Keychain/Keystore Access for React Native

• Keychain/Keystore Access for React Native
  • Installation
  • Usage
  • API
    • setGenericPassword(username, password, [{ accessControl, accessible, accessGroup, service, securityLevel }])
    • getGenericPassword([{ authenticationPrompt, service, accessControl }])
    • resetGenericPassword([{ service }])
    • getAllGenericPasswordServices()
    • setInternetCredentials(server, username, password, [{ accessControl, accessible, accessGroup, securityLevel }])
    • hasInternetCredentials(server)
    • getInternetCredentials(server, [{ authenticationPrompt }])
    • resetInternetCredentials(server)
    • requestSharedWebCredentials() (iOS only)
    • setSharedWebCredentials(server, username, password) (iOS only)
    • canImplyAuthentication([{ authenticationType }]) (iOS only)
    • getSupportedBiometryType()
    • getSecurityLevel([{ accessControl }]) (Android only)
    • Options
      • Data Structure Properties/Fields
        • authenticationPrompt Properties
      • Keychain.ACCESS_CONTROL enum
      • Keychain.ACCESSIBLE enum
      • Keychain.AUTHENTICATION_TYPE enum
      • Keychain.BIOMETRY_TYPE enum
      • Keychain.SECURITY_LEVEL enum (Android only)
      • Keychain.STORAGE_TYPE enum (Android only)
      • Keychain.SECURITY_RULES enum (Android only)
  • Important Behavior
    • Rule 1: Automatic Security Level
  • Manual Installation
    • iOS
      • Option: Manually
      • Option: With CocoaPods
      • Enable Keychain Sharing entitlement for iOS 10+
    • Android
      • Option: Manually
      • Proguard Rules
  • Unit Testing with Jest
    • Using a Jest __mocks__ Directory
    • Using a Jest Setup File
  • Notes
    • Android Notes
      • Configuring the Android-specific behavior
    • iOS Notes
    • macOS Catalyst
    • Security
  • Maintainers
  • For Developers / Contributors
  • License

Installation

1. Run yarn add @getclave/react-native-keychain

   1 a. Only for React Native <= 0.59: $ react-native link @getclave/react-native-keychain and check MainApplication.java to verify the package was added. See manual installation below if you have issues with react-native link.

2. Run pod install in ios/ directory to install iOS dependencies.

3. If you want to support FaceID, add a NSFaceIDUsageDescription entry in your Info.plist.

4. Re-build your Android and iOS projects.

Usage

import * as Keychain from '@getclave/react-native-keychain';

async () => {
  const username = 'zuck';
  const password = 'poniesRgr8';

  // Store the credentials
  await Keychain.setGenericPassword(username, password);

  try {
    // Retrieve the credentials
    const credentials = await Keychain.getGenericPassword();
    if (credentials) {
      console.log(
        'Credentials successfully loaded for user ' + credentials.username
      );
    } else {
      console.log('No credentials stored');
    }
  } catch (error) {
    console.log("Keychain couldn't be accessed!", error);
  }
  await Keychain.resetGenericPassword();
};

See KeychainExample for fully working project example.

Both setGenericPassword and setInternetCredentials are limited to strings only, so if you need to store objects etc, please use JSON.stringify/JSON.parse when you store/access it.

API

setGenericPassword(username, password, [{ accessControl, accessible, accessGroup, service, securityLevel }])

Will store the username/password combination in the secure storage. Resolves to {service, storage} or rejects in case of an error. storage - is a name of used internal cipher for saving secret; service - name used for storing secret in internal storage (empty string resolved to valid default name).

getGenericPassword([{ authenticationPrompt, service, accessControl }])

Will retrieve the username/password combination from the secure storage. Resolves to { username, password, service, storage } if an entry exists or false if it doesn't. It will reject only if an unexpected error is encountered like lacking entitlements or permission.

resetGenericPassword([{ service }])

Will remove the username/password combination from the secure storage. Resolves to true in case of success.

getAllGenericPasswordServices()

Will retrieve all known service names for which a generic password has been stored (e.g., setGenericPassword).

Note: on iOS this will actully read the encrypted entries, so it will trigger an authentication UI if you have encrypted any entries with password/biometry.

setInternetCredentials(server, username, password, [{ accessControl, accessible, accessGroup, securityLevel }])

Will store the server/username/password combination in the secure storage. Resolves to { username, password, service, storage };

hasInternetCredentials(server)

Will check if the username/password combination for server is available in the secure storage. Resolves to true if an entry exists or false if it doesn't.

getInternetCredentials(server, [{ authenticationPrompt }])

Will retrieve the server/username/password combination from the secure storage. Resolves to { username, password } if an entry exists or false if it doesn't. It will reject only if an unexpected error is encountered like lacking entitlements or permission.

resetInternetCredentials(server)

Will remove the server/username/password combination from the secure storage.

requestSharedWebCredentials() (iOS only)

Asks the user for a shared web credential. Requires additional setup both in the app and server side, see Apple documentation. Resolves to { server, username, password } if approved and false if denied and throws an error if not supported on platform or there's no shared credentials.

setSharedWebCredentials(server, username, password) (iOS only)

Sets a shared web credential. Resolves to true when successful.

canImplyAuthentication([{ authenticationType }]) (iOS only)

Inquire if the type of local authentication policy is supported on this device with the device settings the user chose. Should be used in combination with accessControl option in the setter functions. Resolves to true if supported.

getSupportedBiometryType()

On iOS: Get what type of hardware biometry support the device can use for biometric encryption. Resolves to a Keychain.BIOMETRY_TYPE value when supported and enrolled, otherwise null.

On Android: Get what type of Class 3 (strong) biometry support the device has. Resolves to a Keychain.BIOMETRY_TYPE value when supported, otherwise null. In most devices this will return FINGERPRINT (except for Pixel 4 or similar where fingerprint sensor is not present).

This method returns null, if the device haven't enrolled into fingerprint/FaceId. Even though it has hardware for it.

getSecurityLevel([{ accessControl }]) (Android only)

Get security level that is supported on the current device with the current OS. Resolves to Keychain.SECURITY_LEVEL enum value.

Options

Data Structure Properties/Fields

| Key | Platform | Description | Default | | -------------------------- | ------------ | ------------------------------------------------------------------------------------------------ | ------------------------------------------------------------------------- | | accessControl | All | This dictates how a keychain item may be used, see possible values in Keychain.ACCESS_CONTROL. | None | | accessible | iOS only | This dictates when a keychain item is accessible, see possible values in Keychain.ACCESSIBLE. | Keychain.ACCESSIBLE.WHEN_UNLOCKED | | accessGroup | iOS only | In which App Group to share the keychain. Requires additional setup with entitlements. | None | | authenticationPrompt | All | What to prompt the user when unlocking the keychain with biometry or device password. | See authenticationPrompt Properties | | authenticationType | iOS only | Policies specifying which forms of authentication are acceptable. | Keychain.AUTHENTICATION_TYPE.DEVICE_PASSCODE_OR_BIOMETRICS | | service | All | Reverse domain name qualifier for the service associated with password. | App bundle ID | | storage | Android only | Force specific cipher storage usage during saving the password | Select best available storage | | rules | Android only | Force following to a specific security rules | Keychain.RULES.AUTOMATIC_UPGRADE |

authenticationPrompt Properties

| Key | Platform | Description | Default | | ----------------- | ------------ | ------------------------------------------------------------------------------------------ | --------------------------------- | | title | All | Title of the authentication prompt when requesting a stored secret. | Authenticate to retrieve secret | | subtitle | Android only | Subtitle of the Android authentication prompt when requesting a stored secret. | None. Optional | | description | Android only | Description of the Android authentication prompt when requesting a stored secret. | None. Optional | | cancel | Android only | Negative button text of the Android authentication prompt when requesting a stored secret. | Cancel |

Keychain.ACCESS_CONTROL enum

| Key | Description | | --------------------------------------------- | -------------------------------------------------------------------------------------- | | USER_PRESENCE | Constraint to access an item with either Touch ID or passcode. | | BIOMETRY_ANY | Constraint to access an item with Touch ID for any enrolled fingers. | | BIOMETRY_CURRENT_SET | Constraint to access an item with Touch ID for currently enrolled fingers. | | DEVICE_PASSCODE | Constraint to access an item with a passcode. | | APPLICATION_PASSWORD | Constraint to use an application-provided password for data encryption key generation. | | BIOMETRY_ANY_OR_DEVICE_PASSCODE | Constraint to access an item with Touch ID for any enrolled fingers or passcode. | | BIOMETRY_CURRENT_SET_OR_DEVICE_PASSCODE | Constraint to access an item with Touch ID for currently enrolled fingers or passcode. |

Note #1: BIOMETRY_ANY, BIOMETRY_CURRENT_SET, BIOMETRY_ANY_OR_DEVICE_PASSCODE, BIOMETRY_CURRENT_SET_OR_DEVICE_PASSCODE - recognized by Android as a requirement for Biometric enabled storage (Till we got a better implementation);

Note #2: For Android we support only two states: None (default) and Fingerprint (use only biometric protected storage); Face recognition fails with "User not authenticated" exception, see issue #318

Refs:

• https://developer.apple.com/documentation/security/secaccesscontrolcreateflags?language=objc

Keychain.ACCESSIBLE enum

| Key | Description | | ----------------------------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | WHEN_UNLOCKED | The data in the keychain item can be accessed only while the device is unlocked by the user. | | AFTER_FIRST_UNLOCK | The data in the keychain item cannot be accessed after a restart until the device has been unlocked once by the user. | | ALWAYS | The data in the keychain item can always be accessed regardless of whether the device is locked. | | WHEN_PASSCODE_SET_THIS_DEVICE_ONLY | The data in the keychain can only be accessed when the device is unlocked. Only available if a passcode is set on the device. Items with this attribute never migrate to a new device. | | WHEN_UNLOCKED_THIS_DEVICE_ONLY | The data in the keychain item can be accessed only while the device is unlocked by the user. Items with this attribute do not migrate to a new device. | | AFTER_FIRST_UNLOCK_THIS_DEVICE_ONLY | The data in the keychain item cannot be accessed after a restart until the device has been unlocked once by the user. Items with this attribute never migrate to a new device. |

Refs:

• https://developer.apple.com/documentation/security/ksecattraccessiblewhenunlocked

Keychain.AUTHENTICATION_TYPE enum

| Key | Description | | ----------------------------------- | ----------------------------------------------------------------------------------------- | | DEVICE_PASSCODE_OR_BIOMETRICS | Device owner is going to be authenticated by biometry or device passcode. | | BIOMETRICS | Device owner is going to be authenticated using a biometric method (Touch ID or Face ID). |

Refs:

• https://developer.apple.com/documentation/localauthentication/lapolicy

Keychain.BIOMETRY_TYPE enum

| Key | Description | | ----------------- | -------------------------------------------------------------------- | | TOUCH_ID | Device supports authentication with Touch ID. (iOS only) | | FACE_ID | Device supports authentication with Face ID. (iOS only) | | FINGERPRINT | Device supports authentication with Fingerprint. (Android only) | | FACE | Device supports authentication with Face Recognition. (Android only) | | IRIS | Device supports authentication with Iris Recognition. (Android only) |

Refs:

• https://developer.apple.com/documentation/localauthentication/labiometrytype?language=objc

Keychain.SECURITY_LEVEL enum (Android only)

If set, securityLevel parameter specifies minimum security level that the encryption key storage should guarantee for storing credentials to succeed.

| Key | Description | | ----------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | ANY | no security guarantees needed (default value); Credentials can be stored in FB Secure Storage; | | SECURE_SOFTWARE | requires for the key to be stored in the Android Keystore, separate from the encrypted data; | | SECURE_HARDWARE | requires for the key to be stored on a secure hardware (Trusted Execution Environment or Secure Environment). Read this article for more information. |

Keychain.STORAGE_TYPE enum (Android only)

| Key | Description | | ----- | -------------------------------------- | | FB | Facebook compatibility cipher | | AES | Encryptions without human interaction. | | RSA | Encryption with biometrics. |

Keychain.SECURITY_RULES enum (Android only)

| Key | Description | | ------------------- | -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | | NONE | No rules. Be dummy, developer control everything | | AUTOMATIC_UPGRADE | Upgrade secret to the best available storage as soon as it is available and user request secret extraction. Upgrade not applied till we request the secret. This rule only applies to secrets stored with FacebookConseal. |

Important Behavior

Rule 1: Automatic Security Level

As a rule the library will try to apply the best possible encryption for storing secrets. Once the secret is stored however its does not try to upgrade it unless FacebookConseal was used and the option 'SECURITY_RULES' is set to 'AUTOMATIC_UPGRADE'

Q: What will happen if user disables/drops biometric usage?

A: User will lose ability to extract secret from storage. On re-enable biometric access to the secret will be possible again.

Q: Is it possible to implement automatic downgrading?

A: From security perspective any Automatic downgrading is treated as "a loss of the trust" point. Developer should implement own logic to allow downgrade and deal with "security loss". (My recommendation - never do that!)

Q: How to enable automatic upgrade for FacebookConseal?

A: Do call getGenericPassword({ ...otherProps, rules: "AUTOMATIC_UPGRADE" }) with extra property rules set to AUTOMATIC_UPGRADE string value.

Q: How to force a specific level of encryption during saving the secret?

A: Do call setGenericPassword({ ...otherProps, storage: "AES" }) with forced storage.

Note: attempt to force storage RSA when biometrics is not available will force code to reject call with errors specific to device biometric configuration state.

Manual Installation

iOS

Option: Manually

• Right click on Libraries, select Add files to "…" and select node_modules/@getclave/react-native-keychain/RNKeychain.xcodeproj
• Select your project and under Build Phases -> Link Binary With Libraries, press the + and select libRNKeychain.a.
• make sure pod 'RNKeychain' is not in your Podfile

Option: With CocoaPods

Add the following to your Podfile and run pod update:

pod 'RNKeychain', :path => '../node_modules/@getclave/react-native-keychain'

Enable Keychain Sharing entitlement for iOS 10+

For iOS 10 you'll need to enable the Keychain Sharing entitlement in the Capabilities section of your build target. (See screenshot). Otherwise you'll experience the error shown below.

Error: {
  code = "-34018";
  domain = NSOSStatusErrorDomain;
  message = "The operation couldn\U2019t be completed. (OSStatus error -34018.)";
}

Android

Option: Manually

• Edit android/settings.gradle to look like this (without the +):

rootProject.name = 'MyApp'

include ':app'

+ include ':@getclave/react-native-keychain'
+ project(':@getclave/react-native-keychain').projectDir = new File(rootProject.projectDir, '../node_modules/react-native-keychain/android')

• Edit android/app/build.gradle (note: app folder) to look like this:

apply plugin: 'com.android.application'

android {
  ...
}

dependencies {
  implementation fileTree(dir: 'libs', include: ['*.jar'])
  implementation 'com.android.support:appcompat-v7:23.0.1'
  implementation 'com.facebook.react:react-native:0.19.+'
+ implementation project(':@getclave/react-native-keychain')
}

• Edit your MainApplication.java (deep in android/app/src/main/java/...) to look like this (note two places to edit):

package com.myapp;

+ import com.oblador.keychain.KeychainPackage;

....

public class MainActivity extends extends ReactActivity {

  @Override
  protected List<ReactPackage> getPackages() {
      return Arrays.<ReactPackage>asList(
              new MainReactPackage(),
+             new KeychainPackage()
      );
  }
  ...
}

Proguard Rules

On Android builds that use proguard (like release), you may see the following error:

RNKeychainManager: no keychain entry found for service:
JNI DETECTED ERROR IN APPLICATION: JNI FindClass called with pending exception java.lang.NoSuchFieldError: no "J" field "mCtxPtr" in class "Lcom/facebook/crypto/cipher/NativeGCMCipher;" or its superclasses

If so, add a proguard rule in proguard-rules.pro:

-keep class com.facebook.crypto.** {
   *;
}

Unit Testing with Jest

The keychain manager relies on interfacing with the native application itself. As such, it does not successfully compile and run in the context of a Jest test, where there is no underlying app to communicate with. To be able to call the JS functions exposed by this module in a unit test, you should mock them in one of the following two ways:

First, let's create a mock object for the module:

const keychainMock = {
  SECURITY_LEVEL_ANY: "MOCK_SECURITY_LEVEL_ANY",
  SECURITY_LEVEL_SECURE_SOFTWARE: "MOCK_SECURITY_LEVEL_SECURE_SOFTWARE",
  SECURITY_LEVEL_SECURE_HARDWARE: "MOCK_SECURITY_LEVEL_SECURE_HARDWARE",
  setGenericPassword: jest.fn().mockResolvedValue(),
  getGenericPassword: jest.fn().mockResolvedValue(),
  resetGenericPassword: jest.fn().mockResolvedValue(),
  ...
}

Using a Jest __mocks__ Directory

1. Read the jest docs for initial setup

2. Create a @getclave/react-native-keychain folder in the __mocks__ directory and add index.js file in it. It should contain the following code:

export default keychainMock;

Using a Jest Setup File

1. In your Jest config, add a reference to a setup file

2. Inside your setup file, set up mocking for this package:

jest.mock('@getclave/react-native-keychain', () => keychainMock);

Now your tests should run successfully, though note that writing and reading to the keychain will be effectively a no-op.

Notes

Android Notes

The module will automatically use the appropriate CipherStorage implementation based on API level:

• API level 16-22 will en/de crypt using Facebook Conceal
• API level 23+ will en/de crypt using Android Keystore

Encrypted data is stored in SharedPreferences.

The setInternetCredentials(server, username, password) call will be resolved as call to setGenericPassword(username, password, server). Use the server argument to distinguish between multiple entries.

Configuring the Android-specific behavior

Android implementation has behavioural specifics incurred by existing inconsistency between implementations by different vendors. E.g., some Samsung devices show very slow startup of crypto system. To alleviate this, a warm-up strategy is introduced in Android implementation of this library.

Using default constructor you get default behaviour, i.e. with the warming up on.

    private List<ReactPackage> createPackageList() {
      return Arrays.asList(
        ...
        new KeychainPackage(),  // warming up is ON
        ...
      )

Those who want finer control are required to use constructor with a builder which can be configured as they like:

    private List<ReactPackage> createPackageList() {
      return Arrays.asList(
        ...
        new KeychainPackage(
                new KeychainModuleBuilder()
                        .withoutWarmUp()),   // warming up is OFF
        ...
      )

iOS Notes

If you need Keychain Sharing in your iOS extension, make sure you use the same App Group and Keychain Sharing group names in your Main App and your Share Extension. To then share the keychain between the Main App and Share Extension, use the accessGroup and service option on setGenericPassword and getGenericPassword, like so: getGenericPassword({ accessGroup: 'group.appname', service: 'com.example.appname' })

Refs:

• https://developer.apple.com/documentation/localauthentication
• https://developer.apple.com/documentation/security

macOS Catalyst

This package supports macOS Catalyst.

Security

On API levels that do not support Android keystore, Facebook Conceal is used to en/decrypt stored data. The encrypted data is then stored in SharedPreferences. Since Conceal itself stores its encryption key in SharedPreferences, it follows that if the device is rooted (or if an attacker can somehow access the filesystem), the key can be obtained and the stored data can be decrypted. Therefore, on such a device, the conceal encryption is only an obscurity. On API level 23+ the key is stored in the Android Keystore, which makes the key non-exportable and therefore makes the entire process more secure. Follow best practices and do not store user credentials on a device. Instead use tokens or other forms of authentication and re-ask for user credentials before performing sensitive operations.

• Android authentication
• Android Cipher
• Android Protected Confirmation

Maintainers

For Developers / Contributors

• How to Configure Android Studio for Development

License

MIT © Joel Arvidsson 2016-2020