(iOS) Fingerprinting, identifying a device

Fingerprinting.swift

//https://nshipster.com/device-identifiers/
//Besides identifierForVendor..

/*
Locale information is the greatest source of identifying information on Apple platforms.
The combination of your preferred languages, region, calendar, time zone,
and which keyboards you have installed say a lot about who you are
especially if you have less conventional preferences.
*/

import Foundation

Locale.current.languageCode
log2(Double(Locale.isoLanguageCodes.count)) // 9.217 bits

Locale.current.regionCode
log2(Double(Locale.isoRegionCodes.count)) // 8 bits

Locale.current.calendar.identifier
// ~2^4 (16) Calendars

TimeZone.current.identifier
log2(Double(TimeZone.knownTimeZoneIdentifiers.count)) // 8.775 bits

UserDefaults.standard.object(forKey: "AppleKeyboards")
// ~2^6 (64) iOS keyboards

//-----------------

//Accessibility

UIAccessibility.isBoldTextEnabled
UIAccessibility.isShakeToUndoEnabled
UIAccessibility.isReduceMotionEnabled
UIAccessibility.isDarkerSystemColorsEnabled
UIAccessibility.isReduceTransparencyEnabled
UIAccessibility.isAssistiveTouchRunning

//-----------------

//Dynamic type check

let application = UIApplication.shared
application.preferredContentSizeCategory

//-----------------

//Hardware Information
//On iOS, you can get the current model and amount of storage of a user’s device:

import UIKit

let device = UIDevice.current
device.name // "iPhone 11 Pro"

let fileManager = FileManager.default
if let path = fileManager.urls(for: .libraryDirectory, in: .systemDomainMask).last?.path,
    let systemSize = try? fileManager.attributesOfFileSystem(forPath: path)[.systemSize] as? Int
{
    Measurement<UnitInformationStorage>(value: Double(systemSize), unit: .bytes)
        .converted(to: .gigabytes)  // ~256GB
}

//processor count and amount of RAM:

processInfo.processorCount // 8

Measurement<UnitInformationStorage>(value: Double(processInfo.physicalMemory),
                                    unit: .bytes)
    .converted(to: .gigabytes) // 16GB

//-----------------

//Cellular Network

import CoreTelephony

let networkInfo = CTTelephonyNetworkInfo()
let carriers = networkInfo.serviceSubscriberCellularProviders?.values
carriers?.map { ($0.mobileNetworkCode, $0.mobileCountryCode) }

//-----------------

//Communication Preferences (2 bits)

import MessageUI

MFMailComposeViewController.canSendMail()
MFMessageComposeViewController.canSendText()

//-----------------

//Battery health

var timestampedBatteryLevels: [(Date, Float)] = []

if UIDevice.current.isBatteryMonitoringEnabled {
    timestampedBatteryLevels.append((Date(), UIDevice.current.batteryLevel))
}