CURLOPT_BUFFERSIZE.php

<?php

class Test {

    protected $handle;

    protected $data = '';

    private $chunkIndex = 0;

    public function __construct() {

        $url = "*****";

        $this->handle = curl_init($url);

        curl_setopt($this->handle, CURLOPT_WRITEFUNCTION, array(
            $this,
            'stream_body'
        ));
        curl_setopt($this->handle, CURLOPT_BUFFERSIZE, 1160);

        curl_exec($this->handle);
        curl_close($this->handle);


        $md5 = md5($this->data);

        if ($md5 !== '231732259d67fe83ed6fc02d7ad9be57') {

            echo "<h1>Error, not valid md5</h1>";
        }

        echo "<h1>" . $md5 . "</h1>";
    }

    public function stream_body($handle, $data) {

        $data_length = strlen($data);

        $this->data.= $data;

        echo 'Chunk #' . ($this->chunkIndex++) . ': ' . md5($data) . ' '.$data_length.'<br>';

        return $data_length;
    }
}

new Test();