Merge pull request from GHSA-h2q2-vch3-72qm

Add CSP and sanitize chat messages in Obsidian, Desktop, Web apps

src/interface/desktop/chat.html

@@ -8,6 +8,7 @@
         <link rel="icon" type="image/png" sizes="128x128" href="./assets/icons/favicon-128x128.png">
         <link rel="manifest" href="/static/khoj.webmanifest">
     </head>
+    <script type="text/javascript" src="./assets/purify.min.js?v={{ khoj_version }}"></script>
     <script type="text/javascript" src="./assets/markdown-it.min.js"></script>
     <script src="./utils.js"></script>
 
@@ -282,6 +283,8 @@
 
             // Render markdown
             newHTML = raw ? newHTML : md.render(newHTML);
+            // Sanitize the rendered markdown
+            newHTML = DOMPurify.sanitize(newHTML);
             // Set rendered markdown to HTML DOM element
             let element = document.createElement('div');
             element.innerHTML = newHTML;

src/interface/desktop/main.js

@@ -1,4 +1,4 @@
-const { app, BrowserWindow, ipcMain, Tray, Menu, nativeImage, shell } = require('electron');
+const { app, BrowserWindow, ipcMain, Tray, Menu, nativeImage, shell, session } = require('electron');
 const todesktop = require("@todesktop/runtime");
 const khojPackage = require('./package.json');
 
@@ -401,6 +401,33 @@ async function getUserInfo() {
     }
 }
 
+function addCSPHeaderToSession () {
+    // Get hostURL from store or use default
+    const hostURL = store.get('hostURL') || KHOJ_URL;
+
+    // Construct Content Security Policy
+    const defaultDomains = `'self' ${hostURL} https://app.khoj.dev https://assets.khoj.dev`;
+    const default_src = `default-src ${defaultDomains};`;
+    const script_src = `script-src ${defaultDomains} 'unsafe-inline';`;
+    const connect_src = `connect-src ${hostURL} https://ipapi.co/json;`;
+    const style_src = `style-src ${defaultDomains} 'unsafe-inline' https://fonts.googleapis.com;`;
+    const img_src = `img-src ${defaultDomains} data: https://*.khoj.dev https://*.googleusercontent.com;`;
+    const font_src = `font-src https://fonts.gstatic.com;`;
+    const child_src = `child-src 'none';`;
+    const objectSrc = `object-src 'none';`;
+    const csp = `${default_src} ${script_src} ${connect_src} ${style_src} ${img_src} ${font_src} ${child_src} ${objectSrc}`;
+
+    // Add Content Security Policy to all web requests
+    session.defaultSession.webRequest.onHeadersReceived((details, callback) => {
+        callback({
+            responseHeaders: {
+                ...details.responseHeaders,
+                'Content-Security-Policy': [csp]
+            }
+        })
+    })
+ }
+
 let firstRun = true;
 let win = null;
 let titleBarStyle = process.platform === 'win32' ? 'default' : 'hidden';
@@ -480,6 +507,8 @@ const createWindow = (tab = 'chat.html') => {
 }
 
 app.whenReady().then(() => {
+    addCSPHeaderToSession();
+
     ipcMain.on('set-title', handleSetTitle);
 
     ipcMain.handle('handleFileOpen', (event, type) => {

src/interface/obsidian/package.json

@@ -17,6 +17,7 @@
         "assistant"
     ],
     "devDependencies": {
+        "@types/dompurify": "^3.0.5",
         "@types/node": "^16.11.6",
         "@typescript-eslint/eslint-plugin": "5.29.0",
         "@typescript-eslint/parser": "5.29.0",
@@ -25,5 +26,8 @@
         "obsidian": "latest",
         "tslib": "2.4.0",
         "typescript": "4.7.4"
+    },
+    "dependencies": {
+        "dompurify": "^3.1.4"
     }
 }

src/interface/obsidian/src/chat_view.ts

@@ -1,4 +1,5 @@
 import { MarkdownRenderer, WorkspaceLeaf, request, requestUrl, setIcon } from 'obsidian';
+import * as DOMPurify from 'dompurify';
 import { KhojSetting } from 'src/settings';
 import { KhojPaneView } from 'src/pane_view';
 import { KhojView, createCopyParentText, getLinkToEntry, pasteTextAtCursor } from 'src/utils';
@@ -80,6 +81,20 @@ export class KhojChatView extends KhojPaneView {
 
         super.onOpen();
 
+        // Construct Content Security Policy
+        let defaultDomains = `'self' ${this.setting.khojUrl} https://app.khoj.dev https://assets.khoj.dev`;
+        const defaultSrc = `default-src ${defaultDomains};`;
+        const scriptSrc = `script-src ${defaultDomains} 'unsafe-inline';`;
+        const connectSrc = `connect-src ${this.setting.khojUrl} https://ipapi.co/json;`;
+        const styleSrc = `style-src ${defaultDomains} 'unsafe-inline';`;
+        const imgSrc = `img-src ${defaultDomains} data: https://*.khoj.dev https://*.googleusercontent.com;`;
+        const childSrc = `child-src 'none';`;
+        const objectSrc = `object-src 'none';`;
+        const csp = `${defaultSrc} ${scriptSrc} ${connectSrc} ${styleSrc} ${imgSrc} ${childSrc} ${objectSrc}`;
+
+        // Add CSP meta tag to the Khoj Chat modal
+        document.head.createEl("meta", { attr: { "http-equiv": "Content-Security-Policy", "content": `${csp}` } });
+
         // Create area for chat logs
         let chatBodyEl = contentEl.createDiv({ attr: { id: "khoj-chat-body", class: "khoj-chat-body" } });
 
@@ -289,6 +304,9 @@ export class KhojChatView extends KhojPaneView {
         // Remove any text between <s>[INST] and </s> tags. These are spurious instructions for the AI chat model.
         rendered_msg = rendered_msg.replace(/<s>\[INST\].+(<\/s>)?/g, '');
 
+        // Sanitize the markdown to render
+        message = DOMPurify.sanitize(message);
+
         // Render markdow to HTML DOM element
         let chat_message_body_text_el = this.contentEl.createDiv();
         chat_message_body_text_el.className = "chat-message-text-response";
@@ -375,6 +393,10 @@ export class KhojChatView extends KhojPaneView {
         let chat_message_body_el = chatMessageEl.createDiv();
         chat_message_body_el.addClasses(["khoj-chat-message-text", sender]);
         let chat_message_body_text_el = chat_message_body_el.createDiv();
+
+        // Sanitize the markdown to render
+        message = DOMPurify.sanitize(message);
+
         if (raw) {
             chat_message_body_text_el.innerHTML = message;
         } else {
@@ -422,6 +444,8 @@ export class KhojChatView extends KhojPaneView {
     async renderIncrementalMessage(htmlElement: HTMLDivElement, additionalMessage: string) {
         this.result += additionalMessage;
         htmlElement.innerHTML = "";
+        // Sanitize the markdown to render
+        this.result = DOMPurify.sanitize(this.result);
         // @ts-ignore
         await MarkdownRenderer.renderMarkdown(this.result, htmlElement, '', null);
         // Render action buttons for the message

src/khoj/interface/web/chat.html

@@ -4,6 +4,15 @@
         <meta charset="utf-8">
         <meta name="viewport" content="width=device-width, initial-scale=1.0 maximum-scale=1.0">
         <meta property="og:image" content="https://assets.khoj.dev/khoj_hero.png">
+        <meta http-equiv="Content-Security-Policy"
+              content="default-src 'self' https://assets.khoj.dev;
+                       script-src 'self' https://assets.khoj.dev 'unsafe-inline';
+                       connect-src 'self' https://ipapi.co/json;
+                       style-src 'self' https://assets.khoj.dev 'unsafe-inline' https://fonts.googleapis.com;
+                       img-src 'self' data: https://*.khoj.dev https://*.googleusercontent.com;
+                       font-src https://assets.khoj.dev https://fonts.gstatic.com;
+                       child-src 'none';
+                       object-src 'none';">
         <title>Khoj - Chat</title>
 
         <link rel="stylesheet" href="/static/assets/khoj.css?v={{ khoj_version }}">
@@ -18,6 +27,7 @@
         <!-- To automatically render math in text elements, include the auto-render extension: -->
         <script defer src="https://assets.khoj.dev/katex/auto-render.min.js" onload="renderMathInElement(document.body);"></script>
     </head>
+    <script type="text/javascript" src="/static/assets/purify.min.js?v={{ khoj_version }}"></script>
     <script type="text/javascript" src="/static/assets/utils.js?v={{ khoj_version }}"></script>
     <script type="text/javascript" src="/static/assets/markdown-it.min.js?v={{ khoj_version }}"></script>
     <script>
@@ -365,6 +375,9 @@ To get started, just start typing below. You can also type / to see a list of co
             newHTML = newHTML.replace(/LEFTPAREN/g, '\\(').replace(/RIGHTPAREN/g, '\\)')
                              .replace(/LEFTBRACKET/g, '\\[').replace(/RIGHTBRACKET/g, '\\]');
 
+            // Sanitize the rendered markdown
+            newHTML = DOMPurify.sanitize(newHTML);
+
             // Set rendered markdown to HTML DOM element
             let element = document.createElement('div');
             element.innerHTML = newHTML;