Keychain

A simple inteferace for using the iOS Keychain, written in Swift. Heavily based on the work done by Jason Rendel in SwiftKeychainWrapper.

Provides singleton instance Keychain.default that is setup to work for most needs.

If you need to customize the keychain access to use a custom identifier or access group, you can create your own instance instead of using the provided singleton.

By default, the Keychain saves data as a Generic Password type in the iOS Keychain. It saves items such that they can only be accessed when the app is unlocked and open. If you are not familiar with the iOS Keychain usage, this provides a safe default for using the keycain.

Users that want to deviate from this default implementation can specifiy keychain accessibility for each request (store, retrieve, etc…) to a Keychain instance.

Requirements

• Swift 5.0+

Notes

Keychain 0.1.2 is the last version that supports cocoapods Keychain 0.1.2 is the last release with Swift 4.2 support

Installation

Swift Package Manager

The Swift Package Manager is a tool for automating the distribution of Swift code and is integrated into the swift compiler.

Once you have your Swift package set up, adding Keychain as a dependency is as easy as adding it to the dependencies value of your Package.swift.

dependencies: [
    .Package(url: "https://github.com/rauhul/keychain.git", from: "0.2.0")
]

To use the keychain in your app, import Keychain into the file(s) where you want to use it.

import Keychain

General Usage

Store a string value to keychain:

let saveSuccessful = Keychain.default.store("exampleValue", forKey: "exampleKey")

Retrieve a string value from keychain:

let retrievedString = Keychain.default.retrieve(String.self, forKey: "exampleKey")

Delete a string value from keychain:

let removeSuccessful = Keychain.default.removeObject(forKey: "exampleKey")

Custom Instance

When the Keychain Wrapper is used, all keys are linked to a common identifier for your app, called the service name. By default this uses your main bundle identifier. However, you may also change it, or store multiple items to the keycahin under different identifiers.

To share keychain items between your applications, you may specify an access group and use that same access group in each application.

To set a custom service name identifier or access group, you may create your own keychain instance as follows:

let uniqueServiceName = "customServiceName"

let uniqueAccessGroup = "sharedAccessGroupName"

let customKeychainInstance = Keychain(serviceName: uniqueServiceName, accessGroup: uniqueAccessGroup)

The custom instance can then be used in place of the provided instance:

let saveSuccessful = customKeychainInstance.store("exampleValue", forKey: "exampleKey")

let retrievedString = customKeychainInstance.retrieve(String.self, forKey: "exampleKey")

let removeSuccessful = customKeychainInstance.removeObject(forKey: "exampleKey")

Accessibility Options

By default, all items saved to keychain can only be accessed when the device is unlocked. To change this accessibility, an optional “withAccessibility” param can be set on all requests. The enum Keychain.Accessibilty provides an easy way to select the accessibility level desired:

Keychain.default.store(<KeychainStorable>, forKey: "exampleKey", withAccessibility: .afterFirstUnlock)