[AltStore] Validates minimum iOS version when installing apps

AltStore/Operations/DownloadAppOperation.swift

@@ -52,25 +52,31 @@ class DownloadAppOperation: ResultOperation<InstalledApp>
                 var isDirectory: ObjCBool = false
                 guard FileManager.default.fileExists(atPath: fileURL.path, isDirectory: &isDirectory) else { throw OperationError.appNotFound }
                 
+                let temporaryDirectory = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
+                try FileManager.default.createDirectory(at: temporaryDirectory, withIntermediateDirectories: true, attributes: nil)
+                defer { try? FileManager.default.removeItem(at: temporaryDirectory) }
+                
+                let appBundleURL: URL
+                
                 if isDirectory.boolValue
                 {
                     // Directory, so assuming this is .app bundle.
                     guard Bundle(url: fileURL) != nil else { throw OperationError.invalidApp }
                     
-                    try FileManager.default.copyItem(at: fileURL, to: self.destinationURL, shouldReplace: true)
+                    appBundleURL = fileURL
                 }
                 else
                 {
                     // File, so assuming this is a .ipa file.
-                    
+                    appBundleURL = try FileManager.default.unzipAppBundle(at: fileURL, toDirectory: temporaryDirectory)
-                    let temporaryDirectory = FileManager.default.temporaryDirectory.appendingPathComponent(UUID().uuidString)
-                    try FileManager.default.createDirectory(at: temporaryDirectory, withIntermediateDirectories: true, attributes: nil)
-                    defer { try? FileManager.default.removeItem(at: temporaryDirectory) }
-                    
-                    let bundleURL = try FileManager.default.unzipAppBundle(at: fileURL, toDirectory: temporaryDirectory)
-                    try FileManager.default.copyItem(at: bundleURL, to: self.destinationURL, shouldReplace: true)
                 }
                 
+                guard let application = ALTApplication(fileURL: appBundleURL) else { throw OperationError.invalidApp }
+                
+                guard ProcessInfo.processInfo.isOperatingSystemAtLeast(application.minimumiOSVersion) else { throw OperationError.iOSVersionNotSupported(application) }
+                
+                try FileManager.default.copyItem(at: appBundleURL, to: self.destinationURL, shouldReplace: true)
+                
                 self.context.perform {
                     let app = self.context.object(with: self.app.objectID) as! App
                     

AltStore/Operations/OperationError.swift

@@ -7,6 +7,7 @@
 //
 
 import Foundation
+import AltSign
 
 enum OperationError: LocalizedError
 {
@@ -22,6 +23,8 @@ enum OperationError: LocalizedError
     case invalidApp
     case invalidParameters
     
+    case iOSVersionNotSupported(ALTApplication)
+    
     var errorDescription: String? {
         switch self {
         case .unknown: return NSLocalizedString("An unknown error occured.", comment: "")
@@ -32,6 +35,17 @@ enum OperationError: LocalizedError
         case .unknownUDID: return NSLocalizedString("Unknown device UDID.", comment: "")
         case .invalidApp: return NSLocalizedString("The app is invalid.", comment: "")
         case .invalidParameters: return NSLocalizedString("Invalid parameters.", comment: "")
+        case .iOSVersionNotSupported(let app):
+            let name = app.name
+            
+            var version = "iOS \(app.minimumiOSVersion.majorVersion).\(app.minimumiOSVersion.minorVersion)"
+            if app.minimumiOSVersion.patchVersion > 0
+            {
+                version += ".\(app.minimumiOSVersion.patchVersion)"
+            }
+            
+            let localizedDescription = String(format: NSLocalizedString("%@ requires %@.", comment: ""), name, version)
+            return localizedDescription
         }
     }
 }