{"id":3115,"date":"2022-03-25T22:09:00","date_gmt":"2022-03-25T21:09:00","guid":{"rendered":"https:\/\/www.albertopasca.it\/whiletrue\/?p=3115"},"modified":"2023-06-26T01:30:42","modified_gmt":"2023-06-25T23:30:42","slug":"ios-secure-app-sensitive-information","status":"publish","type":"post","link":"https:\/\/www.albertopasca.it\/whiletrue\/ios-secure-app-sensitive-information\/","title":{"rendered":"iOS – Secure app sensitive information"},"content":{"rendered":"\n

Today I want to share a fresh new Swift Package<\/strong> SDK that helps you to hide sensitive informations on your app, like banking apps<\/em>, in a easy way!<\/p>\n\n\n\n

You’ll be notified via callback (optional<\/em>) when a defined rule occur, and apply the right custom protection you prefer or simply use the integrated blur that cover your app automatically.<\/p>\n\n\n\n

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Available protections<\/h2>\n\n\n\n

While writing this post, the SDK<\/em> provide these protections callbacks:<\/p>\n\n\n\n\n\n\n\n

QuickTime<\/strong> screen recording<\/td>\"iOS<\/td><\/tr>
iOS screen recording<\/strong><\/td>\"iOS<\/td><\/tr>
iOS native Airplay<\/strong> \/ Mirroring<\/strong><\/td>\"iOS<\/td><\/tr>
Background app screenshot cache<\/strong><\/td>\"iOS<\/td><\/tr>
User taken screenshots<\/strong><\/td>\"iOS<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

<\/p>\n\n\n\n

How it works<\/h2>\n\n\n\n

Simply, add a view on top of your root window, in order to hide sensitive content behind.<\/p>\n\n\n\n

Imagine that you app is this one:<\/p>\n\n\n

\n
\"\"<\/figure>\n<\/div>\n\n\n

When one of the defined rules to apply is recognized, a custom view<\/strong> or a blurred view<\/strong> can appear on top:<\/p>\n\n\n\n

\n
\"\"
Background catch with custom view<\/figcaption><\/figure>\n\n\n\n
\"\"
Background catch with integrated blur<\/figcaption><\/figure>\n\n\n\n
\"\"
Screen recording detection<\/figcaption><\/figure>\n<\/figure>\n\n\n\n

<\/p>\n\n\n\n

You can handle more of these rules, the code is on Github<\/a>, feel free to open merge requests.<\/p>\n\n\n\n

You can also apply a custom behavior when detected (show an alert, send an API request, or what you prefer…).<\/p>\n\n\n\n

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Code usage.<\/h2>\n\n\n\n

Add the repo directly in Swift Package Manager through XCode<\/em> and import the SDK (generally in SceneDelegate<\/strong> or AppDelegate<\/strong>, because you need the window):<\/p>\n\n\n\n

import ScreenSecuritySDK<\/code><\/pre>\n\n\n\n
Next in your sceneWillConnect<\/strong>, initialize the SDK:<\/p>\n\n\n\n
var screenSecurity: ScreenSecurity?\n[...]\nfunc scene(_ scene: UIScene, willConnectTo session: UISceneSession, options connectionOptions: UIScene.ConnectionOptions) {\n    screenSecurity = ScreenSecurity( window! )\n}<\/code><\/pre>\n\n\n\n
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Creating security rules<\/h5>\n\n\n\n
Allowed types are defined in this enum:<\/p>\n\n\n\n
case quickTime\ncase screenRecording\ncase mirroring\ncase screenCache\ncase screenshot<\/code><\/pre>\n\n\n\n
You can create the rules you prefer, in this way:<\/p>\n\n\n\n
let mirroringRule = ScreenSecurityRules {\n    $0.type = .mirroring\n    $0.callback = self.mirrorDetected\n}<\/code><\/pre>\n\n\n\n
In every rule you can add a type<\/strong>, that is mandatory and a callback<\/strong> that is optional and can be used inline<\/em> or with a custom defined function<\/em> (as you prefer).<\/p>\n\n\n\n
\/\/ example as custom callback\nvar mirrorDetected: (Any?, Bool) -> Void = \n  { (arg: Any?, status: Bool) -> Void in\n    print(\"mirrorDetected: \\(status)\")\n}\n\n\/\/ example of inline callback\nlet mirroringRule = ScreenSecurityRules {\n    $0.type = .mirroring\n    $0.callback = (arg: Any?, status: Bool) -> Void in {\n\t    print(\"mirrorDetected: \\(status)\")\n    }\n}<\/code><\/pre>\n\n\n\n
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ScreenCache extra settings<\/h5>\n\n\n\n
In case you need the screenCache<\/strong> rule, you need also to add the sceneDelegate<\/strong> or appDelegate<\/strong> param:<\/p>\n\n\n\n
let screenCacheRule = ScreenSecurityRules {\n    $0.type = .screenCache\n    $0.callback = self.screenCacheDetected\n    $0.sceneDelegate = self \/\/ one of these\n    $0.appDelegate = self \/\/ one of these\n}<\/code><\/pre>\n\n\n\n
You need also to inform the SDK<\/em> when the app-lifecycle methods are called, and you need to call the screenSecurity?.listen()<\/code> method in these delegates:<\/p>\n\n\n\n
func sceneDidBecomeActive(_ scene: UIScene) {\n    screenSecurity?.listen(type: .didBecomeActive)\n}\n\nfunc sceneWillResignActive(_ scene: UIScene) {\n    screenSecurity?.listen(type: .willResignActive)\n}\n\nfunc sceneWillEnterForeground(_ scene: UIScene) {\n    screenSecurity?.listen(type: .willEnterForeground)\n}\n\nfunc sceneDidEnterBackground(_ scene: UIScene) {\n    screenSecurity?.listen(type: .didEnterBackground)\n}<\/code><\/pre>\n\n\n\n
If you need to go deep on how iOS save automatically the screenshot of your app when is in background, take a read here: https:\/\/www.albertopasca.it\/whiletrue\/ios-data-leakage-app-background-cache\/<\/a> .<\/pre>\n\n\n\n
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Composing rules<\/h5>\n\n\n\n
Now, create the rules your prefer and next configure the SDK passing the rules and the settings needed:<\/p>\n\n\n\n
var rules = [ScreenSecurityRules]()\nrules = [\n    mirroringRule,\n    quickTimeRule,\n    screenRecordingRule,\n    screenCacheRule,\n    screenshotRule\n]<\/code><\/pre>\n\n\n\n
and pass it to initializer<\/p>\n\n\n\n
screenSecurity?.configure(rules: rules, autoBlur: true)<\/code><\/pre>\n\n\n\n
The configure<\/strong> method take as parameters:<\/p>\n\n\n\n
rules<\/strong>: your custom created rules<\/p>\n\n\n\n
autoBlur<\/strong>: to use integrated automatic blur<\/p>\n\n\n\n
customView<\/strong>: UIVIew, if you want to use your custom view + logo<\/p>\n\n\n\n
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Add a custom view instead of blur<\/h5>\n\n\n\n
If you prefer to use your custom view, you can pass it creating a new UIView, simply:<\/p>\n\n\n\n
let customView = UIView(frame: self.window!.bounds)\ncustomView.backgroundColor = .red.withAlphaComponent(0.9)\n\nlet image = UIImage(named: \"logo\")!\nlet midX = UIScreen.main.bounds.midX - 200 \/ 2\nlet midY = UIScreen.main.bounds.midY - 100\nlet imageView = UIImageView(frame: CGRect(\n    x: midX,\n    y: midY,\n    width: 200,\n    height: 100))\nimageView.image = image\nimageView.contentMode = .scaleAspectFit\nimageView.backgroundColor = .clear\ncustomView.addSubview(imageView)\n\nscreenSecurity?.configure(rules: rules, autoBlur: false, customOverlay: customView)<\/code><\/pre>\n\n\n\n
Build and run.<\/p>\n\n\n\n
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Open points:<\/h3>\n\n\n\n