PHP Cryptography code explanation

Question

  public static function getEncryptedData($value){
       if(!$value){return false;}
       $text = $value;
       $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_ECB);
       $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
       $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, _PR_ACCOUNT_ACTIVATION_SECURE_KEY_, $text, MCRYPT_MODE_ECB, $iv);
       return trim(base64_encode($crypttext)); //encode for cookie
    }

I came across the above code in PHP.
I need to understand :
1. What is it doing?
2. How to do the same using Apache Shiro in Java?

What it is doing is partly insensible: it is generating an IV for a mode (ECB) that doesn't use IVs. — President James K. Polk, Jul 21 '12 at 14:12

score 1 · Answer 1 · answered Jul 20 '12 at 12:40

/*Sets the function with the ability to be called globally without instantiating the object. Take one value into method through classname::getEncryptedData($value)*/
public static function getEncryptedData($value){
   /*Checks to see  if value is populated and an erroneous value hasn't been passed in such as null returns false if it has*/
   if(!$value){return false;}
/* instantiated a local variable called text and populate it with the value $value*/
   $text = $value;
 /*as per the docs http://php.net/manual/en/function.mcrypt-get-iv-size.php gets the size of the iv and sets it in the var $iv_size*/
   $iv_size = mcrypt_get_iv_size(MCRYPT_RIJNDAEL_128, MCRYPT_MODE_ECB);
/*Creates an initialization vector as per http://uk3.php.net/manual/en/function.mcrypt-create-iv.php*/
   $iv = mcrypt_create_iv($iv_size, MCRYPT_RAND);
/*Encrypt the data $text(from $value passed it) and store it in $crypttext */
   $crypttext = mcrypt_encrypt(MCRYPT_RIJNDAEL_128, _PR_ACCOUNT_ACTIVATION_SECURE_KEY_, $text, MCRYPT_MODE_ECB, $iv);
/*return a base64 encoded string with the whitespace trimmed from front and back*/
   return trim(base64_encode($crypttext)); //encode for cookie
}

as for how to do it in java I dunno :-(

Downvoted for what? Anon downvoting is the worst SO feature going, how can anything be improved if there is no explanation to why you are downvoting! — Nicholas King, Jul 23 '12 at 10:30

PHP Cryptography code explanation

1 Answers1