Php Encryption/Decryption with Key issues

[jargen]

Hi,

 

Im using this code:

function encryptdata($data_input,$key){      

    $td = mcrypt_module_open('cast-256', '', 'ecb', ''); 
    $iv = mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND); 
    mcrypt_generic_init($td, $key, $iv); 
    $encrypted_data = mcrypt_generic($td, $data_input); 
    mcrypt_generic_deinit($td); 
    mcrypt_module_close($td); 
    $encoded_64=base64_encode($encrypted_data); 
    return $encoded_64; 
}    


function decryptdata($encoded_64,$key){ 
    $decoded_64=base64_decode($encoded_64); 
    $td = mcrypt_module_open('cast-256', '', 'ecb', ''); 
    $iv = mcrypt_create_iv (mcrypt_enc_get_iv_size($td), MCRYPT_RAND); 
    mcrypt_generic_init($td, $key, $iv); 
    $decrypted_data = mdecrypt_generic($td, $decoded_64); 
    mcrypt_generic_deinit($td); 
    mcrypt_module_close($td); 
    return $decrypted_data; 
} 

 

To try to encrypt and decrypt some data, However the decrypted password has the first 2 letters missing. Whatever length string i put in its always the first 2 letters that go missing. I have tried multiple pieces of code over the internet with the exact same problem.

 

Example: (Original Password, Encrypted Password, Decrypted Password)

BEBw3nJ9rT y3CdmtNeTmhO3Jrq/00YOA== Bw3nJ9rT

 

Any help?

Thanks.

 

P.s Yes i am using the same key for the encryption and decryption.

[scootstah]

You shouldn't be encrypting passwords.

[jargen]

You shouldn't be encrypting passwords.

 

That isnt the point.

[kicken]

Appears to work fine for me if I copy/paste to a test script.

 

define('ENCKEY', 'asdf');

$txt = 'kicken';
$enctxt = encryptdata($txt, ENCKEY);
$out = decryptdata($enctxt, ENCKEY);
var_dump($txt, $enctxt, $out);

/*

string(6) "kicken"
string(24) "k9+Jryul9CZ3Bi9GvnwEaw=="
string(16) "kicken"

*/

 

Sure there isn't a small bug in your test code somewhere?

 

edit:

 

Just noticed the output is string(16) as it's padded with NUL bytes.  A quick rtrim solved that.

[jargen]

The test code is

 

$password = generatepassword();
$passwordsafe = encryptdata($password,"dddsgsdfnhjkdgh");
$test = decryptdata($passwordsafe, "dddsgsdfnhjkdgh");
print($password."       ".$passwordsafe." ".$test);

 

So i dont understand what is happening