- pack: documentation ( source)
<?php
//echo openssl_cipher_iv_length('aes-256-gcm');
//echo $key = openssl_random_pseudo_bytes(16);
$secret="This is a secret message.";
$key=pack("H*", "d8b163deda806acaede2f807");
//echo $iv=openssl_random_pseudo_bytes(12);
$iv = "0e42519c0eda67c22c52b605ff41fde395880ebf6ed40a560b5f5ecc8183d26a";
$method="aes-256-gcm";
$encrypted = "95b52983e7dfb2bac4cc11ed84644656dc6266674d58edb1750dfb8e2adf13c7";
//$encrypted=openssl_encrypt($secret,$method,$key,false,$iv);
$decrypted=openssl_decrypt($encrypted,$method,$key,false,$iv);
echo $encrypted;
echo "<br>";
echo $decrypted;