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rss-bridge/bridges/FacebookBridge.php
ORelio d16d514736 [Facebook] Capcha retrieval and response submit
This does not solve the captcha issue but allows the viewer to manually
solve the captcha by displaying a form and using the response from the
viewer. Maybe a first step to automated captcha solving?

This process relies on the use of a PHP session for storing captcha
details so that the user cannot submit anything else than the response
to the captcha. Response is filtered before being forwarded, also. Once
captcha is solved we get a page ready to be parsed, as usual.

Combined to some kind of OCR, this could automatically solve the
captcha, but currently if only automates the process of retrieving the
challenge and submitting the response.
2016-01-23 21:53:25 +01:00

235 lines
8.3 KiB
PHP

<?php
class FacebookBridge extends BridgeAbstract{
public function loadMetadatas() {
$this->maintainer = "teromene";
$this->name = "Facebook";
$this->uri = "http://www.facebook.com/";
$this->description = "Input a page title or a profile log. For a profile log, please insert the parameter as follow : myExamplePage/132621766841117";
$this->update = "23/10/2015";
$this->parameters[] =
'[
{
"name" : "Username",
"identifier" : "u",
"required" : "required"
}
]';
}
public function collectData(array $param) {
//Extract a string using start and end delimiters
function ExtractFromDelimiters($string, $start, $end) {
if (strpos($string, $start) !== false) {
$section_retrieved = substr($string, strpos($string, $start) + strlen($start));
$section_retrieved = substr($section_retrieved, 0, strpos($section_retrieved, $end));
return $section_retrieved;
} return false;
}
//Utility function for cleaning a Facebook link
$unescape_fb_link = function ($matches) {
if (is_array($matches) && count($matches) > 1) {
$link = $matches[1];
if (strpos($link, '/') === 0)
$link = 'https://www.facebook.com'.$link.'"';
if (strpos($link, 'facebook.com/l.php?u=') !== false)
$link = urldecode(ExtractFromDelimiters($link, 'facebook.com/l.php?u=', '&'));
return ' href="'.$link.'"';
}
};
//Utility function for converting facebook emoticons
$unescape_fb_emote = function ($matches) {
static $facebook_emoticons = array(
'smile' => ':)',
'frown' => ':(',
'tongue' => ':P',
'grin' => ':D',
'gasp' => ':O',
'wink' => ';)',
'pacman' => ':<',
'grumpy' => '>_<',
'unsure' => ':/',
'cry' => ':\'(',
'kiki' => '^_^',
'glasses' => '8-)',
'sunglasses' => 'B-)',
'heart' => '<3',
'devil' => ']:D',
'angel' => '0:)',
'squint' => '-_-',
'confused' => 'o_O',
'upset' => 'xD',
'colonthree' => ':3',
'like' => '&#x1F44D;');
$len = count($matches);
if ($len > 1)
for ($i = 1; $i < $len; $i++)
foreach ($facebook_emoticons as $name => $emote)
if ($matches[$i] === $name)
return $emote;
return $matches[0];
};
$html = null;
//Handle captcha response sent by the viewer
if (isset($_POST['captcha_response']))
{
if (session_status() == PHP_SESSION_NONE)
session_start();
if (isset($_SESSION['captcha_fields'], $_SESSION['captcha_action']))
{
$captcha_action = $_SESSION['captcha_action'];
$captcha_fields = $_SESSION['captcha_fields'];
$captcha_fields['captcha_response'] = preg_replace("/[^a-zA-Z0-9]+/", "", $_POST['captcha_response']);
$http_options = array(
'http' => array(
'method' => 'POST',
'user_agent'=> ini_get('user_agent'),
'header'=>array("Content-type: application/x-www-form-urlencoded\r\nReferer: $captcha_action\r\nCookie: noscript=1\r\n"),
'content' => http_build_query($captcha_fields),
),
);
$context = stream_context_create($http_options);
$html = file_get_contents($captcha_action, false, $context);
if ($html === FALSE) { $this->returnError('Failed to submit captcha response back to Facebook', 500); }
unset($_SESSION['captcha_fields']);
$html = str_get_html($html);
}
unset($_SESSION['captcha_fields']);
unset($_SESSION['captcha_action']);
}
//Retrieve page contents
if (is_null($html)) {
if (isset($param['u'])) {
if (!strpos($param['u'], "/")) {
$html = file_get_html('https://www.facebook.com/'.urlencode($param['u']).'?_fb_noscript=1') or $this->returnError('No results for this query.', 404);
} else {
$html = file_get_html('https://www.facebook.com/pages/'.$param['u'].'?_fb_noscript=1') or $this->returnError('No results for this query.', 404);
}
} else {
$this->returnError('You must specify a Facebook username.', 400);
}
}
//Handle captcha form?
$captcha = $html->find('div.captcha_interstitial', 0);
if (!is_null($captcha))
{
//Save form for submitting after getting captcha response
if (session_status() == PHP_SESSION_NONE)
session_start();
$captcha_fields = array();
foreach ($captcha->find('input, button') as $input)
$captcha_fields[$input->name] = $input->value;
$_SESSION['captcha_fields'] = $captcha_fields;
$_SESSION['captcha_action'] = 'https://www.facebook.com'.$captcha->find('form', 0)->action;
//Show captcha filling form to the viewer, proxying the captcha image
$img = base64_encode(file_get_contents($captcha->find('img', 0)->src));
header('HTTP/1.1 500 '.Http::getMessageForCode(500));
header('Content-Type: text/html');
die('<form method="post" action="?'.$_SERVER['QUERY_STRING'].'">'
.'<h2>Facebook captcha challenge</h2>'
.'<p>Unfortunately, rss-bridge cannot fetch the requested page.<br />'
.'Facebook wants rss-bridge to resolve the following captcha:</p>'
.'<p><img src="data:image/png;base64,'.$img.'" /></p>'
.'<p><b>Response:</b> <input name="captcha_response" placeholder="please fill in" />'
.'<input type="submit" value="Submit!" /></p>'
.'</form>');
}
//No captcha? We can carry on retrieving page contents :)
$element = $html->find('[id^=PagePostsSectionPagelet-]')[0]->children(0)->children(0);
if(isset($element)) {
$author = str_replace(' | Facebook', '', $html->find('title#pageTitle', 0)->innertext);
$profilePic = 'https://graph.facebook.com/'.$param['u'].'/picture?width=200&amp;height=200';
$this->name = $author;
foreach($element->children() as $post) {
$item = new \Item();
if($post->hasAttribute("data-time")) {
//Retrieve post contents
$content = preg_replace('/(?i)><div class=\"clearfix([^>]+)>(.+?)div\ class=\"userContent\"/i', '', $post);
$content = preg_replace('/(?i)><div class=\"_59tj([^>]+)>(.+?)<\/div><\/div><a/i', '', $content);
$content = preg_replace('/(?i)><div class=\"_3dp([^>]+)>(.+?)div\ class=\"[^u]+userContent\"/i', '', $content);
$content = preg_replace('/(?i)><div class=\"_4l5([^>]+)>(.+?)<\/div>/i', '', $content);
//Remove html nodes, keep only img, links, basic formatting
$content = strip_tags($content,'<a><img><i><u>');
//Adapt link hrefs: convert relative links into absolute links and bypass external link redirection
$content = preg_replace_callback('/ href=\"([^"]+)\"/i', $unescape_fb_link, $content);
//Clean useless html tag properties and fix link closing tags
foreach (array('onmouseover', 'onclick', 'target', 'ajaxify', 'tabindex',
'class', 'style', 'data-[^=]*', 'aria-[^=]*', 'role', 'rel', 'id') as $property_name)
$content = preg_replace('/ '.$property_name.'=\"[^"]*\"/i', '', $content);
$content = preg_replace('/<\/a [^>]+>/i', '</a>', $content);
//Convert textual representation of emoticons eg "<i><u>smile emoticon</u></i>" back to ASCII emoticons eg ":)"
$content = preg_replace_callback('/<i><u>([^ <>]+) ([^<>]+)<\/u><\/i>/i', $unescape_fb_emote, $content);
//Retrieve date of the post
$date = $post->find("abbr")[0];
if(isset($date) && $date->hasAttribute('data-utime')) {
$date = $date->getAttribute('data-utime');
} else {
$date = 0;
}
//Build title from username and content
$title = $author;
if (strlen($title) > 24)
$title = substr($title, 0, strpos(wordwrap($title, 24), "\n")).'...';
$title = $title.' | '.strip_tags($content);
if (strlen($title) > 64)
$title = substr($title, 0, strpos(wordwrap($title, 64), "\n")).'...';
//Use first image as thumbnail if available, or profile pic fallback
$thumbnail = $post->find('img', 1)->src;
if (strlen($thumbnail) == 0)
$thumbnail = $profilePic;
//Build and add final item
$item->uri = 'https://facebook.com'.$post->find('abbr')[0]->parent()->getAttribute('href');
$item->thumbnailUri = $thumbnail;
$item->content = $content;
$item->title = $title;
$item->author = $author;
$item->timestamp = $date;
$this->items[] = $item;
}
}
}
}
public function setDatas(array $param){
if (isset($param['captcha_response']))
unset($param['captcha_response']);
parent::setDatas($param);
}
public function getName() {
return (isset($this->name) ? $this->name.' - ' : '').'Facebook Bridge';
}
public function getURI() {
return 'http://facebook.com';
}
public function getCacheDuration() {
return 300; // 5 minutes
}
}