using System;

using System.Collections.Generic;

using System.Linq;

using System.Security;

using System.Text;

using System.Threading.Tasks;

namespace SharpDisplayManager

{

    /// <summary>

    /// As per: http://weblogs.asp.net/jongalloway/encrypting-passwords-in-a-net-app-config-file

    /// </summary>

    class Secure

    {

        static byte[] entropy = System.Text.Encoding.Unicode.GetBytes("kd566slqfjls234895DFG743fqdlskj345SDFDepozwxc,n*ù^$^é");

        public static string EncryptString(System.Security.SecureString input)

        {

            byte[] encryptedData = System.Security.Cryptography.ProtectedData.Protect(

                System.Text.Encoding.Unicode.GetBytes(ToInsecureString(input)),

                entropy,

                System.Security.Cryptography.DataProtectionScope.CurrentUser);

            return Convert.ToBase64String(encryptedData);

        }

        public static SecureString DecryptString(string encryptedData)

        {

            try

            {

                byte[] decryptedData = System.Security.Cryptography.ProtectedData.Unprotect(

                    Convert.FromBase64String(encryptedData),

                    entropy,

                    System.Security.Cryptography.DataProtectionScope.CurrentUser);

                return ToSecureString(System.Text.Encoding.Unicode.GetString(decryptedData));

            }

            catch

            {

                return new SecureString();

            }

        }

        public static SecureString ToSecureString(string input)

        {

            SecureString secure = new SecureString();

            foreach (char c in input)

            {

                secure.AppendChar(c);

            }

            secure.MakeReadOnly();

            return secure;

        }

        public static string ToInsecureString(SecureString input)

        {

            string returnValue = string.Empty;

            IntPtr ptr = System.Runtime.InteropServices.Marshal.SecureStringToBSTR(input);

            try

            {

                returnValue = System.Runtime.InteropServices.Marshal.PtrToStringBSTR(ptr);

            }

            finally

            {

                System.Runtime.InteropServices.Marshal.ZeroFreeBSTR(ptr);

            }

            return returnValue;

        }

    }

}