Cryptura/Cryptura/EncryptionLibrary.cs

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

namespace Cryptura;

public static class EncryptionLibrary
{
    private const int SaltSize = 16;
    private const int KeySize = 32; 
    private const int Iterations = 10000;

    public static string Encrypt(string masterPassword, string plainPassword)
    {
        byte[] salt = new byte[SaltSize];
        using (var rng = new RNGCryptoServiceProvider())
        {
            rng.GetBytes(salt);
        }

        using (var aesAlg = Aes.Create())
        {
            var key = new Rfc2898DeriveBytes(masterPassword, salt, Iterations);
            aesAlg.Key = key.GetBytes(KeySize);
            aesAlg.IV = new byte[16];

            using (var encryptor = aesAlg.CreateEncryptor(aesAlg.Key, aesAlg.IV))
            using (var ms = new MemoryStream())
            {
                ms.Write(salt, 0, salt.Length);

                using (var cs = new CryptoStream(ms, encryptor, CryptoStreamMode.Write))
                using (var writer = new StreamWriter(cs))
                {
                    writer.Write(plainPassword);
                }

                return Convert.ToBase64String(ms.ToArray());
            }
        }
    }
    public static string Decrypt(string masterPassword, string encryptedPassword)
    {
        byte[] cipherBytes = Convert.FromBase64String(encryptedPassword);
        byte[] salt = new byte[SaltSize];
        Array.Copy(cipherBytes, 0, salt, 0, SaltSize);  // Extract the salt

        using (var aesAlg = Aes.Create())
        {
            var key = new Rfc2898DeriveBytes(masterPassword, salt, Iterations);
            aesAlg.Key = key.GetBytes(KeySize);
            aesAlg.IV = new byte[16];

            using (var decryptor = aesAlg.CreateDecryptor(aesAlg.Key, aesAlg.IV))
            using (var ms = new MemoryStream(cipherBytes, SaltSize, cipherBytes.Length - SaltSize))
            using (var cs = new CryptoStream(ms, decryptor, CryptoStreamMode.Read))
            using (var reader = new StreamReader(cs))
            {
                return reader.ReadToEnd();
            }
        }
    }
}