I have this script written by myself. Basically what I wanted was script that "unlock" the front usb only for specific device. The situation is such that we have a workstation with registry key USBSTOR\Start set to 4(disable) so the front usb is not available without some additional work of our IT department - this way we control who can access the usb
But the employees must use a camera to take pictures for specific needs and to send them through email clients.So we want to automate the "lock/unlock" phase.
The usb is unlocked when the device of interest is inserted,it stays "unlocked" while the device is in usb and after the device is plugged out,the script "lock" the usb again.
I have decided to use .vbs.The script works as I expected,but after the "lock" phase,the USB_MASS_STORAGE driver get crashed.I must uninstall it and restart the Windows for the driver to be reloaded again and to work properly.After I have run the script several times,the registry value in USBSTOR\Start does not affect the usb,i.e the usb is unlocked even if there is 4.If I change the value from 4 to 3 the driver crashes.
I am looking for some advices.
Here is the code for usbstor.vbs script. I have used a lot of comments,some of them explain a pretty obvious things,but I have decide so.
' Script for access to Front Usb (a.k.a USB MASS STORAGE)
' The usb is locked by default(the value in Registry Key USBSTOR/Start is 4 - disable).It is enabled(the value in Registry Key USBSTOR/Start is 3 - enable) when the device of interest is put into front usb.
' The usb is in "enable" state ,while the device is into it. After it is removed,the Registry Key USBSTOR/Start value is set to 4(disable).
' The device is recognized by hardware id ,which is known in advance by searching USBSTOR,when the device is inserted. This script is for pc,where what we want is access to front usb only for spcecific device(a camera in our case).
' For everything else the usb should be disabled.The script is loaded in RAM and if the while loop condition isn't change to false,we must kill the process within TaskManager
' The CPU time is high > 98 while the script runs.I came to this solution for my problem,but any ideas for improvements or for different logic are highly welcomed.
Option Explicit On
Dim Shell,Start,Hwid,Enum_0,Enum_1,Count,Flag_0,Flag_1,Check_0,Check_1 'Dimension of varables we are going to use in the script.
Set Shell = CreateObject("WScript.Shell") 'Create an object to work with Windows Registry.
'Start = Shell.RegRead("HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Start") 'Save the value of the registry key into Start variable
Hwid = "USB\Vid_0930&Pid_6545\001D92A866B8B8B1934703FE" 'hardawre id of device of interest.We get it from the registry and the script scan for this id.It is constant string
Count = 1 'Initialize the Count variable with value of 1.We use it as a condition in endless while() loop.It makes script run in real-time,so it can scan uninterupted for changes in the registry
QueryEnum0 ' The subroutines QueryEnum0 and QueryEnum1.The id is either in USBSTOR\Enum\0 or in USBSTOR\Enum\1 .That is for sure.
QueryEnum1 ' Declaration before definition - not exactly explanation.
'The purpose of these two subroutines is: create an object everytime the sub is called ,thus read the value in Enum\0 or in Enum\1 constantly as "scanning"
'Probably not so elegant solution to somebody,but actually it works.
Sub QueryEnum0 ' Enter the sub
Dim Flag_Enum_0,Shell ' Declare local variables.They will be created each time the sub is invoked.
Set Shell = CreateObject("WScript.Shell") 'Create an object to work wirh registry any time the sub is called
On Error Resume Next 'Error handling
Flag_Enum_0 = Shell.RegRead("HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Enum\0") 'Try to read reg value into Flag_Enum_0. The purpose
On Error GoTo 0
Flag_0 = Flag_Enum_0 'Assign the value to variable Flag_0,outside of sub.The memory for Flag_0 is set once and lasts while the script runs.
End Sub
' Same as QueryEnum0
Sub QueryEnum1
Dim Flag_Enum_1,Shell
Set Shell = CreateObject("WScript.Shell")
On Error Resume Next
Flag_Enum_1 = Shell.RegRead("HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Enum\1")
On Error GoTo 0
Flag_1 = Flag_Enum_1
End Sub
Do While Count = 1 'Real-time loop,the code within while is running while count is equal to 1. The script is loaded in memory constanlty.
On Error Resume Next
Enum_0 = Shell.RegRead("HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Enum\0") ' Try to read hardware id if it is in Enum\0
On Error GoTo 0 '
On Error Resume Next
Enum_1 = Shell.RegRead("HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Enum\1") 'Try to read hardware id if it is in Enum\1
On Error GoTo 0
If StrComp(Hwid,Enum_0) <> 0 And StrComp(Hwid,Enum_1) <> 0 Then 'Check if both reg keys are empty
MsgBox "There is no device in the front usb.Please put the device or see the connection"
ElseIf StrComp(Hwid,Enum_0) = 0 Then 'If the hardware id is in Enum\0,thus assigned to Enum_0
Shell.RegWrite "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Start",3 'Enable the usb by "unlock" it
On Error Resume Next
QueryEnum0 'Invoke sub QueryEnum0.If the id we looking for is in Enum\0,we know that it is assigned to Flag_0 also
Check_0 = Flag_0 'Use another variable to copy value from Flag_0.
On Error GoTo 0
If StrComp(Hwid,Check_0) = 0 Then 'Compare the constant Hwid with the value in Check_0,test for id
Msgbox "Check_0 still holds the hardware id" 'Some messages to inform us whats happening
else
MsgBox "Check_0 does not contain the hardware id anymore"
Shell.RegWrite "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Start",4 'Disable the front usb
Count = 2 'End the while loop,count is 2,so the condition is false .The loop breaks.
End If
ElseIf StrComp(Hwid,Enum_1) = 0 Then 'If the hardware is in Enum\1....same as above mentioned
Shell.RegWrite "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Start",3
On Error Resume Next
QueryEnum1
Check_1 = Flag_1
On Error GoTo 0
If StrComp(Hwid,Check_1) = 0 Then
MsgBox "Check_1 still holds the hardware id"
MsgBox Check_1
else
MsgBox "Check_0 does not contain the hardware id anymore"
Shell.RegWrite "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Start",4
Count = 2
End If
End If
Loop
' Useful information for me
'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR -> value name -> Start ,value data = 3(enable) = 4(disable)
'HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\USBSTOR\Enum -> value name -> 1 or 0 ,value data we look for is -> USB\Vid_04da&Pid_2372\5&2f621ee5&0&8
' USB\Vid_04da&Pid_2372\5&2f621ee5&0&8 - camera id in our case
' fantom value - USB\Vid_03f0&Pid_032a\000000000Q912WFBSI1c - name: 0 ,type: REG_SZ,in the key Enum.This is another hardware id,which is strange somehow,because I do not have any device
' inserted in my usb.However,I take this value into account,thus use both keys 0 and 1 within Enum to scan for the id I need.
