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Encryption class wrapper

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Encryption class wrapper for Blowfish. Can be adapted to other encryption algorithms.

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  1. <?php
  2. /*
  3.  * This class encapsulates Blowfish encryption and decryption.
  4.  */ 
  5. class Encrypter{
  6.    protected $key;
  7.    protected $iv;
  8.  
  9.    function __construct($iv=null, $key=null){
  10.       $this->iv = $iv;
  11.       $this->key = $key;
  12.    }
  13.  
  14.    /**
  15.     * Encrypts data
  16.     * Returns binary data.    
  17.     */       
  18.    function encrypt($data){
  19.       $len = strlen($data);
  20.       $enc = mcrypt_encrypt( MCRYPT_BLOWFISH, $this->key, $data, MCRYPT_MODE_CBC, $this->iv );
  21.       return $enc;
  22.    }
  23.  
  24.    /**
  25.     * Encrypts data and convert to hex. 
  26.     * Ideal for storing as text.   
  27.     */       
  28.    function encryptToHex($data){
  29.       return $this->bin2hex($this->encrypt($data));
  30.    }
  31.  
  32.    /**
  33.     * Takes hex input, convert from hex to binary then decrypt.
  34.     */       
  35.    function decryptFromHex($data){
  36.       //echo "hex \"$data\"\n";
  37.       return $this->decrypt($this->hex2bin($data));
  38.    }
  39.  
  40.    /**
  41.     *
  42.     */       
  43.    function decrypt($data){
  44.       $decode = mcrypt_decrypt( MCRYPT_BLOWFISH, $this->key, $data, MCRYPT_MODE_CBC, $this->iv );
  45.       //echo "decode \"$decode\"\n";
  46.       $realdata = rtrim($decode, "\0");
  47.  
  48.       //echo sprintf("[%s]\n", $realdata);
  49.       return $realdata;
  50.    }
  51.  
  52.    /**
  53.     * Convert from binary to hex
  54.     */       
  55.    function bin2hex($s){
  56.       return bin2hex($s);
  57.    }
  58.  
  59.    /**
  60.     * Convert from hex to binary
  61.     */       
  62.    function hex2bin($s){
  63.       return pack("H*", $s);   
  64.    }
  65.  
  66.    /**
  67.     * loads key and iv from a file.
  68.     * Key is on line 1 in hex.
  69.     * IV is on line 2 in hex.        
  70.     */       
  71.    function loadKeysFromFile($filename){
  72.       return $this->loadKeysFromString(file_get_contents($filename));
  73.    }
  74.  
  75.    /**
  76.     * String is the key and the iv separates by a newline.
  77.     * Use this when storing the key in a file.
  78.     * Line 1 would be the key, line 2 is the iv.        
  79.     */       
  80.    function loadKeysFromString($string){
  81.       $keys = explode("\n", $string);
  82.       $key = $keys[0];
  83.       $iv = pack("H*", $keys[1]);
  84.       $this->key = $key;
  85.       $this->iv = $iv;
  86.       return array($key, $iv);
  87.    }
  88.  
  89.    function showKeys(){
  90.       return sprintf("%s %s", $this->key, $this->bin2hex($this->iv));
  91.    }
  92. }
  93.  
  94. --- put the following 2 lines in a file names 'keys' to get the demo to work ---
  95. 4987bf894deh898efae46384efffeabcc387da8d7e8af893783745d1
  96. 4fecabab1234bcbc
  97. ----- end keys ------
  98.  
  99. <?php
  100. require_once 'Encrypter.php';
  101. class MyApp {
  102.  
  103.  
  104. 	public function run() {
  105. 		$e = new Encrypter;
  106. 		$e->loadKeysFromFile('keys');
  107.  
  108. 		echo $e->showKeys() . "\n";
  109. 		$hex = $e->encryptToHex("4646123412341234");
  110. 		print $hex . "\n";
  111. 		print $e->decryptFromHex($hex) . "\n";
  112. 	}
  113. }
  114. $app = new MyApp;
  115. $app->run();

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