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

/*
 *
 * (c) Copyright Ascensio System Limited 2010-2018
 *
 * This program is freeware. You can redistribute it and/or modify it under the terms of the GNU 
 * General Public License (GPL) version 3 as published by the Free Software Foundation (https://www.gnu.org/copyleft/gpl.html). 
 * In accordance with Section 7(a) of the GNU GPL its Section 15 shall be amended to the effect that 
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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 Microsoft.Extensions.DependencyInjection;
using Microsoft.Extensions.DependencyInjection.Extensions;

namespace ASC.Security.Cryptography
{
    public class InstanceCrypto
    {
        public 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 = Rijndael.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 Encoding.UTF8.GetString(Decrypt(Convert.FromBase64String(data)));
        }

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

            using var ms = new MemoryStream(data);
            using var ss = new CryptoStream(ms, hasher.CreateDecryptor(), CryptoStreamMode.Read);
            var buffer = new byte[data.Length];
            var size = ss.Read(buffer, 0, buffer.Length);
            hasher.Clear();
            var newBuffer = new byte[size];
            Array.Copy(buffer, newBuffer, size);
            return newBuffer;
        }

        private byte[] EKey()
        {
            return MachinePseudoKeys.GetMachineConstant(32);
        }
    }
    public static class InstanceCryptoFactory
    {
        public static IServiceCollection AddInstanceCryptoService(this IServiceCollection services)
        {
            services.TryAddSingleton<InstanceCrypto>();

            return services
                .AddHttpContextAccessor()
                .AddMachinePseudoKeysService();
        }
    }
}