WMMEGA FW >= 2.1147 WM-M2 FW >= 3.1147

Decrypt AES-encrypted data in string

Decrypts the string $data with length $length bytes. Pass the encryption key and iv value in the corresponding fields.

$data: AES-encrypted string - it should be a multiple of 16 bytes long

$length: length of encrypted string

$key: Encryption key - this should be multiples of 16 bytes long. A 16 character string will yield 128-bit encryption.

$iv: This should be a unique 16 character string which will be used for the iv table

Decrypted string (or int 0 for error)

<pre><? 
 
// create your custom key and IV value
 
  $key="0123456789abcdef";  // this is 16 bytes, or 128 bits
  $iv="abcdef0123456789";   // this needs to be 16 bytes long
 
 
  $data="This is my super secret encrypted string";
 
  // round up the string length to the nearest multiple of 16
 
  $len=intval((strlen($data)+1)/16)*16;
 
  // encrypt the data  
 
  $encrypted_data = aes_encrypt($data,$len,$key,$iv);
 
  // store encrypted data into a base64-encoded string for easy tranport
 
  $base64_encrypted = base64_encode($encrypted_data);
 
  print("Your encrypted data is: ".$base64_encrypted);
 
  // this will yield: 
  // fcPkxhW0UM4VIYB1CsbK/7wEBuC4WAwcO5tDBkcMXbfmf/gOHqdnrz5qHBRVY8Ls
 
 
  // base64 decode the string again
 
  $base64_decrypted = base64_decode($base64_encrypted);
 
  // we will calculated the length from the base64 string rather than the encrypted 
  // one as the strlen() function may not yield a valid result if the encrypted string 
  // has a zero in it.  As base64 is 6 bits and our data is 8, we just need to multiply 
  // the the length by 6/8 or 0.75 to get the base64-decoded size.
 
  $len = intval(strlen($base64_encrypted) * 0.75);
 
  // decryption  routine
 
  $plain_data = aes_decrypt(&$base64_decrypted,$len,$key,$iv);
 
  print("\r\nYour decrypted data is: ".$plain_data);
 
?>

The above example will output something similar to:

Your encrypted data is: fcPkxhW0UM4VIYB1CsbK/7wEBuC4WAwcO5tDBkcMXbckp5yUp4a92BeD7VpVGwd1
Your decrypted data is: This is my super secret encrypted string 

aes_encrypt() - Encrypt data using the AES algorithm