c# 代码实现 访问SMB加密的共享文件

访问SMB加密的共享文件需要使用SMB2协议，并且在连接时需要提供用户名和密码。以下是使用C#代码实现访问SMB加密的共享文件的示例：

using System;
using System.IO;
using System.Net;
using System.Runtime.InteropServices;
using System.Security;

namespace SMBClient
{
    class Program
    {
        static void Main(string[] args)
        {
            string smbPath = @"\\smbserver\sharedfolder\file.txt";
            string username = "username";
            string password = "password";
            string domain = "domain";

            NetworkCredential credential = new NetworkCredential(username, password, domain);
            SecureString securePassword = new SecureString();
            foreach (char c in password)
            {
                securePassword.AppendChar(c);
            }

            try
            {
                using (new NetworkConnection(smbPath, credential))
                {
                    byte[] data = File.ReadAllBytes(smbPath);
                    Console.WriteLine("File content: " + System.Text.Encoding.UTF8.GetString(data));
                }
            }
            catch (Exception ex)
            {
                Console.WriteLine(ex.Message);
            }

            Console.ReadLine();
        }
    }

    public class NetworkConnection : IDisposable
    {
        string _networkName;

        public NetworkConnection(string networkName, NetworkCredential credentials)
        {
            _networkName = networkName;

            var netResource = new NetResource
            {
                Scope = ResourceScope.GlobalNetwork,
                ResourceType = ResourceType.Disk,
                DisplayType = ResourceDisplayType.Share,
                RemoteName = networkName
            };

            var userName = credentials.UserName;
            var password = credentials.SecurePassword;
            var domain = credentials.Domain;

            var result = WNetAddConnection2(
                netResource,
                password,
                userName,
                0);

            if (result != 0)
            {
                throw new IOException("Error connecting to remote share", result);
            }
        }

        ~NetworkConnection()
        {
            Dispose(false);
        }

        public void Dispose()
        {
            Dispose(true);
            GC.SuppressFinalize(this);
        }

        protected virtual void Dispose(bool disposing)
        {
            WNetCancelConnection2(_networkName, 0, true);
        }

        [DllImport("mpr.dll")]
        private static extern int WNetAddConnection2(NetResource netResource,
            SecureString password, string username, uint flags);

        [DllImport("mpr.dll")]
        private static extern int WNetCancelConnection2(string name, uint flags,
            bool force);
    }

    public enum ResourceScope : int
    {
        Connected = 1,
        GlobalNetwork,
        Remembered,
        Recent,
        Context
    }

    public enum ResourceType : int
    {
        Any = 0,
        Disk = 1,
        Print = 2,
        Reserved = 8
    }

    public enum ResourceDisplayType : int
    {
        Generic = 0x0,
        Domain = 0x01,
        Server = 0x02,
        Share = 0x03,
        File = 0x04,
        Group = 0x05,
        Network = 0x06,
        Root = 0x07,
        ShareAdmin = 0x08,
        Directory = 0x09,
        Tree = 0x0a,
        NdsContainer = 0x0b
    }

    [StructLayout(LayoutKind.Sequential)]
    public class NetResource
    {
        public ResourceScope Scope;
        public ResourceType ResourceType;
        public ResourceDisplayType DisplayType;
        public int Usage;
        public string LocalName;
        public string RemoteName;
        public string Comment;
        public string Provider;
    }
}

上面的代码使用了Windows API函数`WNetAddConnection2`和`WNetCancelConnection2`，它们分别用于建立和取消SMB连接。在建立连接时，需要提供共享文件的路径、用户名和密码。如果连接成功，就可以使用.NET Framework提供的文件操作函数（如`File.ReadAllBytes`）来读取文件内容了。在连接完成后，需要调用`WNetCancelConnection2`函数来关闭连接。