pixelfed/app/Observer/UserObserver.php

<?php

namespace App\Observers;

use App\{Profile, User};
use App\Jobs\AvatarPipeline\CreateAvatar;

class UserObserver
{
    /**
     * Listen to the User created event.
     *
     * @param  \App\User  $user
     * @return void
     */
    public function saved(User $user)
    {
        if(empty($user->profile)) {
            $profile = new Profile;
            $profile->user_id = $user->id;
            $profile->username = $user->username;
            $profile->name = $user->name;
            $pkiConfig = [
                "digest_alg" => "sha512",
                "private_key_bits" => 2048,
                "private_key_type" => OPENSSL_KEYTYPE_RSA,
            ];
            $pki = openssl_pkey_new($pkiConfig);
            openssl_pkey_export($pki, $pki_private);
            $pki_public = openssl_pkey_get_details($pki);
            $pki_public = $pki_public['key'];

            $profile->private_key = $pki_private;
            $profile->public_key = $pki_public;
            $profile->save();

            CreateAvatar::dispatch($profile);
        }
    }

}