WindowsImpersonationContext クラス
偽装操作を行う前の Windows ユーザーを表します。
この型のすべてのメンバの一覧については、WindowsImpersonationContext メンバ を参照してください。
System.Object
System.Security.Principal.WindowsImpersonationContext
Public Class WindowsImpersonationContext
[C#]
public class WindowsImpersonationContext
[C++]
public __gc class WindowsImpersonationContext
[JScript]
public class WindowsImpersonationContext
スレッドセーフ
この型の public static (Visual Basicでは Shared) のすべてのメンバは、マルチスレッド操作で安全に使用できます。インスタンスのメンバの場合は、スレッドセーフであるとは限りません。
解説
このクラスは、ユーザーが別のユーザーを偽装した後で、元のユーザーの ID を元に戻します。
実装時の注意: Microsoft Windows 98 および Windows Millennium Edition にはユーザーやユーザー トークンがないため、これらのプラットフォームで偽装を行うことはできません。
使用例
[Visual Basic, C#, C++] ユーザーを偽装した後で、元の ID に戻す方法を次の例に示します。
' This sample demonstrates the use of the WindowsIdentity class to impersonate a user.
' IMPORTANT NOTES:
' This sample can be run only on Windows XP. The default Windows 2000 security policy
' prevents this sample from executing properly, and changing the policy to allow
' proper execution presents a security risk.
' This sample requests the user to enter a password on the console screen.
' Because the console window does not support methods allowing the password to be masked,
' it will be visible to anyone viewing the screen.
Imports System
Imports System.Runtime.InteropServices
Imports System.Security.Principal
Imports System.Security.Permissions
Imports Microsoft.VisualBasic
<Assembly: SecurityPermissionAttribute(SecurityAction.RequestMinimum, UnmanagedCode:=True), _
Assembly: PermissionSetAttribute(SecurityAction.RequestMinimum, Name:="FullTrust")>
Module Module1
Public Class ImpersonationDemo
Private Declare Auto Function LogonUser Lib "advapi32.dll" (ByVal lpszUsername As [String], _
ByVal lpszDomain As [String], ByVal lpszPassword As [String], _
ByVal dwLogonType As Integer, ByVal dwLogonProvider As Integer, _
ByRef phToken As IntPtr) As Boolean
<DllImport("kernel32.dll")> _
Public Shared Function FormatMessage(ByVal dwFlags As Integer, ByRef lpSource As IntPtr, _
ByVal dwMessageId As Integer, ByVal dwLanguageId As Integer, ByRef lpBuffer As [String], _
ByVal nSize As Integer, ByRef Arguments As IntPtr) As Integer
End Function
Public Declare Auto Function CloseHandle Lib "kernel32.dll" (ByVal handle As IntPtr) As Boolean
Public Declare Auto Function DuplicateToken Lib "advapi32.dll" (ByVal ExistingTokenHandle As IntPtr, _
ByVal SECURITY_IMPERSONATION_LEVEL As Integer, _
ByRef DuplicateTokenHandle As IntPtr) As Boolean
'GetErrorMessage formats and returns an error message
'corresponding to the input errorCode.
Public Shared Function GetErrorMessage(ByVal errorCode As Integer) As String
Dim FORMAT_MESSAGE_ALLOCATE_BUFFER As Integer = &H100
Dim FORMAT_MESSAGE_IGNORE_INSERTS As Integer = &H200
Dim FORMAT_MESSAGE_FROM_SYSTEM As Integer = &H1000
Dim messageSize As Integer = 255
Dim lpMsgBuf As String
Dim dwFlags As Integer = FORMAT_MESSAGE_ALLOCATE_BUFFER Or FORMAT_MESSAGE_FROM_SYSTEM Or FORMAT_MESSAGE_IGNORE_INSERTS
Dim ptrlpSource As IntPtr = IntPtr.Zero
Dim prtArguments As IntPtr = IntPtr.Zero
Dim retVal As Integer = FormatMessage(dwFlags, ptrlpSource, errorCode, 0, lpMsgBuf, _
messageSize, prtArguments)
If 0 = retVal Then
Throw New Exception("Failed to format message for error code " + errorCode.ToString() + ". ")
End If
Return lpMsgBuf
End Function 'GetErrorMessage
' Test harness.
' If you incorporate this code into a DLL, be sure to demand FullTrust.
<PermissionSetAttribute(SecurityAction.Demand, Name:="FullTrust")> _
Public Overloads Shared Sub Main(ByVal args() As String)
Dim tokenHandle As New IntPtr(0)
Dim dupeTokenHandle As New IntPtr(0)
Try
Dim userName, domainName As String
' Get the user token for the specified user, domain, and password using the
' unmanaged LogonUser method.
' The local machine name can be used for the domain name to impersonate a user on this machine.
Console.Write("Enter the name of a domain on which to log on: ")
domainName = Console.ReadLine()
Console.Write("Enter the login of a user on {0} that you wish to impersonate: ", domainName)
userName = Console.ReadLine()
Console.Write("Enter the password for {0}: ", userName)
Const LOGON32_PROVIDER_DEFAULT As Integer = 0
'This parameter causes LogonUser to create a primary token.
Const LOGON32_LOGON_INTERACTIVE As Integer = 2
Const SecurityImpersonation As Integer = 2
tokenHandle = IntPtr.Zero
dupeTokenHandle = IntPtr.Zero
' Call LogonUser to obtain a handle to an access token.
Dim returnValue As Boolean = LogonUser(userName, domainName, Console.ReadLine(), LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT, tokenHandle)
Console.WriteLine("LogonUser called.")
If False = returnValue Then
Dim ret As Integer = Marshal.GetLastWin32Error()
Console.WriteLine("LogonUser failed with error code : {0}", ret)
Console.WriteLine(ControlChars.Cr + "Error: [{0}] {1}" + ControlChars.Cr, ret, GetErrorMessage(ret))
Return
End If
Dim success As String
If returnValue Then success = "Yes" Else success = "No"
Console.WriteLine(("Did LogonUser succeed? " + success))
Console.WriteLine(("Value of Windows NT token: " + tokenHandle.ToString()))
' Check the identity.
Console.WriteLine(("Before impersonation: " + WindowsIdentity.GetCurrent().Name))
Dim retVal As Boolean = DuplicateToken(tokenHandle, SecurityImpersonation, dupeTokenHandle)
If False = retVal Then
CloseHandle(tokenHandle)
Console.WriteLine("Exception thrown in trying to duplicate token.")
Return
End If
' TThe token that is passed to the following constructor must
' be a primary token in order to use it for impersonation.
Dim newId As New WindowsIdentity(dupeTokenHandle)
Dim impersonatedUser As WindowsImpersonationContext = newId.Impersonate()
' Check the identity.
Console.WriteLine(("After impersonation: " + WindowsIdentity.GetCurrent().Name))
' Stop impersonating the user.
impersonatedUser.Undo()
' Check the identity.
Console.WriteLine(("After Undo: " + WindowsIdentity.GetCurrent().Name))
' Free the tokens.
If Not System.IntPtr.op_Equality(tokenHandle, IntPtr.Zero) Then
CloseHandle(tokenHandle)
End If
If Not System.IntPtr.op_Equality(dupeTokenHandle, IntPtr.Zero) Then
CloseHandle(dupeTokenHandle)
End If
Catch ex As Exception
Console.WriteLine(("Exception occurred. " + ex.Message))
End Try
End Sub 'Main
End Class 'Class1
[C#]
// This sample demonstrates the use of the WindowsIdentity class to impersonate a user.
// IMPORTANT NOTES:
// This sample can be run only on Windows XP. The default Windows 2000 security policy
// prevents this sample from executing properly, and changing the policy to allow
// proper execution presents a security risk.
// This sample requests the user to enter a password on the console screen.
// Because the console window does not support methods allowing the password to be masked,
// it will be visible to anyone viewing the screen.
using System;
using System.Runtime.InteropServices;
using System.Security.Principal;
using System.Security.Permissions;
[assembly:SecurityPermissionAttribute(SecurityAction.RequestMinimum, UnmanagedCode=true)]
[assembly:PermissionSetAttribute(SecurityAction.RequestMinimum, Name = "FullTrust")]
public class ImpersonationDemo
{
[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=System.Runtime.InteropServices.CharSet.Auto)]
private unsafe static extern int FormatMessage(int dwFlags, ref IntPtr lpSource,
int dwMessageId, int dwLanguageId, ref String lpBuffer, int nSize, IntPtr *Arguments);
[DllImport("kernel32.dll", CharSet=CharSet.Auto)]
public extern static bool CloseHandle(IntPtr handle);
[DllImport("advapi32.dll", CharSet=CharSet.Auto, SetLastError=true)]
public extern static bool DuplicateToken(IntPtr ExistingTokenHandle,
int SECURITY_IMPERSONATION_LEVEL, ref IntPtr DuplicateTokenHandle);
// GetErrorMessage formats and returns an error message
// corresponding to the input errorCode.
public unsafe static string GetErrorMessage(int errorCode)
{
int FORMAT_MESSAGE_ALLOCATE_BUFFER = 0x00000100;
int FORMAT_MESSAGE_IGNORE_INSERTS = 0x00000200;
int FORMAT_MESSAGE_FROM_SYSTEM = 0x00001000;
//int errorCode = 0x5; //ERROR_ACCESS_DENIED
//throw new System.ComponentModel.Win32Exception(errorCode);
int messageSize = 255;
String lpMsgBuf = "";
int dwFlags = FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
IntPtr ptrlpSource = IntPtr.Zero;
IntPtr prtArguments = IntPtr.Zero;
int retVal = FormatMessage(dwFlags, ref ptrlpSource, errorCode, 0, ref lpMsgBuf, messageSize, &prtArguments);
if (0 == retVal)
{
throw new Exception("Failed to format message for error code " + errorCode + ". ");
}
return lpMsgBuf;
}
// Test harness.
// If you incorporate this code into a DLL, be sure to demand FullTrust.
[PermissionSetAttribute(SecurityAction.Demand, Name = "FullTrust")]
public static void Main(string[] args)
{
IntPtr tokenHandle = new IntPtr(0);
IntPtr dupeTokenHandle = new IntPtr(0);
try
{
string userName, domainName;
// Get the user token for the specified user, domain, and password using the
// unmanaged LogonUser method.
// The local machine name can be used for the domain name to impersonate a user on this machine.
Console.Write("Enter the name of the domain on which to log on: ");
domainName = Console.ReadLine();
Console.Write("Enter the login of a user on {0} that you wish to impersonate: ", domainName);
userName = Console.ReadLine();
Console.Write("Enter the password for {0}: ", userName);
const int LOGON32_PROVIDER_DEFAULT = 0;
//This parameter causes LogonUser to create a primary token.
const int LOGON32_LOGON_INTERACTIVE = 2;
const int SecurityImpersonation = 2;
tokenHandle = IntPtr.Zero;
dupeTokenHandle = IntPtr.Zero;
// Call LogonUser to obtain a handle to an access token.
bool returnValue = LogonUser(userName, domainName, Console.ReadLine(),
LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT,
ref tokenHandle);
Console.WriteLine("LogonUser called.");
if (false == returnValue)
{
int ret = Marshal.GetLastWin32Error();
Console.WriteLine("LogonUser failed with error code : {0}", ret);
Console.WriteLine("\nError: [{0}] {1}\n", ret, GetErrorMessage(ret));
int errorCode = 0x5; //ERROR_ACCESS_DENIED
throw new System.ComponentModel.Win32Exception(errorCode);
}
Console.WriteLine("Did LogonUser Succeed? " + (returnValue? "Yes" : "No"));
Console.WriteLine("Value of Windows NT token: " + tokenHandle);
// Check the identity.
Console.WriteLine("Before impersonation: "
+ WindowsIdentity.GetCurrent().Name);
bool retVal = DuplicateToken(tokenHandle, SecurityImpersonation, ref dupeTokenHandle);
if (false == retVal)
{
CloseHandle(tokenHandle);
Console.WriteLine("Exception thrown in trying to duplicate token.");
return;
}
// The token that is passed to the following constructor must
// be a primary token in order to use it for impersonation.
WindowsIdentity newId = new WindowsIdentity(dupeTokenHandle);
WindowsImpersonationContext impersonatedUser = newId.Impersonate();
// Check the identity.
Console.WriteLine("After impersonation: "
+ WindowsIdentity.GetCurrent().Name);
// Stop impersonating the user.
impersonatedUser.Undo();
// Check the identity.
Console.WriteLine("After Undo: " + WindowsIdentity.GetCurrent().Name);
// Free the tokens.
if (tokenHandle != IntPtr.Zero)
CloseHandle(tokenHandle);
if (dupeTokenHandle != IntPtr.Zero)
CloseHandle(dupeTokenHandle);
}
catch(Exception ex)
{
Console.WriteLine("Exception occurred. " + ex.Message);
}
}
}
[C++]
// This sample demonstrates the use of the WindowsIdentity class to impersonate a user.
// IMPORTANT NOTES:
// This sample can be run only on Windows XP. The default Windows 2000 security policy
// prevents this sample from executing properly, and changing the policy to allow
// proper execution presents a security risk.
// This sample requests the user to enter a password on the console screen.
// Because the console window does not support methods allowing the password to be masked,
// it will be visible to anyone viewing the screen.
#using <mscorlib.dll>
#using <System.dll>
using namespace System;
using namespace System::Runtime::InteropServices;
using namespace System::Security::Principal;
using namespace System::Security::Permissions;
[assembly:SecurityPermissionAttribute(SecurityAction::RequestMinimum, UnmanagedCode=true)]
[assembly:PermissionSetAttribute(SecurityAction::RequestMinimum, Name = S"FullTrust")];
[DllImport(S"advapi32.dll", SetLastError=true)]
bool LogonUser(String* lpszUsername, String* lpszDomain, String* lpszPassword,
int dwLogonType, int dwLogonProvider, IntPtr* phToken);
[DllImport(S"kernel32.dll", CharSet=System::Runtime::InteropServices::CharSet::Auto)]
int FormatMessage(int dwFlags, IntPtr* lpSource,
int dwMessageId, int dwLanguageId, String** lpBuffer, int nSize, IntPtr *Arguments);
[DllImport(S"kernel32.dll", CharSet=CharSet::Auto)]
bool CloseHandle(IntPtr handle);
[DllImport(S"advapi32.dll", CharSet=CharSet::Auto, SetLastError=true)]
bool DuplicateToken(IntPtr ExistingTokenHandle,
int SECURITY_IMPERSONATION_LEVEL, IntPtr* DuplicateTokenHandle);
// GetErrorMessage formats and returns an error message
// corresponding to the input errorCode.
String* GetErrorMessage(int errorCode)
{
int FORMAT_MESSAGE_ALLOCATE_BUFFER = 0x00000100;
int FORMAT_MESSAGE_IGNORE_INSERTS = 0x00000200;
int FORMAT_MESSAGE_FROM_SYSTEM = 0x00001000;
//int errorCode = 0x5; //ERROR_ACCESS_DENIED
//throw new System.ComponentModel.Win32Exception(errorCode);
int messageSize = 255;
String* lpMsgBuf = S"";
int dwFlags = FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM | FORMAT_MESSAGE_IGNORE_INSERTS;
IntPtr ptrlpSource = IntPtr::Zero;
IntPtr prtArguments = IntPtr::Zero;
int retVal = FormatMessage(dwFlags, &ptrlpSource, errorCode, 0, &lpMsgBuf, messageSize, &prtArguments);
if (0 == retVal)
{
throw new Exception(String::Format( S"Failed to format message for error code {0}. ", __box(errorCode)));
}
return lpMsgBuf;
}
// Test harness.
// If you incorporate this code into a DLL, be sure to demand FullTrust.
[PermissionSetAttribute(SecurityAction::Demand, Name = S"FullTrust")]
int main()
{
IntPtr tokenHandle = IntPtr(0);
IntPtr dupeTokenHandle = IntPtr(0);
try
{
String* userName;
String* domainName;
// Get the user token for the specified user, domain, and password using the
// unmanaged LogonUser method.
// The local machine name can be used for the domain name to impersonate a user on this machine.
Console::Write(S"Enter the name of the domain on which to log on: ");
domainName = Console::ReadLine();
Console::Write(S"Enter the login of a user on {0} that you wish to impersonate: ", domainName);
userName = Console::ReadLine();
Console::Write(S"Enter the password for {0}: ", userName);
const int LOGON32_PROVIDER_DEFAULT = 0;
//This parameter causes LogonUser to create a primary token.
const int LOGON32_LOGON_INTERACTIVE = 2;
const int SecurityImpersonation = 2;
tokenHandle = IntPtr::Zero;
dupeTokenHandle = IntPtr::Zero;
// Call LogonUser to obtain a handle to an access token.
bool returnValue = LogonUser(userName, domainName, Console::ReadLine(),
LOGON32_LOGON_INTERACTIVE, LOGON32_PROVIDER_DEFAULT,
&tokenHandle);
Console::WriteLine(S"LogonUser called.");
if (false == returnValue)
{
int ret = Marshal::GetLastWin32Error();
Console::WriteLine(S"LogonUser failed with error code : {0}", __box(ret));
Console::WriteLine(S"\nError: [{0}] {1}\n", __box(ret), GetErrorMessage(ret));
int errorCode = 0x5; //ERROR_ACCESS_DENIED
throw new System::ComponentModel::Win32Exception(errorCode);
}
Console::WriteLine(S"Did LogonUser Succeed? {0}", (returnValue?S"Yes":S"No"));
Console::WriteLine(S"Value of Windows NT token: {0}", __box(tokenHandle));
// Check the identity.
Console::WriteLine(S"Before impersonation: {0}", WindowsIdentity::GetCurrent()->Name);
bool retVal = DuplicateToken(tokenHandle, SecurityImpersonation, &dupeTokenHandle);
if (false == retVal)
{
CloseHandle(tokenHandle);
Console::WriteLine(S"Exception thrown in trying to duplicate token.");
return -1;
}
// The token that is passed to the following constructor must
// be a primary token in order to use it for impersonation.
WindowsIdentity* newId = new WindowsIdentity(dupeTokenHandle);
WindowsImpersonationContext* impersonatedUser = newId->Impersonate();
// Check the identity.
Console::WriteLine(S"After impersonation: {0}", WindowsIdentity::GetCurrent()->Name);
// Stop impersonating the user.
impersonatedUser->Undo();
// Check the identity.
Console::WriteLine(S"After Undo: {0}", WindowsIdentity::GetCurrent()->Name);
// Free the tokens.
if (tokenHandle != IntPtr::Zero)
CloseHandle(tokenHandle);
if (dupeTokenHandle != IntPtr::Zero)
CloseHandle(dupeTokenHandle);
}
catch(Exception* ex)
{
Console::WriteLine(S"Exception occurred. {0}", ex->Message);
}
}
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必要条件
名前空間: System.Security.Principal
プラットフォーム: Windows 98, Windows NT 4.0, Windows Millennium Edition, Windows 2000, Windows XP Home Edition, Windows XP Professional, Windows Server 2003 ファミリ
アセンブリ: Mscorlib (Mscorlib.dll 内)
参照
WindowsImpersonationContext メンバ | System.Security.Principal 名前空間