From Pascal to PHP

PHP
1

This is code from Pascal:

      x := Ord(s[i]) xor (Key shr 8);

Is it possible to write it in PHP?

2

It’s possible, yes. PHP’s bit shifting is arithmetic rather than logical which means you’ll need to do extra checking around your shr translation. If you provide the rest of the surrounding context of your code, there might be a neater way to get the result you want.

3

Thank you for the reply.

Here is the complete function:

function EncryptStr(const S :WideString; Key: Word): String;
var   i          :Integer;
      RStr       :RawByteString;
      RStrB      :TBytes Absolute RStr;
begin
  Result:= '';
  RStr:= UTF8Encode(S);
  for i := 0 to Length(RStr)-1 do begin
    RStrB[i] := RStrB[i] xor (Key shr 8);
    Key := (RStrB[i] + Key) * CKEY1 + CKEY2;
  end;
  for i := 0 to Length(RStr)-1 do begin
    Result:= Result + IntToHex(RStrB[i], 2);
  end;
end;

Taken from here: https://stackoverflow.com/questions/6798188/delphi-simple-string-encryption

4

But it is actually only this part I am trying to convert to php:

5

What is the real problem you are trying to solve by doing this?

6

Thanks for the reply.

What is the real problem you are trying to solve by doing this?

I need to write a Encryption-function in PHP, similar to the Pascal encryption-function.

7 
<?php

class Aes
{
    public $key ;

    public $iv = '1234567890123456';

    public function __construct()
    {
    	$this->key = '1234567890123456';
    }

    public  function decode($str)
    {
        return openssl_decrypt(base64_decode($str),"AES-128-CBC",$this->key,OPENSSL_RAW_DATA, $this->iv);
    }

    public  function encode($str)
    {
        return base64_encode(openssl_encrypt($str,"AES-128-CBC",$this->key,OPENSSL_RAW_DATA, $this->iv));
    }

}

$aes = new AES();
$encryptedMessage = $aes->encode('My Secret Message');

var_dump($encryptedMessage); // 4jZf0a8oV3Xa5e0TyI7EcLAI3FGstD9Hn6teGkzjFIQ=
var_dump($aes->decode($encryptedMessage));// My Secret Message
8

Libsodium Example (Php >= 7.2)
* Need to add extension=php_sodium.dll to php.ini

$msg = 'Secret message!';

$key   = random_bytes(SODIUM_CRYPTO_SECRETBOX_KEYBYTES);
$nonce = random_bytes(SODIUM_CRYPTO_SECRETBOX_NONCEBYTES); 

// Encrypt
$ciphertext = sodium_crypto_secretbox($msg, $nonce, $key);
// Decrypt
$plaintext = sodium_crypto_secretbox_open($ciphertext, $nonce, $key);

echo $plaintext === $msg ? 'Success' : 'Error';
9

Do you need it to encrypt using the same algorithm that the Pascal function does, so that it produces the same output for a given input? PHP has several encryption functions built into it, could you use one of those?

10

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