Sesame-iOS/Sesame-Watch Watch App/KeyManagement.swift

import Foundation
import CryptoKit
import SwiftUI

private let localKey: [UInt8] = [
    0x98, 0x36, 0x91, 0x09, 0x29, 0xa0, 0x54, 0x44,
    0x03, 0x0c, 0xa5, 0xb4, 0x20, 0x16, 0x10, 0x0d,
    0xaf, 0x41, 0x9b, 0x26, 0x4f, 0x75, 0xa4, 0x61,
    0xed, 0x15, 0x0c, 0xb3, 0x06, 0x39, 0x92, 0x59]


private let remoteKey: [UInt8] = [
    0xfa, 0x23, 0xf6, 0x98, 0xea, 0x87, 0x23, 0xa0,
    0xa0, 0xbe, 0x9a, 0xdb, 0x31, 0x28, 0xcb, 0x7d,
    0xd3, 0xa5, 0x7b, 0xf0, 0xc0, 0xeb, 0x45, 0x65,
    0x4d, 0x94, 0x50, 0x1a, 0x2f, 0x6f, 0xeb, 0x70]

private let authToken: [UInt8] = {
    let s = "Y6QzDK5DaFK1w2oEX5OkzoC0nTqP8w5IxpvWAR1mpro="
    let t = Data(base64Encoded: s.data(using: .utf8)!)!
    return Array(t)
}()

extension KeyManagement {

    enum KeyType: String, Identifiable, CaseIterable {

        case deviceKey = "sesame-device"
        case remoteKey = "sesame-remote"
        case authToken = "sesame-remote-auth"

        var id: String {
            rawValue
        }

        var displayName: String {
            switch self {
            case .deviceKey:
                return "Device Key"
            case .remoteKey:
                return "Remote Key"
            case .authToken:
                return "Authentication Token"
            }
        }

        var keyLength: SymmetricKeySize {
            .bits256
        }

        var usesHashing: Bool {
            switch self {
            case .authToken:
                return true
            default:
                return false
            }
        }
    }
}

extension KeyManagement.KeyType: CustomStringConvertible {

    var description: String {
        displayName
    }
}

final class KeyManagement: ObservableObject {


    @Published
    private(set) var hasRemoteKey = true

    @Published
    private(set) var hasDeviceKey = true

    @Published
    private(set) var hasAuthToken = true

    var hasAllKeys: Bool {
        hasRemoteKey && hasDeviceKey && hasAuthToken
    }

    init() {}

    func has(_ type: KeyType) -> Bool {
        switch type {
        case .deviceKey:
            return hasDeviceKey
        case .remoteKey:
            return hasRemoteKey
        case .authToken:
            return hasAuthToken
        }
    }

    func get(_ type: KeyType) -> SymmetricKey? {
        let bytes: [UInt8] = get(type)
        return SymmetricKey(data: bytes)
    }
    
    private func get(_ type: KeyType) -> [UInt8] {
        switch type {
        case .deviceKey:
            return remoteKey
        case .remoteKey:
            return localKey
        case .authToken:
            return authToken
        }
    }

    func delete(_ type: KeyType) {
        
    }

    func generate(_ type: KeyType) {
        
    }
}