
  7:         $newRdns = array();
  8:         foreach ($rdns as $rdn) {
  9:             $newRdns[] = array(
 10:                 'attribute' => strtolower($rdn['attribute']),
 11:                 'value' => trim($rdn['value'])
 12:             );
 13:         }
 14: 
 15:         return self::implodeDn($newRdns, true);
 16:     }
 17: 
 18:     public static function explodeDn($dn, $explodeRdns = false) {
 19:         $rdns = explode(',', $dn);
 20:         unset($rdns['count']);
 21: 
 22:         if ($explodeRdns) {
 23:             $explodedRdns = array();
 24:             foreach ($rdns as $rdn) {
 25:                 $explodedRdns[] = self::explodeRdn($rdn);
 26:             }
 27:             return $explodedRdns;
 28:         } else {
 29:             return $rdns;
 30:         }
 31:     }
 32: 
 33:     public static function explodeRdn($rdn) {
 34:         $equalsSymbolPosition = strpos($rdn, '=');
 35: 
 36:         if ($equalsSymbolPosition === false) {
 37:             throw new Exception("RDN \"$rdn\" has no equals symbol");
 38:         }
 39: 
 40:         return array(
 41:             'attribute' => substr($rdn, 0, $equalsSymbolPosition),
 42:             'value' => substr($rdn, $equalsSymbolPosition + 1)
 43:         );
 44:     }
 45: 
 46:     public static function implodeDn($rdns, $isExplodedRdns) {
 47:         if ($isExplodedRdns) {
 48:             $implodedRdns = array();
 49:             foreach ($rdns as $rdn) {
 50:                 $implodedRdns[] = "{$rdn['attribute']}={$rdn['value']}";
 51:             }
 52:             $rdns = $implodedRdns;
 53:         }
 54: 
 55:         return implode(',', $rdns);
 56:     }
 57:     
 58:     public static function firstRdn($dn, $field = null) {
 59:         $explodedDn = self::explodeDn($dn);
 60: 
 61:         switch ($field) {
 62:             case 'attribute':
 63:             case 'value':
 64:                 $rdn = self::explodeRdn($explodedDn[0]);
 65:                 return $rdn[$field];
 66: 
 67:             default:
 68:                 return $explodedDn[0];
 69:         }
 70:     }
 71: 
 72:     public static function joinDns($dn1, $dn2) {
 73:         $dn1 = trim($dn1);
 74:         $dn2 = trim($dn2);
 75:         if ($dn1 != '' && $dn2 != '') {
 76:             return $dn1 . ',' . $dn2;
 77:         } else {
 78:             return $dn1 . $dn2;
 79:         }
 80:     }
 81: 
 82:     public static function parentDn($dn) {
 83:         $rdns = self::explodeDn($dn, true);
 84:         array_shift($rdns);
 85:         if (empty($rdns)) {
 86:             return false;
 87:         } else {
 88:             return self::implodeDn($rdns, true);
 89:         }
 90:     }
 91: 
 92:     public static function isDnParent($parentDn, $childDn) {
 93:         $parentRdns = array_reverse(self::explodeDn($parentDn));
 94:         $childRdns = array_reverse(self::explodeDn($childDn));
 95:         if (count($childRdns) <= count($parentRdns)) {
 96:             return false;
 97:         }
 98:         for ($i = 0; $i < count($parentRdns); $i++) {
 99:             if (strtolower($parentRdns[$i]) != strtolower($childRdns[$i])) {
100:                 return false;
101:             }
102:         }
103:         return true;
104:     }
105: 
106: }