class.ilVirusScannerClamAV.php

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<?php
/* Copyright (c) 1998-2009 ILIAS open source, Extended GPL, see docs/LICENSE */

require_once "./Services/VirusScanner/classes/class.ilVirusScanner.php";

class ilVirusScannerClamAV extends ilVirusScanner
{
    const ADD_SCAN_PARAMS = '--no-summary -i';

    public function __construct($a_scancommand, $a_cleancommand)
    {
        parent::__construct($a_scancommand, $a_cleancommand);
        $this->type = "clamav";
        $this->scanZipFiles = true;
    }

    protected function buildScanCommand($file = '-') // default means piping
    {
        return $this->scanCommand . ' ' . self::ADD_SCAN_PARAMS . ' ' . $file;
    }
    
    protected function isBufferScanPossible()
    {
        $functions = array('proc_open', 'proc_close');
        
        foreach ($functions as $func) {
            if (function_exists($func)) {
                continue;
            }
            
            return false;
        }
        
        return true;
    }
    
    public function scanBuffer($buffer)
    {
        if (!$this->isBufferScanPossible()) {
            return $this->scanFileFromBuffer($buffer);
        }
        
        return $this->processBufferScan($buffer);
    }
    
    protected function processBufferScan($buffer)
    {
        $descriptorspec = array(
            0 => array("pipe", "r"),  // stdin is a pipe that the child will read from
            1 => array("pipe", "w"),  // stdout is a pipe that the child will write to
            2 => array("pipe", "w")             // stderr for the child
        );
        
        $pipes = array(); // will look like follows after passing
        // 0 => writeable handle connected to child stdin
        // 1 => readable handle connected to child stdout

        $process = proc_open($this->buildScanCommand(), $descriptorspec, $pipes);
        
        if (!is_resource($process)) {
            return false; // no scan, no virus detected
        }

        fwrite($pipes[0], $buffer);
        fclose($pipes[0]);

        $detectionReport = stream_get_contents($pipes[1]);
        fclose($pipes[1]);

        $errorReport = stream_get_contents($pipes[2]);
        fclose($pipes[2]);

        $return = proc_close($process);
        
        return $this->hasDetections($detectionReport);
    }
    
    protected function hasDetections($detectionReport)
    {
        return preg_match("/FOUND/", $detectionReport);
    }

    public function scanFile($a_filepath, $a_origname = "")
    {
        // This function should:
        // - call the external scanner for a_filepath
        // - set scanFilePath to a_filepath
        // - set scanFileOrigName to a_origname
        // - set scanFileIsInfected according the scan result
        // - set scanResult to the scanner output message
        // - call logScanResult() if file is infected
        // - return the scanResult, if file is infected
        // - return an empty string, if file is not infected

        $this->scanFilePath = $a_filepath;
        $this->scanFileOrigName = $a_origname;

        // Make group readable for clamdscan
        $currentPermission = fileperms($a_filepath);
        $perm = $currentPermission | 0640;
        chmod($a_filepath, $perm);

        // Call of antivir command
        $cmd = $this->buildScanCommand($a_filepath) . " 2>&1";
        exec($cmd, $out, $ret);
        $this->scanResult = implode("\n", $out);

        if ($perm != $currentPermission) {
            chmod($a_filepath, $currentPermission);
        }

        // sophie could be called
        if ($this->hasDetections($this->scanResult)) {
            $this->scanFileIsInfected = true;
            $this->logScanResult();
            return $this->scanResult;
        } else {
            $this->scanFileIsInfected = false;
            return "";
        }

        // antivir has failed (todo)
        $this->log->write("ERROR (Virus Scanner failed): "
            . $this->scanResult
            . "; COMMAMD=" . $cmd);
    }
}