secret_passphrase1 := "dave_is_the_man_123"
   secret_passphrase2 := "456_blah_789"

   Gui, Add, Text,, USE THIS TO GENERATE
   Gui, Add, Text, section, Users Hardware ID:
   Gui, Add, Button, gGenerateButton, Generate
   Gui, Add, Text,, Users Key:
   Gui, Add, Edit, ys w240 vHw_Id_To_Generate_For,
   Gui, Add, Text
   Gui, Add, Edit, w240 vGenerated_Key
   Gui, Add, Text, xs
   Gui, Add, Text,, TEST CLIENT SIDE ACCESS
   Gui, Add, Text, section, Your Hardware ID is:
   Gui, Add, Text,, Enter the Key given to you:
   Gui, Add, Button, gCheckButton, Check License Key
   Gui, Add, Edit, ys w240 vHw_Id_To_Check, % MachineFingerprint()
   Gui, Add, Edit, w240 vKey_To_Check,
   Gui, Show

return


GuiClose:
   ExitApp
return


GenerateButton:
   Gui, Submit, NoHide
   concatenated := secret_passphrase1 . Hw_Id_To_Generate_For . secret_passphrase2
   hash := AuthHash(concatenated, StrLen(concatenated), 3)
   GuiControl,, Generated_Key, %hash%
return


CheckButton:
   Gui, Submit, NoHide
   concatenated := secret_passphrase1 . Hw_Id_To_Check . secret_passphrase2
   hash := AuthHash(concatenated, StrLen(concatenated), 3)
   if (hash = Key_To_Check)
      MsgBox, key good! proceed with install
   else
      MsgBox, key bad   
return



AuthHash(ByRef sData, nLen, SID = 4) {  ; SID: 3 for MD5, 4 for SHA
  DllCall("advapi32\CryptAcquireContextA", "UintP", hProv, "Uint", 0, "Uint", 0, "Uint", 1, "Uint", 0xF0000000)
  DllCall("advapi32\CryptCreateHash", "Uint", hProv, "Uint", 0x8000|0|SID , "Uint", 0, "Uint", 0, "UintP", hHash)
  DllCall("advapi32\CryptHashData", "Uint", hHash, "Uint", &sData, "Uint", nLen, "Uint", 0)
  DllCall("advapi32\CryptGetHashParam", "Uint", hHash, "Uint", 2, "Uint", 0, "UintP", nSize, "Uint", 0)
  VarSetCapacity(HashVal, nSize, 0)
  DllCall("advapi32\CryptGetHashParam", "Uint", hHash, "Uint", 2, "Uint", &HashVal, "UintP", nSize, "Uint", 0)
  DllCall("advapi32\CryptDestroyHash", "Uint", hHash)
  DllCall("advapi32\CryptReleaseContext", "Uint", hProv, "Uint", 0)

  format = %A_FormatInteger%       ; save original integer format
  SetFormat, Integer, H
  Loop, %nSize% {
    nValue := *(&HashVal + A_Index - 1)
    StringReplace, nValue, nValue, 0x, % (nValue < 16 ? 0 :)
    sHash .= nValue
  }
  SetFormat Integer, %format%      ; restore original format

  Return sHash
}



MachineFingerprint() {

   EnvGet, COMPUTERNAME, COMPUTERNAME
   EnvGet, PROCESSOR_ARCHITECTURE, PROCESSOR_ARCHITECTURE
   EnvGet, PROCESSOR_REVISION, PROCESSOR_REVISION
   DriveGet, DRIVESERIAL, Serial, C:\
   
   PCdata := A_OSType . A_OSVersion . COMPUTERNAME
   PCdata .= PROCESSOR_ARCHITECTURE . PROCESSOR_REVISION . DRIVESERIAL
   
   fingerprint := AuthHash(PCdata, StrLen(PCdata))
   fingerprint := SubStr(fingerprint, 1, 16)
   return fingerprint
}