From 16f88562645b219915a94a91d23f45db1913c739 Mon Sep 17 00:00:00 2001
From: hackademix <giorgio@maone.net>
Date: Fri, 29 May 2020 00:30:28 +0200
Subject: [PATCH] Unspoofable browser version detection.

---
 src/bg/RequestGuard.js | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/bg/RequestGuard.js b/src/bg/RequestGuard.js
index f244b3a..72d3da2 100644
--- a/src/bg/RequestGuard.js
+++ b/src/bg/RequestGuard.js
@@ -533,7 +533,11 @@ var RequestGuard = (() => {
       let filterAll = {urls: allUrls};
       listen("onBeforeRequest", filterAll, ["blocking"]);
 
-      const mergingCSP = parseInt(navigator.userAgent.replace(/.*Firefox\/(\d+).*/, "$1")) >= 77;
+      let mergingCSP = "getBrowserInfo" in browser.runtime;
+      if (mergingCSP) {
+        let {vendor, version} = await browser.runtime.getBrowserInfo();
+        mergingCSP = vendor === "Mozilla" && parseInt(version) >= 77;
+      }
       if (mergingCSP) {
         // In Gecko>=77 (https://bugzilla.mozilla.org/show_bug.cgi?id=1462989)
         // we need to cleanup our own cached headers in a dedicated listener :(