<?php

/*
 * Copyright (C) 2022 Lukas Buchs
 * license https://github.com/lbuchs/WebAuthn/blob/master/LICENSE MIT
 *
 * Server test script for WebAuthn library. Saves new registrations in session.
 *
 *            JAVASCRIPT            |          SERVER
 * ------------------------------------------------------------
 *
 *               REGISTRATION
 *
 *      window.fetch  ----------------->     getCreateArgs
 *                                                |
 *   navigator.credentials.create   <-------------'
 *           |
 *           '------------------------->     processCreate
 *                                                |
 *         alert ok or fail      <----------------'
 *
 * ------------------------------------------------------------
 *
 *              VALIDATION
 *
 *      window.fetch ------------------>      getGetArgs
 *                                                |
 *   navigator.credentials.get   <----------------'
 *           |
 *           '------------------------->      processGet
 *                                                |
 *         alert ok or fail      <----------------'
 *
 * ------------------------------------------------------------
 */

require_once './incs/WebAuthn/src/WebAuthn.php';


try {
    require_once("incs/constants.php");
    session_name(SESSION_NAME);
    session_start();
    require_once("incs/authHelper.php");
    require_once("incs/settings.php");
    $settings=readsettings();
    if($settings != "valid")
        $action = "setup";

    if($settings == "valid")
    {
        if(!$dbconn = db_verbinden($mysql_server, $mysql_user, $mysql_pw, $mysql_db))
            $err = error("Verbindung zur Datenbank fehlgeschlagen: ".htmlspecialchars(mysqli_connect_error()));
    }
    // read get argument and post body
    $fn = filter_input(INPUT_GET, 'fn');
    $requireResidentKey = false;
    $userVerification = false;
    $formats = [];
    $msg="";
    
    $formats[] = 'android-key';
            $formats[] = 'android-safetynet';
            $formats[] = 'apple';
            $formats[] = 'fido-u2f';
            $formats[] = 'none';
            $formats[] = 'packed';
            $formats[] = 'tpm';
    $userId = "E071229F004A4CDE";
    $userName = "SmartHomeWagner";
    $userDisplayName = "2025Bym0";

    $post = trim(file_get_contents('php://input'));
    if ($post) {
        $post = json_decode($post, null, 512, JSON_THROW_ON_ERROR);
    }

    $rpId = "wm.el-wa.org";
    if ($rpId === false) {
        throw new Exception('invalid relying party ID');
    }

    // cross-platform: true, if type internal is not allowed
    //                 false, if only internal is allowed
    //                 null, if internal and cross-platform is allowed
    $crossPlatformAttachment = null;

    // new Instance of the server library.
    // make sure that $rpId is the domain name.
    $WebAuthn = new lbuchs\WebAuthn\WebAuthn('WebAuthn Library', $rpId, $formats);
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/isrg-root-x2.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/solo.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/solokey_f1.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/solokey_r1.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/apple.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/yubico.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/hypersecu.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/globalSign.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/googleHardware.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/microsoftTpmCollection.pem');
    $WebAuthn->addRootCertificates('./restricted/WebAuthn/rootCertificates/mds');

    // ------------------------------------
    // request for create arguments
    // ------------------------------------

    // Passkeys anlegen darf nur ein angemeldeter Superadmin, der vorher in
    // sites/userkeys.php eine gültige Einmal-Freigabe (addKey) eingelöst hat.
    // Die Freigabe liegt in der Session und legt fest, für welchen Benutzer
    // der Schlüssel gilt - die id aus der URL zählt nicht.
    $passkeyFreigabe = null;
    if (isset($_SESSION["passkey_freigabe"]) && $_SESSION["passkey_freigabe"]["bis"] >= time()
        && ($_SESSION["login"] ?? "") == "valid"
        && ((int)substr($_SESSION["rights"] ?? "", RIGHTS_SUPERADMIN, 1) & RIGHTS_CHANGE)) {
        $passkeyFreigabe = $_SESSION["passkey_freigabe"];
    }
    if (($fn === 'getCreateArgs' || $fn === 'processCreate') && $passkeyFreigabe === null) {
        throw new Exception('Keine Berechtigung, Passkeys anzulegen.');
    }
    if ($fn === 'queryFidoMetaDataService'
        && !(($_SESSION["login"] ?? "") == "valid" && ((int)substr($_SESSION["rights"] ?? "", RIGHTS_SUPERADMIN, 1) & RIGHTS_CHANGE))) {
        throw new Exception('Keine Berechtigung.');
    }

    if ($fn === 'getCreateArgs') {
        $createArgs = $WebAuthn->getCreateArgs(\hex2bin($userId), $userName, $userDisplayName, 60*4, $requireResidentKey, $userVerification, $crossPlatformAttachment);

        header('Content-Type: application/json');
        print(json_encode($createArgs));

        // save challange to session. you have to deliver it to processGet later.
        $_SESSION['challenge'] = $WebAuthn->getChallenge();


    // ------------------------------------
    // request for get arguments
    // ------------------------------------

    } else if ($fn === 'getGetArgs') {
        $userId = db_wert($dbconn, "SELECT id FROM user WHERE nick = ?", array((string)filter_input(INPUT_GET, 'user')));
        if ($userId === false) {
            throw new Exception(mysqli_error($dbconn));
        }
        if ($userId === null) {
            throw new Exception('Username not found');
        }
    	$ids = [];
		$zeilen = db_zeilen($dbconn, "SELECT credentialId FROM passkeys WHERE userId = ?", array($userId));
		if ($zeilen === false) {
			throw new Exception(mysqli_error($dbconn));
		}
		foreach ($zeilen as $row) {
			$ids[] = base64_decode($row["credentialId"]);
		}
 
        if (count($ids) === 0) {
            throw new Exception('no registrations in session for userId ' . $userId);
        }

        $getArgs = $WebAuthn->getGetArgs($ids, 60*4, true, true, true, true, true, $userVerification);

        header('Content-Type: application/json');
        print(json_encode($getArgs));

        // save challange to session. you have to deliver it to processGet later.
        $_SESSION['challenge'] = $WebAuthn->getChallenge();


    // ------------------------------------
    // process create
    // ------------------------------------

    } else if ($fn === 'processCreate') {
		//$mysql = new mysqli($mysql_server,$mysql_user,$mysql_pass,$mysql_db);
        $clientDataJSON = !empty($post->clientDataJSON) ? base64_decode($post->clientDataJSON) : null;
        $attestationObject = !empty($post->attestationObject) ? base64_decode($post->attestationObject) : null;
        $challenge = $_SESSION['challenge'] ?? null;

        // processCreate returns data to be stored for future logins.
        // in this example we store it in the php session.
        // Normally you have to store the data in a database connected
        // with the username.
        $data = $WebAuthn->processCreate($clientDataJSON, $attestationObject, $challenge, $userVerification === 'required', true, false);

        // add user infos
        $data->userId = $userId;
        $data->userName = $userName;
        $data->userDisplayName = $userDisplayName;
        //set Null to 0
        $data->signatureCounter ??= 0;
        /*
        if (!isset($_SESSION['registrations']) || !array_key_exists('registrations', $_SESSION) || !is_array($_SESSION['registrations'])) {
            $_SESSION['registrations'] = [];
        }*/
    	if(!db_abfrage($dbconn, "INSERT INTO passkeys SET credentialId = ?, credentialPublicKey = ?, signatureCounter = ?, name = ?, userId = ?, lastAuth = NOW(), authKey = 0",
    			array(base64_encode($data->credentialId), base64_encode($data->credentialPublicKey), base64_encode($data->signatureCounter), (string)filter_input(INPUT_GET, 'name'), $passkeyFreigabe["user"]))){
			$msg = "Error:<br>".mysqli_error($dbconn)."<br />";
		}
		else{
			// Freigabe gilt für genau einen Schlüssel
			unset($_SESSION["passkey_freigabe"]);
        	if ($data->rootValid === false) {
	            $msg = 'registration ok, but certificate does not match any of the selected root ca. NO PROBLEM FOR THIS APP';
	        }
	       // $msg = "Data: ".json_last_error();//json_encode($data);//'registration success.';
		}
        /*
        $_SESSION['registrations'][] = $data;
*/
        $return = new stdClass();
        $return->success = true;
        $return->msg = $msg;

        header('Content-Type: application/json');
        print(json_encode($return));


    // ------------------------------------
    // proccess get
    // ------------------------------------

    } else if ($fn === 'processGet') {
        $clientDataJSON = !empty($post->clientDataJSON) ? base64_decode($post->clientDataJSON) : null;
        $authenticatorData = !empty($post->authenticatorData) ? base64_decode($post->authenticatorData) : null;
        $signature = !empty($post->signature) ? base64_decode($post->signature) : null;
        $userHandle = !empty($post->userHandle) ? base64_decode($post->userHandle) : null;
        $id = !empty($post->id) ? base64_decode($post->id) : null;
        $challenge = $_SESSION['challenge'] ?? '';
        $credentialPublicKey = null;

        // looking up correspondending public key of the credential id
        // you should also validate that only ids of the given user name
        // are taken for the login.
		$row = db_zeile($dbconn, "SELECT credentialPublicKey, userId, name FROM passkeys WHERE credentialId = ?", array(base64_encode((string)$id)));
		if ($row === false) {
			throw new Exception(mysqli_error($dbconn));
		}
        if ($row) {
            $userId = $row["userId"];
		    $credentialPublicKey = base64_decode($row["credentialPublicKey"]);
		    $reg = (object) ['userId' =>  base64_decode($row["userId"])];
            $username = $row["name"];
		} /*else {
	        if (isset($_SESSION['registrations']) && is_array($_SESSION['registrations'])) {
	            foreach ($_SESSION['registrations'] as $reg) {
	                if ($reg->credentialId === $id) {
	                    $credentialPublicKey = $reg->credentialPublicKey;
	                    break;
	                }
	            }
	        }
		}*/
        if ($credentialPublicKey === null) {
            throw new Exception('Public Key for credential ID not found!');
        }

        // if we have resident key, we have to verify that the userHandle is the provided userId at registration
        if ($requireResidentKey && $userHandle !== hex2bin($reg->userId)) {
            throw new \Exception('userId doesnt match (is ' . bin2hex($userHandle) . ' but expect ' . $reg->userId . ')');
        }

        // process the get request. throws WebAuthnException if it fails
        $WebAuthn->processGet($clientDataJSON, $authenticatorData, $signature, $credentialPublicKey, $challenge, null, $userVerification === 'required');


        $authKey = strval(random_int(0,99999999));
        db_abfrage($dbconn, "UPDATE passkeys SET authKey = ?, lastAuth = NOW() WHERE credentialId = ?", array($authKey, base64_encode($id)));
        // Gesperrte Benutzer bleiben gesperrt, auch mit gültigem Passkey
        $udata = db_zeile($dbconn, "SELECT * FROM user WHERE id = ? AND blocked = 0", array($userId));
		if(!$udata)
		{
			throw new Exception('Benutzer nicht gefunden oder gesperrt.');
		}
		else
		{
			session_regenerate_id(true);
			$_SESSION["login"] = "valid";
			$_SESSION["logedout"] = $udata["logedout"];
			$_SESSION["user"] = $udata["id"];
			$_SESSION["nick"] = $udata["nick"];
			$_SESSION["vname"] = $udata["vname"];
			$_SESSION["nname"] = $udata["nname"];
			$_SESSION["rights"] = $udata["rights"];
			$_SESSION["lastlogin"] = $udata["lastlogin"];
			$_SESSION["numlogins"] = $udata["numlogins"];
			$_SESSION["style"] = getUserSetting($dbconn,"style", $udata["id"]);
			if(!is_file("styles/".$_SESSION["style"]))
			{
				updateUserSetting($dbconn,"style", "default.css", $udata["id"]);
				$_SESSION["style"] = getUserSetting($dbconn,"style", $udata["id"]);
			}
			$_SESSION["zoom"] = getUserSetting($dbconn,"zoom", $_SESSION["user"], 1);
			$_SESSION["privateNotes"] = getUserSetting($dbconn,"privnotes", $_SESSION["user"], "");
			
			db_abfrage($dbconn, "UPDATE user SET wrongpw = 0, lastlogin = NOW(), numlogins = numlogins + 1, logedout = 0 WHERE id = ?", array($userId));
		}
        $return = new stdClass();
        $return->success = true;
        header('Content-Type: application/json');
        print(json_encode($return));

    // ------------------------------------
    // proccess clear registrations
    // ------------------------------------

    } else if ($fn === 'clearRegistrations') {
        $_SESSION['registrations'] = null;
        $_SESSION['challenge'] = null;

        $return = new stdClass();
        $return->success = true;
        $return->msg = 'all registrations deleted';

        header('Content-Type: application/json');
        print(json_encode($return));

    // ------------------------------------
    // display stored data as HTML
    // ------------------------------------

    } /*else if ($fn === 'getStoredDataHtml') {
        $html = '<!DOCTYPE html>' . "\n";
        $html .= '<html><head><style>tr:nth-child(even){background-color: #f2f2f2;}</style></head>';
        $html .= '<body style="font-family:sans-serif">';
        if (isset($_SESSION['registrations']) && is_array($_SESSION['registrations'])) {
            $html .= '<p>There are ' . count($_SESSION['registrations']) . ' registrations in this session:</p>';
            foreach ($_SESSION['registrations'] as $reg) {
                $html .= '<table style="border:1px solid black;margin:10px 0;">';
                foreach ($reg as $key => $value) {

                    if (is_bool($value)) {
                        $value = $value ? 'yes' : 'no';

                    } else if (is_null($value)) {
                        $value = 'null';

                    } else if (is_object($value)) {
                        $value = chunk_split(strval($value), 64);

                    } else if (is_string($value) && strlen($value) > 0 && htmlspecialchars($value, ENT_QUOTES) === '') {
                        $value = chunk_split(bin2hex($value), 64);
                    }
                    $html .= '<tr><td>' . htmlspecialchars($key) . '</td><td style="font-family:monospace;">' . nl2br(htmlspecialchars($value)) . '</td>';
                }
                $html .= '</table>';
            }
        } else {
            $html .= '<p>There are no registrations.</p>';
        }
        $html .= '</body></html>';

        header('Content-Type: text/html');
        print $html;

    // ------------------------------------
    // get root certs from FIDO Alliance Metadata Service
    // ------------------------------------

    } */else if ($fn === 'queryFidoMetaDataService') {

        $mdsFolder = './restricted/WebAuthn/rootCertificates/mds';
        $success = false;
        $msg = null;

        // fetch only 1x / 24h
        $lastFetch = \is_file($mdsFolder .  '/lastMdsFetch.txt') ? \strtotime(\file_get_contents($mdsFolder .  '/lastMdsFetch.txt')) : 0;
        if ($lastFetch + (3600*48) < \time()) {
            $cnt = $WebAuthn->queryFidoMetaDataService($mdsFolder);
            $success = true;
            \file_put_contents($mdsFolder .  '/lastMdsFetch.txt', date('r'));
            $msg = 'successfully queried FIDO Alliance Metadata Service - ' . $cnt . ' certificates downloaded.';

        } else {
            $msg = 'Fail: last fetch was at ' . date('r', $lastFetch) . ' - fetch only 1x every 48h';
        }

        $return = new stdClass();
        $return->success = $success;
        $return->msg = $msg;

        header('Content-Type: application/json');
        print(json_encode($return));
    }

} catch (Throwable $ex) {
    $return = new stdClass();
    $return->success = false;
    $return->msg = $ex->getMessage()." File: ".$ex->getFile()." Line: ".$ex->getLine();

    header('Content-Type: application/json');
    print(json_encode($return));
}