[MM 17255] Fix OneLogin and other OAUTH/SAML custom login attempts (#1025)

* allow custom login activity (oath, saml)

* fix electron missing cursor bug

* change variable name

* tweaks to custom login process

src/browser/components/MattermostView.jsx

@@ -120,7 +120,10 @@ export default class MattermostView extends React.Component {
     // So this would be emitted again when reloading a webview
     webview.addEventListener('dom-ready', () => {
       // webview.openDevTools();
-
+      // Remove this once https://github.com/electron/electron/issues/14474 is fixed
+      // - fixes missing cursor bug in electron
+      webview.blur();
+      webview.focus();
       if (!this.state.isContextMenuAdded) {
         contextMenu.setup(webview, {
           useSpellChecker: this.props.useSpellChecker,

src/main.js

@@ -67,6 +67,23 @@ let config = null;
 let trayIcon = null;
 let trayImages = null;
 
+// supported custom login paths (oath, saml)
+const customLoginRegexPaths = [
+  /^\/oauth\/authorize$/i,
+  /^\/oauth\/deauthorize$/i,
+  /^\/oauth\/access_token$/i,
+  /^\/oauth\/[A-Za-z0-9]+\/complete$/i,
+  /^\/oauth\/[A-Za-z0-9]+\/login$/i,
+  /^\/oauth\/[A-Za-z0-9]+\/signup$/i,
+  /^\/api\/v3\/oauth\/[A-Za-z0-9]+\/complete$/i,
+  /^\/signup\/[A-Za-z0-9]+\/complete$/i,
+  /^\/login\/[A-Za-z0-9]+\/complete$/i,
+  /^\/login\/sso\/saml$/i,
+];
+
+// tracking in progress custom logins
+const customLogins = {};
+
 /**
  * Main entry point for the application, ensures that everything initializes in the proper order
  */
@@ -361,26 +378,77 @@ function handleAppWillFinishLaunching() {
 }
 
 function handleAppWebContentsCreated(dc, contents) {
+  // initialize custom login tracking
+  customLogins[contents.id] = {
+    inProgress: false,
+    startingURL: null,
+    externalHostname: null,
+  };
+
   contents.on('will-attach-webview', (event, webPreferences) => {
     webPreferences.nodeIntegration = false;
     webPreferences.contextIsolation = true;
   });
-  contents.on('will-navigate', (event, navigationUrl) => {
-    const parsedUrl = new URL(navigationUrl);
-    const trustedURLs = config.teams.map((team) => new URL(team.url)); //eslint-disable-line max-nested-callbacks
 
-    let trusted = false;
-    for (const url of trustedURLs) {
-      if (parsedUrl.origin === url.origin) {
-        trusted = true;
-        break;
+  contents.on('will-navigate', (event, url) => {
+    const contentID = event.sender.id;
+    const parsedUrl = new URL(url);
+    const urlIsTrusted = isTrustedURL(parsedUrl);
+    const urlIsTrustedExternalLoginPath = parsedUrl.hostname === customLogins[contentID].externalHostname;
+
+    // don't prevent custom login attempts (oath, saml)
+    if (!urlIsTrusted && !urlIsTrustedExternalLoginPath) {
+      event.preventDefault();
+
+      // reset custom login if in progress
+      if (customLogins[contentID].inProgress) {
+        customLogins[contentID].inProgress = false;
+        customLogins[contentID].externalHostname = null;
+
+        // redirect to starting url if set
+        if (customLogins[contentID].startingURL) {
+          event.sender.loadURL(customLogins[contentID].startingURL);
+          customLogins[contentID].startingURL = null;
+        }
       }
     }
+  });
 
-    if (!trusted) {
-      event.preventDefault();
+  // handle custom login requests (oath, saml):
+  // 1. are we navigating to a supported local custom login path from the `/login` page? (did-start-navigation listener)
+  //    - indicate custom login is in progress and store starting point for possible reset
+  // 2. is a custom login in progress but we don't have the 3rd party hostname yet? (will-redirect listener)
+  //    - store 3rd party hostname to trust subsequent navigation changes within that hostname
+  // 3. are we finished with the custom login process? (did-start-navigation listener)
+  //    - indicate custom login is NOT in progress and clear any stored 3rd party hostname's
+  contents.on('did-start-navigation', (event, url) => {
+    const contentID = event.sender.id;
+    const parsedUrl = new URL(url);
+    const urlIsTrusted = isTrustedURL(parsedUrl);
+    const urlIsCustomLoginPath = isCustomLoginURL(parsedUrl);
+    const previousPage = event.sender.history[event.sender.history.length - 1];
+
+    if (urlIsTrusted && urlIsCustomLoginPath && !customLogins[contentID].inProgress && previousPage.endsWith('/login')) {
+      customLogins[contentID].inProgress = true;
+      customLogins[contentID].startingURL = event.sender.getURL();
+    } else if (urlIsTrusted && customLogins[contentID].inProgress && customLogins[contentID].externalHostname) {
+      customLogins[contentID].inProgress = false;
+      customLogins[contentID].externalHostname = null;
     }
   });
+
+  contents.on('will-redirect', (event, url) => {
+    const contentID = event.sender.id;
+    const parsedUrl = new URL(url);
+    const urlIsTrusted = isTrustedURL(parsedUrl);
+    const previousPage = event.sender.history[event.sender.history.length - 1];
+    const previousPageIsTrusted = isTrustedURL(previousPage);
+
+    if (!urlIsTrusted && previousPageIsTrusted && customLogins[contentID].inProgress && !customLogins[contentID].externalHostname) {
+      customLogins[contentID].externalHostname = parsedUrl.hostname;
+    }
+  });
+
   contents.on('new-window', (event) => {
     event.preventDefault();
   });
@@ -674,6 +742,39 @@ function handleMainWindowWebContentsCrashed() {
 // helper functions
 //
 
+function isTrustedURL(url) {
+  let parsedUrl = url;
+  if (typeof url === 'string') {
+    parsedUrl = new URL(url);
+  }
+  const trustedURLs = config.teams.map((team) => new URL(team.url));
+
+  for (const trustedURL of trustedURLs) {
+    if (parsedUrl.origin === trustedURL.origin) {
+      return true;
+    }
+  }
+
+  return false;
+}
+
+function isCustomLoginURL(url) {
+  if (!isTrustedURL(url)) {
+    return false;
+  }
+  let parsedUrl = url;
+  if (typeof url === 'string') {
+    parsedUrl = new URL(url);
+  }
+  const urlPath = parsedUrl.pathname;
+  for (const regexPath of customLoginRegexPaths) {
+    if (urlPath.match(regexPath)) {
+      return true;
+    }
+  }
+  return false;
+}
+
 function getTrayImages() {
   switch (process.platform) {
   case 'win32':