Verifies downloaded app’s permissions match source

Renames source JSON permissions key to “appPermissions” in order to preserve backwards compatibility, since we’ve changed the schema for permissions.

AltStoreCore/Protocols/ALTAppPermission.swift

@@ -0,0 +1,89 @@
+//
+//  ALTAppPermission.swift
+//  AltStoreCore
+//
+//  Created by Riley Testut on 5/3/23.
+//  Copyright © 2023 Riley Testut. All rights reserved.
+//
+
+import AltSign
+
+public extension ALTAppPermissionType
+{
+    var localizedName: String? {
+        switch self
+        {
+        case .unknown: return NSLocalizedString("Permission", comment: "")
+        case .entitlement: return NSLocalizedString("Entitlement", comment: "")
+        case .privacy: return NSLocalizedString("Privacy Permission", comment: "")
+        case .backgroundMode: return NSLocalizedString("Background Mode", comment: "")
+        default: return nil
+        }
+    }
+}
+
+public protocol ALTAppPermission: RawRepresentable<String>, Hashable
+{
+    var type: ALTAppPermissionType { get }
+    var symbolName: String? { get }
+    
+    var localizedName: String? { get }
+    var localizedDisplayName: String { get } // Default implementation
+}
+
+public extension ALTAppPermission
+{
+    var localizedDisplayName: String {
+        return self.localizedName ?? self.rawValue
+    }
+    
+    func isEqual(_ permission: any ALTAppPermission) -> Bool
+    {
+        guard let permission = permission as? Self else { return false }
+        return self == permission
+    }
+    
+    static func ==(lhs: Self, rhs: any ALTAppPermission) -> Bool
+    {
+        return lhs.isEqual(rhs)
+    }
+}
+
+public struct UnknownAppPermission: ALTAppPermission
+{
+    public var type: ALTAppPermissionType { .unknown }
+    public var symbolName: String? { nil }
+    
+    public var localizedName: String? { nil }
+        
+    public var rawValue: String
+    
+    public init(rawValue: String)
+    {
+        self.rawValue = rawValue
+    }
+}
+
+extension ALTEntitlement: ALTAppPermission
+{
+    public var type: ALTAppPermissionType { .entitlement }
+    public var symbolName: String? { nil }
+    
+    public var localizedName: String? { nil }
+}
+
+extension ALTAppPrivacyPermission: ALTAppPermission
+{
+    public var type: ALTAppPermissionType { .privacy }
+    public var symbolName: String? { nil }
+    
+    public var localizedName: String? { nil }
+}
+
+extension ALTAppBackgroundMode: ALTAppPermission
+{
+    public var type: ALTAppPermissionType { .backgroundMode }
+    public var symbolName: String? { nil }
+    
+    public var localizedName: String? { nil }
+}