Initial commit.

src/LicenseManager.swift

@@ -0,0 +1,129 @@
+//
+//  LicenseManager.swift
+//  CmdBar
+//
+//  Created by Igor Kolokolnikov on 8/26/23.
+//
+
+import Cocoa
+import CryptoKit
+
+fileprivate struct LicenseModel: Codable {
+    let valid: Bool
+    let error: String
+    let email: String
+    let key:   String
+}
+
+// Converts string to a hash.
+fileprivate func hashString(_ string: String) -> String {
+    return SHA256.hash(data: Data(string.utf8)).compactMap { String(format: "%02x", $0) }.joined()
+}
+
+// Converts passphrase to a SymmetricKey.
+fileprivate func passToKey(from passphrase: String) -> SymmetricKey {
+    let passphraseData = Data(passphrase.utf8)
+    let keyData = SHA256.hash(data: passphraseData).withUnsafeBytes { buffer in
+        return Data(buffer)
+    }
+    return SymmetricKey(data: keyData)
+}
+
+final class LicenseManager {
+    static let standard = LicenseManager()
+    
+    private let passkey = passToKey(from: "B2B67FB0E22B814CE5A6E7DA729A068BF21C9490919EA0B42FCEB322F9C9BA82")
+    private let defaults = UserDefaults.standard
+    private var timer: DispatchSourceTimer?
+    private var quitAfterMinutes = 20.0 * 60.0 // quit after 20 minutes
+    
+    func isRegistered() -> Bool {
+        guard let email = defaults.object(forKey: "Email") as? String,
+              let key = defaults.object(forKey: "Key") as? String,
+              let licenseData = defaults.object(forKey: "License") as? Data,
+              let unsealedBox = try? AES.GCM.SealedBox(combined: licenseData),
+              let licenseHashData = try? AES.GCM.open(unsealedBox, using: passkey),
+              !email.isEmpty,
+              !key.isEmpty
+        else { return false }
+        
+        let currentHashData = Data(SHA256.hash(data: Data(hashString("\(email)\(key)\(NSUserName())").utf8))
+            .compactMap { String(format: "%02x", $0) }.joined().utf8)
+        
+        return licenseHashData == currentHashData
+    }
+    
+    func activateLicense(email: String, key: String, completionHandler: @escaping (_ data: Resulting<Bool, String>) -> Void) {
+        guard let url = URL(string: EndpointConstants.validateURL)?.appending(component: key)
+        else { completionHandler(.failure); return }
+        
+        URLSession.shared.dataTask(with: url) { [weak self] (data, response, error) in
+            guard
+                let data = data,
+                error == nil,
+                let response = response as? HTTPURLResponse,
+                (200...299).contains(response.statusCode)
+            else { completionHandler(.failure); return }
+            
+            guard let jsonResponse = try? JSONDecoder().decode(LicenseModel.self, from: data)
+            else { completionHandler(.failure); return }
+            
+            if jsonResponse.email == email && jsonResponse.key == key {
+                self?.saveLicense(with: email, and: key)
+                self?.stopTimer()
+                completionHandler(.success)
+            } else {
+                completionHandler(.failure)
+            }
+        }.resume()
+    }
+    
+    func deactivateLicense() {
+        clearLicense()
+        startTimer()
+    }
+    
+    func getLicense() -> (email: String, key: String) {
+        guard
+            let email = defaults.object(forKey: "Email") as? String,
+            let key = defaults.object(forKey: "Key") as? String
+        else { return ("", "") }
+        return (email, key)
+    }
+    
+    private func saveLicense(with email: String, and key: String) {
+        let defaults = UserDefaults.standard
+        
+        let licenseHashData = Data(SHA256.hash(data: Data(hashString("\(email)\(key)\(NSUserName())").utf8))
+            .compactMap { String(format: "%02x", $0) }.joined().utf8)
+        
+        guard let sealedBoxData = try? AES.GCM.seal(licenseHashData, using: passkey).combined else { return }
+        defaults.set(email, forKey: "Email")
+        defaults.set(key, forKey: "Key")
+        defaults.set(sealedBoxData, forKey: "License")
+    }
+    
+    func clearLicense() {
+        defaults.set(nil, forKey: "Email")
+        defaults.set(nil, forKey: "Key")
+        defaults.set(nil, forKey: "License")
+    }
+    
+    // MARK: - Timer
+    func startTimer() {
+        timer = DispatchSource.makeTimerSource(queue: DispatchQueue.global())
+        timer?.schedule(
+            deadline: .now() + quitAfterMinutes,
+            repeating: DispatchTimeInterval.never
+        )
+        timer?.setEventHandler {
+            DispatchQueue.main.async { NSApplication.shared.terminate(self) }
+        }
+        timer?.resume()
+    }
+    
+    func stopTimer() {
+        timer?.cancel()
+        timer = nil
+    }
+}