Selective handling of Tor Browser options and work-around for https://bugzilla.mozilla.org/show_bug.cgi?id=1532530

src/_locales/en/messages.json

@@ -267,6 +267,18 @@
   "OptFilterXPost": {
     "message": "Turn cross-site POST requests into data-less GET requests"
   },
+  "OptScanXUpload": {
+    "message": "Scan uploads for potential cross-site attacks"
+  },
+  "OptBlockUnscannedXPost": {
+    "message": "Ask confirmation for cross-site POST requests which could not be scanned"
+  },
+  "UnscannedXPost": {
+    "message": "This cross-site request could not be scanned for XSS.\nIt might be innocuous, but NoScript cannot tell for sure. Allow only if you trust both sites."
+  },
+  "OptOverrideTorBrowserPolicy": {
+    "message": "Override Tor Browser's Security Level preset"
+  },
   "Options": {
     "message": "Options…"
   },

src/bg/Defaults.js

@@ -12,7 +12,10 @@ var Defaults = {
       sync: {
         "global": false,
         "xss": true,
-        "clearclick": true
+        "xssScanRequestBody": true,
+        "xssBlockUnscannedPOST": false,
+        "overrideTorBrowserPolicy": false, // note: Settings.update() on reset will flip this to true
+        "clearclick": true,
       }
     };
     let defaultsClone = JSON.parse(JSON.stringify(defaults));

src/bg/RequestGuard.js

@@ -379,7 +379,7 @@ var RequestGuard = (() => {
       if (pending) {
         pending.scriptBlocked = scriptBlocked;
         if (!(pending.headersProcessed &&
-            (scriptBlocked || !ns.isEnforced(tabId) || ns.policy.can(url, "script", request.documentURL))
+            (scriptBlocked || !ns.requestCan(request, "script"))
           )) {
           debug("[WARNING] onHeadersReceived %s %o", frameId, tabId,
             pending.headersProcessed ? "has been overridden on": "could not process",

src/bg/Settings.js

@@ -81,8 +81,56 @@ var Settings = {
       tabId,
       unrestrictedTab,
       reloadAffected,
+      isTorBrowser,
     } = settings;
-    if (xssUserChoices) await XSS.saveUserChoices(xssUserChoices);
+
+    let oldDebug = ns.local.debug;
+
+    let reloadOptionsUI = false;
+
+    if (isTorBrowser) {
+      // Tor Browser-specific settings
+      ns.defaults.local.isTorBrowser = true; // prevents reset from forgetting
+      if (!this.gotTorBrowserInit) {
+        // First initialization message from the Tor Browser
+        this.gotTorBrowserInit = true;
+        if (ns.sync.overrideTorBrowserPolicy) {
+          // If the user chose to override Tor Browser's policy we skip
+          // copying the Security Level preset on startup (only).
+          // Manually changing the security level works as usual.
+          ns.local.isTorBrowser = true;
+          await ns.save(ns.local);
+          return;
+        }
+      } else {
+        reloadOptionsUI = true;
+      }
+      if (!settings.local) settings.local = {};
+      settings.local.isTorBrowser = true;
+      if (!settings.sync) settings.sync = {};
+      settings.sync.xssScanRequestBody = false;
+      settings.sync.xssBlockUnscannedPOST = true;
+    }
+
+    if (settings.sync === null) {
+      // overriden defaults when user manually resets options
+
+      // we want the reset options to stick (otherwise it gets very confusing)
+      ns.defaults.sync.overrideTorBrowserPolicy = true;
+      reloadOptionsUI = true;
+    }
+
+    await Promise.all(["local", "sync"].map(
+      async storage => (settings[storage] || // changed or...
+          settings[storage] === null // ... needs reset to default
+        ) && await ns.save(settings[storage]
+            ? Object.assign(ns[storage], settings[storage]) : ns[storage] = ns.defaults[storage])
+    ));
+    if (ns.local.debug !== oldDebug) {
+      await include("/lib/log.js");
+      if (oldDebug) debug = () => {};
+    }
+
     if (policy) {
       ns.policy = new Policy(policy);
       await ns.savePolicy();
@@ -95,22 +143,15 @@ var Settings = {
       browser.tabs.reload(tabId);
     }
 
-    let oldDebug = ns.local.debug;
-    await Promise.all(["local", "sync"].map(
-      storage => (settings[storage] || // changed or...
-          settings[storage] === null // ... needs reset to default
-        ) && ns.save(
-            ns[storage] = settings[storage] || ns.defaults[storage])
-    ));
-    if (ns.local.debug !== oldDebug) {
-      await include("/lib/log.js");
-      if (oldDebug) debug = () => {};
-    }
+    if (xssUserChoices) await XSS.saveUserChoices(xssUserChoices);
+
     if (ns.sync.xss) {
       XSS.start();
     } else {
       XSS.stop();
     }
+
+    if (reloadOptionsUI) await this.reloadOptionsUI();
   },
 
   export() {
@@ -125,5 +166,15 @@ var Settings = {
   async enforceTabRestrictions(tabId, unrestricted = ns.unrestrictedTabs.has(tabId)) {
     await ChildPolicies.storeTabInfo(tabId, unrestricted && {unrestricted: true});
     return unrestricted;
+  },
+
+  async reloadOptionsUI() {
+    try {
+      for (let t of await browser.tabs.query({url: browser.runtime.getManifest().options_ui.page })) {
+        browser.tabs.reload(t.id);
+      };
+    } catch (e) {
+      error(e);
+    }
   }
 }

src/bg/main.js

@@ -180,6 +180,10 @@
       return this.policy.enforced && (tabId === -1 || !this.unrestrictedTabs.has(tabId));
     },
 
+    requestCan(request, capability) {
+      return !this.isEnforced(request.tabId) || this.policy.can(request.url, "script", request.documentURL);
+    },
+
     start() {
       if (this.running) return;
       this.running = true;

src/ui/options.css

@@ -136,9 +136,19 @@ input[type="file"] {
 .opt-group {
   padding: 0.5em 0;
 }
+
 #xssFaq {
   padding: 0.5em 1em;
 }
+
+#tb-options {
+  display: none;
+}
+
+.tor #tb-options {
+  display: initial;
+}
+
 #clearclick-options {
   display: none;
 }

src/ui/options.html

@@ -99,17 +99,33 @@
 
 <h3 class="flextabs__tab"><button class="flextabs__toggle">__MSG_SectionAdvanced__</button></h3>
 <div class="flextabs__content">
-  <div class="opt-group">
-  <span id="xss-opts">
+  <div id="xss-options" class="opt-group">
+  <span id="xss-opt">
     <input type="checkbox" id="opt-xss"><label for="opt-xss" id="lbl-xss">__MSG_OptFilterXGet__</label>
-  <span id="xssFaq">(<a href="https://noscript.net/faq#xss" title="https://noscript.net/faq#xss">__MSG_XssFaq__</a>)</span>
+    <span id="xssFaq">(<a href="https://noscript.net/faq#xss" title="https://noscript.net/faq#xss">__MSG_XssFaq__</a>)</span>
   </span>
   <button id="btn-delete-xss-choices" disabled>__MSG_XSS_clearUserChoices__</button>
+  <br />
+  <span id="xssScanRequestBody-opt">
+    <input type="checkbox" id="opt-xssScanRequestBody">
+      <label for="opt-xssScanRequestBody" id="lbl-opt-xssScanRequestBody">__MSG_OptScanXUpload__</label>
+  </span>
+  <span id="xssBlockUnscannedPOST-opt">
+    <input type="checkbox" id="opt-xssBlockUnscannedPOST">
+      <label for="opt-xssBlockUnscannedPOST" id="lbl-opt-xssBlockUnscannedPOST">__MSG_OptBlockUnscannedXPost__</label>
+  </span>
   </div>
   <div id="clearclick-options" class="opt-group">
   <input type="checkbox" id="opt-clearclick"><label for="opt-clearclick" id="lbl-clearclick">ClearClick</label>
   </div>
 
+  <div id="tb-options" class="opt-group">
+    <span id="overrideTorBrowserPolicy-opt">
+      <input type="checkbox" id="opt-overrideTorBrowserPolicy">
+        <label for="opt-overrideTorBrowserPolicy" id="lbl-opt-overrideTorBrowserPolicy">__MSG_OptOverrideTorBrowserPolicy__</label>
+    </span>
+  </div>
+
   <section id="debug" class="browser-style">
   <div class="opt-group">
     <span><input type="checkbox" id="opt-debug"><label id="label-debug" for="opt-debug">Debug</label></span>

src/ui/options.js

@@ -8,9 +8,9 @@
   let version = browser.runtime.getManifest().version;
   document.querySelector("#version").textContent = _("Version", version);
   // simple general options
-  
+
   let opt = UI.wireOption;
-  
+
   opt("global", o => {
     if (o) {
       policy.enforced = !o.checked;
@@ -33,6 +33,11 @@
   });
 
   opt("xss");
+  opt("xssScanRequestBody");
+  opt("xssBlockUnscannedPOST");
+
+  opt("overrideTorBrowserPolicy");
+
   {
     let button = document.querySelector("#btn-reset");
     button.onclick = async () => {

src/ui/ui.js

@@ -41,6 +41,9 @@ var UI = (() => {
             if (UI.local && !UI.local.debug) {
               debug = () => {}; // be quiet!
             }
+            if (UI.local) {
+              document.documentElement.classList.toggle("tor", !!UI.local.isTorBrowser);
+            }
             resolve();
             if (UI.onSettings) UI.onSettings();
             await HighContrast.init();

src/xss/XSS.js

@@ -114,6 +114,13 @@ var XSS = (() => {
   return {
     async start() {
       let {onBeforeRequest} = browser.webRequest;
+      let  {xssScanRequestBody} = ns.sync;
+      if (xssScanRequestBody !== this.xssScanRequestBody) {
+        this.stop();
+        this.xssScanRequestBody = xssScanRequestBody;
+      }
+      this.xssBlockUnscannedPOST = ns.sync.xssBlockUnscannedPOST;
+
       if (onBeforeRequest.hasListener(requestListener)) return;
 
       await include("/legacy/Legacy.js");
@@ -135,7 +142,9 @@ var XSS = (() => {
       onBeforeRequest.addListener(requestListener, {
         urls: ["*://*/*"],
         types: ["main_frame", "sub_frame", "object"]
-      }, ["blocking", "requestBody"]);
+      },
+        // work-around for https://bugzilla.mozilla.org/show_bug.cgi?id=1532530
+        xssScanRequestBody ? ["blocking", "requestBody"] : ["blocking"]);
     },
 
     stop() {
@@ -233,8 +242,11 @@ var XSS = (() => {
       ic.reset();
 
       let postInjection = xssReq.isPost &&
-        request.requestBody && request.requestBody.formData &&
-        ic.checkPost(request.requestBody.formData, skipParams);
+       (XSS.xssScanRequestBody ?
+          request.requestBody && request.requestBody.formData &&
+            ic.checkPost(request.requestBody.formData, skipParams)
+        : XSS.xssBlockUnscannedPOST && ns.requestCan(request, "script") && _("UnscannedXPost")
+      );
 
       let protectName = ic.nameAssignment;
       let urlInjection = ic.checkUrl(destUrl, skipRx);