From b73b590964151edaf24c37911e319588ad64a1e5 Mon Sep 17 00:00:00 2001
From: hackademix <giorgio@maone.net>
Date: Mon, 28 Sep 2020 23:21:33 +0200
Subject: [PATCH] Better cross-browser media handling.

---
 build.sh                         | 6 +++---
 src/content/content.js           | 6 ++++--
 src/content/embeddingDocument.js | 4 +++-
 src/content/media.js             | 4 ++--
 src/lib/CSP.js                   | 3 +++
 5 files changed, 15 insertions(+), 8 deletions(-)

diff --git a/build.sh b/build.sh
index de4051c..b9c73e5 100644
--- a/build.sh
+++ b/build.sh
@@ -19,7 +19,7 @@ strip_rc_ver() {
 VER=$(grep '"version":' "$MANIFEST_IN" | sed -re 's/.*": "(.*?)".*/\1/')
 if [ "$1" == "tag" ]; then
   echo "Tagging at $VER"
-  git tag -a "$VER" 
+  git tag -a "$VER"
   git push origin "$VER"
   exit 0
 fi
@@ -140,9 +140,9 @@ ln -fs $XPI.xpi "$BASE/latest.xpi"
 # create chromium pre-release
 rm -rf "$CHROMIUM"
 strip_rc_ver "$MANIFEST_OUT"
-# skip "application" manifest key
+# skip "application" manifest key and embeddingDocument.js
 (grep -B1000 '"name": "NoScript"' "$MANIFEST_OUT"; \
-  grep -A2000 '"version":' "$MANIFEST_OUT") > "$MANIFEST_OUT".tmp && \
+  grep -A2000 '"version":' "$MANIFEST_OUT" | grep -v 'content/embeddingDocument.js') > "$MANIFEST_OUT".tmp && \
   mv "$MANIFEST_OUT.tmp" "$MANIFEST_OUT"
 mv "$BUILD" "$CHROMIUM"
 web-ext $CHROMIUM_BUILD_OPTS --source-dir="$CHROMIUM" --artifacts-dir="$WEBEXT_OUT" $COMMON_BUILD_OPTS
diff --git a/src/content/content.js b/src/content/content.js
index f631ac1..7c49c1a 100644
--- a/src/content/content.js
+++ b/src/content/content.js
@@ -113,12 +113,14 @@ window.addEventListener("pageshow", notifyPage);
 let violations = new Set();
 window.addEventListener("securitypolicyviolation", e => {
   if (!e.isTrusted) return;
-  let {violatedDirective} = e;
+  let {violatedDirective, originalPolicy} = e;
   if (violatedDirective === `script-src 'none'`) onScriptDisabled();
 
   let type = violatedDirective.split("-", 1)[0]; // e.g. script-src 'none' => script
   let url = e.blockedURI;
-  if (/^data\b/.test(url) && !document.querySelector("video,audio")) return;
+  if (type === "media" && /^data\b/.test(url) && (!CSP.isMediaBlocker(originalPolicy) ||
+      ns.embeddingDocument || !document.querySelector("video,audio")))
+    return;
   if (!(url && url.includes(":"))) {
     url = document.URL;
   }
diff --git a/src/content/embeddingDocument.js b/src/content/embeddingDocument.js
index d565fc5..7439258 100644
--- a/src/content/embeddingDocument.js
+++ b/src/content/embeddingDocument.js
@@ -1,4 +1,5 @@
 if (ns.embeddingDocument) {
+
   let replace = () => {
     for (let policyType of ["object", "media"]) {
       let request = {
@@ -23,8 +24,9 @@ if (ns.embeddingDocument) {
       }
     }
   };
+
   ns.on("capabilities", () => {
-    if (!document.body.firstChild) { // we've been called early
+    if (!(document.body && document.body.firstChild)) { // we've been called early
       setTimeout(replace, 0);
       let types = {
         // Reminder: order is important because media matches also for
diff --git a/src/content/media.js b/src/content/media.js
index bb45aae..a75ccef 100644
--- a/src/content/media.js
+++ b/src/content/media.js
@@ -35,8 +35,8 @@ if ("MediaSource" in window) {
     }
     let processedURIs = new Set();
     addEventListener("securitypolicyviolation", e => {
-      let {blockedURI, violatedDirective} = e;
-      if (!(e.isTrusted && violatedDirective.startsWith("media-src"))) return;
+      let {blockedURI, violatedDirective, originalPolicy} = e;
+      if (!(e.isTrusted && violatedDirective === "media-src" && CSP.isMediaBlocker(originalPolicy))) return;
       if (mediaBlocker === undefined && /^data\b/.test(blockedURI)) { // Firefox 81 reports just "data"
         debug("mediaBlocker set via CSP listener.")
         mediaBlocker = true;
diff --git a/src/lib/CSP.js b/src/lib/CSP.js
index ad0afa2..74cb7e9 100644
--- a/src/lib/CSP.js
+++ b/src/lib/CSP.js
@@ -1,6 +1,9 @@
 "use strict";
 
 class CSP {
+  static isMediaBlocker(csp) {
+    return /(?:^| )media-src (?:'none'|http)(?:;|$)/.test(csp);
+  }
 
   build(...directives) {
     return directives.join(';');