PHP cURL不起作用

我与HttpFox合作，并将url和post数据的值与代码生成的值进行了比较。它们完全相同，但我总是在网页上看到“登录失败”的消息。我不知道有什么问题

代码：

你能帮我一下吗

require 'domparser_1_5/simple_html_dom.php';

$username = "username";
$password = "password";

function login($url,$data){
    $fp = fopen("cookie.txt", "w");
    fclose($fp);
    $login = curl_init();
    curl_setopt($login, CURLOPT_URL, $url);
    curl_setopt($login, CURLOPT_SSL_VERIFYPEER, false);
    curl_setopt($login, CURLOPT_COOKIEJAR, "cookie.txt");
    curl_setopt($login, CURLOPT_COOKIEFILE, "cookie.txt");
    curl_setopt($login, CURLOPT_TIMEOUT, 40000);
    curl_setopt($login, CURLOPT_RETURNTRANSFER, true);
    curl_setopt($login, CURLOPT_USERAGENT, $_SERVER['HTTP_USER_AGENT']);
    curl_setopt($login, CURLOPT_FOLLOWLOCATION, true);
    curl_setopt($login, CURLOPT_POST, true);
    curl_setopt($login, CURLOPT_POSTFIELDS, $data);
    ob_start();
    return curl_exec($login);
    ob_end_clean();
    curl_close($login);
    unset($login);
}

function generate_pass($user, $password) {
    $token = get_token();
    if ($password) {
        $enc_pass = md5($password);
        $pass = $user.':'.$enc_pass.':'.$token;
        return md5($pass);
    }
}

function get_token() {
    $html = file_get_html('https://www.foo.com/');
    $token = "";
    foreach($html->find('input') as $element) {
        if($element->name == "token") {
            $token = $element->value;
        }
    }
    if (!$token) {
        die('No token found');
    }
    return $token;
}

echo login("https://www.foo.com/login/start.html", "user=".$username."&password=".$password."&submit=Anmelden&logintype=login&pid=4%2C93%2C1828&pass=".generate_pass($username, $password)."&redirect_url=login%2Fstart.html&tx_felogin_pi1%5Bnoredirect%5D=0&token=".get_token()."");