Fix #8556: Add GPC toggle

Package.swift

@@ -409,6 +409,7 @@ var braveTarget: PackageDescription.Target = .target(
     .copy("Frontend/UserContent/UserScripts/Scripts_Dynamic/Scripts/DomainSpecific/Paged/FrameCheckWrapper.js"),
     .copy("Frontend/UserContent/UserScripts/Scripts_Dynamic/Scripts/Paged/CookieControlScript.js"),
     .copy("Frontend/UserContent/UserScripts/Scripts_Dynamic/Scripts/Paged/FarblingProtectionScript.js"),
+    .copy("Frontend/UserContent/UserScripts/Scripts_Dynamic/Scripts/Paged/gpc.js"),
     .copy("Frontend/UserContent/UserScripts/Scripts_Dynamic/Scripts/Paged/MediaBackgroundingScript.js"),
     .copy("Frontend/UserContent/UserScripts/Scripts_Dynamic/Scripts/Paged/PlaylistScript.js"),
     .copy("Frontend/UserContent/UserScripts/Scripts_Dynamic/Scripts/Paged/PlaylistSwizzlerScript.js"),

Sources/Brave/Frontend/Browser/PageData.swift

@@ -9,6 +9,7 @@ import Data
 import BraveShared
 import BraveCore
 import Shared
+import BraveShields
 
 /// The data for the current web-page which is needed for loading and executing privacy scripts
 ///
@@ -71,7 +72,9 @@ struct PageData {
 
   /// Return all the user script types for this page. The number of script types grows as more frames are loaded.
   @MainActor func makeUserScriptTypes(domain: Domain) async -> Set<UserScriptType> {
-    var userScriptTypes: Set<UserScriptType> = [.siteStateListener]
+    var userScriptTypes: Set<UserScriptType> = [
+      .siteStateListener, .gpc(ShieldPreferences.enableGPC.value)
+    ]
 
     // Handle dynamic domain level scripts on the main document.
     // These are scripts that change depending on the domain and the main document

Sources/Brave/Frontend/Browser/User Scripts/ScriptFactory.swift

@@ -124,6 +124,11 @@ class ScriptFactory {
       let source = try makeScriptSource(of: .nacl)
       resultingScript = WKUserScript(source: source, injectionTime: .atDocumentStart, forMainFrameOnly: false, in: .page)
 
+    case .gpc(let isEnabled):
+      let source = try makeScriptSource(of: .gpc)
+        .replacingOccurrences(of: "$<is_enabled>", with: isEnabled ? "true" : "false")
+      resultingScript = WKUserScript(source: source, injectionTime: .atDocumentStart, forMainFrameOnly: false, in: .page)
+
     case .domainUserScript(let domainUserScript):
       resultingScript = try self.makeScript(for: domainUserScript)
 

Sources/Brave/Frontend/Browser/User Scripts/ScriptSourceType.swift

@@ -22,13 +22,16 @@ enum ScriptSourceType {
   /// This script is a modification of the android and desktop script found here:
   /// https://github.com/brave/brave-core/blob/master/components/cosmetic_filters/resources/data/content_cosmetic.ts
   case selectorsPoller
+  /// Global Privacy Control script
+  case gpc
 
   var fileName: String {
     switch self {
     case .nacl: return "nacl.min"
     case .farblingProtection: return "FarblingProtectionScript"
     case .frameCheckWrapper: return "FrameCheckWrapper"
     case .selectorsPoller: return "SelectorsPollerScript"
+    case .gpc: return "gpc"
     }
   }
 

Sources/Brave/Frontend/Browser/User Scripts/UserScriptType.swift

@@ -63,6 +63,8 @@ enum UserScriptType: Hashable {
   /// Selectors poller script (aka cosmetic filtering script) is responsible for hiding and unhiding css elements as dictated by the ad-block engines.
   /// This script is actually executed rather than injected and this type is solely used for the creation rather than the injection of the script.
   case selectorsPoller(SelectorsPollerSetup)
+  /// Global Privacy Control (GPC) script
+  case gpc(Bool)
 
   /// The order in which we want to inject the scripts
   var order: Int {
@@ -72,7 +74,8 @@ enum UserScriptType: Hashable {
     case .domainUserScript: return 2
     case .siteStateListener: return 3
     case .selectorsPoller: return 4
-    case .engineScript(let configuration): return 5 + configuration.order
+    case .gpc: return 5
+    case .engineScript(let configuration): return 6 + configuration.order
     }
   }
 }
@@ -88,6 +91,8 @@ extension UserScriptType: CustomDebugStringConvertible {
       return "farblingProtection(\(etld))"
     case .nacl:
       return "nacl"
+    case .gpc(let isEnabled):
+      return "gpc(\(isEnabled)"
     case .siteStateListener:
       return "siteStateListener"
     case .selectorsPoller:

Sources/Brave/Frontend/Settings/Features/ShieldsPrivacy/DefaultShieldsSectionView.swift

@@ -97,6 +97,12 @@ struct DefaultShieldsViewView: View {
         option: Preferences.Shields.fingerprintingProtection
       )
 
+      OptionToggleView(
+        title: Strings.Shields.enableGPCLabel,
+        subtitle: Strings.Shields.enableGPCDescription,
+        option: ShieldPreferences.enableGPC
+      )
+
       ShieldToggleView(
         title: Strings.blockCookieConsentNotices,
         subtitle: nil,

Sources/Brave/Frontend/UserContent/UserScripts/Scripts_Dynamic/Scripts/Paged/gpc.js

@@ -0,0 +1,13 @@
+// Copyright 2023 The Brave Authors. All rights reserved.
+// This Source Code Form is subject to the terms of the Mozilla Public
+// License, v. 2.0. If a copy of the MPL was not distributed with this
+// file, You can obtain one at https://mozilla.org/MPL/2.0/.
+
+'use strict'
+
+Object.defineProperty(navigator, 'globalPrivacyControl', {
+  enumerable: false,
+  configurable: false,
+  writable: false,
+  value: $<is_enabled>
+})

Sources/BraveShields/ShieldPreferences.swift

@@ -21,4 +21,10 @@ public class ShieldPreferences {
     get { ShieldLevel(rawValue: blockAdsAndTrackingLevelRaw.value) ?? defaultBlockAdsAndTrackingLevel }
     set { blockAdsAndTrackingLevelRaw.value = newValue.rawValue }
   }
+
+  /// A boolean value inidicating if GPC is enabled
+  public static var enableGPC = Preferences.Option<Bool>(
+    key: "shields.enable-gpc",
+    default: true
+  )
 }

Sources/BraveShields/ShieldStrings.swift

@@ -146,3 +146,20 @@ public extension Strings.Shields {
     comment: "A button that ignores the brave player"
   )
 }
+
+// MARK: - Shields
+public extension Strings.Shields {
+  /// A label of the GPC toggle
+  static let enableGPCLabel = NSLocalizedString(
+    "EnableGPCLabel", tableName: "BraveShared", bundle: .module,
+    value: "Enable Global Privacy Control",
+    comment: "A label of the GPC toggle"
+  )
+
+  /// A description of what the Enable GPC toggle does
+  static let enableGPCDescription = NSLocalizedString(
+    "EnableGPCDescription", tableName: "BraveShared", bundle: .module,
+    value: "Enable the Global Privacy Control JS API",
+    comment: "A description of what the Enable GPC toggle does"
+  )
+}

Tests/ClientTests/PageDataTests.swift

@@ -5,6 +5,7 @@
 
 import XCTest
 import WebKit
+import BraveShields
 @testable import Brave
 
 final class PageDataTests: XCTestCase {
@@ -14,7 +15,6 @@ final class PageDataTests: XCTestCase {
     let mainFrameURL = URL(string: "http://example.com")!
     let subFrameURL = URL(string: "http://example.com/1p/subframe")!
     let upgradedMainFrameURL = URL(string: "https://example.com")!
-    let upgradedSubFrameURL = URL(string: "https://example.com/1p/subframe")!
     var pageData = PageData(mainFrameURL: mainFrameURL, adBlockStats: AdBlockStats())
     let expectation = expectation(description: "")
 
@@ -28,7 +28,7 @@ final class PageDataTests: XCTestCase {
       // We get only entries of the main frame
       // NOTE: If we were to add some engines we might see additional types
       let expectedMainFrameTypes: Set<UserScriptType> = [
-        .siteStateListener, .nacl, .farblingProtection(etld: "example.com")
+        .siteStateListener, .nacl, .farblingProtection(etld: "example.com"), .gpc(ShieldPreferences.enableGPC.value)
       ]
       XCTAssertEqual(mainFrameRequestTypes, expectedMainFrameTypes)
 
@@ -50,7 +50,7 @@ final class PageDataTests: XCTestCase {
       // If we were to add some engines we might see additional types
       let addedSubFrameFrameRequestTypes = await pageData.makeUserScriptTypes(domain: domain)
       let expectedMainAndSubFrameTypes: Set<UserScriptType> = [
-        .siteStateListener, .nacl, .farblingProtection(etld: "example.com")
+        .siteStateListener, .nacl, .farblingProtection(etld: "example.com"), .gpc(ShieldPreferences.enableGPC.value)
       ]
       XCTAssertEqual(expectedMainAndSubFrameTypes, addedSubFrameFrameRequestTypes)