StealthyStash

A Swifty database interface into the Keychain Services.

Table of Contents

• Introduction
  • Requirements
  • Installation
• Usage
  • Further Documentation
• References
• License

Introduction

StealthyStash provides an pluggable easy abstract layer for accessing Keychain data as well as an API for encoding and decoding complex data in the Keychain.

Requirements

Apple Platforms

• Xcode 14.3.1 or later
• Swift 5.8 or later
• iOS 14 / watchOS 7 / tvOS 14 / macOS 12 or later deployment targets

Linux

• Ubuntu 18.04 or later
• Swift 5.8 or later

Installation

Use the Swift Package Manager to install this library via the repository url:

https://github.com/brightdigit/StealthyStash.git

Use version up to 1.0.

Usage

Accessing the Keychain like a Database

StealthyStash supports the adding, updating, and querying for both generic and internet passwords. To do this you need to create a KeychainRepository to access the database to.

let repository = KeychainRepository(
  defaultServiceName: "com.brightdigit.KeychainSyncDemo",
  defaultServerName: "com.brightdigit.KeychainSyncDemo",
  defaultAccessGroup: "MLT7M394S7.com.brightdigit.KeychainSyncDemo"
)

To call KeychainRepository.init(defaultServiceName:defaultServerName:defaultAccessGroup:defaultSynchronizable:logger:) you need to supply a the default InternetPasswordItem/server and GenericPasswordItem/service which is required by both types to query and create.

You can also supply a logger to use for logging as well as an InternetPasswordItem.accessGroup for your InternetPasswordItem and GenericPasswordItem.accessGroup for your GenericPasswordItem

To query, update, or add a new password, check out the documentation under StealthyRepository.

Using StealthyModel for Composite Objects

In many cases, you may want to use multiple items to store a single object such as the user’s password with InternetPasswordItem as well as their token via GenericPasswordItem. In this case, you’ll want to use a StealthyModel:

struct CompositeCredentials: StealthyModel {
  typealias QueryBuilder = CompositeCredentialsQueryBuilder

  internal init(userName: String, password: String?, token: String?) {
    self.userName = userName
    self.password = password
    self.token = token
  }

  let userName: String

  let password: String?

  let token: String?
}

This is the perfect use case for StealthyModel and it only requires the implementation of a ModelQueryBuilder which defines how to build the queries for creating, updating, and deleting StealthyModel objects from the keychain:

• ModelQueryBuilder.updates(from:to:) require you to build an array of StealthyPropertyUpdate object which define the previous and new properties for the Keychain. Both the previous and new are optional in case you are only adding a new item as part of the update or only removing an old item.

• ModelQueryBuilder.properties(from:for:) is for creating a new model and requires the individual AnyStealthyProperty for each item to add to the keychain.

• ModelQueryBuilder.model(from:) builds the StealthyModel based on the AnyStealthyProperty items

• ModelQueryBuilder.queries(from:) builds a query dictionary depending the ModelQueryBuilder.QueryType passed. The keys to the query dictionary will be used by ModelQueryBuilder.model(from:) to define the keys of their resulting AnyStealthyProperty. If there’s only one object in your app, you can define ModelQueryBuilder.QueryType as Void:

static func queries(from _: Void) -> [String: Query] {
  [
    "password": TypeQuery(type: .internet),
    "token": TypeQuery(type: .generic)
  ]
}

For more help, take a look at the Sample projects located in the Swift Package.

Further Documentation

Further documentation is available at the Swift Package Index.

References

• Using the Keychain to Manage User Secret

License

This code is distributed under the MIT license. See the LICENSE file for more info.