Re: [PHP] mcrypt and PHP to encrypt values to be passed to differend server

Hi,

Monday, December 29, 2003, 9:30:11 AM, you wrote:
MW> Hello!

MW> I'm trying to use mcrypt to encrypt some values (login and password) I have
MW> to pass from one website to another.


You will need to pass the $iv which kinda defeats the object of it, or
use a null one. Here is a class I use for this which also corrects the
string lengths as decryption will usually have a few /0 tacked on to
make it a block size:

class encrypt_class{
var $secret;
function encrypt_class(){
$this->secret = 'choose your own pass phrase here';
}
Function encode($id){
$eid = $iv = 0;
$len = strlen($id);
$id = $len.'-'.$id;
$td = mcrypt_module_open(MCRYPT_TripleDES, "", MCRYPT_MODE_ECB, "");
$key = substr($this->secret, 0, mcrypt_enc_get_key_size ($td));
$iv = pack("a".mcrypt_enc_get_iv_size($td),$iv);
mcrypt_generic_init ($td, $key, $iv);
$eid = base64_encode(mcrypt_generic ($td, $id));
mcrypt_generic_deinit($td);
return $eid;
}
Function decode($eid){
$id = $iv = 0;
$td = mcrypt_module_open (MCRYPT_TripleDES, "", MCRYPT_MODE_ECB, "");
$key = substr($this->secret, 0, mcrypt_enc_get_key_size ($td));
$iv = pack("a".mcrypt_enc_get_iv_size($td),$iv);
mcrypt_generic_init ($td, $key, $iv);
$id = mdecrypt_generic ($td, base64_decode($eid));
$len = strtok($id,'-');
$id = substr($id,(strlen($len)+1),$len);
mcrypt_generic_deinit($td);
return $id;
}
}
//usage
$password = 'password';
$name = 'me';

$mesage[0] = $password;
$message[1] = $name;

$serial = serialize($message);

$enc = new encrypt_class();
$enc_message = $enc->encode($serial);
//send message ....?enc_message=$enc_message

//next page
$enc = new encrypt_class();
$serial = $enc->decode($_GET['enc_message']);
$message = unserialize($serial);
print_r($message);

--
regards,
Tom