Simple Impersonation Library for .Net

This library provides a managed wrapper for the LogonUser function of the Win32 API. Basically, it allows you to impersonate any user, as long as you have their credentials.

It is dual compiled for both .Net 2.0 and .Net 4.0 runtimes. It should work well under .Net 2.0, 3.0, 3.5, 4.0, 4.5, 4.5.1, 4.5.2, 4.6, 4.6.1, 4.6.2, and the various "client profiles". It has no dependencies.

Note that it is not compiled for PCL or .NET Core, as it is Windows specific.

Use NuGet package SimpleImpersonation.

PM> Install-Package SimpleImpersonation

using (Impersonation.LogonUser(domain, username, password, logonType))
{
    // do whatever you want as this user.
}

The password parameter can be specified as a SecureString. You can still pass a regular string if desired, however SecureString is recommended.

Be sure to specify a logon type that makes sense for what you are doing. For example:

• If you are interactively working as a particular user from a desktop application, use LogonType.Interactive.

• If you are trying to connect to a SQL server with trusted authentication using specific credentials, use LogonType.NewCredentials.

  • But be aware that impersonation is not taken into account in connection pooling.
  • You will also need to vary your connection string.
  • Read more here

• If impersonation fails, it will throw a custom ImpersonationException, which has the following properties:

  • Message : The string message describing the error.
  • NativeErrorCode : The native Windows error code, as described here.
  • ErrorCode : The HResult of the error.
  • InnerException : A Win32Exception used to derive the other properties.

  Note that it derives from ApplicationException for better compatibility with previous versions of this library.

See the MSDN documentation for additional logon types.

1.0.0

• Initial Version

1.0.1

• Issue #2 - Fixes possible "SafeHandle cannot be null"

1.1.0

• Issue #9 - Adds support for passing the password as a SecureString

2.0.0

• Issue #14 - Throws a more useful exception. (This is a breaking change if you were previously parsing the error code out of the message string).

2.0.1

• Issue #17 - Adds the NativeError code to the exception.