Encyption with blowfish without plus sign

Question

I want to pass an encrypted string as url parameter, below is my php script

$passphrase = "testte@t";
$cipher = "blowfish";
$id = "20220228-12";
$enc_str = openssl_encrypt($id, $cipher, $passphrase);
$url = "https://example.com/?p={$enc_str}";

finally the $url is encrypted as

https://example.com/?p=BNrdu+t/YVgefLcrCxmuug==

if I get the value of parameter using $_REQUEST['p'], the encryped string will be returned as BNrdu t/YVgefLcrCxmuug== which lost the char sign '+', how can I avoid the encrypted string with the char '+'? Should I change another cipher? Which one is the best?

Answer 1

$param = "BNrdu+t/YVgefLcrCxmuug==";

$encoded = urlencode($param);


echo "https://example.com/?p=$encoded";

will output https://example.com/?p=BNrdu%2Bt%2FYVgefLcrCxmuug%3D%3D.

Then when receiving data:

$param = urldecode($_GET["p"] ?? ""); // BNrdu+t/YVgefLcrCxmuug==