asp.net - 如何临时冒充用户打开文件？

Question

我想临时模拟一个域用户帐户以从 ASP.NET 站点读取网络驱动器上的文件。

我宁愿不为整个站点设置模拟或在服务器上设置映射驱动器。

Answer 1

我最终使用了Michiel van Otegem 的代码：WindowsImpersonationContext 变得简单，并添加了 IDisposable 的实现。我在另一个关于 ASP.NET 中的模拟的问题中发现了这一点。

用法：

using (WindowsImpersonationContextFacade impersonationContext
     = new WindowsImpersonationContextFacade(
                    Settings.Default.ImpersonationDomain, 
                    Settings.Default.ImpersonationUser,
                    Settings.Default.ImpersonationPass))
                {
                    transactions  = TransactionLoader.Load(filePath);
                }

代码：

using System;
using System.Runtime.InteropServices;
using System.Security.Principal;
using System.Security.Permissions;
using System.ComponentModel;

namespace MyNamespace
{
    public class WindowsImpersonationContextFacade : IDisposable
    {
        [DllImport("advapi32.dll", SetLastError = true)]
        public static extern bool LogonUser(String lpszUsername, String lpszDomain,
                                            String lpszPassword, int dwLogonType, int dwLogonProvider,
                                            ref IntPtr phToken);

        [DllImport("kernel32.dll", CharSet = CharSet.Auto)]
        public static extern bool CloseHandle(IntPtr handle);

        private const int LOGON32_PROVIDER_DEFAULT = 0;
        private const int LOGON32_LOGON_INTERACTIVE = 2;

        private string m_Domain;
        private string m_Password;
        private string m_Username;
        private IntPtr m_Token;

        private WindowsImpersonationContext m_Context = null;

        protected bool IsInContext
        {
            get { return m_Context != null; }
        }

        public WindowsImpersonationContextFacade(string domain, string username, string password)
        {
            m_Domain = domain;
            m_Username = username;
            m_Password = password;
            Enter();
        }

        [PermissionSetAttribute(SecurityAction.Demand, Name = "FullTrust")]
        private void Enter()
        {
            if (this.IsInContext) return;
            m_Token = IntPtr.Zero;
            bool logonSuccessfull = LogonUser(
                m_Username,
                m_Domain,
                m_Password,
                LOGON32_LOGON_INTERACTIVE,
                LOGON32_PROVIDER_DEFAULT,
                ref m_Token);
            if (logonSuccessfull == false)
            {
                int error = Marshal.GetLastWin32Error();
                throw new Win32Exception(error);
            }
            WindowsIdentity identity = new WindowsIdentity(m_Token);
            m_Context = identity.Impersonate();
        }

        [PermissionSetAttribute(SecurityAction.Demand, Name = "FullTrust")]
        private void Leave()
        {
            if (this.IsInContext == false) return;
            m_Context.Undo();

            if (m_Token != IntPtr.Zero) CloseHandle(m_Token);
            m_Context = null;
        }

        public void Dispose()
        {
            Leave();
        }
    }
}

Answer 2

实际上，这个过程很简单，你可以使用这样的代码；

using System.Security.Principal;
...
// Obtain the authenticated user's Identity
WindowsIdentity winId = (WindowsIdentity)HttpContext.Current.User.Identity;
WindowsImpersonationContext ctx = null;
try
{
  // Start impersonating
  ctx = winId.Impersonate();
  // Now impersonating
  // Access resources using the identity of the authenticated user
}
// Prevent exceptions from propagating
catch
{
}
finally
{
  // Revert impersonation
  if (ctx != null)
    ctx.Undo();
}
// Back to running under the default ASP.NET process identity

您的代码位于“现在模拟”部分。KEY 是 finally 块，这非常重要。您可以查看此MSDN文章以了解有关其工作原理的完整详细信息。