我需要从Web App访问远程驱动器。 ASP.NET进程无法访问该驱动器，因此我想模拟当前用户的请求。
我看到了一些使用WindowsImpersonationContext的基本示例，并尝试了以下操作。
WindowsImpersonationContext impersonationContext = null;
try
{
impersonationContext = ((WindowsIdentity)User.Identity).Impersonate();
file.SaveAs(filePath);
}
finally
{
if (impersonationContext != null)
{
impersonationContext.Undo();
}
}
我仍然收到拒绝访问权限。
我已经阅读了一些有关LogonUser的内容，但据我所知，您需要一个用户名和密码才能从中获取凭据。我不打算以不同的特定用户身份登录，只是当前用户（谁应该有权访问文件存储），所以我认为我实际上并不需要LogonUser API。
有没有人知道我错过了什么？上述代码应该有效吗？
我还要注意包括
<identity impersonate="true" />
不起作用，但包括
<identity impersonate="true" userName="myName" password="myPassword" />
web.config中的让我进来。我看到有几个人会问这是为什么，但我没有看到任何解释。我想知道它是否与我的问题有关。
答案 0 :(得分：9)
我写了一个辅助类来完成它：
public static class ImpersonationUtils
{
private const int SW_SHOW = 5;
private const int TOKEN_QUERY = 0x0008;
private const int TOKEN_DUPLICATE = 0x0002;
private const int TOKEN_ASSIGN_PRIMARY = 0x0001;
private const int STARTF_USESHOWWINDOW = 0x00000001;
private const int STARTF_FORCEONFEEDBACK = 0x00000040;
private const int CREATE_UNICODE_ENVIRONMENT = 0x00000400;
private const int TOKEN_IMPERSONATE = 0x0004;
private const int TOKEN_QUERY_SOURCE = 0x0010;
private const int TOKEN_ADJUST_PRIVILEGES = 0x0020;
private const int TOKEN_ADJUST_GROUPS = 0x0040;
private const int TOKEN_ADJUST_DEFAULT = 0x0080;
private const int TOKEN_ADJUST_SESSIONID = 0x0100;
private const int STANDARD_RIGHTS_REQUIRED = 0x000F0000;
private const int TOKEN_ALL_ACCESS =
STANDARD_RIGHTS_REQUIRED |
TOKEN_ASSIGN_PRIMARY |
TOKEN_DUPLICATE |
TOKEN_IMPERSONATE |
TOKEN_QUERY |
TOKEN_QUERY_SOURCE |
TOKEN_ADJUST_PRIVILEGES |
TOKEN_ADJUST_GROUPS |
TOKEN_ADJUST_DEFAULT |
TOKEN_ADJUST_SESSIONID;
[StructLayout(LayoutKind.Sequential)]
private struct PROCESS_INFORMATION
{
public IntPtr hProcess;
public IntPtr hThread;
public int dwProcessId;
public int dwThreadId;
}
[StructLayout(LayoutKind.Sequential)]
private struct SECURITY_ATTRIBUTES
{
public int nLength;
public IntPtr lpSecurityDescriptor;
public bool bInheritHandle;
}
[StructLayout(LayoutKind.Sequential)]
private struct STARTUPINFO
{
public int cb;
public string lpReserved;
public string lpDesktop;
public string lpTitle;
public int dwX;
public int dwY;
public int dwXSize;
public int dwYSize;
public int dwXCountChars;
public int dwYCountChars;
public int dwFillAttribute;
public int dwFlags;
public short wShowWindow;
public short cbReserved2;
public IntPtr lpReserved2;
public IntPtr hStdInput;
public IntPtr hStdOutput;
public IntPtr hStdError;
}
private enum SECURITY_IMPERSONATION_LEVEL
{
SecurityAnonymous,
SecurityIdentification,
SecurityImpersonation,
SecurityDelegation
}
private enum TOKEN_TYPE
{
TokenPrimary = 1,
TokenImpersonation
}
[DllImport("advapi32.dll", SetLastError = true)]
private static extern bool CreateProcessAsUser(
IntPtr hToken,
string lpApplicationName,
string lpCommandLine,
ref SECURITY_ATTRIBUTES lpProcessAttributes,
ref SECURITY_ATTRIBUTES lpThreadAttributes,
bool bInheritHandles,
int dwCreationFlags,
IntPtr lpEnvironment,
string lpCurrentDirectory,
ref STARTUPINFO lpStartupInfo,
out PROCESS_INFORMATION lpProcessInformation);
[DllImport("advapi32.dll", SetLastError = true)]
private static extern bool DuplicateTokenEx(
IntPtr hExistingToken,
int dwDesiredAccess,
ref SECURITY_ATTRIBUTES lpThreadAttributes,
int ImpersonationLevel,
int dwTokenType,
ref IntPtr phNewToken);
[DllImport("advapi32.dll", SetLastError = true)]
private static extern bool OpenProcessToken(
IntPtr ProcessHandle,
int DesiredAccess,
ref IntPtr TokenHandle);
[DllImport("userenv.dll", SetLastError = true)]
private static extern bool CreateEnvironmentBlock(
ref IntPtr lpEnvironment,
IntPtr hToken,
bool bInherit);
[DllImport("userenv.dll", SetLastError = true)]
private static extern bool DestroyEnvironmentBlock(
IntPtr lpEnvironment);
[DllImport("kernel32.dll", SetLastError = true)]
private static extern bool CloseHandle(
IntPtr hObject);
private static void LaunchProcessAsUser(string cmdLine, IntPtr token, IntPtr envBlock, int sessionId)
{
var pi = new PROCESS_INFORMATION();
var saProcess = new SECURITY_ATTRIBUTES();
var saThread = new SECURITY_ATTRIBUTES();
saProcess.nLength = Marshal.SizeOf(saProcess);
saThread.nLength = Marshal.SizeOf(saThread);
var si = new STARTUPINFO();
si.cb = Marshal.SizeOf(si);
si.lpDesktop = @"WinSta0\Default";
si.dwFlags = STARTF_USESHOWWINDOW | STARTF_FORCEONFEEDBACK;
si.wShowWindow = SW_SHOW;
if (!CreateProcessAsUser(
token,
null,
cmdLine,
ref saProcess,
ref saThread,
false,
CREATE_UNICODE_ENVIRONMENT,
envBlock,
null,
ref si,
out pi))
{
throw new Win32Exception(Marshal.GetLastWin32Error(), "CreateProcessAsUser failed");
}
}
private static IDisposable Impersonate(IntPtr token)
{
var identity = new WindowsIdentity(token);
return identity.Impersonate();
}
private static IntPtr GetPrimaryToken(Process process)
{
var token = IntPtr.Zero;
var primaryToken = IntPtr.Zero;
if (OpenProcessToken(process.Handle, TOKEN_DUPLICATE, ref token))
{
var sa = new SECURITY_ATTRIBUTES();
sa.nLength = Marshal.SizeOf(sa);
if (!DuplicateTokenEx(
token,
TOKEN_ALL_ACCESS,
ref sa,
(int)SECURITY_IMPERSONATION_LEVEL.SecurityImpersonation,
(int)TOKEN_TYPE.TokenPrimary,
ref primaryToken))
{
throw new Win32Exception(Marshal.GetLastWin32Error(), "DuplicateTokenEx failed");
}
CloseHandle(token);
}
else
{
throw new Win32Exception(Marshal.GetLastWin32Error(), "OpenProcessToken failed");
}
return primaryToken;
}
private static IntPtr GetEnvironmentBlock(IntPtr token)
{
var envBlock = IntPtr.Zero;
if (!CreateEnvironmentBlock(ref envBlock, token, false))
{
throw new Win32Exception(Marshal.GetLastWin32Error(), "CreateEnvironmentBlock failed");
}
return envBlock;
}
public static void LaunchAsCurrentUser(string cmdLine)
{
var process = Process.GetProcessesByName("explorer").FirstOrDefault();
if (process != null)
{
var token = GetPrimaryToken(process);
if (token != IntPtr.Zero)
{
var envBlock = GetEnvironmentBlock(token);
if (envBlock != IntPtr.Zero)
{
LaunchProcessAsUser(cmdLine, token, envBlock, process.SessionId);
if (!DestroyEnvironmentBlock(envBlock))
{
throw new Win32Exception(Marshal.GetLastWin32Error(), "DestroyEnvironmentBlock failed");
}
}
CloseHandle(token);
}
}
}
public static IDisposable ImpersonateCurrentUser()
{
var process = Process.GetProcessesByName("explorer").FirstOrDefault();
if (process != null)
{
var token = GetPrimaryToken(process);
if (token != IntPtr.Zero)
{
return Impersonate(token);
}
}
throw new Exception("Could not find explorer.exe");
}
}
你可以这样使用它：
ImpersonationUtils.LaunchAsCurrentUser("notepad");
using (ImpersonationUtils.ImpersonateCurrentUser())
{
}
您可以在此处找到更多解释和示例：
答案 1 :(得分：3)
您可能遇到了模拟与委派问题。模拟用户时，您可以以该用户身份访问本地资源，但不能访问远程资源。使用Delegation，您也可以访问远程资源。请尝试以下方法：
<authentication mode="Windows" />以确保ASP.NET处理Windows身份验证（这应该仅适用于经典管道模式）。<identity impersonate="true" />就足够了。您可能需要做的另一件事是确保允许运行AppPool的帐户像委托一样行事。