Replace cookie-based hacks with synchronous messaging (currently shimmed) to retrieve fallback and per-tab restriction policies.

src/bg/RequestGuard.js

@@ -287,8 +287,12 @@ var RequestGuard = (() => {
         if (policyType) {
           let {url, originUrl, documentUrl} = request;
           let isFetch = "fetch" === policyType;
+
           if ((isFetch || "frame" === policyType) &&
-              (((isFetch && !originUrl || url === originUrl) && originUrl === documentUrl
+              (((isFetch && (!originUrl ||
+                browser.runtime.onSyncMessage &&
+                url.includes(browser.runtime.onSyncMessage.ENDPOINT_PREFIX)
+                ) || url === originUrl) && originUrl === documentUrl
                 // some extensions make them both undefined,
                 // see https://github.com/eight04/image-picka/issues/150
               ) ||

src/bg/main.js

@@ -141,24 +141,26 @@
     },
 
     fetchChildPolicy({url, contextUrl}, sender) {
-      if (!url) url = sender.url;
       let {tab} = sender;
-      let tabUrl = tab.url;
+      let topUrl = tab.url || TabCache.get(tab.id);
-      if (!contextUrl) contextUrl = tabUrl;
-
       let policy = !Sites.isInternal(url) && ns.isEnforced(tab.id)
         ? ns.policy : null;
 
-      let permissions = Permissions.ALL;
+      let permissions, unrestricted, cascaded;
       if (policy) {
         let perms = policy.get(url, contextUrl).perms;
-        if (tabUrl && ns.sync.cascadeRestrictions) {
+        cascaded = ns.sync.cascadeRestrictions;
-          perms = policy.cascadeRestrictions(perms, tabUrl);
+        if (topUrl && cascaded) {
+          perms = policy.cascadeRestrictions(perms, topUrl);
         }
         permissions = perms.dry();
-      } // otherwise either internal URL or unrestricted
+      } else {
-
+        // otherwise either internal URL or unrestricted
-      return {permissions};
+        permissions = new Permissions(Permissions.ALL);
+        unrestricted = true;
+        cascaded = false;
+      }
+      return {permissions, unrestricted, cascaded};
     },
 
     async openStandalonePopup() {

src/content/content.js

@@ -58,10 +58,6 @@ var notifyPage = async () => {
   debug("Page %s shown, %s", document.URL, document.readyState);
   if (document.readyState === "complete") {
     try {
-      if (!("canScript" in ns)) {
-        ns.fetchPolicy();
-        return;
-      }
       await Messages.send("pageshow", {seen: seen.list, canScript: ns.canScript});
       return true;
     } catch (e) {
@@ -74,8 +70,6 @@ var notifyPage = async () => {
   return false;
 }
 
-notifyPage();
-
 window.addEventListener("pageshow", notifyPage);
 
 ns.on("capabilities", () => {
@@ -105,3 +99,6 @@ ns.on("capabilities", () => {
 
   notifyPage();
 });
+
+ns.fetchPolicy();
+notifyPage();

src/content/staticNS.js

@@ -33,78 +33,27 @@
       backlog.add(eventName);
     },
 
-    async fetchPolicy() {
+    fetchPolicy() {
-        let policy = await Messages.send("fetchChildPolicy", {url: document.URL});
+      let url = document.URL;
+      let policy = browser.runtime.sendSyncMessage(
+        {id: "fetchPolicy", url, contextUrl: document.URL});
       if (!policy) {
-          debug(`No answer to fetchChildPolicy message. This should not be happening.`);
+        debug(`No answer to fetchPolicy message. This should not be happening.`);
         return false;
       }
-        this.setup(policy.permissions, policy.MARKER, true);
+      this.setup(policy);
       return true;
     },
 
-    setup(permissions, MARKER, fetched = false) {
+    setup(policy) {
-      this.config.permissions = permissions;
+      this.policy = policy;
 
-      // ugly hack: since now we use registerContentScript instead of the
+      if (!policy.permissions || policy.unrestricted) {
-      // filterRequest dynamic script injection hack, we use a session cookie
-      // to store per-tab information,  erasing it as soon as we see it
-      // (before any content can access it)
-
-      let checkUnrestricted = challenge => sha256(`${MARKER}:${challenge}`);
-
-      if ((this.config.MARKER = MARKER) && permissions) {
-        let cookieRx = new RegExp(`(?:^|;\\s*)(${MARKER}(?:_\\d+){2})=([^;]*)`);
-        let match = document.cookie.match(cookieRx);
-        if (match) {
-          let [cookie, cookieName, cookieValue] = match;
-          // delete cookie NOW
-          document.cookie = `${cookieName}=;expires=${new Date(Date.now() - 31536000000).toGMTString()}`;
-          try {
-            this.config.tabInfo = JSON.parse(decodeURIComponent(cookieValue));
-          } catch (e) {
-            error(e);
-          }
-        } else if (UA.isMozilla && window !== window.top) {
-          // The cookie hack won't work for non-HTTP subframes (issue #48),
-          // or the cookie might have been deleted in a race condition,
-          // so here we try to check the parent
-          let checkParent = null;
-          try {
-            checkParent = parent.wrappedJSObject.checkNoScriptUnrestricted;
-          } catch (e) {
-            // may throw a SecurityException for cross-origin wrappedJSObject access
-          }
-          if (typeof checkParent  === "function") {
-            try {
-              let challenge = uuid();
-              let unrestricted = checkParent(challenge) === checkUnrestricted(challenge);
-              this.config.tabInfo = {unrestricted, inherited: true};
-            } catch (e) {
-              debug("Exception thrown while checking parent unrestricted tab marker. Something fishy going on...")
-              error(e);
-            }
-          }
-        }
-      }
-
-      if (!this.config.permissions || this.config.tabInfo.unrestricted) {
-        exportFunction(checkUnrestricted, window, {defineAs: "checkNoScriptUnrestricted"});
-        debug("%s is loading unrestricted by user's choice (%o).", document.URL, this.config);
         this.allows = () => true;
         this.capabilities =  Object.assign(
           new Set(["script"]), { has() { return true; } });
       } else {
-        if (!fetched) {
+        let perms = policy.permissions;
-          let hostname = window.location.hostname;
-          if (hostname && hostname.startsWith("[")) {
-            // WebExt match patterns don't seem to support IPV6 (Firefox 63)...
-            debug("Ignoring child policy setup parameters for IPV6 address %s, forcing IPC...", hostname);
-            this.fetchPolicy();
-            return;
-          }
-        }
-        let perms = this.config.permissions;
         this.capabilities = new Set(perms.capabilities);
         new DocumentCSP(document).apply(this.capabilities, this.embeddingDocument);
       }
@@ -112,7 +61,8 @@
       this.canScript = this.allows("script");
       this.fire("capabilities");
     },
-    config: { permissions: null, tabInfo: {}, MARKER: "" },
+
+    policy: null,
 
     allows(cap) {
       return this.capabilities && this.capabilities.has(cap);