From 6cf08f79ecedb707d7e1b9e04876f7f83520dc82 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?A=CC=81lvaro=20Velad=20Galva=CC=81n?= <ladvan91@hotmail.com>
Date: Mon, 6 May 2024 13:01:59 +0200
Subject: [PATCH 1/4] fix: Fix CBCS support in some platforms

---
 index.js | 34 ++++++++++++++++++++++++++++------
 1 file changed, 28 insertions(+), 6 deletions(-)

diff --git a/index.js b/index.js
index 3a26cf9..88a3719 100644
--- a/index.js
+++ b/index.js
@@ -202,10 +202,8 @@ class EmeEncryptionSchemePolyfill {
     }
 
     return capabilities.filter((capability) => {
-      // No specific scheme always works.  In addition, accept the specific
-      // scheme we guessed for this UA.
-      return !capability['encryptionScheme'] ||
-          capability['encryptionScheme'] == supportedScheme;
+      return checkSupportedScheme(
+          capability['encryptionScheme'], supportedScheme);
     });
   }
 }
@@ -369,10 +367,10 @@ class McEncryptionSchemePolyfill {
         configuration: requestedConfiguration,
       };
 
-      if (audioScheme && audioScheme != supportedScheme) {
+      if (audioScheme && !checkSupportedScheme(audioScheme, supportedScheme)) {
         return notSupportedResult;
       }
-      if (videoScheme && videoScheme != supportedScheme) {
+      if (videoScheme && !checkSupportedScheme(videoScheme, supportedScheme)) {
         return notSupportedResult;
       }
     }
@@ -600,6 +598,30 @@ function hasEncryptionScheme(mediaKeySystemAccess) {
   return false;
 }
 
+/**
+ * @param {?string} scheme Encryption scheme to check
+ * @param {?string} supportedScheme A guess at the encryption scheme this
+ *   supports.
+ * @return {boolean} True if the scheme is compatible.
+ */
+function checkSupportedScheme(scheme, supportedScheme) {
+  if (scheme && scheme != supportedScheme) {
+    if (scheme == 'cbcs') {
+      // Firefox supports CBCS since version 100, but does not yet implement
+      // encryptionScheme support.
+      if (parseInt(navigator.userAgent.split('Firefox/').pop(), 10) >= 100) {
+        return true;
+      }
+      // All Chromecast supports CBCS.
+      if (navigator.userAgent.includes('CrKey')) {
+        return true;
+      }
+    }
+    return false;
+  }
+  return true;
+}
+
 /**
  * The original requestMediaKeySystemAccess, before we patched it.
  *

From d77fca417b7a82654cf104868c0cdf21cc97c500 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?A=CC=81lvaro=20Velad=20Galva=CC=81n?= <ladvan91@hotmail.com>
Date: Tue, 7 May 2024 06:35:48 +0200
Subject: [PATCH 2/4] Update implementation

---
 index.js | 43 ++++++++++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 13 deletions(-)

diff --git a/index.js b/index.js
index aa4695b..a11b1b6 100644
--- a/index.js
+++ b/index.js
@@ -605,21 +605,26 @@ function hasEncryptionScheme(mediaKeySystemAccess) {
  * @return {boolean} True if the scheme is compatible.
  */
 function checkSupportedScheme(scheme, supportedScheme) {
-  if (scheme && scheme != supportedScheme) {
-    if (scheme == 'cbcs') {
-      // Firefox supports CBCS since version 100, but does not yet implement
-      // encryptionScheme support.
-      if (parseInt(navigator.userAgent.split('Firefox/').pop(), 10) >= 100) {
-        return true;
-      }
-      // All Chromecast supports CBCS.
-      if (navigator.userAgent.includes('CrKey')) {
-        return true;
-      }
+  if (!scheme) {
+    // Not encrypted = always supported
+    return true;
+  }
+
+  if (scheme == supportedScheme) {
+    // The assumed-supported legacy scheme for this platform.
+    return true;
+  }
+
+  if (scheme == 'cbcs' || scheme == 'cbcs-1-9') {
+    if (EncryptionSchemePolyfills.isRecentFirefox ||
+        EncryptionSchemePolyfills.isChromecast) {
+      // Firefox >= 100 supports CBCS, but doesn't support queries yet.
+      // Older Chromecast devices are assumed to support CBCS as well.
+      return true;
     }
-    return false;
   }
-  return true;
+
+  return false;
 }
 
 /**
@@ -664,6 +669,18 @@ class EncryptionSchemePolyfills {
   }
 }
 
+/**
+ * @const {boolean}
+ */
+EncryptionSchemePolyfills.isChromecast =
+    navigator.userAgent.includes('CrKey');
+
+/**
+ * @const {boolean}
+ */
+EncryptionSchemePolyfills.isRecentFirefox =
+    parseInt(navigator.userAgent.split('Firefox/').pop(), 10) >= 100;
+
 // Support for CommonJS and AMD module formats.
 /** @suppress {undefinedVars} */
 (() => {

From e2565c382fed69df52892bd60304a0a7193ebf1d Mon Sep 17 00:00:00 2001
From: Joey Parrish <joeyparrish@users.noreply.github.com>
Date: Tue, 7 May 2024 09:04:35 -0700
Subject: [PATCH 3/4] Drop null check

---
 index.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/index.js b/index.js
index a11b1b6..d2382ba 100644
--- a/index.js
+++ b/index.js
@@ -367,10 +367,10 @@ class McEncryptionSchemePolyfill {
         configuration: requestedConfiguration,
       };
 
-      if (audioScheme && !checkSupportedScheme(audioScheme, supportedScheme)) {
+      if (!checkSupportedScheme(audioScheme, supportedScheme)) {
         return notSupportedResult;
       }
-      if (videoScheme && !checkSupportedScheme(videoScheme, supportedScheme)) {
+      if (!checkSupportedScheme(videoScheme, supportedScheme)) {
         return notSupportedResult;
       }
     }

From 58ddea5f51672a32138f81c3519c3545fece7f73 Mon Sep 17 00:00:00 2001
From: Joey Parrish <joeyparrish@users.noreply.github.com>
Date: Tue, 7 May 2024 09:12:30 -0700
Subject: [PATCH 4/4] Tweak input type

---
 index.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/index.js b/index.js
index d2382ba..f2c4d6b 100644
--- a/index.js
+++ b/index.js
@@ -599,7 +599,7 @@ function hasEncryptionScheme(mediaKeySystemAccess) {
 }
 
 /**
- * @param {?string} scheme Encryption scheme to check
+ * @param {(string|undefined)} scheme Encryption scheme to check
  * @param {?string} supportedScheme A guess at the encryption scheme this
  *   supports.
  * @return {boolean} True if the scheme is compatible.