PHP GnuPG Extension Not Working with Nginx, Fails to add PGP Key

Question

I'm trying to use the PHP GnuPG extension to perform PGP encryption in my PHP script. The script works as expected when running with the built-in test server (php -S), but it fails to import a PGP public key when served through Nginx. I'm encountering the "Error importing public key" issue.

Here's an overview of the situation:

PHP Version: 8.1.24 Nginx Version: nginx/1.18.0 (Ubuntu)

putenv("GNUPGHOME=/tmp");

$pubkey = "-----BEGIN PGP PUBLIC KEY BLOCK-----
Version: GnuPG v1.2.6 (GNU/Linux)
[KEY HERE]
-----END PGP PUBLIC KEY BLOCK-----";

$enc = (null);
$res = gnupg_init();
var_dump($res);
$rtv = gnupg_import($res, $pubkey);
$rtv = gnupg_addencryptkey($res, "C25F29936D9046D73A77DCF8244F423AED8F1481");
var_dump($rtv);
$enc = gnupg_encrypt($res, "just a test to see if anything works");
var_dump($enc);
echo "Encrypted Data: " . $enc . "<br/>";

I tested the script with nginx and the php test server. While using the php server I get a output like this:

resource(2) of type (ctx) 

array(9) { ["imported"]=> int(0) ["unchanged"]=> int(1) ["newuserids"]=> int(0) 
["newsubkeys"]=> int(0) 
["secretimported"]=> int(0) 
["secretunchanged"]=> int(0) 
["newsignatures"]=> int(0) 
["skippedkeys"]=> int(0) 
["fingerprint"]=> string(40) "C25F29936D9046D73A77DCF8244F423AED8F1481" 
} 

bool(true) 

Encrypted Data: -----BEGIN PGP MESSAGE----- [MESSAGE]-----END PGP MESSAGE-----

But with nginx the output is only:

resource(2) of type (ctx) 
array(9) { 
["imported"]=> int(0) 
["unchanged"]=> int(1) 
["newuserids"]=> int(0) 
["newsubkeys"]=> int(0) 
["secretimported"]=> int(0) 
["secretunchanged"]=> int(0) 
["newsignatures"]=> int(0) 
["skippedkeys"]=> int(0) 
["fingerprint"]=> string(40) "C25F29936D9046D73A77DCF8244F423AED8F1481" } 

bool(false) 

Encrypted Data:

I added the line extension = gnupg.so to these files:

/etc/php/8.1/cli/php.ini
/etc/php/8.1/fpm/php.ini

I also added a file to the conf.d folder called gnupg.ini

I've noticed that when I run phpinfo() on the test server, there's a PATH environment variable that includes GnuPG, but this variable is not present when running the same script through Nginx.

Any suggestions or insights would be greatly appreciated. Thank you!