<?php
// From: https://github.com/nico3333fr/CSP-useful
//
// Note: this script requires PHP ≥ 5.4.
// Inspired from https://mathiasbynens.be/notes/csp-reports

// Dareboost wants it? Not a problem.
header('X-Content-Type-Options: "nosniff"');

require dirname(__FILE__).'/../inc/admin/prepend.php';

// Specify admin CSP log file if necessary
if (!defined('LOGFILE')) {
	define('LOGFILE',path::real(DC_VAR).'/csp/csp_report.json');
}

// Get the raw POST data
$data = file_get_contents('php://input');

// Only continue if it’s valid JSON that is not just `null`, `0`, `false` or an
// empty string, i.e. if it could be a CSP violation report.
if ($data = json_decode($data,true)) {

	// get source-file and blocked-URI to perform some tests
	$source_file = $data['csp-report']['source-file'];
	$blocked_uri = $data['csp-report']['blocked-uri'];

	if (
		// avoid false positives notifications coming from Chrome extensions (Wappalyzer, MuteTab, etc.)
		// bug here https://code.google.com/p/chromium/issues/detail?id=524356
		strpos($source_file, 'chrome-extension://') === false

		// avoid false positives notifications coming from Safari extensions (diigo, evernote, etc.)
		&& strpos($source_file, 'safari-extension://') === false
		&& strpos($blocked_uri, 'safari-extension://') === false

		// search engine extensions ?
		&& strpos($source_file, 'se-extension://') === false

		// added by browsers in webviews
		&& strpos($blocked_uri, 'webviewprogressproxy://') === false

		// Google Search App see for details https://github.com/nico3333fr/CSP-useful/commit/ecc8f9b0b379ae643bc754d2db33c8b47e185fd1
		&& strpos($blocked_uri, 'gsa://onpageload') === false

	) {
		// Prepare report data (hash => info)
		$hash = hash('md5',
			$data['csp-report']['blocked-uri'].
			$data['csp-report']['document-uri'].
			$data['csp-report']['source-file'].
			$data['csp-report']['line-number'].
			$data['csp-report']['violated-directive']);

		try {
			// Check report dir (create it if necessary)
			files::makeDir(dirname(LOGFILE),true);

			// Check if report is not already stored in log file
			$contents = '';
			if (file_exists(LOGFILE)) {
				$contents = file_get_contents(LOGFILE);
				if ($contents && $contents != '') {
					if (substr($contents,-1) == ',') {
						// Remove final comma if present
						$contents = substr($contents,0,-1);
					}
					if ($contents != '') {
						$list = json_decode('['.$contents.']',true);
						if (is_array($list)) {
							foreach ($list as $idx => $value) {
								if (isset($value['hash']) && $value['hash'] == $hash) {
									// Already stored, ignore
									return;
								}
							}
						}
					}
				}
			}

			// Add report to the file
			if (!($fp = @fopen(LOGFILE,'a'))) {
				// Unable to open file, ignore
				return;
			}

			// Prettify the JSON-formatted data
			$violation = array_merge(array('hash' => $hash),$data['csp-report']);
			$output = json_encode($violation,JSON_PRETTY_PRINT | JSON_UNESCAPED_SLASHES);

			// The file content will have to be enclosed in brackets [] before
			// beeing decoded with json_decoded(<content>,true);
			fprintf($fp,($contents != '' ? ',' : '').'%s',$output);

		}  catch (Exception $e) {
			return;
		}
	}
}
