prep for 2023. Fixed many bugs. Added pdf guide

oauth.php

@@ -0,0 +1,51 @@
+<?php
+/* oauth.php Azure AD oAuth web callback script
+ *
+ * Katy Nicholson, last updated 17/11/2021
+ *
+ * https://github.com/CoasterKaty
+ * https://katytech.blog/
+ * https://twitter.com/coaster_katy
+ *
+ */
+require_once '../inc/mysql.php';
+require_once '../inc/oauth.php';
+
+
+session_start();
+$modDB = new modDB();
+$oAuth = new modOAuth();
+if ($_GET['error']) {
+	echo $oAuth->errorMessage($_GET['error_description']);
+	exit;
+}
+//retrieve session data from database
+$sessionData = $modDB->QuerySingle('SELECT * FROM tblAuthSessions WHERE txtSessionKey=\'' . $modDB->Escape($_SESSION['sessionkey']) . '\'');
+
+if ($sessionData) {
+    // Request token from Azure AD
+	$oauthRequest = $oAuth->generateRequest('grant_type=authorization_code&client_id=' . _OAUTH_CLIENTID . '&redirect_uri=' . urlencode(_URL . '/oauth.php') . '&code=' . $_GET['code'] . '&code_verifier=' . $sessionData['txtCodeVerifier']);
+
+	$response = $oAuth->postRequest('token', $oauthRequest);
+
+	// Decode response from Azure AD. Extract JWT data from supplied access_token and id_token and update database.
+	if (!$response) { 
+		echo $oAuth->errorMessage('Unknown error acquiring token');
+		exit;
+	}
+	$reply = json_decode($response);
+	if ($reply->error) {
+	        echo $oAuth->errorMessage($reply->error_description);
+		exit;
+	}
+
+	$idToken = base64_decode(explode('.', $reply->id_token)[1]);
+
+	$modDB->Update('tblAuthSessions', array('txtToken' => $reply->access_token, 'txtRefreshToken' => $reply->refresh_token, 'txtIDToken' => $idToken, 'txtRedir' => '', 'dtExpires' => date('Y-m-d H:i:s', strtotime('+' . $reply->expires_in . ' seconds'))), array('intAuthID' => $sessionData['intAuthID']));
+	// Redirect user back to where they came from.
+	header('Location: ' . $sessionData['txtRedir']);
+} else {
+	header('Location: /');
+}
+
+?>