[RESOLVED] Checking lock status of another user's pc

[AdorablePlum]

Searched but couldn't find a solution so not holding out much hope, but is there a way to check if another user's workstation is locked either by passing the machine name or the logged on name?

[Zvoni]

Searched but couldn't find a solution so not holding out much hope, but is there a way to check if another user's workstation is locked either by passing the machine name or the logged on name?

Hmmmm...... https://community.spiceworks.com/t/w...unlocks/685905

And as always: Read until the end

[fafalone]

The WTS APIs looked promising but I dead-ended for regular networked computers. I could get a server handle but access denied enumerating sessions, registering for session change events i only got them for my local account.

So my next thought was seeing if I could get a logged on user count from NetWkstaGetInfo. Access denied.

Suffice it to say, I can access the shares from these systems so I should have access.

What I tried:

    Sub lou1()
        Dim tInfo As WKSTA_INFO_102
        Dim ppBuf As LongPtr
        Dim lRet As Long
      
        lRet = NetWkstaGetInfo(StrPtr("\\server"), 102, ppBuf)
        Debug.Print "lRet=0x" & Hex$(lRet)
        If ppBuf Then
            CopyMemory tInfo, ByVal ppBuf, LenB(tInfo)
            Debug.Print "users=" & tInfo.wki102_logged_on_users
        End If
    End Sub
    Sub gls()
        Dim hServer As LongPtr
        Dim tSessionInfo() As WTS_SESSION_INFO
        Dim tInfo As WTSINFOEXW
        Dim ppBuffer As LongPtr
        Dim lRet As Long
        Dim cbRet As Long
        Dim pc As Long
        Dim i As Long
        hServer = WTSOpenServerW(StrPtr("\\server"))
        If hServer Then
            If WTSEnumerateSessionsW(hServer, 0, 1, ppBuffer, pc) Then
                If pc Then
                    ReDim tSessionInfo(pc - 1)
                    CopyMemory tSessionInfo(0), ByVal ppBuffer, LenB(tSessionInfo(0)) * pc
                    WTSFreeMemory ppBuffer: ppBuffer = 0
                    For i = 0 To UBound(tSessionInfo)
                        MsgBox "Session id=" & tSessionInfo(i).SessionId & ", state=" & tSessionInfo(i).State
                        If WTSQuerySessionInformationW(hServer, tSessionInfo(i).SessionId, WTSSessionInfoEx, ppBuffer, cbRet) Then
                            If cbRet Then
                                CopyMemory tInfo, ByVal ppBuffer, LenB(tInfo)
                                MsgBox "Session flags=" & tInfo.Data.SessionFlags & " (Level " & tInfo.Level & ")"
                            End If
                            If ppBuffer Then WTSFreeMemory ppBuffer: ppBuffer = 0
                        Else
                            MsgBox "WTSQuerySessionInformationW error 0x" & Hex$(Err.LastDllError) & ": " & GetSystemErrorString(Err.LastDllError)
                        End If
                    Next
                Else
                    MsgBox "WTSEnumerateSessionsW succeeded but no sessions returned."
                End If
            Else
                MsgBox "WTSEnumerateSessionsW error 0x" & Hex$(Err.LastDllError) & ": " & GetSystemErrorString(Err.LastDllError)
            End If

            WTSCloseServer hServer
        Else
            MsgBox "WTSOpenServerW error 0x" & Hex$(Err.LastDllError) & ": " & GetSystemErrorString(Err.LastDllError)
        End If
    End Sub

Going straight past enum sessions to WTSQuerySessionInformationW with 0, 1, or WTS_CURRENT_SESSION all end in access denied too.

(APIs defined in WinDevLib; exported at wdWTS.twin and wdAPI.twin if you want to copy them out for VB6 without using tB.



Last things to try for those are restarting to see if the EnableRemoteRPC option works after that (HKLM\SYSTEM\CurrentControlSet\Control); and maybe logging on by code somehow (Explorer prompts for credentials to access shares; maybe it doesn't apply to other processes?).

[Elroy]

I'm not going to dig it all out, but I've been down this rabbit hole before. IIRC, to do this via the LAN, you've got to have Windows Pro on the machine wanting to know, and the user trying to do it has to have administrative rights on the "target" machine. So, to do it, it's going to need to be someone with LAN-wide administrative rights.

If you're on a Windows Pro machine and have administrative rights, explore the "query" command line program.

[DllHell]

When windows is locked, it starts a process called "LogonUI.exe". You could check the process list to see if it running with a WMI query

SELECT * FROM Win32_Process WHERE Name='LogonUI.exe'

You will need to turn on remote wmi in most environments https://learn.microsoft.com/en-us/wi...ing-with-vista

[fafalone]

I'm logged on as admin on both; Win10 Pro on remote, Win10 Ent on local. Tried as SYSTEM\TrustedInstaller too.

Wondering if WTSConnectSessionW would help... but can it connect to the existing session; and how could you get the logon ID without hitting access denied?

[DllHell]

dont know if this helps you but

WTSQuerySessionInformation
https://learn.microsoft.com/en-us/wi...oninformationa

can return WTS_INFO_CLASS
https://learn.microsoft.com/en-us/wi...wts_info_class

Which has WTS_CONNECTSTATE_CLASS
https://learn.microsoft.com/en-us/wi...ectstate_class

WTSActive

[fafalone]

I'll try it later but will just asking for WTSConnectState instead of WTSSessionInfoEx matter?

[Elroy]

I've looked at it a bit more, and it should be a command line query (as administrator) that looks something like the following:

> query user /server:user_name_here

Apparently, the Remote Procedure Call (RPC) service needs to be running, possibly on both machines.

I don't really have a full-blown LAN here, so I can't test.

If you could get a command line running, then you'd just need to figure out how to do that from VB6. Worst case, just create a BAT file and pipe the results out to a file, and then run the BAT and read the file from VB6.

[fafalone]

Good chance my code will work if that does and just changing the registry setting wasn't enough to enable Remote RPC.

[fafalone]

I've looked at it a bit more, and it should be a command line query (as administrator) that looks something like the following:

> query user /server:user_name_here

Apparently, the Remote Procedure Call (RPC) service needs to be running, possibly on both machines.

I don't really have a full-blown LAN here, so I can't test.

If you could get a command line running, then you'd just need to figure out how to do that from VB6. Worst case, just create a BAT file and pipe the results out to a file, and then run the BAT and read the file from VB6.

Yeah it's probably calling the same API under the hood...

Even after restarting after changing the EnableRemoteRPC option to 1... your command is giving me this:

C:\Users\Jon>query user /server:<name>
Error 0x00000005 enumerating sessionnames
Error [5]:Access is denied.

Where <name> is the string after the \\ in the network name for the tablet I was checking (while Explorer was browsing its shares).

Do you know any more details of what to enable? From my searches for using those APIs, only EnableRemoteRPC came up.

[Zvoni]

I don't understand, why you're so hung up on the Username.....
If a PC is locked or not has nothing to do with the logged in user, but only with the machine itself

Think about it: 5 Users can log in on the same Computer, but only one has an "active/unlocked" Session.
The Moment User 6 logs in, the previous "active" user gets locked out, the other 4 already being locked out, since User 5 grabbed the active Session.
Remember when you want to switch to another User, who is already logged in, but has not the active Session: You have to enter your credentials

So with all those queries/code/API based on Username, what result do you expect, if you query if User 3 is locked out? The Result is Yes, while User 6 is working on a fully functional machine

Read the Link i posted above

[AdorablePlum]

Thanks for the input everyone. I tried various things but either I couldn't get them to work or they were blocked due to permissions.
In then end I went for dirty method of checking the lock status locally on a timer and writing a file on the server which can be read by the application. Seems to work so far.