<?php

namespace Zotlabs\Module;

use Zotlabs\Web\HTTPSig;
use Zotlabs\Lib\Verify;
use Zotlabs\Web\Controller;

/**
 * OpenWebAuth verifier and token generator
 * See spec/OpenWebAuth/Home.md
 * Requests to this endpoint should be signed using HTTP Signatures
 * using the 'Authorization: Signature' authentication method
 * If the signature verifies a token is returned.
 *
 * This token may be exchanged for an authenticated cookie.
 */

class Owa extends Controller {

	function init() {

		$ret = [ 'success' => false ];

		if (array_key_exists('REDIRECT_REMOTE_USER',$_SERVER) && (! array_key_exists('HTTP_AUTHORIZATION',$_SERVER))) {
			$_SERVER['HTTP_AUTHORIZATION'] = $_SERVER['REDIRECT_REMOTE_USER'];
		}

		if (array_key_exists('HTTP_AUTHORIZATION',$_SERVER) && substr(trim($_SERVER['HTTP_AUTHORIZATION']),0,9) === 'Signature') {
			$sigblock = HTTPSig::parse_sigheader($_SERVER['HTTP_AUTHORIZATION']);
			if ($sigblock) {
				$keyId = $sigblock['keyId'];
				if ($keyId) {
					$r = q("SELECT * FROM hubloc LEFT JOIN xchan ON hubloc_hash = xchan_hash
						WHERE hubloc_id_url = '%s'",
						dbesc($keyId)
					);
					if (! $r) {
						$found = discover_by_webbie(str_replace('acct:','',$keyId));
						if ($found) {
							$r = q("SELECT * FROM hubloc LEFT JOIN xchan ON hubloc_hash = xchan_hash
								WHERE hubloc_id_url = '%s'",
								dbesc($keyId)
							);
						}
					}
					if ($r) {
						foreach ($r as $hubloc) {
							$verified = HTTPSig::verify(file_get_contents('php://input'), $hubloc['xchan_pubkey']);
							if ($verified && $verified['header_signed'] && $verified['header_valid'] && ($verified['content_valid'] || (! $verified['content_signed']))) {
								logger('OWA header: ' . print_r($verified,true),LOGGER_DATA);
								logger('OWA success: ' . $hubloc['hubloc_id_url'],LOGGER_DATA);
								$ret['success'] = true;
								$token = random_string(32);
								Verify::create('owt',0,$token,$hubloc['hubloc_id_url']);
								$result = '';
								openssl_public_encrypt($token,$result,$hubloc['xchan_pubkey']);
								$ret['encrypted_token'] = base64url_encode($result);
								break;
							} else {
								logger('OWA fail: ' . $hubloc['hubloc_id'] . ' ' . $hubloc['hubloc_id_url']);
							}
						}
					}
				}
			}
		}
		json_return_and_die($ret,'application/x-zot+json');
	}
}