what dose this code do to my website is it harmful
<?php
namespace wapmorganUnifiedArchive;
class LzwStreamWrapper
{
private static $registered = false;
private static $installed = 0;
public static function registerWrapper()
{
if (!self::$registered)
stream_wrapper_register('compress.lzw', __CLASS__);
self::$registered = true;
}
public static $TMP_FILE_THRESHOLD = 0.5;
private static $AVERAGE_COMPRESSION_RATIO = 2;
public static $forceTmpFile = false;
/** High limit. unit: MBytes.
*/
public static $highLimit = 512;
private $mode;
private $path;
private $tmp;
private $tmp2;
private $data;
private $dataSize;
private $pointer;
private $writtenBytes = 0;
/**
* @param $path
* @param $mode
* @param $options
* @return bool
* @throws Exception
*/
public function stream_open($path, $mode, $options)
{
// check for compress & uncompress utility
if (self::$installed === 0) {
$this->exec('command -v compress', $output);
if (empty($output))
throw new Exception(__FILE__.', line '.__LINE__.
': compress command is required');
$this->exec('command -v uncompress', $output);
if (empty($output))
throw new Exception(__FILE__.', line '.__LINE__.
': uncompress command is required');
self::$installed = true;
}
$schema = 'compress.lzw://';
if (strncasecmp($schema, $path, strlen($schema)) == 0)
$path = substr($path, strlen($schema));
if (file_exists($path)) {
$this->path = realpath($path);
$expected_data_size = filesize($path)
* self::$AVERAGE_COMPRESSION_RATIO;
$available_memory = $this->getAvailableMemory();
if ($expected_data_size <=
(self::$TMP_FILE_THRESHOLD * $available_memory)
&& !self::$forceTmpFile
&& $expected_data_size < (self::$highLimit * 1024 * 1024)) {
$this->read();
} else {
$prefix = basename(__FILE__, '.php');
if (($tmp = tempnam(sys_get_temp_dir(), $prefix)) === false)
throw new Exception(__CLASS__.', line '.__LINE__.
': Could not create temporary file in '.
sys_get_temp_dir());
if (($tmp2 = tempnam(sys_get_temp_dir(), $prefix)) === false)
throw new Exception(__CLASS__.', line '.__LINE__.
': Could not create temporary file in '.
sys_get_temp_dir());
$this->tmp = $tmp;
$this->tmp2 = $tmp2;
$this->read();
}
} else {
$this->path = $path;
if (self::$forceTmpFile) {
$prefix = basename(__FILE__, '.php');
if (($tmp = tempnam(sys_get_temp_dir(), $prefix)) === false)
throw new Exception(__CLASS__.', line '.__LINE__.
': Could not create temporary file in '.
sys_get_temp_dir());
if (($tmp2 = tempnam(sys_get_temp_dir(), $prefix)) === false)
throw new Exception(__CLASS__.', line '.__LINE__.
': Could not create temporary file in '.
sys_get_temp_dir());
$this->tmp = $tmp;
$this->tmp2 = $tmp2;
$this->pointer = 0;
} else {
$this->pointer = 0;
}
}
$this->mode = $mode;
return true;
}
/**
* @return float|int|string
* @throws Exception
*/
public function getAvailableMemory()
{
$limit = strtoupper(ini_get('memory_limit'));
$s = array('K', 'M', 'G');
if (($multipleer = array_search(substr($limit, -1), $s)) !== false) {
$limit = substr($limit, 0, -1) * pow(1024, $multipleer + 1);
$limit -= memory_get_usage();
} elseif ($limit == -1) {
$limit = $this->getSystemMemory();
}
// var_dump(('multipleer' => $multipleer));
// var_dump(('memory_limit' => $memory_limit));
return $limit;
}
/**
* @return string
* @throws Exception
*/
public function getSystemMemory()
{
$this->exec('free --bytes | head -n3 | tail -n1 | awk '{print $4}'',
$output, $resultCode);
return trim($output);
}
/**
* @param $command
* @param $output
* @param null $resultCode
* @throws Exception
*/
private function exec($command, &$output, &$resultCode = null)
{
if (function_exists('system')) {
ob_start();
system($command, $resultCode);
$output = ob_get_contents();
ob_end_clean();
return;
} elseif (function_exists('exec')) {
$execOutput = array();
exec($command, $execOutput, $resultCode);
$output = implode(PHP_EOL, $execOutput);
return;
} elseif (function_exists('proc_open')) {
$process = proc_open($command, array(1 =>
fopen('php://memory', 'w')), $pipes);
$output = stream_get_contents($pipes(1));
fclose($pipes(1));
$resultCode = proc_close($process);
return;
} elseif (function_exists('shell_exec')) {
$output = shell_exec($command);
return;
} else {
throw new Exception(__FILE__.', line '.__LINE__
.': Execution functions is required! Make sure one of exec'.
' function is allowed (system, exec, proc_open, shell_exec)');
}
}
/**
* @throws Exception
*/
private function read()
{
if ($this->tmp !== null) {
$this->exec('uncompress --stdout '.escapeshellarg($this->path).
' > '.$this->tmp, $output, $resultCode);
// var_dump(('command' => 'uncompress --stdout '.
// escapeshellarg($this->path).' > '.$this->tmp, 'output' =>
// $output, 'resultCode' => $resultCode));
if ($resultCode == 0 || $resultCode == 2 || is_null($resultCode)) {
$this->dataSize = filesize($this->tmp);
// rewind pointer
$this->pointer = 0;
} else {
throw new Exception(__FILE__.', line '.__LINE__.
': Could not read file '.$this->path);
}
} else {
$this->exec('uncompress --stdout '.escapeshellarg($this->path),
$output, $resultCode);
$this->data = &$output;
if ($resultCode == 0 || $resultCode == 2 || is_null($resultCode)) {
$this->dataSize = strlen($this->data);
// rewind pointer
$this->pointer = 0;
} else {
throw new Exception(__FILE__.', line '.__LINE__.
': Could not read file '.$this->path);
}
}
}
/**
* @return array
*/
public function stream_stat()
{
return array(
'size' => $this->dataSize,
);
}
/**
* @throws Exception
*/
public function stream_close()
{
// rewrite file
if ($this->writtenBytes > 0) {
// stored in temp file
if ($this->tmp !== null) {
// compress in tmp2
$this->exec('compress -c '.escapeshellarg($this->tmp).' > '.
escapeshellarg($this->tmp2), $output, $code);
// var_dump(('command' => 'compress -c '.
// escapeshellarg($this->tmp).' > '.escapeshellarg($this->tmp2),
// 'output' => $output, 'code' => $code));
if ($code == 0 || $code == 2 || is_null($code)) {
// rewrite original file
if (rename($this->tmp2, $this->path) === true) {
// ok
} else {
throw new Exception(__FILE__.', line '.__LINE__.
': Could not replace original file '.$this->path);
}
} else {
throw new Exception(__FILE__.', line '.__LINE__.
': Could not compress changed data in '.$this->tmp2);
}
} else { // stored in local var
// compress in original path
// $this->exec('compress '.escapeshellarg($this->tmp).' > '.
// escapeshellarg($this->tmp2), $output, $resultCode);
if (!function_exists('proc_open')) {
throw new Exception('proc_open is necessary for writing '.
'changed data in the file');
}
//var_dump(('command' => 'compress > '.
// escapeshellarg($this->path), 'path' => $this->path));
$process = proc_open('compress > '.escapeshellarg($this->path),
array(0 => array('pipe', 'r')), $pipes);
// write data to process' input
fwrite($pipes(0), $this->data);
fclose($pipes(0));
$resultCode = proc_close($process);
if ($resultCode == 0 || $resultCode == 2) {
// ok
} else {
throw new Exception(__FILE__.', line '.__LINE__.
': Could not compress changed data in '.$this->path);
}
}
}
if ($this->tmp !== null) {
unlink($this->tmp);
if (file_exists($this->tmp2)) unlink($this->tmp2);
} else {
$this->data = null;
}
}
/**
* @param $count
* @return bool|string
*/
public function stream_read($count)
{
if ($this->tmp !== null) {
$fp = fopen($this->tmp, 'r'.(strpos($this->mode, 'b') !== 0 ? 'b'
: null));
fseek($fp, $this->pointer);
$data = fread($fp, $count);
$this->pointer = ftell($fp);
fclose($fp);
return $data;
} else {
$data = substr($this->data, $this->pointer,
($this->pointer + $count));
$this->pointer = $this->pointer + $count;
return $data;
}
}
/**
* @return bool
*/
public function stream_eof()
{
return $this->pointer >= $this->dataSize;
}
/**
* @return mixed
*/
public function stream_tell()
{
return $this->pointer;
}
/**
* @param $data
* @return bool|int
*/
public function stream_write($data)
{
$this->writtenBytes += strlen($data);
if ($this->tmp !== null) {
$fp = fopen($this->tmp, 'w'.(strpos($this->mode, 'b') !== 0 ? 'b'
: null));
fseek($fp, $this->pointer);
$count = fwrite($fp, $data);
$this->pointer += $count;
fclose($fp);
return $count;
} else {
$count = strlen($data);
$prefix = substr($this->data, 0, $this->pointer);
$postfix = substr($this->data, ($this->pointer + $count));
$this->data = $prefix.$data.$postfix;
$this->pointer += $count;
return $count;
}
}
/**
* @param $offset
* @param int $whence
* @return bool
*/
public function stream_seek($offset, $whence = SEEK_SET)
{
switch ($whence) {
case SEEK_SET:
$this->pointer = $offset;
break;
case SEEK_CUR:
$this->pointer += $offset;
break;
case SEEK_END:
$actual_data_size = (is_null($this->tmp)) ? strlen($this->data)
: filesize($this->tmp);
$this->pointer = $actual_data_size - $offset;
break;
default:
return false;
}
return true;
}
/**
* @param $operation
* @return bool
*/
public function stream_lock($operation)
{
if ($this->tmp !== null) {
return false;
} else {
return true;
}
}
/**
* @param $new_size
*/
public function stream_truncate($new_size)
{
$actual_data_size = (is_null($this->tmp)) ? strlen($this->data)
: filesize($this->tmp);
if ($new_size > $actual_data_size) {
$this->stream_write(str_repeat(" 0", $new_size
- $actual_data_size));
} elseif ($new_size < $actual_data_size) {
if ($this->tmp === null) {
$this->data = substr($this->data, 0, $new_size);
} else {
$fp = fopen($this->tmp, 'w'.(strpos($this->mode, 'b') !== 0
? 'b' : null));
ftruncate($fp, $new_size);
fclose($fp);
}
}
}
}
what dose this code do to my website is it harmful? in what way is it harmful it seems like shell
can it be used to gain accesses to my server
what dose this code do to my website is it harmful? in what way is it harmful it seems like shell
can it be used to gain accesses to my server
