06.05.03
 By Michael
Bright
Welcome to another "How-to" article in Visual C#.NET. This article will focus
on the Network functions within the Win32 API library associated with Network
Management. The first thing is to point out is that there are two ways to manage
users using the .NET Framework, the first being the Active Directory method, as
you will notice you need to have Active Directory Installed and if you were managing
users on a small network or on a stand alone station Active Directory won't be
install and it would be not worth installing it.
Therefore the other method and focus of this article is using the Platform
Invoke layer and the Network functions of the Win32 API library. In this article
we will look at how to Add, Delete and Modify Users and Groups using C# and also
how we can query User and Network information for a machine or network, we will
look at the following functions: |
- NetUserAdd
- NetUserDel
- NetUserGetInfo
- NetUserSetInfo
- NetUserChangePassword
- NetUserEnum
- NetUserGetLocalGroups
Getting Started
First of all as I'm sure most C# developers out there know we have to include
the InteropServices namespace in our project to allow us to access functions from
DLL's and this can be done using the following snippet of code:
Programming
Resource Downloads |
///// CODE SNIPPET 1.0
using System.Runtime.InteropServices;
//// END OF CODE
Once we have included the access we can now include the declarations of the DLL's
we are going to use and the Structures (structs) associated with them. Each of
the calls needed will be discussed under the headings relating to what they do.
Adding a User using C#
One of the most important operations within the Network functions is that of Adding
Users to either a network or Computer. To Add a user via C# we will need to use
the NetAddUser
function, using this function allows us to specify a machine to add the user to
or we can leave that null an the User is added to the local machine. In the below
code snippet we can see how we can declare and use the NetUserAdd function. One
important item associated with the NetUserAdd function is that the user you are
added must be in the form of a specific structure. The structures (structs) that
are used in association with this call are
USER INFO 1,
USER INFO 2,
USER INFO 3
or USER INFO 4.
In this practical example we shall use USER_INFO_1 to define our UserArea to add.
///// CODE SNIPPET 1.1 Declaration
[DllImport("Netapi32.dll")]
extern static int NetUserAdd([MarshalAs(UnmanagedType.LPWStr)] string
servername, int level, ref USER_INFO_1 buf, int parm_err);
//// END OF CODE
You should also note that when i used this code, i didn't need to know about the
errors returned, hence the use of an int as the last parameter, if you did want
to know about errors returned you would need to amend this code. Now that we have
declared our external API to use we should also include our USER_INFO_1 structure,
using the following code snippet:
///// CODE SNIPPET 1.2 Structure Declaration
[StructLayout(LayoutKind.Sequential, CharSet=CharSet.Unicode)]
public struct USER_INFO_1
{
public string usri1_name;
public string usri1_password;
public int usri1_password_age;
public int usri1_priv;
public string usri1_home_dir;
public string comment;
public int usri1_flags;
public string usri1_script_path;
}
//// END OF CODE
Once we have both of these block of code declare we can now use the call from
within our program, i should also note that in this case we have used the structure
about you can use any of the other three, and if you click the link you can convert
the code from C++ to C# pretty easily. Below is a code snippet to show the usage
of the NetUserAdd function.
Click Here to Read the Full Article
About
the Author:
My name is Michael Bright, I'm a university student studying a Bsc in
Computer Science at University College Chester. I have a love for all thing computers
and have only worked with C# for about 3 months. I am currently training for my
MCP in it. My other interests are C, VB, HTML, ASP and also Flash. I have interests
in Developing Network app's and Network Security. My Web site is csharp.brightweb.co.uk
where you can find examples of my Work, including my Defender Security applications.
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