A Sample LDAP Application in PHP Page 16

This function encapsulates the connection to the LDAP server and also the binding to the appropriate part of the DN tree:

function connectBindServer($bindRDN = 0, $bindPassword = 0)
{
    global $ldapServer;
    global $ldapServerPort;
    $linkIdentifier = ldap_connect($ldapServer, $ldapServerPort);

    if ($linkIdentifier) {

If no RDN and password is specified, we attempt an anonymous bind, else we bind using the provided credentials:

        if (!$bindRDN && !$bindPassword) {
            if (!@ldap_bind($linkIdentifier)) {
                displayErrMsg("Unable to bind to LDAP server ! !");
                return 0;
            }
        } else {
            if (!ldap_bind($linkIdentifier, $bindRDN, $bindPassword)) {
                displayErrMsg("Unable to bind to LDAP server ! !");
                return 0;
            }
        }
    } else {
        displayErrMsg("Unable to connect to the LDAP server! !");
        return 0;
    }
    return $linkIdentifier;
}

[In the code above, there should be no space between the double "!" marks. They have been separated for formatting purposes.]

Given a search criteria string, this function creates a search filter expression:

function createSearchFilter($searchCriteria)
{
    $noOfFieldsSet = 0;
    if ($searchCriteria["cn"]) {
        $searchFilter = "(cn=*" . $searchCriteria["cn"] . "*)";
        ++$noOfFieldsSet;
    }

    if ($searchCriteria["sn"]) {
        $searchFilter .= "(sn=*" . $searchCriteria["sn"] . "*)";
        ++$noOfFieldsSet;
    }

    if ($searchCriteria["mail"]) {
        $searchFilter .= "(mail=*" . $searchCriteria["mail"] . "*)";
        ++$noOfFieldsSet;
    }

    if ($searchCriteria["employeenumber"]) {
        $searchFilter .= "(employeenumber=*" .
                          $searchCriteria["employeenumber"] . "*)";
        ++$noOfFieldsSet;
    }

    if ($searchCriteria["ou"]) {
        $searchFilter .= "(ou=*" . $searchCriteria["ou"] . "*)";
        ++$noOfFieldsSet;
    }

    if ($searchCriteria["telephonenumber"]) {
        $searchFilter .= "(telephonenumber=*" .
            $searchCriteria["telephonenumber"] . "*)";
        ++$noOfFieldsSet;
    }

We perform a logical AND on all specified search criteria to create the final search filter:

    if ($noOfFieldsSet >= 2) {
        $searchFilter = "(&" .$searchFilter. ")";
    }
    return $searchFilter;
}

This function given a link identifier obtained from the connectBindServer() function and the search filter created by createSearchFilter() performs a search on the directory:

function searchDirectory($linkIdentifier, $searchFilter)
{
    global $baseDN;
    $searchResult = ldap_search($linkIdentifier, $baseDN, $searchFilter);

We count the search results to see if we got any entries at all:

    if (ldap_count_entries($linkIdentifier, $searchResult) <= 0) {
        displayErrMsg("No entries returned from the directory");
        return 0;
    } else {
        $resultEntries = ldap_get_entries($linkIdentifier, $searchResult);
        return $resultEntries;
   }
}

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