不管是asp.net、web service还是window service，程序运行的时候只有本地计算机的部分权限，有时候需要更大的权限，比如读写某台服务器或域中的一台计算机上的文件等，这就需要更大的权限，比如域帐户权限。
通过获取不同身份的WindowsImpersonationContext对象，可以模拟不同用户登陆，请看我生成的NetworkSecurity类的
public static WindowsImpersonationContext ImpersonateUser(string strDomain,
string strLogin,
string strPwd,
LogonType logonType,
LogonProvider logonProvider)；
附NetworkSecurity.cs源代码如下：
/*
* Author : TongWei
* Date : 2005-1-25
* Rights : China Netwave Inc.@2005
*/
using System;
using System.Runtime.InteropServices;
using System.Security.Principal;
using System.Security.Permissions;
namespace CNW.OMP.Common.Utility
{
public enum LogonType : int
{
/// <summary>
/// This logon type is intended for users who will be interactively using the computer, such as a user
/// being logged on by a terminal server, remote shell, or similar process. This logon type has the
/// additional expense of caching logon information for disconnected operation, and is therefore
/// inappropriate for some client/server applications, such as a mail server.
/// </summary>
LOGON32_LOGON_INTERACTIVE = 2,
/// <summary>
/// This logon type is intended for high performance servers to authenticate clear text passwords.
/// The LogonUser function does not cache credentials for this logon type.
/// </summary>
LOGON32_LOGON_NETWORK = 3,
/// <summary>
/// This logon type is intended for batch servers, where processes may be executing on behalf of a user
/// without their direct intervention; or for higher performance servers that process many clear-text
/// authentication attempts at a time, such as mail or web servers. The LogonUser function does not cache
/// credentials for this logon type.
/// </summary>
LOGON32_LOGON_BATCH = 4,
/// <summary>
/// Indicates a service-type logon. The account provided must have the service privilege enabled.
/// </summary>
LOGON32_LOGON_SERVICE = 5,
/// <summary>
/// This logon type is intended for GINA DLLs logging on users who will be interactively using the computer.
/// This logon type allows a unique audit record to be generated that shows when the workstation was unlocked.
/// </summary>
LOGON32_LOGON_UNLOCK = 7,
/// <summary>
/// Windows XP/2000: This logon type preserves the name and password in the authentication packages,
/// allowing the server to make connections to other network servers while impersonating the client.
/// This allows a server to accept clear text credentials from a client, call LogonUser, verify that
/// the user can access the system across the network, and still communicate with other servers.
/// </summary>
LOGON32_LOGON_NETWORK_CLEARTEXT = 8,
/// <summary>
/// Windows XP/2000: This logon type allows the caller to clone its current token and specify new credentials
/// for outbound connections. The new logon session has the same local identity, but uses different credentials
/// for other network connections.
/// This logon type is supported only by the LOGON32_PROVIDER_WINNT50 logon provider.
/// </summary>
LOGON32_LOGON_NEW_CREDENTIALS = 9
};
public enum LogonProvider : int
{
/// <summary>
/// Use the standard logon provider for the system. The default security provider is NTLM.
/// Windows XP: The default provider is negotiate, unless you pass NULL for the domain name and
/// the user name is not in UPN format. In this case the default provider is NTLM.
/// </summary>
LOGON32_PROVIDER_DEFAULT = 0,
/// <summary>
/// Use the Windows NT 3.5 logon provider.
/// </summary>
LOGON32_PROVIDER_WINNT35 = 1,
/// <summary>
/// Use the NTLM logon provider.
/// </summary>
LOGON32_PROVIDER_WINNT40 = 2,
/// <summary>
/// Windows XP/2000: Use the negotiate logon provider.
/// </summary>
LOGON32_PROVIDER_WINNT50 = 3
};
class SecuUtil32
{
[DllImport("advapi32.dll", SetLastError=true)]
public static extern bool LogonUser(String lpszUsername, String lpszDomain, String lpszPassword,
int dwLogonType, int dwLogonProvider, ref IntPtr TokenHandle);
[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);
}
public class NetworkSecurity
{
public NetworkSecurity()
{
//
// TODO: Add constructor logic here
//
}
/// <summary>
/// The ImpersonateUser function attempts to log a user on to the local computer.
/// The local computer is the computer from which ImpersonateUser was called.
/// You cannot use ImpersonateUser to log on to a remote computer.
/// You specify the user with a user name and domain, and authenticate the user with a clear-text password.
/// If the function succeeds, you receive a handle to a token that represents the logged-on user.
/// You can then use this token handle to impersonate the specified user, or in most cases,
/// to create a process running in the context of the specified user.
/// </summary>
/// <param name="strDomain">
/// specifies the name of the domain or server whose account database contains the strLogin account.
/// </param>
/// <param name="strLogin">specifies the name of the user.</param>
/// <param name="strPwd">specifies the clear-text password for the user account specified by strLogin.</param>
/// <param name="logonType">Specifies the type of logon operation to perform.</param>
/// <param name="logonProvider">Specifies the logon provider.</param>
/// <example>
/// //Add System.Security.dll
/// //using System.Security.Principal;
///
/// string strDomain=ConfigurationSettings.AppSettings["mSALoginDomainName"];
/// string strUser=ConfigurationSettings.AppSettings["mSALoginDomainUser"];
/// string strPassword=ConfigurationSettings.AppSettings["mSALoginDomainPassword"];
///
/// WindowsImpersonationContext impContext = null;
/// try
/// {
/// impContext = NetworkSecurity.ImpersonateUser(strDomain,strUser,strPassword,
/// LogonType.LOGON32_LOGON_SERVICE,
/// LogonProvider.LOGON32_PROVIDER_DEFAULT);
/// }
/// catch
/// {
///
/// }
///
/// //work under this logined user
///
/// impContext.Undo();
/// </example>
/// <returns>
/// </returns>
public static WindowsImpersonationContext ImpersonateUser(string strDomain,
string strLogin,
string strPwd,
LogonType logonType,
LogonProvider logonProvider)
{
// Initialize tokens
IntPtr tokenHandle = new IntPtr(0);
IntPtr dupeTokenHandle = new IntPtr(0);
tokenHandle = IntPtr.Zero;
dupeTokenHandle = IntPtr.Zero;
// If domain name was blank, assume local machine
if (strDomain == "")
strDomain = System.Environment.MachineName;
try
{
const int SecurityImpersonation = 2;
// Call LogonUser to obtain a handle to an access token.
bool returnValue = SecuUtil32.LogonUser(
strLogin,
strDomain,
strPwd,
(int)logonType,
(int)logonProvider,
ref tokenHandle);
// Did impersonation fail?
if (false == returnValue)
{
int ret = Marshal.GetLastWin32Error();
// Throw the exception show the reason why LogonUser failed
string strErr = String.Format("LogonUser failed with error code : {0}", ret);
throw new ApplicationException(strErr, null);
}
// Get identity before impersonation
bool retVal = SecuUtil32.DuplicateToken(tokenHandle, SecurityImpersonation, ref dupeTokenHandle);
// Did DuplicateToken fail?
if (false == retVal)
{
// Close existing handle
SecuUtil32.CloseHandle(tokenHandle);
// Throw the exception show the reason why DuplicateToken failed
throw new ApplicationException("Failed to duplicate token", null);
}
// Create new identity using new primary token
// 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();
return impersonatedUser;
}
catch (Exception ex)
{
throw new ApplicationException(ex.Message, ex);
}
finally
{
// Close handle
if (tokenHandle != IntPtr.Zero)
SecuUtil32.CloseHandle(tokenHandle);
if (dupeTokenHandle != IntPtr.Zero)
SecuUtil32.CloseHandle(dupeTokenHandle);
}
}
}
}
