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

namespace SafeMobileLib
{
    static public class Encryption
    {
        
        static public byte[] Encrypt(byte[] inputArray, EncryptionAlgorithm algorithm)
        {
            if (algorithm == EncryptionAlgorithm.Aes256)
                return AesEncrypt(inputArray);
            else if (algorithm == EncryptionAlgorithm.Des64)
                return DesEncrypt(inputArray);
            else if (algorithm == EncryptionAlgorithm.None)
                return inputArray;
            else
                throw new ApplicationException("No ecryption defined for algorithm " + algorithm);
        }

        static public byte[] Decrypt(byte[] dataToDecrypt, EncryptionAlgorithm algorithm)
        {
            if (algorithm == EncryptionAlgorithm.Aes256)
                return AesDecrypt(dataToDecrypt);
            else if (algorithm == EncryptionAlgorithm.Des64)
                return DesDecrypt(dataToDecrypt);
            else if (algorithm == EncryptionAlgorithm.None)
                return dataToDecrypt;
            else
                throw new ApplicationException("No decryption defined for algorithm " + algorithm);
        }
      

        #region DES64 encryption

        private static byte[] bytes = ASCIIEncoding.ASCII.GetBytes("SafeMobi"); //DES 64bit !

        private static byte[] DesEncrypt(byte[] inputArray)
        {
            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            MemoryStream memoryStream = new MemoryStream();
            CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateEncryptor(bytes, bytes), CryptoStreamMode.Write);
            
            cryptoStream.Write(inputArray,0,inputArray.Length);
            
            cryptoStream.Close(); memoryStream.Close();
            return memoryStream.ToArray();
        }

        private static byte[] DesDecrypt(byte[] DataToDecrypt)
        {
            DESCryptoServiceProvider cryptoProvider = new DESCryptoServiceProvider();
            MemoryStream memoryStream = new MemoryStream();
            CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateDecryptor(bytes, bytes), CryptoStreamMode.Write);
            
            cryptoStream.Write(DataToDecrypt, 0, DataToDecrypt.Length);
            cryptoStream.Close(); memoryStream.Close();
            return memoryStream.ToArray();
        }

        #endregion

        #region AES256 Encryption

        private static byte[] aesKey = new byte[32] { 206, 156, 144,  76,  93, 170,  62,  42, 240, 216,  24,  84, 160, 145,  53,  37,
                                                28,  37, 139, 150,  18,  10,  84, 151, 239,  29, 123, 240,  13, 168,  40,  72};

        private static byte[] aesIV = new byte[16] { 153, 54, 221, 187, 162, 171, 189, 223, 248, 123, 97, 197, 148, 196, 29, 59 };

        private static byte[] AesEncrypt(byte[] inputArray)
        {

            byte[] encrypted = null;
            using (AesCryptoServiceProvider cryptoProvider = new AesCryptoServiceProvider())
            {
                using (MemoryStream memoryStream = new MemoryStream())
                {
                    using (CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateEncryptor(aesKey, aesIV), CryptoStreamMode.Write))
                    {
                        cryptoStream.Write(inputArray, 0, inputArray.Length);
                    }
                    encrypted = memoryStream.ToArray();
                }
            }
            return encrypted;
        }


        private static byte[] AesDecrypt(byte[] DataToDecrypt)
        {
            byte[] decrypted = null;
            using (AesCryptoServiceProvider cryptoProvider = new AesCryptoServiceProvider())
            {
                using (MemoryStream memoryStream = new MemoryStream())
                {
                    using (CryptoStream cryptoStream = new CryptoStream(memoryStream, cryptoProvider.CreateDecryptor(aesKey, aesIV), CryptoStreamMode.Write))
                    {
                        cryptoStream.Write(DataToDecrypt, 0, DataToDecrypt.Length);
                    }
                    decrypted = memoryStream.ToArray();
                }
            }
            return decrypted;
        }

        #endregion
    }

    public enum EncryptionAlgorithm
    {
        Des64,
        Aes256,
        None
    }

    public class TESEncryption
    {
        private static string key = "safemobileTriple";

        public static string Encryption(string input)
        {
            return Encrypt(input, key);
        }

        public static string Encrypt(string input, string key)
        {
            byte[] inputArray = UTF8Encoding.UTF8.GetBytes(input);
            TripleDESCryptoServiceProvider tripleDES = new TripleDESCryptoServiceProvider();
            tripleDES.Key = UTF8Encoding.UTF8.GetBytes(key);
            tripleDES.Mode = CipherMode.ECB;
            tripleDES.Padding = PaddingMode.PKCS7;
            ICryptoTransform cTransform = tripleDES.CreateEncryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
            tripleDES.Clear();
            return Convert.ToBase64String(resultArray, 0, resultArray.Length);
        }

        public static string Decrypt(string input)
        {
            return Decrypt(input, key);
        }

        public static string Decrypt(string input, string key)
        {
            byte[] inputArray = Convert.FromBase64String(input);
            TripleDESCryptoServiceProvider tripleDES = new TripleDESCryptoServiceProvider();
            tripleDES.Key = UTF8Encoding.UTF8.GetBytes(key);
            tripleDES.Mode = CipherMode.ECB;
            tripleDES.Padding = PaddingMode.PKCS7;
            ICryptoTransform cTransform = tripleDES.CreateDecryptor();
            byte[] resultArray = cTransform.TransformFinalBlock(inputArray, 0, inputArray.Length);
            tripleDES.Clear();
            return UTF8Encoding.UTF8.GetString(resultArray);
        }
    }
}