C# Signature:

[DllImport("advapi32.dll", SetLastError=true)]
public static extern bool LogonUser(
    string lpszUsername,
    string lpszDomain,
    string lpszPassword,
    int dwLogonType,
    int dwLogonProvider,
    ref IntPtr phToken
    );

VB .NET Signature:

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 Integer

User-Defined Types:

None.

Notes:

It is very important to know which LOGON type you need. LOGON_NETWORK will allow access to network resources, while LOGON_INTERACTIVE will not. This will cause you hours of consteration if you don't pay attention to it.

To make this useful, you will also need to implement DuplicateToken.

Tips & Tricks:

Please add some!

Sample Code:

const int LOGON32_LOGON_NETWORK = 3;
Int16 LOGON32_LOGON_INTERACTIVE  = 2;
Int16 LOGON32_PROVIDER_DEFAULT  = 0;

if (LogonUser(userName, domain, passWord, interactiveValue, LOGON32_PROVIDER_DEFAULT, ref token))
{
     if (DuplicateToken(token, 2, ref tokenDuplicate))
     {
     tempWindowsIdentity = new WindowsIdentity(tokenDuplicate);
     impersonationContext = tempWindowsIdentity.Impersonate();

     return impersonationContext == null;
     }
     else
     return false;
}
else
     return false;

Alternative Managed API:

TODO