From e2b63cf98204a45f4c55ba446689d20e524c188c Mon Sep 17 00:00:00 2001
From: hackademix
Date: Mon, 27 Aug 2018 00:31:37 +0200
Subject: Further CSP refactoring and removal of obsolete fallbacks.

---
 src/content/DocumentCSP.js       |   7 +-
 src/content/PlaceHolder.js       |  26 ++++-
 src/content/content.js           | 218 ++++++---------------------------------
 src/content/dynamicNS.js         |  21 ++++
 src/content/embeddingDocument.js |  20 ++++
 src/content/media.js             |   4 +-
 src/content/staticNS.js          |  99 ++++++++++++++++++
 src/content/webglHook.js         |   4 +-
 8 files changed, 200 insertions(+), 199 deletions(-)
 create mode 100644 src/content/dynamicNS.js
 create mode 100644 src/content/embeddingDocument.js
 create mode 100644 src/content/staticNS.js

(limited to 'src/content')

diff --git a/src/content/DocumentCSP.js b/src/content/DocumentCSP.js
index 228b2a2..371e547 100644
--- a/src/content/DocumentCSP.js
+++ b/src/content/DocumentCSP.js
@@ -6,9 +6,9 @@ class DocumentCSP {
     this.builder = new CapsCSP();
   }
   
-  apply(capabilities) {
+  apply(capabilities, embedding = CSP.isEmbedType(this.document.contentType)) {
     let csp = this.builder;
-    let blocker = csp.buildFromCapabilities(capabilities);
+    let blocker = csp.buildFromCapabilities(capabilities, embedding);
     if (!blocker) return;
     
     let document = this.document;
@@ -19,8 +19,11 @@ class DocumentCSP {
     let parent = document.head || document.documentElement;
     try {
       parent.insertBefore(meta, parent.firstChild);
+      debug(`Failsafe <meta> CSP inserted in the DOM: "%s"`, header.value);
+      if (capabilities.has("script")) meta.remove();
     } catch (e) {
       error(e, "Error inserting CSP %s in the DOM", header && header.value);
     }
   }
+  
 }
diff --git a/src/content/PlaceHolder.js b/src/content/PlaceHolder.js
index ec2ab5b..09f6767 100644
--- a/src/content/PlaceHolder.js
+++ b/src/content/PlaceHolder.js
@@ -1,6 +1,17 @@
 var PlaceHolder = (() => {
   const HANDLERS = new Map();
-
+  
+  let checkStyle = async () => {
+    checkStyle = () => {};
+    if (!ns.embeddingDocument) return;
+    let replacement = document.querySelector("a.__NoScript_PlaceHolder__");
+    if (!replacement) return;
+    if (window.getComputedStyle(replacement, null).opacity !== "0.8") {
+      document.head.appendChild(createHTMLElement("style")).textContent = await
+        (await fetch(browser.extension.getURL("/content/content.css"))).text();
+    }
+  }
+  
   class Handler {
     constructor(type, selector) {
       this.type = type;
@@ -9,6 +20,7 @@ var PlaceHolder = (() => {
       HANDLERS.set(type, this);
     }
     filter(element, request) {
+      if (request.embeddingDocument) return true;
       let url = request.initialUrl || request.url;
       return "data" in element ? element.data === url : element.src === url;
     }
@@ -77,10 +89,14 @@ var PlaceHolder = (() => {
         .filter(element => this.handler.filter(element, request))
           .forEach(element => this.replace(element));
       };
-      if (this.replacements.size) PlaceHolder.listen();
+      if (this.replacements.size) {
+        PlaceHolder.listen();
+        checkStyle();
+      }
     }
 
     replace(element) {
+      if (!element.parentElement) return;
       let {
         url
       } = this.request;
@@ -108,10 +124,10 @@ var PlaceHolder = (() => {
 
       replacement._placeHolderObj = this;
       replacement._placeHolderElement = element;
-      this.replacements.add(replacement);
+      
 
-      if (element.parentNode) element.parentNode.replaceChild(replacement, element);
-      else document.body.appendChild(replacement);
+      element.parentNode.replaceChild(replacement, element);
+      this.replacements.add(replacement);
     }
 
     async enable(replacement) {
diff --git a/src/content/content.js b/src/content/content.js
index a5d996d..c7fc045 100644
--- a/src/content/content.js
+++ b/src/content/content.js
@@ -1,112 +1,12 @@
 'use strict';
+// debug = () => {}; // REL_ONLY
 
- // debug = () => {}; // REL_ONLY
-{
-  let listenersMap = new Map();
-  let backlog = new Set();
-  var ns = {
-    on(eventName, listener) {
-      let listeners = listenersMap.get(eventName);
-      if (!listeners) listenersMap.set(eventName, listeners = new Set());
-      listeners.add(listener);
-      if (backlog.has(eventName)) this.fire(eventName, listener);
-    },
-    detach(eventName, listener) {
-      let listeners = listenersMap.get(eventName);
-      if (listeners) listeners.delete(listener);
-    },
-    fire(eventName, listener = null) {
-      if (listener) {
-        listener({type:eventName, source: this});
-        return;
-      }
-      let listeners = listenersMap.get(eventName);
-      if (listeners) {
-        for (let l of listeners) {
-          this.fire(eventName, l);
-        }
-      }
-      backlog.add(eventName);
-    },
-    setup(DEFAULT, MARKER) {
-      this.perms.DEFAULT = DEFAULT;
-      if(!this.perms.CURRENT) this.perms.CURRENT = DEFAULT;
-      
-      // ugly hack: since now we use registerContentScript instead of the
-      // filterRequest dynamic script injection hack, we use top.name
-      // to store per-tab information. We don't want web content to
-      // mess with it, though, so we wrap it around auto-hiding accessors
-      this.perms.MARKER = MARKER;
-      let eraseTabInfoRx = new RegExp(`[^]*${MARKER},?`);
-      if (eraseTabInfoRx.test(top.name)) {
-        let _name = top.name;
-        let tabInfoRx = new RegExp(`^${MARKER}\\[([^]*?)\\]${MARKER},`);
-        if (top === window) { // wrap to hide
-          Reflect.defineProperty(top.wrappedJSObject, "name", {
-            get: exportFunction(() => top.name.replace(eraseTabInfoRx, ""), top.wrappedJSObject),
-            set: exportFunction(value => {
-              let preamble = top.name.match(tabInfoRx);
-              top.name = `${preamble && preamble[0] || ""}${value}`;
-              return value;
-            }, top.wrappedJSObject)
-          });
-        }
-        let tabInfoMatch = _name.match(tabInfoRx);
-        if (tabInfoMatch) try {
-          this.perms.tabInfo = JSON.parse(tabInfoMatch[1]);
-        } catch (e) {
-          error(e);
-        }
-      }
-      
-      if (!this.perms.DEFAULT || this.perms.tabInfo.unrestricted) {
-        this.allows = () => true;
-        this.capabilities =  Object.assign(
-          new Set(["script"]), { has() { return true; } });
-      } else {
-        let perms = this.perms.CURRENT || this.perms.DEFAULT;
-        this.capabilities = new Set(perms.capabilities);
-        new DocumentCSP(document).apply(this.capabilities);
-      }
-      ns.fire("perms");
-    },
-    perms: { DEFAULT: null, CURRENT: null, tabInfo: {}, MARKER: "" },
-        
-    allows(cap) {
-      return this.capabilities && this.capabilities.has(cap);
-    },
-    
-    getWindowName() {
-      return top !== window || !this.perms.MARKER ? window.name
-        : window.name.split(this.perms.MARKER + ",").pop();
-    }
-  }
-}
-
-var canScript = true, shouldScript = false;
-
-let now = () => performance.now() + performance.timeOrigin;
+var _ = browser.i18n.getMessage;
 
 function createHTMLElement(name) {
   return document.createElementNS("http://www.w3.org/1999/xhtml", name);
 }
 
-function probe() {
-  try {
-    debug("Probing execution...");
-    let s = document.createElement("script"); 
-    s.textContent = ";"; 
-    document.documentElement.appendChild(s);
-    s.remove();
-  } catch(e) {
-    debug(e);
-  }
-}
-
-var _ = browser.i18n.getMessage;
-
-var embeddingDocument = false;
-
 var seen = {
   _map: new Map(),
   _list: null,
@@ -128,9 +28,8 @@ Messages.addHandler({
       seen.record(event);
     }
     if (ownFrame) {
-      init();
       if (!allowed && PlaceHolder.canReplace(policyType)) {
-        request.embeddingDocument = embeddingDocument;
+        request.embeddingDocument = ns.embeddingDocument;
         PlaceHolder.create(policyType, request);
       }
     }
@@ -142,87 +41,38 @@ Messages.addHandler({
   }
 });
 
-if (document.readyState !== "complete") {
-  let pageshown = e => {
-    removeEventListener("pageshow", pageshown);
-    init();
-  };
-  addEventListener("pageshow", pageshown);
-} else {
-  init(true);
-}
-let notifyPage = async () => {
+
+debug(`Loading NoScript in document %s, scripting=%s, readyState %s`,
+  document.URL, ns.canScript, document.readyState);
+
+var notifyPage = async () => {
   debug("Page %s shown, %s", document.URL, document.readyState);
   if (document.readyState === "complete") {
     try {
-      await Messages.send("pageshow", {seen: seen.list, canScript});
+      if (!("canScript" in ns)) {
+        let childPolicy = await Messages.send("fetchChildPolicy", {url: document.URL, contextUrl: top.location.href});
+        ns.config.CURRENT = childPolicy.CURRENT;
+        ns.setup(childPolicy.DEFAULT, childPolicy.MARKER);
+        return;
+      }
+
+      await Messages.send("pageshow", {seen: seen.list, canScript: ns.canScript});
       return true;
     } catch (e) {
       debug(e);
+      if (/Receiving end does not exist/.test(e.message)) {
+        window.setTimeout(notifyPage, 2000);
+      }
     }
   }
   return false;
 }
 
-var queryingStatus = false;
-
-function reload(noCache = false) {
-  init = () => {};
-  location.reload(noCache);
-}
+notifyPage();
 
-async function init(oldPage = false) {
-  if (queryingStatus) return;
-  if (!document.URL.startsWith("http")) {
-    return;
-  }
-  queryingStatus = true;
+window.addEventListener("pageshow", notifyPage);
 
-  debug(`init() called in document %s, contentType %s readyState %s, frameElement %o`,
-    document.URL, document.contentType, document.readyState, window.frameElement && frameElement.data);
-  
-  try {
-    ({canScript, shouldScript} = await Messages.send("queryDocStatus", {url: document.URL}));
-    debug(`document %s, canScript=%s, shouldScript=%s, readyState %s`, document.URL, canScript, shouldScript, document.readyState);
-    if (canScript) {
-      if (oldPage) {
-        probe();
-        return;
-      }
-      if (!shouldScript && 
-          (document.readyState !== "complete" || 
-            now() - performance.timing.domContentLoadedEventStart < 5000)) {
-        // Something wrong: scripts can run, permissions say they shouldn't.
-        // Was webRequest bypassed by caching/session restore/service workers?
-        window.stop();
-        let noCache = !!navigator.serviceWorker.controller;
-        if (noCache) {
-           for (let r of await navigator.serviceWorker.getRegistrations()) {
-             await r.unregister();
-           }
-        }
-        debug("Reloading %s (%s)", document.URL, noCache  ? "no cache" : "cached");
-        reload(noCache);
-        return;
-      }
-    }
-    init = () => {};
-  } catch (e) {
-    debug("Error querying docStatus", e);
-    if (!oldPage &&
-      /Receiving end does not exist/.test(e.message)) {
-      // probably startup and bg page not ready yet, hence no CSP: reload!
-      debug("Reloading", document.URL);
-      reload();
-    } else {
-      setTimeout(() => init(oldPage), 100);
-    }
-    return;
-  } finally {
-    queryingStatus = false;
-  }
-
-  if (!canScript) onScriptDisabled();
+ns.on("capabilities", () => {
   seen.record({
       request: {
         key: "noscript-probe",
@@ -230,21 +80,13 @@ async function init(oldPage = false) {
         documentUrl: document.URL,
         type: window === window.top ? "main_frame" : "script",
       },
-      allowed: canScript
-    }
-  );
-
-  debug(`Loading NoScript in document %s, scripting=%s, readyState %s`,
-    document.URL, canScript, document.readyState);
-
-  if (/application|video|audio/.test(document.contentType)) {
-    debug("Embedding document detected");
-    embeddingDocument = true;
-    window.addEventListener("pageshow", e => {
-      debug("Active content still in document %s: %o", document.url, document.querySelectorAll("embed,object,video,audio"));
-    }, true);
-    // document.write("<plaintext>");
+      allowed: ns.canScript
+    });
+  
+  if (!ns.canScript) {
+    if (document.readyState !== "loading") onScriptDisabled();
+    window.addEventListener("DOMContentLoaded", onScriptDisabled);
   }
+  
   notifyPage();
-  addEventListener("pageshow", notifyPage);
-}
+});
diff --git a/src/content/dynamicNS.js b/src/content/dynamicNS.js
new file mode 100644
index 0000000..cdd7a0e
--- /dev/null
+++ b/src/content/dynamicNS.js
@@ -0,0 +1,21 @@
+'use strict';
+
+// ensure the order which manifest scripts and dynamically registered scripts
+// are executed in doesn't matter for initialization, by using a stub.
+
+if (!this.ns) {
+  let deferredSetup = null;
+  let nsStub = this.ns = {
+    config: {},
+    setup(DEFAULT, MARKER) {
+      deferredSetup = [DEFAULT, MARKER];
+    },
+    merge: ns => {
+      ns.config = Object.assign(ns.config, nsStub.config);
+      this.ns = ns;
+      if (deferredSetup) {
+        ns.setup(...deferredSetup);
+      }
+    }
+  }
+}
diff --git a/src/content/embeddingDocument.js b/src/content/embeddingDocument.js
new file mode 100644
index 0000000..75b0db0
--- /dev/null
+++ b/src/content/embeddingDocument.js
@@ -0,0 +1,20 @@
+if (ns.embeddingDocument) {
+  ns.on("capabilities", () => {
+    for (let policyType of ["object", "media"]) {
+      if (!ns.allows(policyType)) {
+        let request = {
+          id: `noscript-${policyType}-doc`,
+          type: policyType,
+          url: document.URL,
+          documentUrl: document.URL,
+          embeddingDocument: true,
+        };
+        let ph = PlaceHolder.create(policyType, request);
+        if (ph.replacements.size > 0) {
+          debug(`Created placeholder for ${policyType} at ${document.URL}`);
+          seen.record({policyType, request, allowed: false});
+        }
+      }
+    }
+  });
+}
diff --git a/src/content/media.js b/src/content/media.js
index 910fd27..770a43f 100644
--- a/src/content/media.js
+++ b/src/content/media.js
@@ -1,5 +1,5 @@
-ns.on("perms", event => {
-  debug("Media Hook", document.URL, document.documentElement && document.documentElement.innerHTML, ns.perms.CURRENT); // DEV_ONLY
+ns.on("capabilities", event => {
+  debug("Media Hook", document.URL, document.documentElement && document.documentElement.innerHTML, ns.capabilities); // DEV_ONLY
   let mediaBlocker = !ns.allows("media");
   let unpatched = new Map();
   function patch(obj, methodName, replacement) {
diff --git a/src/content/staticNS.js b/src/content/staticNS.js
new file mode 100644
index 0000000..817351a
--- /dev/null
+++ b/src/content/staticNS.js
@@ -0,0 +1,99 @@
+'use strict';
+{
+  let listenersMap = new Map();
+  let backlog = new Set();
+  
+  let ns = {
+    debug: true, // DEV_ONLY
+    get embeddingDocument() {
+      delete this.embeddingDocument;
+      return this.embeddingDocument = CSP.isEmbedType(document.contentType);
+    },
+    on(eventName, listener) {
+      let listeners = listenersMap.get(eventName);
+      if (!listeners) listenersMap.set(eventName, listeners = new Set());
+      listeners.add(listener);
+      if (backlog.has(eventName)) this.fire(eventName, listener);
+    },
+    detach(eventName, listener) {
+      let listeners = listenersMap.get(eventName);
+      if (listeners) listeners.delete(listener);
+    },
+    fire(eventName, listener = null) {
+      if (listener) {
+        listener({type:eventName, source: this});
+        return;
+      }
+      let listeners = listenersMap.get(eventName);
+      if (listeners) {
+        for (let l of listeners) {
+          this.fire(eventName, l);
+        }
+      }
+      backlog.add(eventName);
+    },
+    
+    setup(DEFAULT, MARKER) {
+      this.config.DEFAULT = DEFAULT;
+      if(!this.config.CURRENT) this.config.CURRENT = DEFAULT;
+
+      // ugly hack: since now we use registerContentScript instead of the
+      // filterRequest dynamic script injection hack, we use top.name
+      // to store per-tab information. We don't want web content to
+      // mess with it, though, so we wrap it around auto-hiding accessors
+      this.config.MARKER = MARKER;
+      let eraseTabInfoRx = new RegExp(`[^]*${MARKER},?`);
+      if (eraseTabInfoRx.test(top.name)) {
+        let _name = top.name;
+        let tabInfoRx = new RegExp(`^${MARKER}\\[([^]*?)\\]${MARKER},`);
+        if (top === window) { // wrap to hide
+          Reflect.defineProperty(top.wrappedJSObject, "name", {
+            get: exportFunction(() => top.name.replace(eraseTabInfoRx, ""), top.wrappedJSObject),
+            set: exportFunction(value => {
+              let preamble = top.name.match(tabInfoRx);
+              top.name = `${preamble && preamble[0] || ""}${value}`;
+              return value;
+            }, top.wrappedJSObject)
+          });
+        }
+        let tabInfoMatch = _name.match(tabInfoRx);
+        if (tabInfoMatch) try {
+          this.config.tabInfo = JSON.parse(tabInfoMatch[1]);
+        } catch (e) {
+          error(e);
+        }
+      }
+      
+      if (!this.config.DEFAULT || this.config.tabInfo.unrestricted) {
+        this.allows = () => true;
+        this.capabilities =  Object.assign(
+          new Set(["script"]), { has() { return true; } });
+      } else {
+        let perms = this.config.CURRENT;
+        this.capabilities = new Set(perms.capabilities);
+        new DocumentCSP(document).apply(this.capabilities, this.embeddingDocument);
+      }
+      
+      this.canScript = this.allows("script");
+      this.fire("capabilities");
+    },
+    config: { DEFAULT: null, CURRENT: null, tabInfo: {}, MARKER: "" },
+        
+    allows(cap) {
+      return this.capabilities && this.capabilities.has(cap);
+    },
+    
+    getWindowName() {
+      let marker = this.config.MARKER;
+      return (top === window && marker) ? 
+          window.name.split(`${marker},`).pop()
+          : window.name;
+    }
+  };
+  
+  if (this.ns) {
+    this.ns.merge(ns);
+  } else {
+    this.ns = ns;
+  }
+}
diff --git a/src/content/webglHook.js b/src/content/webglHook.js
index efafcd5..4475585 100644
--- a/src/content/webglHook.js
+++ b/src/content/webglHook.js
@@ -1,5 +1,5 @@
-ns.on("perms", event => {
-  debug("WebGL Hook", document.URL, document.documentElement && document.documentElement.innerHTML, ns.perms.CURRENT); // DEV_ONLY
+ns.on("capabilities", event => {
+  debug("WebGL Hook", document.URL, document.documentElement && document.documentElement.innerHTML, ns.capabilities); // DEV_ONLY
   if (ns.allows("webgl")) return;
   let proto = HTMLCanvasElement.prototype;
   let getContext = proto.getContext;
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