C++ – Getting logged on user’s name with or without domain in Windows

Password: No, this is not retained for security reasons - it's used, then discarded. You could retrieve the encrypted password for this user from the registry, given sufficient privileges, then decrypt it using something like rainbow tables, but that's extremely resource intensive and time consuming using current methods. Much better to prompt the user.

Alternatively, if you want to implement some sort of 'single signon' system as Novell does, you should do it via either a GINA (pre-Vista) or a Credential Provider (Vista), which will result in your code being given the username and password at login, the only time at which the password is available.

For username, getting the current username (the one who is running your code) is easy: the GetUserName function in AdvApi32.dll does exactly this for you.

If you're running as a service, you need to remember there is no one "logged in user": there are several at any time, such as LocalSystem, NetworkService, SYSTEM and other accounts, in addition to any actual people. This article provides some sample code and documentation for doing that.

You can get the SID for the user and then look it up under HKLM\SOFTWARE\Microsoft\Windows NT\CurrentVersion\ProfileList and get the ProfileImagePath value.

Once you have this path, you can get CLSID_LOCAL_APPDATA for your user, convert the absolute path to a relative path to your profile and then append that relative path to the other user profile path.

However, keep in mind that this is relying on an undocumented registry key and can break in future versions of the OS. (Or, as Raymond Chan would say: "Now that you know how to do it, let me tell you why you shouldn't do it this way..." :-))

If you have a token representing the user, you can use the SHGetFolderPath or SHGetKnownFolderPath (on Vista and up). However, there are certain security restrictions and you should read up on MSDN for details.

SHGetFolderPath - http://msdn.microsoft.com/en-us/library/bb762181(VS.85).aspx SHGetKnownFolderPath - http://msdn.microsoft.com/en-us/library/bb762188(VS.85).aspx