ladill-transfer/app/Http/Middleware/AuthenticateService.php

<?php

namespace App\Http\Middleware;

use Closure;
use Illuminate\Http\Request;
use Symfony\Component\HttpFoundation\Response;

/**
 * Service-to-service auth for internal APIs. Validates the bearer token against
 * per-consumer keys in config("{namespace}.service_api_keys").
 */
class AuthenticateService
{
    public function handle(Request $request, Closure $next, string $namespace = 'transfer'): Response
    {
        $token = (string) $request->bearerToken();
        $caller = null;

        if ($token !== '') {
            foreach ((array) config("{$namespace}.service_api_keys", []) as $name => $key) {
                if (is_string($key) && $key !== '' && hash_equals($key, $token)) {
                    $caller = $name;
                    break;
                }
            }
        }

        if ($caller === null) {
            return response()->json(['error' => 'Unauthorized.'], 401);
        }

        $request->attributes->set('service_caller', $caller);

        return $next($request);
    }
}