Overview

Supports iOS only.

Keychain is a wrapper library built around a small subset of features offered by Keychain Services to simplify saving and retrieving data to and from the iOS Keychain using kSecClassGenericPassword class.

While the Keychain Services offer comprehensive set of APIs and could be used directly, the app-side implementation for saving and retrieving data will most likely be verbose.

In a nutshell, to securely store an item using Keychain Services, a dictionary of predefined keys and values, also referred to as the keychain query, must be created first. This query must contain valid values for predefined set of keys that depend on a security class being used. To reduce the amount of manual work required to create a keychain query, this framework takes advantage of Swift features such as default implementation for protocols, generics and Codable for automatic encoding of models into external representation.

This approach leads to a much cleaner interaction with iOS Keychain that's enjoyable to use.

Features

• Simple to setup, easy to use & efficient
• Supports custom data types
• Supports storing multiple instances of the same type
• Supports app and group-specific keychain configurations
• Supports access option for keychain items
• Supports selective Type synchronization through iCloud
• Handles object encoding and decoding from data returned by the iOS keychain
• Comprehensive Unit Test Coverage
• Complete Documentation

Requirements

• iOS 10.0+
• Xcode 10.2+
• Swift 5.0+

Installation

Carthage

Carthage is a decentralized dependency manager that builds your dependencies and provides you with binary frameworks. To integrate Keychain into your Xcode project using Carthage, specify it in your Cartfile:

git "https://github.com/AlaskaAirlines/keychain" ~> 2.0.0

For more information on getting started with Carthage, visit the repo.

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.

Usage

Keychain framework currently supports two access types - App Specific and Group Specific.

Getting started is easy. First, create the keychain instance using one of the supported access types.

let keychain = Keychain(.appSpecific(access: .always, serviceName: "App"))

Any custom type you want to encrypt and store in iOS Keychain needs to conform and implement the KeychainItem protocol. The KeychainItem protocol provides default implementation for all of its properties - except the idKey. See documentation for more information.

struct Credential: KeychainItem {
    let username: String
    let password: String

    // MARK: KeychainItem

    var idKey: String {
        return username
    }
}

Keychain offers a handful of methods that will allow you to save, delete, or retrieve items.

let user = User(username: "username", password: "password")

// save
try? keychain.save(user)

// retrieve users
let users = try? keychain.items(ofType: User.self)

// retrieve a single user
let user = try? keychain.item(ofType: User.self, idKey: "username")

For group specific configuration, please see documentation.

Performance

The following tests were performed on an iPad Mini 4 WiFi + Cellular. The numbers are the average for performing each operation 3000 times.

• Deleting: 0.00662
• Inserting: 0.00862
• Reading: 0.00291
• Replacing: 0.00858

Communication

• If you found a bug, open an issue.
• If you have a feature request, open an issue.
• If you want to contribute, submit a pull request.

Authors

• Michael Babiy

Contributors

• Adam Wallraff
• Krishna Varma