NPPS3 example login/authkey

authkey.php

<?php
// login/authkey
return new class implements NPPS\ActionHandler
{
	private $NPPSDB = NULL;
	function __construct()
	{
		$NPPSDB = NPPS\GetMainDatabase();
	}
	function __destruct() {}
	
	public function Permissions(): int
	{
		return
			NPPS_ACCESSLEVEL_UNAUTHENTICATED |	// Anyone can access this, even without token
			NPPS_PERMISSION_NOMULTI |			// This module can't be accessed under /api
			NPPS_PERMISSION_NOXMC;				// X-Message-Code header is not needed for this
	}
	public function Parameters(): array
	{
		// Check if new authentication method is on (v4.3+)
		if(NPPS\GetConfig('NEW_AUTHENTICATION'))
			return [
				'dummy_token' => NPPS_DATATYPE_STRING,	// dummy_token must be string
				'auth_data' => NPPS_DATATYPE_STRING		// auth_data must be string
			];
		else
			return [];	// No arguments
	}
	public function Execute(array $RequestData): NPPS\ActionHandlerResult
	{
		if(NPPS\GetConfig('NEW_AUTHENTICATION'))
		{
			// New-style authentication
			if(strlen($RequestData['auth_data']) >= 24 && strlen($RequestData['dummy_token']) == 44)
			{
				$ClientKey = NULL;
				// Decrypt client dummy_token
				if(!openssl_private_decrypt(base64_decode($RequestData['dummy_token']), &$ClientKey, NPPS\Authentication\GetRSAPrivateKey()));
					return new NPPS\ActionInvalidArgument('Failed to decrypt client key');	// "new" keyword is optional
				
				// Actually we don't need auth_data, so just ignore it.
				
				$ServerKey = random_bytes(32);		// Generate random server key
				$Token = NPPS\Token\Generate();		// Generate token
				$NPPSDB->query('INSERT INTO `logged_in` (token, xmc_key) VALUES (?, ?)', 'sb',
					$Token,
					$ServerKey ^ $ClientKey			// XOR it on-the-fly
				);
				
				// Return
				return new NPPS\ActionResponse([
					'authorize_token' => $Token,
					'dummy_token' => base64_encode($ServerKey)
				]);
			}
			else
				return new NPPS\ActionInvalidArgument('Invalid dummy_token or auth_data');
		}
		else
		{
			// Old-stype authentication
			$Token = NPPS\Token\Generate();		// Generate token
			$NPPSDB->query('INSERT INTO `logged_in` (token) VALUES (?)', 'sb', $Token);
			
			// Return
			return new NPPS\ActionResponse([
				'authorize_token' => $Token
			]);
		}
	}
};