Implementing Security Best Practices

import Security

let query: [String: Any] = [
    kSecClass as String: kSecClassGenericPassword,
    kSecAttrAccount as String: "user@example.com",
    kSecAttrService as String: "MyApp",
    kSecValueData as String: "secretKey".data(using: .utf8)!
]

// Store data
let status = SecItemAdd(query as CFDictionary, nil)

if status == errSecSuccess {
    print("Data stored successfully")
}

// Retrieve data
let retrieveQuery: [String: Any] = [
    kSecClass as String: kSecClassGenericPassword,
    kSecAttrAccount as String: "user@example.com",
    kSecAttrService as String: "MyApp",
    kSecReturnData as String: true,
    kSecMatchLimit as String: kSecMatchLimitOne
]

var retrievedData: AnyObject?
let retrieveStatus = SecItemCopyMatching(retrieveQuery as CFDictionary, &retrievedData)

if retrieveStatus == errSecSuccess {
    if let data = retrievedData as? Data,
       let string = String(data: data, encoding: .utf8) {
        print("Retrieved data: \(string)")
    }
}

import Foundation

class PinningDelegate: NSObject, URLSessionDelegate {
    func urlSession(_ session: URLSession, didReceive challenge: URLAuthenticationChallenge, completionHandler: @escaping (URLSession.AuthChallengeDisposition, URLCredential?) -> Void) {
        guard challenge.protectionSpace.authenticationMethod == NSURLAuthenticationMethodServerTrust else {
            completionHandler(.performDefaultHandling, nil)
            return
        }

        let serverTrust = challenge.protectionSpace.serverTrust!
        let pinnedCertificates = [/* Array of pinned certificates */]
        
        if validateCertificate(serverTrust, against: pinnedCertificates) {
            completionHandler(.useCredential, URLCredential(trust: serverTrust))
        } else {
            completionHandler(.rejectProtectionSpace, nil)
        }
    }

    private func validateCertificate(_ serverTrust: SecTrust, against pinnedCertificates: [Data]) -> Bool {
        // Implementation logic here
        return true
    }
}

let session = URLSession(configuration: .default, delegate: PinningDelegate(), delegateQueue: nil)

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSAllowsArbitraryLoads</key>
    <false/>
</dict>

<key>NSAppTransportSecurity</key>
<dict>
    <key>NSExceptionDomains</key>
    <dict>
        <key>example.com</key>
        <dict>
            <key>NSExceptionAllowsInsecureHTTPLoads</key>
            <true/>
            <key>NSExceptionRequiresForwardSecrecy</key>
            <false/>
        </dict>
    </dict>
</dict>

import Foundation

let fileURL = FileManager.default.urls(for: .documentDirectory, in: .userDomainMask).first!.appendingPathComponent("secureData.plist")

let data = "Sensitive information".data(using: .utf8)!

// Set protection attributes to encrypt at rest
let attributes = [FileAttributeKey.protectionKey: FileProtectionType.complete]
try FileManager.default.setAttributes(attributes, ofItemAtPath: fileURL.path)

import Security

let query: [String: Any] = [
    kSecClass as String: kSecClassGenericPassword,
    kSecAttrAccount as String: "userToken",
    kSecAttrService as String: "MyApp",
    kSecValueData as String: "encryptedToken".data(using: .utf8)!
]

// Save to keychain
let status = SecItemAdd(query as CFDictionary, nil)

if status == errSecSuccess {
    print("Token stored securely")
} else {
    print("Failed to store token")
}

func secureAPICall() {
    let url = URL(string: "https://api.example.com/data")!
    var request = URLRequest(url: url)
    request.httpMethod = "POST"
    request.setValue("Bearer \(token)", forHTTPHeaderField: "Authorization")
    
    // Validate response before processing
    URLSession.shared.dataTask(with: request) { data, response, error in
        guard let httpResponse = response as? HTTPURLResponse,
              (200...299).contains(httpResponse.statusCode) else {
            print("API Error")
            return
        }
        // Process data securely
    }.resume()
}

import UIKit

class ViewController: UIViewController {
    override func viewDidLoad() {
        super.viewDidLoad()
        
        if #available(iOS 17.0, *) {
            // Disable screen capture for this scene
            if let windowScene = UIApplication.shared.connectedScenes.first as? UIWindowScene {
                windowScene.screenCaptureDisabled = true
            }
        } else {
            // Fallback for older versions
            UIScreen.main.isCaptured = true
        }
    }
}

import LocalAuthentication

let context = LAContext()
var error: NSError?

if context.canEvaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, error: &error) {
    let reason = "Authenticate to access the app"
    
    context.evaluatePolicy(.deviceOwnerAuthenticationWithBiometrics, localizedReason: reason) { success in
        DispatchQueue.main.async {
            if success {
                print("Authentication successful")
            } else {
                print("Authentication failed")
            }
        }
    }
} else {
    print("Biometric authentication not available: \(error?.localizedDescription ?? "Unknown error")")
}

import Security

func generateSecureRandomNumber() -> UInt32 {
    var random: UInt32 = 0
    let status = SecRandomCopyBytes(kSecRandomDefault, MemoryLayout<UInt32>.size, &random)
    
    if status != errSecSuccess {
        fatalError("Failed to generate secure random number")
    }
    
    return random
}

import CryptoKit

let randomBytes = try! ChaChaPoly.Nonce()
let randomInt = Int.random(in: 1...1000)

func isValidEmail(_ email: String) -> Bool {
    let emailRegex = "^[A-Z0-9._%+-]+@[A-Z0-9.-]+\\.[A-Z]{2,}$"
    let emailPredicate = NSPredicate(format: "SELF MATCHES %@", emailRegex)
    return emailPredicate.evaluate(with: email)
}

let userInput = "user@example.com"
if isValidEmail(userInput) {
    print("Valid email")
} else {
    print("Invalid email")
}

import UIKit

func isJailbroken() -> Bool {
    // Check for common jailbreak indicators
    let pathsToCheck = [
        "/Applications/BlackKey.app",
        "/Applications/FakeCarrier.app",
        "/Library/MobileSubstrate/DynamicLibraries/LiveClock.plist",
        "/System/Library/LaunchDaemons/com.ikey.bbot.plist",
        "/etc/ssh/sshd_config"
    ]
    
    for path in pathsToCheck {
        if FileManager.default.fileExists(atPath: path) {
            return true
        }
    }
    
    // Check for Cydia URL scheme
    if UIApplication.shared.canOpenURL(URL(string: "cydia://package/com.example.app")!) {
        return true
    }
    
    // Check for debug symbols in executable
    let image = UnsafeMutablePointer<UInt8>.allocate(capacity: 1)
    defer { image.deallocate() }
    
    if image.pointee == 0x7F {
        // This is a basic check, more complex checks needed for production
        return false
    }
    
    return false
}

// Usage example
if isJailbroken() {
    print("Device is jailbroken")
} else {
    print("Device is not jailbroken")
}