checking the sha1 of the file. ideal for download scripts making sure the file the user is downloading is not currupt
by checking the sha1 key
<?php
$filename = './Path/To/Your/File.zip';
if (file_exists($filename)) {
echo"i see the file";
} else {
echo "recheck the link file maybe broken";
}
$file = sha1_file('./Path/To/Your/File.zip');
echo"<br>is file hash valid?";
echo"hash = add the hash here<br>";
echo"hash of file :";
print($file);
?>
sha1_file
説明
string sha1_file ( string filename [, bool raw_output] )US Secure Hash Algorithm 1 を使用して filename の sha1 ハッシュを計算し、そのハッシュを 返します。ハッシュは 40 文字の 16 進数となります。
sha1_file
admin at cmsrevolution dot com
05-Aug-2006 12:02
05-Aug-2006 12:02
gubatron at gmail dot com
11-Feb-2006 12:02
11-Feb-2006 12:02
P2P programs like LimeWire utilize sha1 to identify files. However they do it in base32. Here's an utility class if you want to write a Gnutella client in PHP5
/**
Utility base32 SHA1 class for PHP5
Copyright (C) 2006 Karl Magdsick (original author for Python)
Angel Leon (ported to PHP5)
Lime Wire LLC
This program is free software; you can redistribute it and/or
modify it under the terms of the GNU General Public License
as published by the Free Software Foundation; either version 2
of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
*/
class SHA1 {
static $BASE32_ALPHABET = 'ABCDEFGHIJKLMNOPQRSTUVWXYZ234567';
/** Given a file it creates a magnetmix */
static function fileSHA1($file) {
$raw = sha1_file($file,true);
return SHA1::base32encode($raw);
} //fileSHA1
/** Takes raw input and converts it to base32 */
static function base32encode($input) {
$output = '';
$position = 0;
$storedData = 0;
$storedBitCount = 0;
$index = 0;
while ($index < strlen($input)) {
$storedData <<= 8;
$storedData += ord($input[$index]);
$storedBitCount += 8;
$index += 1;
//take as much data as possible out of storedData
while ($storedBitCount >= 5) {
$storedBitCount -= 5;
$output .= SHA1::$BASE32_ALPHABET[$storedData >> $storedBitCount];
$storedData &= ((1 << $storedBitCount) - 1);
}
} //while
//deal with leftover data
if ($storedBitCount > 0) {
$storedData <<= (5-$storedBitCount);
$output .= SHA1::$BASE32_ALPHABET[$storedData];
}
return $output;
} //base32encode
}