Supports sideloading more than 3 apps via MacDirtyCow exploit

The MacDirtyCow exploit allows users to remove the 3 active apps limit on iOS 16.1.2 and earlier. To support this, we’ve added a new (hidden) “Enforce 3-App Limit” setting that can be disabled to allow sideloading more than 3 apps.
2026-02-09 06:43:25 +01:00 · 2023-02-06 17:36:05 -06:00
parent 90b4fa7605
commit eeea64f780
7 changed files with 118 additions and 11 deletions
--- a/Apps/MyAppsViewController.swift
+++ b/Apps/MyAppsViewController.swift
@@ -991,7 +991,7 @@ private extension MyAppsViewController
    
    @objc func presentInactiveAppsAlert()
    {
-        let message: String
+        var message: String
        
        if UserDefaults.standard.activeAppLimitIncludesExtensions
        {
@@ -1000,6 +1000,12 @@ private extension MyAppsViewController
        else
        {
            message = NSLocalizedString("Non-developer Apple IDs are limited to 3 apps. Inactive apps are backed up and uninstalled so they don't count towards your total, but will be reinstalled with all their data when activated again.", comment: "")
+            
+            if UserDefaults.standard.ignoreActiveAppsLimit
+            {
+                message += "\n\n"
+                message += NSLocalizedString("If you're using the MacDirtyCow exploit to remove the 3-app limit, you can install up to 10 apps and app extensions instead.", comment: "")
+            }
        }
                
        let alertController = UIAlertController(title: NSLocalizedString("What are inactive apps?", comment: ""), message: message, preferredStyle: .alert)
--- a/AltStore/Operations/AuthenticationOperation.swift
+++ b/AltStore/Operations/AuthenticationOperation.swift
@@ -245,7 +245,7 @@ class AuthenticationOperation: ResultOperation<(ALTTeam, ALTCertificate, ALTAppl
                let activeAppsMinimumVersion = OperatingSystemVersion(majorVersion: 13, minorVersion: 3, patchVersion: 1)
                if team.type == .free, ProcessInfo.processInfo.isOperatingSystemAtLeast(activeAppsMinimumVersion)
                {
-                    UserDefaults.standard.activeAppsLimit = ALTActiveAppsLimit
+                    UserDefaults.standard.activeAppsLimit = InstalledApp.freeAccountActiveAppsLimit
                }
                else
                {
--- a/AltStore/Settings/Settings.storyboard
+++ b/AltStore/Settings/Settings.storyboard
@@ -518,6 +518,46 @@
                                    </tableViewCell>
                                </cells>
                            </tableViewSection>
+                            <tableViewSection headerTitle="" id="2em-H5-kgS">
+                                <cells>
+                                    <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" preservesSuperviewLayoutMargins="YES" selectionStyle="default" indentationWidth="10" rowHeight="51" id="n3X-OX-idC" customClass="InsetGroupTableViewCell" customModule="AltStore" customModuleProvider="target">
+                                        <rect key="frame" x="0.0" y="957" width="375" height="51"/>
+                                        <autoresizingMask key="autoresizingMask"/>
+                                        <tableViewCellContentView key="contentView" opaque="NO" clipsSubviews="YES" multipleTouchEnabled="YES" contentMode="center" preservesSuperviewLayoutMargins="YES" insetsLayoutMarginsFromSafeArea="NO" tableViewCell="n3X-OX-idC" id="IVp-7k-KdM">
+                                            <rect key="frame" x="0.0" y="0.0" width="375" height="51"/>
+                                            <autoresizingMask key="autoresizingMask"/>
+                                            <subviews>
+                                                <label opaque="NO" userInteractionEnabled="NO" contentMode="left" horizontalHuggingPriority="251" verticalHuggingPriority="251" text="Enforce 3-App Limit" textAlignment="natural" lineBreakMode="tailTruncation" baselineAdjustment="alignBaselines" adjustsFontSizeToFit="NO" translatesAutoresizingMaskIntoConstraints="NO" id="IY0-94-5LN">
+                                                    <rect key="frame" x="30" y="15.5" width="163" height="20.5"/>
+                                                    <fontDescription key="fontDescription" type="boldSystem" pointSize="17"/>
+                                                    <color key="textColor" white="1" alpha="1" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                                                    <nil key="highlightedColor"/>
+                                                </label>
+                                                <switch opaque="NO" contentMode="scaleToFill" horizontalHuggingPriority="750" verticalHuggingPriority="750" contentHorizontalAlignment="center" contentVerticalAlignment="center" on="YES" translatesAutoresizingMaskIntoConstraints="NO" id="Oie-te-KSQ">
+                                                    <rect key="frame" x="296" y="10" width="51" height="31"/>
+                                                    <connections>
+                                                        <action selector="toggleEnforceThreeAppLimit:" destination="aMk-Xp-UL8" eventType="valueChanged" id="tfb-kk-C17"/>
+                                                    </connections>
+                                                </switch>
+                                            </subviews>
+                                            <constraints>
+                                                <constraint firstItem="IY0-94-5LN" firstAttribute="leading" secondItem="IVp-7k-KdM" secondAttribute="leadingMargin" id="07y-eS-INC"/>
+                                                <constraint firstItem="Oie-te-KSQ" firstAttribute="centerY" secondItem="IVp-7k-KdM" secondAttribute="centerY" id="1dS-uM-gb1"/>
+                                                <constraint firstItem="IY0-94-5LN" firstAttribute="centerY" secondItem="IVp-7k-KdM" secondAttribute="centerY" id="FyZ-BM-Ss0"/>
+                                                <constraint firstAttribute="trailingMargin" secondItem="Oie-te-KSQ" secondAttribute="trailing" id="I1v-Ub-eJJ"/>
+                                            </constraints>
+                                        </tableViewCellContentView>
+                                        <color key="backgroundColor" white="1" alpha="0.14999999999999999" colorSpace="custom" customColorSpace="genericGamma22GrayColorSpace"/>
+                                        <edgeInsets key="layoutMargins" top="8" left="30" bottom="8" right="30"/>
+                                        <userDefinedRuntimeAttributes>
+                                            <userDefinedRuntimeAttribute type="number" keyPath="style">
+                                                <integer key="value" value="0"/>
+                                            </userDefinedRuntimeAttribute>
+                                            <userDefinedRuntimeAttribute type="boolean" keyPath="isSelectable" value="NO"/>
+                                        </userDefinedRuntimeAttributes>
+                                    </tableViewCell>
+                                </cells>
+                            </tableViewSection>
                            <tableViewSection headerTitle="" id="OMa-EK-hRI">
                                <cells>
                                    <tableViewCell clipsSubviews="YES" contentMode="scaleToFill" preservesSuperviewLayoutMargins="YES" selectionStyle="default" indentationWidth="10" rowHeight="51" id="FMZ-as-Ljo" customClass="InsetGroupTableViewCell" customModule="AltStore" customModuleProvider="target">
@@ -603,6 +643,7 @@
                        <outlet property="accountNameLabel" destination="CnN-M1-AYK" id="Ldc-Py-Bix"/>
                        <outlet property="accountTypeLabel" destination="434-MW-Den" id="mNB-QE-4Jg"/>
                        <outlet property="backgroundRefreshSwitch" destination="DPu-zD-Als" id="eiG-Hv-Vko"/>
+                        <outlet property="enforceThreeAppLimitSwitch" destination="Oie-te-KSQ" id="jKn-t1-gyk"/>
                        <outlet property="versionLabel" destination="bUR-rp-Nw2" id="85I-5R-hqz"/>
                    </connections>
                </tableViewController>
--- a/AltStore/Settings/SettingsViewController.swift
+++ b/AltStore/Settings/SettingsViewController.swift
@@ -25,6 +25,7 @@ extension SettingsViewController
        case instructions
        case techyThings
        case credits
+        case macDirtyCow
        case debug
    }
    
@@ -70,6 +71,7 @@ class SettingsViewController: UITableViewController
    @IBOutlet private var accountTypeLabel: UILabel!
    
    @IBOutlet private var backgroundRefreshSwitch: UISwitch!
+    @IBOutlet private var enforceThreeAppLimitSwitch: UISwitch!
    
    @IBOutlet private var versionLabel: UILabel!
    
@@ -146,6 +148,7 @@ private extension SettingsViewController
        }
        
        self.backgroundRefreshSwitch.isOn = UserDefaults.standard.isBackgroundRefreshEnabled
+        self.enforceThreeAppLimitSwitch.isOn = !UserDefaults.standard.ignoreActiveAppsLimit
        
        if self.isViewLoaded
        {
@@ -209,6 +212,16 @@ private extension SettingsViewController
        case .credits:
            settingsHeaderFooterView.primaryLabel.text = NSLocalizedString("CREDITS", comment: "")
            
+        case .macDirtyCow:
+            if isHeader
+            {
+                settingsHeaderFooterView.primaryLabel.text = NSLocalizedString("MACDIRTYCOW", comment: "")
+            }
+            else
+            {
+                settingsHeaderFooterView.secondaryLabel.text = NSLocalizedString("If you've removed the 3-sideloaded app limit via the MacDirtyCow exploit, disable this setting to sideload more than 3 apps at a time.", comment: "")
+            }
+            
        case .debug:
            settingsHeaderFooterView.primaryLabel.text = NSLocalizedString("DEBUG", comment: "")
        }
@@ -225,6 +238,20 @@ private extension SettingsViewController
        let size = settingsHeaderFooterView.contentView.systemLayoutSizeFitting(UIView.layoutFittingCompressedSize)
        return size.height
    }
+    
+    func isSectionHidden(_ section: Section) -> Bool
+    {
+        switch section
+        {
+        case .macDirtyCow:
+            let ios16_2 = OperatingSystemVersion(majorVersion: 16, minorVersion: 2, patchVersion: 0)
+            
+            let isMacDirtyCowExploitSupported = !ProcessInfo.processInfo.isOperatingSystemAtLeast(ios16_2)
+            return !(isMacDirtyCowExploitSupported && UserDefaults.standard.isDebugModeEnabled)
+            
+        default: return false
+        }
+    }
 }

 private extension SettingsViewController
@@ -279,6 +306,16 @@ private extension SettingsViewController
        UserDefaults.standard.isBackgroundRefreshEnabled = sender.isOn
    }
    
+    @IBAction func toggleEnforceThreeAppLimit(_ sender: UISwitch)
+    {
+        UserDefaults.standard.ignoreActiveAppsLimit = !sender.isOn
+        
+        if UserDefaults.standard.activeAppsLimit != nil
+        {
+            UserDefaults.standard.activeAppsLimit = InstalledApp.freeAccountActiveAppsLimit
+        }
+    }
+    
    @available(iOS 14, *)
    @IBAction func addRefreshAppsShortcut()
    {
@@ -376,6 +413,7 @@ extension SettingsViewController
        let section = Section.allCases[section]
        switch section
        {
+        case _ where isSectionHidden(section): return 0
        case .signIn: return (self.activeTeam == nil) ? 1 : 0
        case .account: return (self.activeTeam == nil) ? 0 : 3
        case .appRefresh: return AppRefreshRow.allCases.count
@@ -404,9 +442,10 @@ extension SettingsViewController
        let section = Section.allCases[section]
        switch section
        {
+        case _ where isSectionHidden(section): return nil
        case .signIn where self.activeTeam != nil: return nil
        case .account where self.activeTeam == nil: return nil
-        case .signIn, .account, .patreon, .appRefresh, .techyThings, .credits, .debug:
+        case .signIn, .account, .patreon, .appRefresh, .techyThings, .credits, .macDirtyCow, .debug:
            let headerView = tableView.dequeueReusableHeaderFooterView(withIdentifier: "HeaderFooterView") as! SettingsHeaderFooterView
            self.prepare(headerView, for: section, isHeader: true)
            return headerView
@@ -420,8 +459,9 @@ extension SettingsViewController
        let section = Section.allCases[section]
        switch section
        {
+        case _ where isSectionHidden(section): return nil
        case .signIn where self.activeTeam != nil: return nil
-        case .signIn, .patreon, .appRefresh:
+        case .signIn, .patreon, .appRefresh, .macDirtyCow:
            let footerView = tableView.dequeueReusableHeaderFooterView(withIdentifier: "HeaderFooterView") as! SettingsHeaderFooterView
            self.prepare(footerView, for: section, isHeader: false)
            return footerView
@@ -435,9 +475,10 @@ extension SettingsViewController
        let section = Section.allCases[section]
        switch section
        {
+        case _ where isSectionHidden(section): return 1.0
        case .signIn where self.activeTeam != nil: return 1.0
        case .account where self.activeTeam == nil: return 1.0
-        case .signIn, .account, .patreon, .appRefresh, .techyThings, .credits, .debug:
+        case .signIn, .account, .patreon, .appRefresh, .techyThings, .credits, .macDirtyCow, .debug:
            let height = self.preferredHeight(for: self.prototypeHeaderFooterView, in: section, isHeader: true)
            return height
            
@@ -450,9 +491,10 @@ extension SettingsViewController
        let section = Section.allCases[section]
        switch section
        {
+        case _ where isSectionHidden(section): return 1.0
        case .signIn where self.activeTeam != nil: return 1.0
        case .account where self.activeTeam == nil: return 1.0            
-        case .signIn, .patreon, .appRefresh:
+        case .signIn, .patreon, .appRefresh, .macDirtyCow:
            let height = self.preferredHeight(for: self.prototypeHeaderFooterView, in: section, isHeader: false)
            return height
            
@@ -520,7 +562,7 @@ extension SettingsViewController
            case .refreshAttempts: break
            }
            
-        case .account, .patreon, .instructions, .techyThings: break
+        case .account, .patreon, .instructions, .techyThings, .macDirtyCow: break
        }
    }
 }
--- a/AltStoreCore/Extensions/UserDefaults+AltStore.swift
+++ b/AltStoreCore/Extensions/UserDefaults+AltStore.swift
@@ -41,6 +41,7 @@ public extension UserDefaults
    
    @NSManaged var trustedSourceIDs: [String]?
    
+    @nonobjc
    var activeAppsLimit: Int? {
        get {
            return self._activeAppsLimit?.intValue
@@ -58,6 +59,8 @@ public extension UserDefaults
    }
    @NSManaged @objc(activeAppsLimit) private var _activeAppsLimit: NSNumber?
    
+    @NSManaged var ignoreActiveAppsLimit: Bool
+    
    class func registerDefaults()
    {
        let ios13_5 = OperatingSystemVersion(majorVersion: 13, minorVersion: 5, patchVersion: 0)
@@ -72,7 +75,8 @@ public extension UserDefaults
            #keyPath(UserDefaults.isLegacyDeactivationSupported): isLegacyDeactivationSupported,
            #keyPath(UserDefaults.activeAppLimitIncludesExtensions): activeAppLimitIncludesExtensions,
            #keyPath(UserDefaults.localServerSupportsRefreshing): localServerSupportsRefreshing,
-            #keyPath(UserDefaults.requiresAppGroupMigration): true
+            #keyPath(UserDefaults.requiresAppGroupMigration): true,
+            #keyPath(UserDefaults.ignoreActiveAppsLimit): false,
        ]
        
        UserDefaults.standard.register(defaults: defaults)
--- a/AltStoreCore/Model/InstalledApp.swift
+++ b/AltStoreCore/Model/InstalledApp.swift
@@ -11,8 +11,22 @@ import CoreData

 import AltSign

-// Free developer accounts are limited to only 3 active sideloaded apps at a time as of iOS 13.3.1.
-public let ALTActiveAppsLimit = 3
+extension InstalledApp
+{
+    public static var freeAccountActiveAppsLimit: Int {
+        if UserDefaults.standard.ignoreActiveAppsLimit
+        {
+            // MacDirtyCow exploit allows users to remove 3-app limit, so return 10 to match App ID limit per-week.
+            // Don't return nil because that implies there is no limit, which isn't quite true due to App ID limit.
+            return 10
+        }
+        else
+        {
+            // Free developer accounts are limited to only 3 active sideloaded apps at a time as of iOS 13.3.1.
+            return 3
+        }
+    }
+}

 public protocol InstalledAppProtocol: Fetchable
 {
--- a/AltStoreCore/Model/Migrations/Policies/InstalledAppPolicy.swift
+++ b/AltStoreCore/Model/Migrations/Policies/InstalledAppPolicy.swift
@@ -50,7 +50,7 @@ class InstalledAppToInstalledAppMigrationPolicy: NSEntityMigrationPolicy
            
            // We can assume there is an active app limit,
            // but will confirm next time user authenticates.
-            UserDefaults.standard.activeAppsLimit = ALTActiveAppsLimit
+            UserDefaults.standard.activeAppsLimit = InstalledApp.freeAccountActiveAppsLimit
        }
        
        return NSNumber(value: isActive)