在课程修复中需要'openssl_encrypt'

Question

This is a simple class with decrypt and encrypt, the code below doesn't work, how can I fix it?

class en{
    const cipher  = "aes-128-gcm";
    const key = "sitekey";

    function iv(){
        return openssl_random_pseudo_bytes(openssl_cipher_iv_length(self::cipher));
    }
    function encrypt($text,$iv){
        return openssl_encrypt($text, self::cipher, self::key, $options=0, $iv, $tag);
    }
    function decrypt($text,$iv){
        return openssl_decrypt($text, self::cipher, self::key, $options=0, $iv, $tag);
    }
}
$en = new en();

$iv = $en->iv();
$encrypted = $en->encrypt("message to be encrypted",$iv);
$decrypted = $en->decrypt($encrypted,$iv);
echo "iv: ".$iv."<br />";
echo "Encrypted: ".$encrypted."<br />";
echo "Decrypted: ".$decrypted."<br />";

Answer 1

When using the openssl_encrypt and openssl_decrypt functions, you have the $tag variable which you pass as a parameter. But $tag isn't declared anywhere.

If you remove the 2 references to $tag and change the encryption method to be

aes-128-cbc

The code works.