WindowsIdentity.Impersonate Method (IntPtr)


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Impersonates the user represented by the specified user token.

Namespace:   System.Security.Principal
Assembly:  mscorlib (in mscorlib.dll)

[<SecurityPermissionAttribute(SecurityAction.Demand, Flags = SecurityPermissionFlag.NoFlags | SecurityPermissionFlag.UnmanagedCode | SecurityPermissionFlag.ControlPrincipal)>]
static member Impersonate : 
        userToken:nativeint -> WindowsImpersonationContext


Type: System.IntPtr

The handle of a Windows account token. This token is usually retrieved through a call to unmanaged code, such as a call to the Win32 API LogonUser function.

Return Value

Type: System.Security.Principal.WindowsImpersonationContext

An object that represents the Windows user prior to impersonation; this object can be used to revert to the original user's context.

Exception Condition

Windows returned the Windows NT status code STATUS_ACCESS_DENIED.


There is insufficient memory available.


The caller does not have the correct permissions.

On Windows NT platforms, the current user must have sufficient rights to allow impersonation.


Calling the Impersonate(IntPtr) method with a userToken value of Zero is equivalent to calling the Win32 RevertToSelf function. If another user is currently being impersonated, control reverts to the original user.

For more information about calls to unmanaged code, see Consuming Unmanaged DLL Functions.

Notes to Implementers:

Because Microsoft Windows 98 and Windows Millennium Edition (Windows Me) platforms do not have user tokens, impersonation cannot take place on those platforms.

Notes to Callers:

After using Impersonate, it is important to call the Undo method to end the impersonation.

The following example demonstrates how to obtain a Windows account token by calling the unmanaged Win32 LogonUser function, and how to use that token to impersonate another user and then revert to the original identity.

No code example is currently available or this language may not be supported.


for the ability to manipulate the principal object and access unmanaged code. Associated enumerations: SecurityPermissionFlag.ControlPrincipal and SecurityPermissionFlag.UnmanagedCode

.NET Framework
Available since 1.1
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