DocSpace-buildtools/common/ASC.Common/Security/Cryptography/InstanceCrypto.cs

/*
 *
 * (c) Copyright Ascensio System Limited 2010-2018
 *
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 * General Public License (GPL) version 3 as published by the Free Software Foundation (https://www.gnu.org/copyleft/gpl.html). 
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 *
 * THIS PROGRAM IS DISTRIBUTED WITHOUT ANY WARRANTY; WITHOUT EVEN THE IMPLIED WARRANTY OF MERCHANTABILITY OR
 * FITNESS FOR A PARTICULAR PURPOSE. For more details, see GNU GPL at https://www.gnu.org/copyleft/gpl.html
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*/


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

using ASC.Common;

namespace ASC.Security.Cryptography
{
    [Singletone]
    public class InstanceCrypto
    {
        private MachinePseudoKeys MachinePseudoKeys { get; }

        public InstanceCrypto(MachinePseudoKeys machinePseudoKeys)
        {
            MachinePseudoKeys = machinePseudoKeys;
        }

        public string Encrypt(string data)
        {
            return Convert.ToBase64String(Encrypt(Encoding.UTF8.GetBytes(data)));
        }

        public byte[] Encrypt(byte[] data)
        {
            var hasher = Aes.Create();
            hasher.Key = EKey();
            hasher.IV = new byte[hasher.BlockSize >> 3];
            using var ms = new MemoryStream();
            using var ss = new CryptoStream(ms, hasher.CreateEncryptor(), CryptoStreamMode.Write);
            ss.Write(data, 0, data.Length);
            ss.FlushFinalBlock();
            hasher.Clear();
            return ms.ToArray();
        }

        public string Decrypt(string data)
        {
            return Decrypt(Convert.FromBase64String(data));
        }

        public string Decrypt(byte[] data)
        {
            var hasher = Aes.Create();
            hasher.Key = EKey();
            hasher.IV = new byte[hasher.BlockSize >> 3];

            using (MemoryStream msDecrypt = new MemoryStream(data))
            {
                using (CryptoStream csDecrypt = new CryptoStream(msDecrypt, hasher.CreateDecryptor(), CryptoStreamMode.Read))
                {
                    using (StreamReader srDecrypt = new StreamReader(csDecrypt))
                    {

                        // Read the decrypted bytes from the decrypting stream
                        // and place them in a string.
                        return srDecrypt.ReadToEnd();
                    }
                }
            }
        }

        private byte[] EKey()
        {
            return MachinePseudoKeys.GetMachineConstant(32);
        }
    }
}