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.

AltStoreCore/Extensions/UserDefaults+AltStore.swift

@@ -52,6 +52,7 @@ public extension UserDefaults
     @NSManaged var trustedSourceIDs: [String]?
     @NSManaged var trustedServerURL: String?
     
+    @nonobjc
     var activeAppsLimit: Int? {
         get {
             return self._activeAppsLimit?.intValue
@@ -69,6 +70,8 @@ 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)
@@ -88,7 +91,8 @@ public extension UserDefaults
             #keyPath(UserDefaults.localServerSupportsRefreshing): localServerSupportsRefreshing,
             #keyPath(UserDefaults.requiresAppGroupMigration): true,
             #keyPath(UserDefaults.menuAnisetteList): "https://servers.sidestore.io/servers.json",
-            #keyPath(UserDefaults.menuAnisetteURL): "https://ani.sidestore.io"
+            #keyPath(UserDefaults.menuAnisetteURL): "https://ani.sidestore.io",
+            #keyPath(UserDefaults.ignoreActiveAppsLimit): false
         ] as [String : Any]
         
         UserDefaults.standard.register(defaults: defaults)

AltStoreCore/Model/InstalledApp.swift

@@ -12,8 +12,22 @@ import CoreData
 import AltSign
 import SemanticVersion
 
-// 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
 {

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)