php - curl を使用してツイートを検索する - Twitter API

Question

$url = "https://api.twitter.com/1.1/search/tweets.json?q=xyz";

        $oauth_access_token = "xxxxxx-xxxxxxxxxxxxxxxxxxxxxxxxxxxx";
        $oauth_access_token_secret = "xxxxxxxxxxxxxxxxxxxxxxxxxxx";
        $consumer_key = "xxxxxxxxxxxxxxxxxxxxxxxx";
        $consumer_secret = "xxxxxxxxxxxxxxxxxxxxxxxxxxxx";

        $oauth = array('oauth_consumer_key' => $consumer_key,
            'oauth_nonce' => time(),
            'oauth_signature_method' => 'HMAC-SHA1',
            'oauth_token' => $oauth_access_token,
            'oauth_timestamp' => time(),
            'oauth_version' => '1.1');
        $base_info = $this->buildBaseString($url, 'GET', $oauth);
        $composite_key = rawurlencode($consumer_secret) . '&' . rawurlencode($oauth_access_token_secret);
        $oauth_signature = base64_encode(hash_hmac('sha1', $base_info, $composite_key, true));
        $oauth['oauth_signature'] = $oauth_signature;
        $header = array($this->buildAuthorizationHeader($oauth), 'Expect:');
        $options = array(CURLOPT_HTTPHEADER => $header,
            CURLOPT_HEADER => false,
            CURLOPT_URL => $url,
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_SSL_VERIFYPEER => false);

        $feed = curl_init();
        curl_setopt_array($feed, $options);
        echo $json = curl_exec($feed);
        curl_close($feed);

        $twitter_data = json_decode($json);

しかし、「Bad Authentication data」というエラーが表示されます