   #PHP Manual Mcrypt Encryption Functions mcrypt_ofb MCVE Payment
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   ______________________________________________________________________

                               mdecrypt_generic

   (PHP 4 >= 4.0.2)
   mdecrypt_generic -- Decrypt data

Description

   string mdecrypt_generic ( resource td, string data)

   This function decrypts data. Note that the length of the returned
   string can in fact be longer then the unencrypted string, due to the
   padding of the data.

   Example 1. mdecrypt_generic() example
   <?php
       /* Data */
       $key = 'this is a very long key, even too long for the cipher';
       $plain_text = 'very important data';

       /* Open module, and create IV */
       $td = mcrypt_module_open('des', '', 'ecb', '');
       $key = substr($key, 0, mcrypt_enc_get_key_size($td));
       $iv_size = mcrypt_enc_get_iv_size($td);
       $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
       /* Initialize encryption handle */
       if (mcrypt_generic_init($td, $key, $iv) != -1) {
           /* Encrypt data */
           $c_t = mcrypt_generic($td, $plain_text);
           mcrypt_generic_deinit($td);
           /* Reinitialize buffers for decryption */
           mcrypt_generic_init($td, $key, $iv);
           $p_t = mdecrypt_generic($td, $c_t);
           /* Clean up */
           mcrypt_generic_deinit($td);
           mcrypt_module_close($td);
       }
       if (strncmp($p_t, $plain_text, strlen($plain_text)) == 0) {
           echo "ok\n";
       } else {
           echo "error\n";
       }
   ?>

   The above example shows how to check if the data before the encryption
   is the same as the data after the decryption. It is very important to
   reinitialize the encryption buffer with mcrypt_generic_init() before
   you try to decrypt the data.

   The decryption handle should always be initialized with
   mcrypt_generic_init() with a key and an IV before calling this
   function. Where the encryption is done, you should free the encryption
   buffers by calling mcrypt_generic_deinit(). See mcrypt_module_open()
   for an example.

   See also mcrypt_generic(), mcrypt_generic_init(), and
   mcrypt_generic_deinit().
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