Spent quite a bit of time pondering this as I am unable to get the desired output similar to the PHP function that im trying to duplicate:

plaintext = ["<foo>","'bar'","\"baz\"","&blong&"] |> Jason.encode!
key = "secreted"
iv = "PlayerAZ"
:crypto.crypto_one_time(:des_cbc, key, iv, plaintext, [{:encrypt, :true},{:padding, :pkcs_padding}] ) |> Base.encode64

PHP:

<?php
        $plaintext = json_encode(array('<foo>',"'bar'",'"baz"','&blong&'));
        $key = 'secreted';
        $vector = 'PlayerAZ';
        $encryptedString = openssl_encrypt($plaintext, 'des-cbc', $key, OPENSSL_RAW_DATA, $vector);
        echo 'Encrypted: '.$encryptedString."\n";
        echo ''.$plaintext."\n";
        
        $encryptedStringBase64 = base64_encode($encryptedString);
        echo 'Encrypted + base 64:'.$encryptedStringBase64."\n";

        echo 'Decrypted:'.openssl_decrypt(base64_decode($encryptedStringBase64),'des-cbc',  $key, OPENSSL_RAW_DATA, $vector)."\n";

Sandbox: https://wtools.io/php-sandbox/b8Xw
In both cases: the output is the same for both: “rQnm2tysllww+bZLSwOa9UQUc0EEH3sNlu84k5o33VgbmbnHnIZx0g==”

The problem when i change the plaintext variable to include unicode character, “\xc3\xa9” as follows:
array(‘’,“‘bar’”,‘“baz”’,‘&blong&’, “\xc3\xa9” (PHP)
[“”,“‘bar’”,“"baz"”,“&blong&”,“\xc3\xa9”] (Elixir)

Both function outputs diverge and no longer agree.

May I know what am i doing wrong? Thanks.