diff options
| -rw-r--r-- | phpBB/includes/captcha/captcha_non_gd.php | 19 |
1 files changed, 7 insertions, 12 deletions
diff --git a/phpBB/includes/captcha/captcha_non_gd.php b/phpBB/includes/captcha/captcha_non_gd.php index f875708f41..5e3b7abd1c 100644 --- a/phpBB/includes/captcha/captcha_non_gd.php +++ b/phpBB/includes/captcha/captcha_non_gd.php @@ -139,12 +139,9 @@ class captcha */ function png_chunk($length, $type, $data) { - $raw = $type; - $raw .= $data; - $crc = crc32($raw); - $raw .= pack('C4', ($crc >> 24) & 255, ($crc >> 16) & 255, ($crc >> 8) & 255, $crc & 255); + $raw = $type . $data; - return pack('C4', ($length >> 24) & 255, ($length >> 16) & 255, ($length >> 8) & 255, $length & 255) . $raw; + return pack('N', $length) . $raw . pack('N', crc32($raw)); } /** @@ -159,8 +156,7 @@ class captcha $image = pack('C8', 137, 80, 78, 71, 13, 10, 26, 10); // IHDR - $raw = pack('C4', ($width >> 24) & 255, ($width >> 16) & 255, ($width >> 8) & 255, $width & 255); - $raw .= pack('C4', ($height >> 24) & 255, ($height >> 16) & 255, ($height >> 8) & 255, $height & 255); + $raw = pack('N2', $width, $height); $raw .= pack('C5', 8, 0, 0, 0, 0); $image .= $this->png_chunk(13, 'IHDR', $raw); @@ -180,11 +176,11 @@ class captcha if (@extension_loaded('hash')) { - $adler_hash = hash('adler32', $raw_image, true); + $adler_hash = strrev(hash('adler32', $raw_image, true)); } else if (@extension_loaded('mhash')) { - $adler_hash = mhash(MHASH_ADLER32, $raw_image); + $adler_hash = strrev(mhash(MHASH_ADLER32, $raw_image)); } else { @@ -212,12 +208,11 @@ class captcha $s1 %= 65521; $s2 %= 65521; } - $adler = ($s2 << 16) | $s1; - $adler_hash = pack('C4', $adler & 255, ($adler >> 8) & 255, ($adler >> 16) & 255, ($adler >> 24) & 255); + $adler_hash = pack('N', ($s2 << 16) | $s1); } // This is the same thing as gzcompress($raw_image, 0) but does not need zlib - $raw_image = pack('C7', 0x78, 0x01, 0x01, $length, ($length >> 8) & 255, ~$length & 255, ~($length >> 8)) . $raw_image . strrev($adler_hash); + $raw_image = pack('C3v2', 0x78, 0x01, 0x01, $length, ~$length) . $raw_image . $adler_hash; // The Zlib header + Adler hash make us add on 11 $length += 11; |