如何?將php的id加密的問題

這篇文章給大家介紹的文章內容是關於如何?講php的id加密，有很好的參考價值，希望可以協助到有需要的朋友。

<?php/** * article url:http://kvz.io/blog/2009/06/10/create-short-ids-with-php-like-youtube-or-tinyurl/ * * Translates a number to a short alhanumeric version * * Translated any number up to 9007199254740992 * to a shorter version in letters e.g.: * 9007199254740989 --> PpQXn7COf * * specifiying the second argument true, it will * translate back e.g.: * PpQXn7COf --> 9007199254740989 * * this function is based on any2dec && dec2any by * fragmer[at]mail[dot]ru * see: http://nl3.php.net/manual/en/function.base-convert.php#52450 * * If you want the alphaID to be at least 3 letter long, use the * $pad_up = 3 argument * * In most cases this is better than totally random ID generators * because this can easily avoid duplicate ID's. * For example if you correlate the alpha ID to an auto incrementing ID * in your database, you're done. * * The reverse is done because it makes it slightly more cryptic, * but it also makes it easier to spread lots of IDs in different * directories on your filesystem. Example: * $part1 = substr($alpha_id,0,1); * $part2 = substr($alpha_id,1,1); * $part3 = substr($alpha_id,2,strlen($alpha_id)); * $destindir = "/".$part1."/".$part2."/".$part3; * // by reversing, directories are more evenly spread out. The * // first 26 directories already occupy 26 main levels * * more info on limitation: * - http://blade.nagaokaut.ac.jp/cgi-bin/scat.rb/ruby/ruby-talk/165372 * * if you really need this for bigger numbers you probably have to look * at things like: http://theserverpages.com/php/manual/en/ref.bc.php * or: http://theserverpages.com/php/manual/en/ref.gmp.php * but I haven't really dugg into this. If you have more info on those * matters feel free to leave a comment. * * The following code block can be utilized by PEAR's Testing_DocTest * <code> * // Input // * $number_in = 2188847690240; * $alpha_in  = "SpQXn7Cb"; * * // Execute // * $alpha_out  = alphaID($number_in, false, 8); * $number_out = alphaID($alpha_in, true, 8); * * if ($number_in != $number_out) { * echo "Conversion failure, ".$alpha_in." returns ".$number_out." instead of the "; * echo "desired: ".$number_in."\n"; * } * if ($alpha_in != $alpha_out) { * echo "Conversion failure, ".$number_in." returns ".$alpha_out." instead of the "; * echo "desired: ".$alpha_in."\n"; * } * * // Show // * echo $number_out." => ".$alpha_out."\n"; * echo $alpha_in." => ".$number_out."\n"; * echo alphaID(238328, false)." => ".alphaID(alphaID(238328, false), true)."\n"; * * // expects: * // 2188847690240 => SpQXn7Cb * // SpQXn7Cb => 2188847690240 * // aaab => 238328 * * </code> * * @authorKevin van Zonneveld <kevin@vanzonneveld.net> * @authorSimon Franz * @authorDeadfish * @author  SK83RJOSH * @copyright 2008 Kevin van Zonneveld (http://kevin.vanzonneveld.net) * @license   http://www.opensource.org/licenses/bsd-license.php New BSD Licence * @version   SVN: Release: $Id: alphaID.inc.php 344 2009-06-10 17:43:59Z kevin $ * @link  http://kevin.vanzonneveld.net/ * * @param mixed   $in  String or long input to translate * @param boolean $to_num  Reverses translation when true * @param mixed   $pad_up  Number or boolean padds the result up to a specified length * @param string  $pass_key Supplying a password makes it harder to calculate the original ID * * @return mixed string or long */function alphaID($in, $to_num = false, $pad_up = false, $pass_key = null){$out   =   '';$index = 'abcdefghijklmnopqrstuvwxyz0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ';$base  = strlen($index);   if ($pass_key !== null) {// Although this function's purpose is to just make the// ID short - and not so much secure,// with this patch by Simon Franz (http://blog.snaky.org/)// you can optionally supply a password to make it harder// to calculate the corresponding numeric ID   for ($n = 0; $n < strlen($index); $n++) {$i[] = substr($index, $n, 1);}   $pass_hash = hash('sha256',$pass_key);$pass_hash = (strlen($pass_hash) < strlen($index) ? hash('sha512', $pass_key) : $pass_hash);   for ($n = 0; $n < strlen($index); $n++) {$p[] =  substr($pass_hash, $n, 1);}   array_multisort($p, SORT_DESC, $i);$index = implode($i);}   if ($to_num) {// Digital number  <<--  alphabet letter code$len = strlen($in) - 1;   for ($t = $len; $t >= 0; $t--) {$bcp = bcpow($base, $len - $t);$out = $out + strpos($index, substr($in, $t, 1)) * $bcp;}   if (is_numeric($pad_up)) {$pad_up--;   if ($pad_up > 0) {$out -= pow($base, $pad_up);}}} else {// Digital number  -->>  alphabet letter codeif (is_numeric($pad_up)) {$pad_up--;   if ($pad_up > 0) {$in += pow($base, $pad_up);}}   for ($t = ($in != 0 ? floor(log($in, $base)) : 0); $t >= 0; $t--) {$bcp = bcpow($base, $t);$a   = floor($in / $bcp) % $base;$out = $out . substr($index, $a, 1);$in  = $in - ($a * $bcp);}}   return $out;}