add php native gzdecode()

diff --git a/include/functions.php b/include/functions.php
index 75ca6daf9c93daa62c768914c60f34e2bfb7f4ba..a559ed1daad3f253cc53fa4eb01d38b6e685a65f 100644 (file)
--- a/include/functions.php
+++ b/include/functions.php
@@ -3934,9 +3934,121 @@
        }
 
        if (!function_exists('gzdecode')) {
-               function gzdecode($string) { // no support for 2nd argument
+               /* function gzdecode($string) { // no support for 2nd argument
                        return file_get_contents('compress.zlib://data:who/cares;base64,'.
                                base64_encode($string));
+               } */
+
+
+               function gzdecode($data, &$filename = '', &$error = '', $maxlength = null) {
+                   $len = strlen($data);
+                   if ($len < 18 || strcmp(substr($data,0,2),"\x1f\x8b")) {
+                       $error = "Not in GZIP format.";
+                       return null;  // Not GZIP format (See RFC 1952)
+                   }
+                   $method = ord(substr($data,2,1));  // Compression method
+                   $flags  = ord(substr($data,3,1));  // Flags
+                   if ($flags & 31 != $flags) {
+                       $error = "Reserved bits not allowed.";
+                       return null;
+                   }
+                   // NOTE: $mtime may be negative (PHP integer limitations)
+                   $mtime = unpack("V", substr($data,4,4));
+                   $mtime = $mtime[1];
+                   $xfl   = substr($data,8,1);
+                   $os    = substr($data,8,1);
+                   $headerlen = 10;
+                   $extralen  = 0;
+                   $extra     = "";
+                   if ($flags & 4) {
+                       // 2-byte length prefixed EXTRA data in header
+                       if ($len - $headerlen - 2 < 8) {
+                           return false;  // invalid
+                       }
+                       $extralen = unpack("v",substr($data,8,2));
+                       $extralen = $extralen[1];
+                       if ($len - $headerlen - 2 - $extralen < 8) {
+                           return false;  // invalid
+                       }
+                       $extra = substr($data,10,$extralen);
+                       $headerlen += 2 + $extralen;
+                   }
+                   $filenamelen = 0;
+                   $filename = "";
+                   if ($flags & 8) {
+                       // C-style string
+                       if ($len - $headerlen - 1 < 8) {
+                           return false; // invalid
+                       }
+                       $filenamelen = strpos(substr($data,$headerlen),chr(0));
+                       if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) {
+                           return false; // invalid
+                       }
+                       $filename = substr($data,$headerlen,$filenamelen);
+                       $headerlen += $filenamelen + 1;
+                   }
+                   $commentlen = 0;
+                   $comment = "";
+                   if ($flags & 16) {
+                       // C-style string COMMENT data in header
+                       if ($len - $headerlen - 1 < 8) {
+                           return false;    // invalid
+                       }
+                       $commentlen = strpos(substr($data,$headerlen),chr(0));
+                       if ($commentlen === false || $len - $headerlen - $commentlen - 1 < 8) {
+                           return false;    // Invalid header format
+                       }
+                       $comment = substr($data,$headerlen,$commentlen);
+                       $headerlen += $commentlen + 1;
+                   }
+                   $headercrc = "";
+                   if ($flags & 2) {
+                       // 2-bytes (lowest order) of CRC32 on header present
+                       if ($len - $headerlen - 2 < 8) {
+                           return false;    // invalid
+                       }
+                       $calccrc = crc32(substr($data,0,$headerlen)) & 0xffff;
+                       $headercrc = unpack("v", substr($data,$headerlen,2));
+                       $headercrc = $headercrc[1];
+                       if ($headercrc != $calccrc) {
+                           $error = "Header checksum failed.";
+                           return false;    // Bad header CRC
+                       }
+                       $headerlen += 2;
+                   }
+                   // GZIP FOOTER
+                   $datacrc = unpack("V",substr($data,-8,4));
+                   $datacrc = sprintf('%u',$datacrc[1] & 0xFFFFFFFF);
+                   $isize = unpack("V",substr($data,-4));
+                   $isize = $isize[1];
+                   // decompression:
+                   $bodylen = $len-$headerlen-8;
+                   if ($bodylen < 1) {
+                       // IMPLEMENTATION BUG!
+                       return null;
+                   }
+                   $body = substr($data,$headerlen,$bodylen);
+                   $data = "";
+                   if ($bodylen > 0) {
+                       switch ($method) {
+                       case 8:
+                           // Currently the only supported compression method:
+                           $data = gzinflate($body,$maxlength);
+                           break;
+                       default:
+                           $error = "Unknown compression method.";
+                           return false;
+                       }
+                   }  // zero-byte body content is allowed
+                   // Verifiy CRC32
+                   $crc   = sprintf("%u",crc32($data));
+                   $crcOK = $crc == $datacrc;
+                   $lenOK = $isize == strlen($data);
+                   if (!$lenOK || !$crcOK) {
+                       $error = ( $lenOK ? '' : 'Length check FAILED. ') . ( $crcOK ? '' : 'Checksum FAILED.');
+                       return false;
+                   }
+                   return $data;
                }
        }