streams/Zotlabs/Module/Getfile.php

<?php
namespace Zotlabs\Module;

/**
 * module: getfile
 * 
 * used for synchronising files and photos across clones
 * 
 * The site initiating the file operation will send a sync packet to known clones.
 * They will respond by building the DB structures they require, then will provide a
 * post request to this site to grab the file data. This is sent as a stream direct to
 * disk at the other end, avoiding memory issues.
 *
 * Since magic-auth cannot easily be used by the CURL process at the other end,
 * we will require a signed request which includes a timestamp. This should not be 
 * used without SSL and is potentially vulnerable to replay if an attacker decrypts 
 * the SSL traffic fast enough. The amount of time slop is configurable but defaults
 * to 3 minutes.
 * 
 */



require_once('include/attach.php');


class Getfile extends \Zotlabs\Web\Controller {

	function post() {

		$header_verified = false;

		$hash     = $_POST['hash'];
		$resource = $_POST['resource'];
		$revision = intval($_POST['revision']);
		$resolution = (-1);

		if(argc() > 1) {
			$verify_hash = argv(1);
			if($verify_hash !== $hash) {
				killme();
			}
		}

		if(! $hash) {
			killme();
		}

		foreach([ 'REDIRECT_REMOTE_USER', 'HTTP_AUTHORIZATION' ] as $head) {
			if(array_key_exists($head,$_SERVER) && substr(trim($_SERVER[$head]),0,9) === 'Signature') {
				if($head !== 'HTTP_AUTHORIZATION') {
					$_SERVER['HTTP_AUTHORIZATION'] = $_SERVER[$head];
					continue;
				}

				$verified = \Zotlabs\Web\HTTPSig::verify('');	
				if($verified && $verified['header_signed'] && $verified['header_valid']) {
					$r = q("select hubloc_hash from hubloc where hubloc_id_url = '%s' or hubloc_addr = '%s' limit 1",
						dbesc($verified['signer']),
						dbesc(str_replace('acct:','',$verified['signer']))
					);
					if($r && $r[0]['hubloc_hash'] === $hash) {
						$header_verified = true;
					}
				}
			}
		}

		if(! $header_verified) {
			http_status_exit(403,'Permission denied');
		}	

		$channel = channelx_by_hash($hash);

		if(! $channel) {
			logger('error: missing info');
			killme();
		}
	
		if(substr($resource,-2,1) == '-') {
			$resolution = intval(substr($resource,-1,1));
			$resource = substr($resource,0,-2);
		}			

		if($resolution > 0) {
			$r = q("select * from photo where resource_id = '%s' and uid = %d and imgscale = %d limit 1",
				dbesc($resource),
				intval($channel['channel_id']),
				intval($resolution)
			);
			if($r) {
				header('Content-type: ' . $r[0]['mimetype']);

				if(intval($r[0]['os_storage'])) {
					$fname = dbunescbin($r[0]['content']);
					if(strpos($fname,'store') !== false)
						$istream = fopen($fname,'rb');
					else
						$istream = fopen('store/' . $channel['channel_address'] . '/' . $fname,'rb');
					$ostream = fopen('php://output','wb');
					if($istream && $ostream) {
						pipe_streams($istream,$ostream);
						fclose($istream);
						fclose($ostream);
					}
				}
				else {
					echo dbunescbin($r[0]['content']);
				}
			}			
			killme();
		}

		$r = attach_by_hash($resource,$channel['channel_hash'],$revision);
	
		if(! $r['success']) {
			logger('attach_by_hash failed: ' . $r['message']);
			notice( $r['message'] . EOL);
			return;
		}
			
		$unsafe_types = array('text/html','text/css','application/javascript');
	
		if(in_array($r['data']['filetype'],$unsafe_types) && (! channel_codeallowed($channel['channel_id']))) {
				header('Content-type: text/plain');
		}
		else {
			header('Content-type: ' . $r['data']['filetype']);
		}

		header('Content-disposition: attachment; filename="' . $r['data']['filename'] . '"');
		if(intval($r['data']['os_storage'])) {
			$fname = dbunescbin($r['data']['content']);
			if(strpos($fname,'store') !== false)
				$istream = fopen($fname,'rb');
			else
				$istream = fopen('store/' . $channel['channel_address'] . '/' . $fname,'rb');
			$ostream = fopen('php://output','wb');
			if($istream && $ostream) {
				pipe_streams($istream,$ostream);
				fclose($istream);
				fclose($ostream);
			}
		}
		else {
			echo dbunescbin($r['data']['content']);
		}
		killme();
	}
}