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

namespace Gestor.Common.Helpers
{
	public static class EncryptionHelper
	{
		private readonly static byte[] Salt;

		private readonly static string EncryptionKey;

		static EncryptionHelper()
		{
			EncryptionHelper.Salt = new byte[] { 38, 220, 255, 0, 173, 237, 122, 238, 197, 254, 7, 175, 77, 8, 34, 60 };
			EncryptionHelper.EncryptionKey = string.Format("aGG3r{0}#w3BDz$", 1012);
		}

		public static string Decrypt(this string cipher)
		{
			string str;
			if (string.IsNullOrEmpty(cipher))
			{
				return null;
			}
			try
			{
				byte[] numArray = Convert.FromBase64String(cipher);
				if ((int)numArray.Length >= 16)
				{
					byte[] numArray1 = numArray.DecryptBytes();
					str = (numArray1 == null ? cipher : Encoding.UTF8.GetString(numArray1));
				}
				else
				{
					str = cipher;
				}
			}
			catch (Exception exception)
			{
				str = cipher;
			}
			return str;
		}

		public static byte[] DecryptBytes(this byte[] plainTextBytes)
		{
			byte[] array;
			try
			{
				using (Rfc2898DeriveBytes rfc2898DeriveByte = new Rfc2898DeriveBytes(EncryptionHelper.EncryptionKey, EncryptionHelper.Salt))
				{
					using (Rijndael bytes = Rijndael.Create())
					{
						bytes.Key = rfc2898DeriveByte.GetBytes(32);
						bytes.IV = rfc2898DeriveByte.GetBytes(16);
						using (MemoryStream memoryStream = new MemoryStream())
						{
							using (CryptoStream cryptoStream = new CryptoStream(memoryStream, bytes.CreateDecryptor(), CryptoStreamMode.Write))
							{
								cryptoStream.Write(plainTextBytes, 0, (int)plainTextBytes.Length);
								cryptoStream.FlushFinalBlock();
								array = memoryStream.ToArray();
							}
						}
					}
				}
			}
			catch (Exception exception)
			{
				array = null;
			}
			return array;
		}

		public static string Encrypt(this string plain)
		{
			return Convert.ToBase64String(Encoding.UTF8.GetBytes(plain).EncryptBytes());
		}

		public static byte[] EncryptBytes(this byte[] plainTextBytes)
		{
			byte[] array;
			using (Rfc2898DeriveBytes rfc2898DeriveByte = new Rfc2898DeriveBytes(EncryptionHelper.EncryptionKey, EncryptionHelper.Salt))
			{
				using (Rijndael bytes = Rijndael.Create())
				{
					bytes.Key = rfc2898DeriveByte.GetBytes(32);
					bytes.IV = rfc2898DeriveByte.GetBytes(16);
					using (MemoryStream memoryStream = new MemoryStream())
					{
						using (CryptoStream cryptoStream = new CryptoStream(memoryStream, bytes.CreateEncryptor(), CryptoStreamMode.Write))
						{
							cryptoStream.Write(plainTextBytes, 0, (int)plainTextBytes.Length);
							cryptoStream.FlushFinalBlock();
							array = memoryStream.ToArray();
						}
					}
				}
			}
			return array;
		}
	}
}