Bug/fix for lock bruteforce (trustwallet#878)

* Add UI fix for lock. Add fix for bruteforcing lock screen.

* Remove responsibility of displaying and hiding keyboard of LockController from Coordinators. Adjust wrok of lock screen.

* Add tests

* Adjust tests for LockEnterPasscodeViewController

* Remove optional type

Trust.xcodeproj/project.pbxproj

@@ -251,6 +251,7 @@
 		61FC5ED11FCFBDEB00CCB12A /* EtherNumberFormatterTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 61FC5ED01FCFBDEB00CCB12A /* EtherNumberFormatterTests.swift */; };
 		664D11A12007D59F0041A0B0 /* EstimateGasRequest.swift in Sources */ = {isa = PBXBuildFile; fileRef = 664D11A02007D59F0041A0B0 /* EstimateGasRequest.swift */; };
 		71A433702113860900985ADC /* ConfirmPaymentDetailsViewModelTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 71A4336F2113860900985ADC /* ConfirmPaymentDetailsViewModelTests.swift */; };
+		71B1B5312114570A00EF23E5 /* LockEnterPasscodeViewControllerTests.swift in Sources */ = {isa = PBXBuildFile; fileRef = 71B1B5302114570A00EF23E5 /* LockEnterPasscodeViewControllerTests.swift */; };
 		7301BA9220A3117000E1AFE5 /* AutoLock.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7301BA9120A3117000E1AFE5 /* AutoLock.swift */; };
 		7301BA9620AB1E5600E1AFE5 /* CookiesStore.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7301BA9520AB1E5600E1AFE5 /* CookiesStore.swift */; };
 		7302405C204C65DF00B327DF /* CollectibleTokenCategory.swift in Sources */ = {isa = PBXBuildFile; fileRef = 7302405B204C65DF00B327DF /* CollectibleTokenCategory.swift */; };
@@ -748,6 +749,7 @@
 		646C8C822C986358D7388602 /* Pods_Trust.framework */ = {isa = PBXFileReference; explicitFileType = wrapper.framework; includeInIndex = 0; path = Pods_Trust.framework; sourceTree = BUILT_PRODUCTS_DIR; };
 		664D11A02007D59F0041A0B0 /* EstimateGasRequest.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EstimateGasRequest.swift; sourceTree = "<group>"; };
 		71A4336F2113860900985ADC /* ConfirmPaymentDetailsViewModelTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = ConfirmPaymentDetailsViewModelTests.swift; sourceTree = "<group>"; };
+		71B1B5302114570A00EF23E5 /* LockEnterPasscodeViewControllerTests.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = LockEnterPasscodeViewControllerTests.swift; sourceTree = "<group>"; };
 		7301BA9120A3117000E1AFE5 /* AutoLock.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AutoLock.swift; sourceTree = "<group>"; };
 		7301BA9520AB1E5600E1AFE5 /* CookiesStore.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CookiesStore.swift; sourceTree = "<group>"; };
 		7302405B204C65DF00B327DF /* CollectibleTokenCategory.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CollectibleTokenCategory.swift; sourceTree = "<group>"; };
@@ -2009,6 +2011,14 @@
 			path = Views;
 			sourceTree = "<group>";
 		};
+		71B1B52F211456F700EF23E5 /* ViewControllers */ = {
+			isa = PBXGroup;
+			children = (
+				71B1B5302114570A00EF23E5 /* LockEnterPasscodeViewControllerTests.swift */,
+			);
+			path = ViewControllers;
+			sourceTree = "<group>";
+		};
 		73200B652044B21100118A82 /* Storage */ = {
 			isa = PBXGroup;
 			children = (
@@ -2244,6 +2254,7 @@
 		772C6DBC210A8B8100FCE4F1 /* Lock */ = {
 			isa = PBXGroup;
 			children = (
+				71B1B52F211456F700EF23E5 /* ViewControllers */,
 				772C6DBD210A8B8600FCE4F1 /* Coordinators */,
 			);
 			path = Lock;
@@ -3247,6 +3258,7 @@
 			files = (
 				771A8480203240BB00528D28 /* PreferencesControllerTests.swift in Sources */,
 				29F1C85620036887003780D8 /* AppTrackerTests.swift in Sources */,
+				71B1B5312114570A00EF23E5 /* LockEnterPasscodeViewControllerTests.swift in Sources */,
 				29BDF19F1FEE51650023A45F /* GasLimitConfigurationTests.swift in Sources */,
 				73200B642040B9D700118A82 /* CryptoAddressValidatorTest.swift in Sources */,
 				733AFC7C210907DE00C0AE35 /* GasViewModelTest.swift in Sources */,

Trust/Lock/Coordinators/AuthenticateUserCoordinator.swift

@@ -35,8 +35,6 @@ final class AuthenticateUserCoordinator: Coordinator {
     }
 
     func showAuthentication() {
-        lockEnterPasscodeViewController.showKeyboard()
-        lockEnterPasscodeViewController.showBioMerickAuth()
         lockEnterPasscodeViewController.cleanUserInput()
     }
 

Trust/Lock/Coordinators/LockEnterPasscodeCoordinator.swift

@@ -34,8 +34,6 @@ final class LockEnterPasscodeCoordinator: Coordinator {
             return
         }
 
-        lockEnterPasscodeViewController.showKeyboard()
-        lockEnterPasscodeViewController.showBioMerickAuth()
         lockEnterPasscodeViewController.cleanUserInput()
     }
 

Trust/Lock/Lock.swift

@@ -20,7 +20,11 @@ final class Lock: LockInterface {
     private let maxAttemptTime = "maxAttemptTime"
     private let autoLockType = "autoLockType"
     private let autoLockTime = "autoLockTime"
-    private let keychain = KeychainSwift(keyPrefix: Constants.keychainKeyPrefix)
+    private let keychain: KeychainSwift
+
+    init(keychain: KeychainSwift = KeychainSwift(keyPrefix: Constants.keychainKeyPrefix)) {
+        self.keychain = keychain
+    }
 
     func shouldShowProtection() -> Bool {
         return isPasscodeSet() && autoLockTriggered()
@@ -90,10 +94,11 @@ final class Lock: LockInterface {
         keychain.set(String(numberOfAttemptsSoFar), forKey: passcodeAttempts)
     }
 
-    func recordedMaxAttemptTime() -> Date {
-        //This method is called only when we knew that maxAttemptTime is set. So no worries with !.
-        let timeString = keychain.get(maxAttemptTime)!
-        return dateFormatter().date(from: timeString)!
+    func recordedMaxAttemptTime() -> Date? {
+        guard let timeString = keychain.get(maxAttemptTime) else {
+            return nil
+        }
+        return dateFormatter().date(from: timeString)
     }
 
     func incorrectMaxAttemptTimeIsSet() -> Bool {

Trust/Lock/ViewControllers/LockEnterPasscodeViewController.swift

@@ -19,9 +19,11 @@ final class LockEnterPasscodeViewController: LockPasscodeViewController {
         if lock.incorrectMaxAttemptTimeIsSet() {
             lockView.lockTitle.text = lockEnterPasscodeViewModel.tryAfterOneMinute
             maxAttemptTimerValidation()
+        } else {
+            showBiometricAuth()
         }
     }
-    func showBioMerickAuth() {
+    private func showBiometricAuth() {
         self.context = LAContext()
         self.touchValidation()
     }
@@ -54,8 +56,13 @@ final class LockEnterPasscodeViewController: LockPasscodeViewController {
         self.hideKeyboard()
     }
     private func maxAttemptTimerValidation() {
+        // if there is no recordedMaxAttemptTime user has logged successfuly previous time
+        guard let maxAttemptTimer = lock.recordedMaxAttemptTime() else {
+            self.lockView.lockTitle.text = lockEnterPasscodeViewModel.initialLabelText
+            self.showKeyboard()
+            return
+        }
         let now = Date()
-        let maxAttemptTimer = lock.recordedMaxAttemptTime()
         let interval = now.timeIntervalSince(maxAttemptTimer)
         //if interval is greater or equal 60 seconds we give 1 attempt.
         if interval >= 60 {
@@ -71,7 +78,6 @@ final class LockEnterPasscodeViewController: LockPasscodeViewController {
         if let unlock = unlockWithResult {
             unlock(success, bioUnlock)
         }
-
     }
     private func canEvaluatePolicy() -> Bool {
         return context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: nil)
@@ -90,7 +96,7 @@ final class LockEnterPasscodeViewController: LockPasscodeViewController {
                     self.lockView.lockTitle.text = self.lockEnterPasscodeViewModel.initialLabelText
                     self.unlock(withResult: true, bioUnlock: true)
                  } else {
-                    self.showKeyboard()
+                    self.maxAttemptTimerValidation()
                 }
             }
         }

Trust/Lock/ViewControllers/LockPasscodeViewController.swift

@@ -6,11 +6,12 @@ class LockPasscodeViewController: UIViewController {
     var willFinishWithResult: ((_ success: Bool) -> Void)?
     let model: LockViewModel
     var lockView: LockView!
-    let lock = Lock()
+    let lock: Lock
     private var invisiblePasscodeField = UITextField()
     private var shouldIgnoreTextFieldDelegateCalls = false
-    init(model: LockViewModel) {
+    init(model: LockViewModel, lock: Lock = Lock()) {
         self.model = model
+        self.lock = lock
         super.init(nibName: nil, bundle: nil)
     }
     override func viewDidLoad() {
@@ -29,7 +30,7 @@ class LockPasscodeViewController: UIViewController {
             invisiblePasscodeField.resignFirstResponder()
         }
     }
-    private func configureInvisiblePasscodeField() {
+    public func configureInvisiblePasscodeField() {
         invisiblePasscodeField = UITextField()
         invisiblePasscodeField.keyboardType = .numberPad
         invisiblePasscodeField.isSecureTextEntry = true
@@ -38,7 +39,7 @@ class LockPasscodeViewController: UIViewController {
         view.addSubview(invisiblePasscodeField)
     }
 
-    private func configureLockView() {
+    public func configureLockView() {
         lockView = LockView(model)
         lockView.translatesAutoresizingMaskIntoConstraints = false
         view.addSubview(lockView)

Trust/Lock/ViewModels/LockViewModel.swift

@@ -3,7 +3,10 @@
 import UIKit
 
 class LockViewModel {
-    private let lock = Lock()
+    private let lock: Lock
+    init(lock: Lock = Lock()) {
+        self.lock = lock
+    }
     func charCount() -> Int {
         //This step is required for old clients to support 4 digit passcode.
         var count = 0

Trust/Lock/Views/LockView.swift

@@ -28,6 +28,7 @@ final class LockView: UIView {
         lockTitle.font = UIFont.systemFont(ofSize: 19)
         lockTitle.textAlignment = .center
         lockTitle.translatesAutoresizingMaskIntoConstraints = false
+        lockTitle.numberOfLines = 0
     }
     private func applyConstraints() {
         characterView.centerXAnchor.constraint(equalTo: self.centerXAnchor).isActive = true

Trust/Settings/Types/Constants.swift

@@ -8,6 +8,7 @@ public struct Constants {
     public static let changellyRefferalID = "968d4f0f0bf9"
     //
     public static let keychainKeyPrefix = "trustwallet"
+    public static let keychainTestsKeyPrefix = "trustwallet-tests"
 
     // social
     public static let website = "https://trustwalletapp.com"

TrustTests/Lock/ViewControllers/LockEnterPasscodeViewControllerTests.swift

@@ -0,0 +1,59 @@
+// Copyright DApps Platform Inc. All rights reserved.
+
+import XCTest
+import KeychainSwift
+@testable import Trust
+
+class LockEnterPasscodeViewControllerTests: XCTestCase {
+
+    let passcode = "123456"
+    let incorrectPasscode = "111111"
+
+    func testCorrectPasscodeInput() {
+        let lock = Lock(keychain: KeychainSwift(keyPrefix: Constants.keychainTestsKeyPrefix))
+        let lockViewModel = LockEnterPasscodeViewModel(lock: lock)
+        let vc = LockEnterPasscodeViewController(model: lockViewModel, lock: lock)
+        vc.configureLockView()
+        vc.configureInvisiblePasscodeField()
+
+        lock.setPasscode(passcode: passcode)
+
+        vc.enteredPasscode(passcode)
+
+        XCTAssertTrue(lock.numberOfAttempts() == 0)
+    }
+
+    func testIncorrectPasscodeInput() {
+        let lock = Lock(keychain: KeychainSwift(keyPrefix: Constants.keychainTestsKeyPrefix))
+        let lockViewModel = LockEnterPasscodeViewModel(lock: lock)
+        let vc = LockEnterPasscodeViewController(model: lockViewModel, lock: lock)
+        vc.configureLockView()
+        vc.configureInvisiblePasscodeField()
+
+        lock.setPasscode(passcode: passcode)
+
+        vc.enteredPasscode(incorrectPasscode)
+
+        XCTAssertTrue(lock.numberOfAttempts() > 0)
+    }
+
+    func testIncorrectPasscodeLimitInput() {
+        let lock = Lock(keychain: KeychainSwift(keyPrefix: Constants.keychainTestsKeyPrefix))
+
+        XCTAssertFalse(lock.incorrectMaxAttemptTimeIsSet())
+
+        let lockViewModel = LockEnterPasscodeViewModel(lock: lock)
+        let vc = LockEnterPasscodeViewController(model: lockViewModel, lock: lock)
+        vc.configureLockView()
+        vc.configureInvisiblePasscodeField()
+
+        lock.setPasscode(passcode: passcode)
+
+        while lock.numberOfAttempts() <= lockViewModel.passcodeAttemptLimit() {
+            vc.enteredPasscode(incorrectPasscode)
+        }
+
+        XCTAssertTrue(lock.incorrectMaxAttemptTimeIsSet())
+    }
+
+}