From a0f2a3e105074380f0f02882ab075ec48049f63a Mon Sep 17 00:00:00 2001 From: Andrew Dolgov Date: Tue, 19 Mar 2013 09:33:04 +0400 Subject: [PATCH] enable automatic decoding of gzipped data when CURL is not available --- include/functions.php | 122 ++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 122 insertions(+) diff --git a/include/functions.php b/include/functions.php index a7ac07b53..ad87c90c2 100644 --- a/include/functions.php +++ b/include/functions.php @@ -352,6 +352,9 @@ $data = @file_get_contents($url); + $gzdecoded = gzdecode($data); + if ($gzdecoded) $data = $gzdecoded; + if (!$data && function_exists('error_get_last')) { $error = error_get_last(); $fetch_last_error = $error["message"]; @@ -3997,4 +4000,123 @@ return $rv; } + // http://php.net/gzencode + function gzdecode($data) { + $len = strlen($data); + if ($len < 18 || strcmp(substr($data,0,2),"\x1f\x8b")) { + 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) { + // Reserved bits are set -- NOT ALLOWED by RFC 1952 + 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 format + } + $extralen = unpack("v",substr($data,8,2)); + $extralen = $extralen[1]; + if ($len - $headerlen - 2 - $extralen < 8) { + return false; // Invalid format + } + $extra = substr($data,10,$extralen); + $headerlen += 2 + $extralen; + } + + $filenamelen = 0; + $filename = ""; + if ($flags & 8) { + // C-style string file NAME data in header + if ($len - $headerlen - 1 < 8) { + return false; // Invalid format + } + $filenamelen = strpos(substr($data,8+$extralen),chr(0)); + if ($filenamelen === false || $len - $headerlen - $filenamelen - 1 < 8) { + return false; // Invalid format + } + $filename = substr($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 format + } + $commentlen = strpos(substr($data,8+$extralen+$filenamelen),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 & 1) { + // 2-bytes (lowest order) of CRC32 on header present + if ($len - $headerlen - 2 < 8) { + return false; // Invalid format + } + $calccrc = crc32(substr($data,0,$headerlen)) & 0xffff; + $headercrc = unpack("v", substr($data,$headerlen,2)); + $headercrc = $headercrc[1]; + if ($headercrc != $calccrc) { + return false; // Bad header CRC + } + $headerlen += 2; + } + + // GZIP FOOTER - These be negative due to PHP's limitations + $datacrc = unpack("V",substr($data,-8,4)); + $datacrc = $datacrc[1]; + $isize = unpack("V",substr($data,-4)); + $isize = $isize[1]; + + // Perform the decompression: + $bodylen = $len-$headerlen-8; + if ($bodylen < 1) { + // This should never happen - 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); + break; + default: + // Unknown compression method + return false; + } + } else { + // I'm not sure if zero-byte body content is allowed. + // Allow it for now... Do nothing... + } + + // Verifiy decompressed size and CRC32: + // NOTE: This may fail with large data sizes depending on how + // PHP's integer limitations affect strlen() since $isize + // may be negative for large sizes. + if ($isize != strlen($data) || crc32($data) != $datacrc) { + // Bad format! Length or CRC doesn't match! + return false; + } + return $data; + } + ?>