Patch old code signature revisions as fallback (#94)

Sources/CLI/Commands/Download.swift

@@ -110,7 +110,7 @@ extension Download {
                     "The country provided does not match with the account you are using.",
                     "Supply a valid country using the \"--country\" flag."
                 ].joined(separator: " "), level: .error)
-            case StoreResponse.Error.passwordTokenExpired:
+            case StoreResponse.Error.passwordTokenExpired, StoreResponse.Error.passwordChanged:
                 logger.log("Token expired. Login again using the \"auth\" command.", level: .error)
             default:
                 logger.log("An unknown error has occurred.", level: .error)
@@ -164,7 +164,7 @@ extension Download {
                     "The country provided does not match with the account you are using.",
                     "Supply a valid country using the \"--country\" flag."
                 ].joined(separator: " "), level: .error)
-            case StoreResponse.Error.passwordTokenExpired:
+            case StoreResponse.Error.passwordTokenExpired, StoreResponse.Error.passwordChanged:
                 logger.log("Token expired. Login again using the \"auth\" command.", level: .error)
             default:
                 logger.log([
@@ -203,6 +203,30 @@ extension Download {
             logger.log("Applying patches...", level: .info)
             try signatureClient.appendMetadata(item: item, email: email)
             try signatureClient.appendSignature(item: item)
+        } catch {
+            switch error {
+            case SignatureClient.Error.fileNotFound:
+                logger.log(
+                    "App uses old code signature version, falling back to alternative patching mechanism.",
+                    level: .debug
+                )
+                logger.log("The produced app package may not be compatible with modern iOS releases.", level: .info)
+                applyOldPatches(item: item, email: email, path: path)
+            default:
+                logger.log("\(error)", level: .debug)
+                logger.log("Failed to apply patches. The ipa file will be left incomplete.", level: .error)
+                _exit(1)
+            }
+        }
+    }
+
+    private mutating func applyOldPatches(item: StoreResponse.Item, email: String, path: String) {
+        logger.log("Creating signature client...", level: .debug)
+        let signatureClient = SignatureClient(fileManager: .default, filePath: path)
+
+        do {
+            logger.log("Applying fallback patches...", level: .info)
+            try signatureClient.appendOldSignature(item: item)
         } catch {
             logger.log("\(error)", level: .debug)
             logger.log("Failed to apply patches. The ipa file will be left incomplete.", level: .error)

Sources/CLI/Commands/Purchase.swift

@@ -103,7 +103,7 @@ extension Purchase {
                     "The country provided does not match with the account you are using.",
                     "Supply a valid country using the \"--country\" flag."
                 ].joined(separator: " "), level: .error)
-            case StoreResponse.Error.passwordTokenExpired:
+            case StoreResponse.Error.passwordTokenExpired, StoreResponse.Error.passwordChanged:
                 logger.log("Token expired. Login again using the \"auth\" command.", level: .error)
             default:
                 logger.log("An unknown error has occurred.", level: .error)

Sources/StoreAPI/Signature/SignatureClient.swift

@@ -51,6 +51,18 @@ public final class SignatureClient: SignatureClientInterface {
             throw Error.invalidArchive
         }
 
+        try appendSignatureFromManfiest(forItem: item, inArchive: archive)
+    }
+
+    public func appendOldSignature(item: StoreResponse.Item) throws {
+        guard let archive = Archive(url: URL(fileURLWithPath: filePath), accessMode: .update) else {
+            throw Error.invalidArchive
+        }
+
+        try appendOldSignature(forItem: item, inArchive: archive)
+    }
+
+    private func appendSignatureFromManfiest(forItem item: StoreResponse.Item, inArchive archive: Archive) throws {
         let manifest = try readPlist(
             archive: archive,
             matchingSuffix: ".app/SC_Info/Manifest.plist",
@@ -87,6 +99,52 @@ public final class SignatureClient: SignatureClientInterface {
         try fileManager.removeItem(at: signatureBaseUrl)
     }
 
+    private func appendOldSignature(forItem item: StoreResponse.Item, inArchive archive: Archive) throws {
+        guard let infoEntry = archive.first(where: { $0.path.hasSuffix(".app/Info.plist") }) else {
+            throw Error.invalidAppBundle
+        }
+
+        let temporaryInfoURL = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(UUID().uuidString)
+        _ = try archive.extract(infoEntry, to: temporaryInfoURL, skipCRC32: true)
+        let infoData = try Data(contentsOf: temporaryInfoURL)
+
+        guard let infoPlist = try PropertyListSerialization.propertyList(
+            from: infoData,
+            format: nil
+        ) as? [String: Any] else {
+            throw Error.invalidAppBundle
+        }
+
+        guard let executableName = infoPlist["CFBundleExecutable"] as? String else {
+            throw Error.invalidAppBundle
+        }
+
+        let appBundleName = URL(fileURLWithPath: infoEntry.path)
+            .deletingLastPathComponent()
+            .deletingPathExtension()
+            .lastPathComponent
+
+        guard let signatureItem = item.signatures.first(where: { $0.id == 0 }) else {
+            throw Error.invalidSignature
+        }
+
+        let signatureBaseUrl = URL(fileURLWithPath: NSTemporaryDirectory()).appendingPathComponent(UUID().uuidString)
+        let signatureUrl = signatureBaseUrl
+            .appendingPathComponent("Payload")
+            .appendingPathComponent(appBundleName)
+            .appendingPathExtension("app")
+            .appendingPathComponent("SC_Info")
+            .appendingPathComponent(executableName)
+            .appendingPathExtension("sinf")
+
+        let signatureRelativePath = signatureUrl.path.replacingOccurrences(of: "\(signatureBaseUrl.path)/", with: "")
+
+        try fileManager.createDirectory(at: signatureUrl.deletingLastPathComponent(), withIntermediateDirectories: true)
+        try signatureItem.sinf.write(to: signatureUrl)
+        try archive.addEntry(with: signatureRelativePath, relativeTo: signatureBaseUrl)
+        try fileManager.removeItem(at: signatureBaseUrl)
+    }
+
     private func readPlist<T: Decodable>(archive: Archive, matchingSuffix: String, type: T.Type) throws -> T {
         guard let entry = archive.first(where: { $0.path.hasSuffix(matchingSuffix) }) else {
             throw Error.fileNotFound(matchingSuffix)
@@ -115,7 +173,7 @@ extension SignatureClient {
         }
     }
 
-    enum Error: Swift.Error {
+    public enum Error: Swift.Error {
         case invalidArchive
         case invalidAppBundle
         case invalidSignature

Sources/StoreAPI/Store/StoreResponse.swift

@@ -15,6 +15,7 @@ public enum StoreResponse {
 
     public enum Error: Int, Swift.Error {
         case unknownError = 0
+        case passwordChanged = 2002
         case genericError = 5002
         case codeRequired = 1
         case invalidLicense = 9610