C# ile Basit Şifre Yöneticisi (AES şifreleme)

using System;
using System.IO;
using System.Security.Cryptography;
using System.Text;

namespace PasswordManager
{
    class Program
    {
        static void Main(string[] args)
        {
            while (true)
            {
                Console.Clear();
                Console.WriteLine("🔐 ŞİFRE YÖNETİCİSİ");
                Console.WriteLine("1. Yeni Şifre Ekle");
                Console.WriteLine("2. Şifreleri Listele");
                Console.WriteLine("3. Çıkış");
                Console.Write("Seçim: ");

                switch (Console.ReadLine())
                {
                    case "1":
                        AddPassword();
                        break;
                    case "2":
                        ListPasswords();
                        break;
                    case "3":
                        return;
                    default:
                        Console.WriteLine("Geçersiz seçim!");
                        Console.ReadKey();
                        break;
                }
            }
        }

        static void AddPassword()
        {
            Console.Write("Servis Adı: ");
            string service = Console.ReadLine();
            Console.Write("Kullanıcı Adı: ");
            string username = Console.ReadLine();
            Console.Write("Şifre: ");
            string password = Console.ReadLine();

            string encrypted = Encrypt($"{service}|{username}|{password}", "sifrelemeAnahtari123");
           
            File.AppendAllText("passwords.dat", encrypted + Environment.NewLine);
            Console.WriteLine("✔️ Şifre kaydedildi!");
            Console.ReadKey();
        }

        static void ListPasswords()
        {
            if (!File.Exists("passwords.dat"))
            {
                Console.WriteLine("Kayıtlı şifre yok!");
                Console.ReadKey();
                return;
            }

            Console.WriteLine("\n📋 KAYITLI ŞİFRELER");
            Console.WriteLine("-----------------------");
           
            foreach (string line in File.ReadAllLines("passwords.dat"))
            {
                string decrypted = Decrypt(line, "sifrelemeAnahtari123");
                string[] parts = decrypted.Split('|');
               
                Console.WriteLine($"🔹 {parts[0]}");
                Console.WriteLine($"   👤 Kullanıcı: {parts[1]}");
                Console.WriteLine($"   🔑 Şifre: {parts[2]}");
                Console.WriteLine("-----------------------");
            }
           
            Console.ReadKey();
        }

        static string Encrypt(string plainText, string key)
        {
            byte[] iv = new byte[16];
            byte[] array;

            using (Aes aes = Aes.Create())
            {
                aes.Key = Encoding.UTF8.GetBytes(key);
                aes.IV = iv;

                ICryptoTransform encryptor = aes.CreateEncryptor(aes.Key, aes.IV);

                using (MemoryStream memoryStream = new MemoryStream())
                {
                    using (CryptoStream cryptoStream = new CryptoStream(memoryStream, encryptor, CryptoStreamMode.Write))
                    {
                        using (StreamWriter streamWriter = new StreamWriter(cryptoStream))
                        {
                            streamWriter.Write(plainText);
                        }
                        array = memoryStream.ToArray();
                    }
                }
            }
            return Convert.ToBase64String(array);
        }

        static string Decrypt(string cipherText, string key)
        {
            byte[] iv = new byte[16];
            byte[] buffer = Convert.FromBase64String(cipherText);

            using (Aes aes = Aes.Create())
            {
                aes.Key = Encoding.UTF8.GetBytes(key);
                aes.IV = iv;

                ICryptoTransform decryptor = aes.CreateDecryptor(aes.Key, aes.IV);

                using (MemoryStream memoryStream = new MemoryStream(buffer))
                {
                    using (CryptoStream cryptoStream = new CryptoStream(memoryStream, decryptor, CryptoStreamMode.Read))
                    {
                        using (StreamReader streamReader = new StreamReader(cryptoStream))
                        {
                            return streamReader.ReadToEnd();
                        }
                    }
                }
            }
        }
    }
}