Lista de filtros estándar

<?php
$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'string.rot13');
fwrite($fp, "Ceci est un test.\n");
/* muestra :  Prpv rfg ha grfg.   */
?>

<?php
$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'string.toupper');
fwrite($fp, "Ceci est un test.\n");
/* muestra :  CECI EST UN TEST.   */
?>

<?php
$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'string.tolower');
fwrite($fp, "Ceci est un test.\n");
/* muestra :  ceci est un test.   */
?>

<?php
$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'string.strip_tags', STREAM_FILTER_WRITE, "<strong><em><span>");
fwrite($fp, "<strong>Ce texte en gras</strong> finit par être agrandi <h1>en un titre 1</h1>\n");
fclose($fp);
/* muestra :  Ce texte en gras finit par être agrandi en un titre 1   */

$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'string.strip_tags', STREAM_FILTER_WRITE, array('strong','em','span'));
fwrite($fp, "<strong>Ce texte en gras</strong> finit par être agrandi <h1>en un titre 1</h1>\n");
fclose($fp);
/* muestra :  Ce texte en gras finit par être agrandi en un titre 1   */
?>

<?php
$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'convert.base64-encode');
fwrite($fp, "This is a test.\n");
fclose($fp);
/* muestra :  VGhpcyBpcyBhIHRlc3QuCg==  */

$param = array('line-length' => 8, 'line-break-chars' => "\r\n");
$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'convert.base64-encode', STREAM_FILTER_WRITE, $param);
fwrite($fp, "This is a test.\n");
fclose($fp);
/* muestra :  VGhpcyBp
           :  cyBhIHRl
           :  c3QuCg==  */

$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'convert.base64-decode');
fwrite($fp, "VGhpcyBpcyBhIHRlc3QuCg==");
fclose($fp);
/* muestra :  This is a test.  */
?>

<?php
$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'convert.quoted-printable-encode');
fwrite($fp, "This is a test.\n");
/* muestra :  =This is a test.=0A  */
?>

<?php
$fp = fopen('php://output', 'w');
stream_filter_append($fp, 'convert.iconv.utf-16le.utf-8');
fwrite($fp, "T\0h\0i\0s\0 \0i\0s\0 \0a\0 \0t\0e\0s\0t\0.\0\n\0");
fclose($fp);
/* Muestra: This is a test. */
?>

<?php
$params = array('level' => 6, 'window' => 15, 'memory' => 9);

$original_text = "This is a test.\nThis is only a test.\nThis is not an important string.\n";
echo "El texto original es largo de " . strlen($original_text) . " bytes.\n";

$fp = fopen('test.deflated', 'w');
stream_filter_append($fp, 'zlib.deflate', STREAM_FILTER_WRITE, $params);
fwrite($fp, $original_text);
fclose($fp);

echo "El fichero comprimido hace " . filesize('test.deflated') . " bytes de largo.\n";
echo "El texto original era :\n";
/* Utiliza readfile y zlib.inflate para descomprimir al vuelo */
readfile('php://filter/zlib.inflate/resource=test.deflated');

/* Muestra :

El texto original es largo de 70 bytes
El fichero comprimido hace 56 bytes de largo.
El texto original era :
This is a test.
This is only a test.
This is not an important string.

 */
?>

<?php
$original_text = "This is a test.\nThis is only a test.\nThis is not an important string.\n";
echo "El texto original es largo de " . strlen($original_text) . " bytes.\n";

$fp = fopen('test.deflated', 'w');
/* Aquí, "6" indica el nivel de compresión de 6 */
stream_filter_append($fp, 'zlib.deflate', STREAM_FILTER_WRITE, 6);
fwrite($fp, $original_text);
fclose($fp);

echo "El fichero comprimido hace " . filesize('test.deflated') . " bytes de largo.\n";

/* Muestra :

El texto original es largo de 70 bytes
El fichero comprimido hace 56 bytes de largo.

 */
?>

<?php
$param = array('blocks' => 9, 'work' => 0);

echo "El fichero original hace " . strlen(LICENSE) . " bytes de largo.\n";

$fp = fopen('LICENSE.compressed', 'w');
stream_filter_append($fp, 'bzip2.compress', STREAM_FILTER_WRITE, $param);
fwrite($fp, file_get_contents('LICENSE'));
fclose($fp);

echo "El fichero comprimido hace " . filesize('LICENSE.compressed') . " bytes de largo.\n";

/* Muestra :

El fichero original hace 3288 bytes de largo.
El fichero comprimido hace 1488 bytes de largo.

 */
?>

<?php
//$key se supone que fue generado previamente
$iv_size = mcrypt_get_iv_size(MCRYPT_BLOWFISH, MCRYPT_MODE_CBC);
$iv = mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM);
$fp = fopen('encrypted-file.enc', 'wb');
fwrite($fp, $iv);
$opts = array('mode'=>'cbc','iv'=>$iv, 'key'=>$key);
stream_filter_append($fp, 'mcrypt.blowfish', STREAM_FILTER_WRITE, $opts);
fwrite($fp, 'message to encrypt');
fclose($fp);

//descifrado...
$fp = fopen('encrypted-file.enc', 'rb');
$iv = fread($fp, $iv_size = mcrypt_get_iv_size(MCRYPT_BLOWFISH, MCRYPT_MODE_CBC));
$opts = array('mode'=>'cbc','iv'=>$iv, 'key'=>$key);
stream_filter_append($fp, 'mdecrypt.blowfish', STREAM_FILTER_READ, $opts);
$data = rtrim(stream_get_contents($fp));//elimina el relleno nulo
fclose($fp);
echo $data;
?>

<?php
AES_CBC::encryptFile($password, "plaintext.txt", "encrypted.enc");
AES_CBC::decryptFile($password, "encrypted.enc", "decrypted.txt");

class AES_CBC
{
   protected static $KEY_SIZES = array('AES-128'=>16,'AES-192'=>24,'AES-256'=>32);
   protected static function key_size() { return self::$KEY_SIZES['AES-128']; } //por defecto AES-128
   public static function encryptFile($password, $input_stream, $aes_filename){
      $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
      $fin = fopen($input_stream, "rb");
      $fc = fopen($aes_filename, "wb+");
      if (!empty($fin) && !empty($fc)) {
         fwrite($fc, str_repeat("_", 32) );//marcador de posición, SHA256 HMAC irá aquí más tarde
         fwrite($fc, $hmac_salt = mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM));
         fwrite($fc, $esalt = mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM));
         fwrite($fc, $iv = mcrypt_create_iv($iv_size, MCRYPT_DEV_URANDOM));
         $ekey = hash_pbkdf2("sha256", $password, $esalt, $it=1000, self::key_size(), $raw=true);
         $opts = array('mode'=>'cbc', 'iv'=>$iv, 'key'=>$ekey);
         stream_filter_append($fc, 'mcrypt.rijndael-128', STREAM_FILTER_WRITE, $opts);
         $infilesize = 0;
         while (!feof($fin)) {
            $block = fread($fin, 8192);
            $infilesize+=strlen($block);
            fwrite($fc, $block);
         }
         $block_size = mcrypt_get_block_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
         $padding = $block_size - ($infilesize % $block_size);//$padding es un número de 1-16
         fwrite($fc, str_repeat(chr($padding), $padding) );//realiza PKCS7 padding
         fclose($fin);
         fclose($fc);
         $hmac_raw = self::calculate_hmac_after_32bytes($password, $hmac_salt, $aes_filename);
         $fc = fopen($aes_filename, "rb+");
         fwrite($fc, $hmac_raw);//sobrescribe el marcador de posición
         fclose($fc);
      }
   }
   public static function decryptFile($password, $aes_filename, $out_stream) {
      $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_CBC);
      $hmac_raw = file_get_contents($aes_filename, false, NULL,  0, 32);
      $hmac_salt = file_get_contents($aes_filename, false, NULL, 32, $iv_size);
      $hmac_calc = self::calculate_hmac_after_32bytes($password, $hmac_salt, $aes_filename);
      $fc = fopen($aes_filename, "rb");
      $fout = fopen($out_stream, 'wb');
      if (!empty($fout) && !empty($fc) && self::hash_equals($hmac_raw,$hmac_calc)) {
         fread($fc, 32+$iv_size);//saltar sha256 hmac y salt
         $esalt = fread($fc, $iv_size);
         $iv    = fread($fc, $iv_size);
         $ekey = hash_pbkdf2("sha256", $password, $esalt, $it=1000, self::key_size(), $raw=true);
         $opts = array('mode'=>'cbc', 'iv'=>$iv, 'key'=>$ekey);
         stream_filter_append($fc, 'mdecrypt.rijndael-128', STREAM_FILTER_READ, $opts);
         while (!feof($fc)) {
            $block = fread($fc, 8192);
            if (feof($fc)) {
               $padding = ord($block[strlen($block) - 1]);//supone PKCS7 padding
               $block = substr($block, 0, 0-$padding);
            }
            fwrite($fout, $block);
         }
         fclose($fout);
         fclose($fc);
      }
   }
   private static function hash_equals($str1, $str2) {
      if(strlen($str1) == strlen($str2)) {
         $res = $str1 ^ $str2;
         for($ret=0,$i = strlen($res) - 1; $i >= 0; $i--) $ret |= ord($res[$i]);
         return !$ret;
      }
      return false;
   }
   private static function calculate_hmac_after_32bytes($password, $hsalt, $filename) {
      static $init=0;
      $init or $init = stream_filter_register("user-filter.skipfirst32bytes", "FileSkip32Bytes");
      $stream = 'php://filter/read=user-filter.skipfirst32bytes/resource=' . $filename;
      $hkey = hash_pbkdf2("sha256", $password, $hsalt, $iterations=1000, 24, $raw=true);
      return hash_hmac_file('sha256', $stream, $hkey, $raw=true);
   }
}
class FileSkip32Bytes extends php_user_filter
{
   private $skipped=0;
   function filter($in, $out, &$consumed, $closing)  {
      while ($bucket = stream_bucket_make_writeable($in)) {
         $outlen = $bucket->datalen;
         if ($this->skipped<32){
            $outlen = min($bucket->datalen,32-$this->skipped);
            $bucket->data = substr($bucket->data, $outlen);
            $bucket->datalen = $bucket->datalen-$outlen;
            $this->skipped+=$outlen;
         }
         $consumed += $outlen;
         stream_bucket_append($out, $bucket);
      }
      return PSFS_PASS_ON;
   }
}
class AES_128_CBC extends AES_CBC {
   protected static function key_size() { return self::$KEY_SIZES['AES-128']; }
}
class AES_192_CBC extends AES_CBC {
   protected static function key_size() { return self::$KEY_SIZES['AES-192']; }
}
class AES_256_CBC extends AES_CBC {
   protected static function key_size() { return self::$KEY_SIZES['AES-256']; }
}