How to implement Crypt::encrypt method manually in PHP? - php

Question

I try to implement Crypt::encrypt function in php and this code is here:
$key = "ygXa6pBJOWSAClY/J6SSVTjvJpMIiPAENiTMjBrcOGw=";
$iv = random_bytes(16);
$value = \openssl_encrypt(serialize('123456'), 'AES-256-CBC', $key, 0, $iv);
bIv = base64_encode($iv);
$mac = hash_hmac('sha256', $bIv.$value, $key);
$c = ['iv'=>$bIv,'value'=>$value,'mac'=>$mac];
$json = json_encode($c);
$b = base64_encode($json);
But result is wrong.
I am thinking i should do something on $key before set in openssl_encrypt function.
Please help.
Thank you.

Answer 1

SOLVED:
We can implement this method like this:
$text = '123456';
$key = "ygXa6pBJOWSAClY/CFEdOTjvJpMIiPAMQiTMjBrcOGw=";
$key = (string)base64_decode($key);
$iv = random_bytes(16);
$value = \openssl_encrypt(serialize($text), 'AES-256-CBC', $key, 0, $iv);
$bIv = base64_encode($iv);
$mac = hash_hmac('sha256', $bIv.$value, $key);
$c_arr = ['iv'=>$bIv,'value'=>$value,'mac'=>$mac];
$json = json_encode($c_arr);
$crypted = base64_encode($json);
echo $crypted;
This work tor me.
enjoy :)
Be Successful

Answer 2

Here is the implementation, directly from the official source code.
public function encrypt($value)
{
$iv = random_bytes(16);
$value = \openssl_encrypt(serialize($value), $this->cipher, $this->key, 0, $iv);
if ($value === false) {
throw new EncryptException('Could not encrypt the data.');
}
// Once we have the encrypted value we will go ahead base64_encode the input
// vector and create the MAC for the encrypted value so we can verify its
// authenticity. Then, we'll JSON encode the data in a "payload" array.
$mac = $this->hash($iv = base64_encode($iv), $value);
$json = json_encode(compact('iv', 'value', 'mac'));
if (! is_string($json)) {
throw new EncryptException('Could not encrypt the data.');
}
return base64_encode($json);
}
$iv should be the same as in the source
$this->key is the encryption key you set in your .env file, encoded in b64
$this->cipher should be the one you configured in your laravel configurations and compatible to your key-length.
In your example, you have set your $key to the value after the "base64:"-string, which is not the key. You need to encode the key with base64 before passing it.
So the the $key to the base64 encode of ygXa6pBJOWSAClY/J6SSVTjvJpMIiPAENiTMjBrcOGw=, which is eWdYYTZwQkpPV1NBQ2xZL0o2U1NWVGp2SnBNSWlQQUVOaVRNakJyY09Hdz0K