PHP string Encryption enhanced version

This article introduces the content is about the PHP string encryption enhanced version, has a certain reference value, now share to everyone, the need for friends can refer to

• To increase the security of your data

• Avoid multiple encryption of the same character to get a consistent result

• You can set the ciphertext validity period

A custom encryption method is listed below.

How to use

Put Mcrypt.class.php into the class file in your project and then introduce it in a require way where you need it, if more references are required than the parent controller can reference:

Encryption method: Mcrypt::encode ($STR, $n);

Decryption method: Mcrypt::d ecode ($STR, $n);

• $Str must need to decrypt the string

• $n non-essential ciphertext validity period, unit s,0 for permanent effect,

  Require ("Mcrypt.class.php"); $code = Mcrypt::encode (' Sajkfcasjcla ', ' 7580 '); echo "code-". $code; $code _ans = Mcrypt:: Decode ("$code", ' 7580 '); echo "answer-". $code _ans;

Mcrypt.class.php

/** string and decryption class; * Once a secret, and time decryption valid * can be used for encryption & dynamic key generation */class mcrypt{public $default _key = ' a!taka:dlmcldev,e ';/** * character encryption, one secret at a time, can be Timed decryption Valid * @param string $string original * @param string $key key * @param int $expiry ciphertext validity, unit s,0 is permanently valid * @return String encrypted content * *    public static function Encode ($string, $key = ", $expiry = 0) {$ckeyLength = 4; $key = MD5 ($key? $key: $this->default_key);         Decryption Key $keya = MD5 (substr ($key, 0, 16));         Do data integrity Verification $KEYB = MD5 (substr ($key, 16, 16));    Ciphertext for change generation (initialization vector iv) $KEYC = SUBSTR (MD5 (Microtime ()),-$ckeyLength); $cryptkey = $keya.      MD5 ($keya. $KEYC);    $keyLength = strlen ($cryptkey); $string = sprintf ('%010d ', $expiry? $expiry + Time (): 0). substr (MD5 ($string. $keyb), 0, 16).    $string;     $stringLength = strlen ($string);         $rndkey = Array ();    for ($i = 0; $i <= 255; $i + +) {$rndkey [$i] = Ord ($cryptkey [$i% $keyLength]);        } $box = Range (0, 255); Scramble the key book to add randomness for ($j = $i = 0; $i <; $i ++) {$j = ($j + $box [$i] + $rndkey [$i])% 256;        $tmp = $box [$i];        $box [$i] = $box [$j];     $box [$j] = $tmp;     }//Add decryption, from the key book to obtain the key to the XOR, and then into a character $result = ';        for ($a = $j = $i = 0; $i < $stringLength; $i + +) {$a = ($a + 1)% 256;        $j = ($j + $box [$a])% 256;        $tmp = $box [$a];        $box [$a] = $box [$j];         $box [$j] = $tmp;      $result. = Chr (ord ($string [$i]) ^ ($box [($box [$a] + $box [$j])% 256])); } $result = $keyc.     Str_replace (' = ', ' ', Base64_encode ($result));     $result = str_replace (Array (' + ', '/', ' = '), array ('-', ' _ ', '. '), $result); return $result; }/** * Character decryption, one secret at a time, can be timed decryption valid * @param string $string ciphertext * @param string $key decryption key * @return string decrypted content */public static F       Unction decode ($string, $key = ') {$string = Str_replace (Array ('-', ' _ ', '. '), Array (' + ', '/', ' = '), $string);       $ckeyLength = 4; $key = MD5 ($key? $key: $this->default_key); Decryption Key $keya = MD5 (substr ($key, 0, 16));         Do data integrity Verification $KEYB = MD5 (substr ($key, 16, 16));       Ciphertext for change generation (initialization vector iv) $KEYC = substr ($string, 0, $ckeyLength); $cryptkey = $keya.         MD5 ($keya. $KEYC);       $keyLength = strlen ($cryptkey);       $string = Base64_decode (substr ($string, $ckeyLength));       $stringLength = strlen ($string);           $rndkey = Array ();        for ($i = 0; $i <= 255; $i + +) {$rndkey [$i] = Ord ($cryptkey [$i% $keyLength]);        } $box = Range (0, 255);              Scrambled key book to increase randomness for ($j = $i = 0; $i < $i + +) {$j = ($j + $box [$i] + $rndkey [$i])% 256;              $tmp = $box [$i];              $box [$i] = $box [$j];        $box [$j] = $tmp;       }//Add decryption, from the key book to obtain the key to the XOR, and then into a character $result = ';          for ($a = $j = $i = 0; $i < $stringLength; $i + +) {$a = ($a + 1)% 256;          $j = ($j + $box [$a])% 256;          $tmp = $box [$a];          $box [$a] = $box [$j];           $box [$j] = $tmp; $result . = Chr (ord ($string [$i]) ^ ($box [($box [$a] + $box [$j]) (% 256])); if (substr ($result, 0, ten) = = 0 | | substr ($result, 0,)-time () > 0) && substr ($result, 10, 16      ) = = substr (MD5 ($result, 0)) {return substr ($result, 26);      } else {return '; }    }}