Added BREACH attack mittigation, #4084

MeshCentralServer.njsproj

@@ -613,6 +613,7 @@
     <Content Include="views\messenger.handlebars" />
     <Content Include="views\mstsc.handlebars" />
     <Content Include="views\player.handlebars" />
+    <Content Include="views\sharing-mobile.handlebars" />
     <Content Include="views\sharing.handlebars" />
     <Content Include="views\ssh.handlebars" />
     <Content Include="views\terms-mobile.handlebars" />

meshcentral-config-schema.json

@@ -120,6 +120,7 @@
         "amtManager": { "type": "boolean", "default": true, "description": "When enabled, MeshCentral will automatically monitor and manage Intel AMT devices." },
         "orphanAgentUser": { "type": "string", "default": null, "description": "If an agent attempts to connect to a unknown device group, automatically create a new device group and grant access to the specified user. Example: admin" },
         "agentIdleTimeout": { "type": "integer", "minimum": 1, "default": 150 ,"description": "How much time in seconds with no traffic from an agent before dropping the agent connection." },
+        "webPageLengthRandomization": { "type": "boolean", "default": true, "description": "Adds a random length string to generated web pages to mitigate a BREACH attack." },
         "compression": { "type": "boolean", "default": true, "description": "Enables GZIP compression for web requests." },
         "wsCompression": { "type": "boolean", "default": false, "description": "Enables server-side, websocket per-message deflate compression." },
         "agentWsCompression": { "type": "boolean", "default": true, "description": "Enables agent-side, websocket per-message deflate compression. wscompression must also be true for this to work." },

public/translate.bat

@@ -1,7 +1,7 @@
 @ECHO OFF
 CD ..\translate
 %LOCALAPPDATA%\..\Roaming\nvm\v12.13.0\node translate.js minifyall
-%LOCALAPPDATA%\..\Roaming\nvm\v12.13.0\node translate.js translateall
-%LOCALAPPDATA%\..\Roaming\nvm\v12.13.0\node translate.js extractall
+REM %LOCALAPPDATA%\..\Roaming\nvm\v12.13.0\node translate.js translateall
+REM %LOCALAPPDATA%\..\Roaming\nvm\v12.13.0\node translate.js extractall
 DEL ..\emails\translations\*-min_*
 Pause

views/agentinvite.handlebars

@@ -167,6 +167,8 @@
     </div>
     <script>
         'use strict';
+
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var uiMode = parseInt(getstore('uiMode', 1));
         var webPageStackMenu = false;
         var webPageFullScreen = true;

views/default-mobile.handlebars

@@ -1192,6 +1192,7 @@
     <iframe name="fileUploadFrame" style=display:none></iframe>
     <script>
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
 
         // Process server-side web state
         var webState = '{{{webstate}}}';

views/default.handlebars

@@ -1402,6 +1402,7 @@
     </div>
     <script type="text/javascript">
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
 
         // Process server-side web state
         var webState = '{{{webstate}}}';

views/download.handlebars

@@ -43,6 +43,7 @@
         </div>
     </div>
     <script>
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var messageid = parseInt('{{{messageid}}}');
         var fileurl = '{{{fileurl}}}';
         var filename = '{{{filename}}}';

views/download2.handlebars

@@ -57,6 +57,7 @@
         </tr>
     </table>
     <script>
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var messageid = parseInt('{{{messageid}}}');
         var fileurl = '{{{fileurl}}}';
         var filename = '{{{filename}}}';

views/error404.handlebars

@@ -148,6 +148,7 @@
     </div>
     <script nonce="{{{cspNonce}}}">
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var uiMode = parseInt(getstore('uiMode', 1));
         var webPageStackMenu = false;
         var webPageFullScreen = true;

views/invite.handlebars

@@ -103,6 +103,7 @@
     </div>
     <script>
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var urlargs = parseUriArgs();
         if (urlargs.key && (isAlphaNumeric(urlargs.key) == false)) { delete urlargs.key; }
         var uiMode = parseInt(getstore('uiMode', 1));

views/login-mobile.handlebars

@@ -311,6 +311,7 @@
     </div>
     <script>
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var loginMode = '{{{loginmode}}}';
         var newAccount = '{{{newAccount}}}';
         var passhint = '{{{passhint}}}';

views/login.handlebars

@@ -305,6 +305,7 @@
     </div>
     <script>
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var passlogin = '{{{passlogin}}}';
         var passhint = '{{{passhint}}}';
         var loginMode = '{{{loginmode}}}';

views/login2.handlebars

@@ -361,6 +361,7 @@
     </div>
     <script>
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var welcomePictureFullScreen = (decodeURIComponent('{{{welcomePictureFullScreen}}}') === 'true');
         var passlogin = '{{{passlogin}}}';
         var passhint = '{{{passhint}}}';

views/message.handlebars

@@ -43,6 +43,7 @@
         </div>
     </div>
     <script>
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var titleid = parseInt('{{{titleid}}}');
         var msgid = parseInt('{{{msgid}}}');
         var domainurl = decodeURIComponent('{{{domainurl}}}');

views/message2.handlebars

@@ -44,6 +44,7 @@
         </tr>
     </table>
     <script>
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var titleid = parseInt('{{{titleid}}}');
         var msgid = parseInt('{{{msgid}}}');
         var domainurl = decodeURIComponent('{{{domainurl}}}');

views/messenger.handlebars

@@ -60,6 +60,7 @@
     <canvas width="256" height="256" id="remoteImage" style="position:absolute;right:24px;top:45px;width:200px;height:200px;background-color:gray;border-radius:12px 12px 12px 12px;box-shadow:3px 3px 10px gray;display:none" />
     <input id="uploadFileInput" type="file" multiple style="display:none">
     <script type="text/javascript" onunload="onUnLoad()">
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var userInputFocus = 0;
         var socket = null;                  // Websocket object
         var state = 0;                      // Connection state. 0 = Disconnected, 1 = Connecting, 2 = Connected.

views/mstsc.handlebars

@@ -75,6 +75,7 @@
         }
     </style>
     <script language="javascript">
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var client = null;
         var canvas = null;
         var urlargs = parseUriArgs();

views/player.handlebars

@@ -96,6 +96,7 @@
         </div>
     </div>
     <script>
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var recFile = null;
         var recFilePtr = 0;
         var recFileStartTime = 0;

views/sharing-mobile.handlebars

@@ -737,6 +737,7 @@
     <iframe name="fileUploadFrame" style=display:none></iframe>
     <script>
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var args = parseUriArgs();
         var urlargs = args;
         var sessionTime = parseInt('{{{sessiontime}}}');

views/sharing.handlebars

@@ -283,6 +283,7 @@
         </div>
     </div>
     <script>
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var sessionActivity = null;
         var desktop = null;
         var agentPresent = true;

views/ssh.handlebars

@@ -68,6 +68,7 @@
         </div>
     </div>
     <script>
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var term = null;
         var termfit = null;
         var resizeTimer = null;

views/terms.handlebars

@@ -161,6 +161,7 @@
     </div>
     <script>
         'use strict';
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var uiMode = parseInt(getstore('uiMode', 1));
         var webPageStackMenu = false;
         var webPageFullScreen = true;

views/xterm.handlebars

@@ -80,6 +80,7 @@
         </div>
     </div>
     <script>
+        var random = '{{{randomlength}}}' // Random length string for BREACH mitigation
         var term = null;
         var termfit = null;
         var tunnel = null;

webserver.js

@@ -7696,6 +7696,10 @@ module.exports.CreateWebServer = function (parent, db, args, certificates, doneF
         xargs.domainurl = domain.url;
         xargs.autocomplete = (domain.autocomplete === false)?'x':'autocomplete'; // This option allows autocomplete to be turned off on the login page.
         if (typeof domain.hide == 'number') { xargs.hide = domain.hide; }
+
+        // To mitigate any possible BREACH attack, we generate a random length string here.
+        xargs.randomlength = (args.webpagelengthrandomization !== false) ? parent.crypto.randomBytes(parent.crypto.randomInt(0, 256)).toString('base64') : '';
+
         return xargs;
     }