<?php
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/*
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+-----------------------------------------------------------------------+
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| program/include/rcube_content_filter.php |
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| |
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| This file is part of the Roundcube Webmail client |
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| Copyright (C) 2011, The Roundcube Dev Team |
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| Licensed under the GNU GPL |
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| |
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| PURPOSE: |
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| PHP stream filter to detect evil content in mail attachments |
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| |
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+-----------------------------------------------------------------------+
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| Author: Thomas Bruederli <roundcube@gmail.com> |
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+-----------------------------------------------------------------------+
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$Id$
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*/
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/**
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* PHP stream filter to detect html/javascript code in attachments
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*/
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class rcube_content_filter extends php_user_filter
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{
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private $buffer = '';
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private $cutoff = 2048;
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function onCreate()
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{
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$this->cutoff = rand(2048, 3027);
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return true;
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}
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function filter($in, $out, &$consumed, $closing)
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{
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while ($bucket = stream_bucket_make_writeable($in)) {
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$this->buffer .= $bucket->data;
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// check for evil content and abort
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if (preg_match('/<(script|iframe|object)/i', $this->buffer))
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return PSFS_ERR_FATAL;
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// keep buffer small enough
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if (strlen($this->buffer) > 4096)
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$this->buffer = substr($this->buffer, $this->cutoff);
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$consumed += $bucket->datalen;
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stream_bucket_append($out, $bucket);
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}
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return PSFS_PASS_ON;
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}
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}
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