LDAP PHP代码的问题 - 无法找到针对LDAP的用户名

Question

我一直在尝试创建一个简单的PHP LDAP登录页面，一旦成功将在我的Web应用程序中实现。我之前从未设置过LDAP身份验证登录，所以这对我来说都是新手。我一直在网上查看几个PHP登录表单示例，但无法工作。我通过https://www.hawaii.edu/bwiki/display/UHIAM/LDAP+Authentication找到了一个示例页面，我正在使用代码来测试我的LDAP测试页面。以下是我设置的验证码：

<?php

    // LDAP configuration
    $host          = 'ldap://ldap.server.name.example';
    $baseDn        = 'ou=people,dc=cgi,dc=ca';
    $username_attr = 'uid';
    $admDn         = '';
    $admPw         = '';

    // Global error message for LDAP authentication
    $ldap_status   = NULL;

    /*
     * Authenticated a username.  The reason for a failure can be
     * gotten from $ldap_status.
     *
     * Return boolean
     */
    function ldap_authenticate($username, $password) {
        global $admDn, $admPw, $ldap_status;

        error_log("authenticate($username)");
        if (!isset($username) || $username == '') {
            $ldap_status = "no username entered";
            return false;
        }

        if (!isset($password) || $password == '') {
            $ldap_status = "no password entered";
            return false;
        }

        $ldap = _get_ldap_conn();
        if (!isset($ldap)) {
            $ldap_status = "No connection to LDAP server";
            return false;
        }

        if (! _bind($ldap, $admDn, $admPw)) {
            $ldap_status = "Can't contact LDAP server";
            return false;
        }

        $dn = _lookup($ldap, $username);
        if (! isset($dn) || $dn == '') {
            return false;
        }

        if (_bind($ldap, $dn, $password)) {
            return true;
        }
        $ldap_status = "No such user or bad password";
        return false;
    }


    //-----------------------------------------------------------------
    //-----  Helpers
    //-----  Don't call these directly.
    //-----------------------------------------------------------------

    // Return LDAP resource or NULL
    function _get_ldap_conn() {
        global $host, $ldap_status;

        $ldap = ldap_connect($host);

        if (isset($ldap)) {
            return $ldap;
        }
        error_log("_get_ldap_conn() can't connect to $host" , 0);
        return NULL;
    }

    // Return boolean
    function _bind($ldap, $dn, $pw) {
        $rc = false;

        /*
         * Caution: The caller must check for a blank password because
         *          binding with a blank password will succeed as
         *          as anonymous bind.  When binding with the user's
         *          DN and password to authenticate them this will yield
         *          a false positive.
         */

        if (!isset($dn) || $dn == '' || !isset($pw) || $pw == '') {
            $rc = ldap_bind($ldap);
            $bind_dn = 'anonymous';
        }
        else {
            $rc = ldap_bind($ldap, $dn, $pw);
            $bind_dn = $dn;
        }


        if ($rc) {
            error_log("_bind() bound as $bind_dn", 0);
        }
        else {
            error_log("_bind() can't bind as $bind_dn", 0);
        }

        return $rc;
    }


    // Return DN for username or NULL
    function _lookup($ldap, $username) {
        global $username_attr, $baseDn, $ldap_status;

        $filter = "$username_attr=$username";
        $results = ldap_search($ldap, $baseDn, $filter,
                               array('dn', 'cn', 'username'));
        $info = ldap_get_entries($ldap, $results);
        $count = $info['count'];
        error_log("_lookup() $count entries returned");

        ldap_free_result($results);

        if ($count < 1) {
            $ldap_status = "$username not found";
            return NULL;
        }
        if ($count == 1) {
            $dn = $info[0]['dn'];
            $cn = $info[0]['cn'][0];
            error_log("_lookup() found $dn ($cn) for $username");
            return $dn;
        }
        error_log("_lookup() found more than one entry for $username");
        $ldap_status = "Too many entries for $username";
        return NULL;
    }
?>

现在尝试使用所有这些设置登录时，我收到一条消息：

ellison.montero is NOT Authenticated!
Reason: ellison.montero not found

我认为这与以下变量$ username_attr，$ admDn和$ admPw有关。我不明白这些是什么或它在寻找什么。我联系了我的LDAP专家并询问了url和base dn。他给了我以下基础DN ou=people,dc=cgi,dc=ca并给了我正确的URL。所以我不确定此时我还需要什么。任何帮助都是适用的。