ExcelVBAのパスワードを解除する

Option Explicit

Private Const PAGE_EXECUTE_READWRITE = &H40

Private Declare Sub MoveMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As Long, Source As Long, ByVal Length As Long)
Private Declare Function VirtualProtect Lib "kernel32" (lpAddress As Long, ByVal dwSize As Long, ByVal flNewProtect As Long, lpflOldProtect As Long) As Long
Private Declare Function GetModuleHandleA Lib "kernel32" (ByVal lpModuleName As String) As Long
Private Declare Function GetProcAddress Lib "kernel32" (ByVal hModule As Long, ByVal lpProcName As String) As Long
Private Declare Function DialogBoxParam Lib "user32" Alias "DialogBoxParamA" (ByVal hInstance As Long, ByVal pTemplateName As Long, ByVal hWndParent As Long, ByVal lpDialogFunc As Long, ByVal dwInitParam As Long) As Integer
Dim HookBytes(0 To 5) As Byte
Dim OriginBytes(0 To 5) As Byte
Dim pFunc As Long
Dim Flag As Boolean

Private Function GetPtr(ByVal Value As Long) As Long
GetPtr = Value
End Function

Private Sub RecoverBytes()
If Flag Then MoveMemory ByVal pFunc, ByVal VarPtr(OriginBytes(0)), 6
End Sub

Private Function Hook() As Boolean
Dim TmpBytes(0 To 5) As Byte
Dim p As Long
Dim OriginProtect As Long
Hook = False pFunc = GetProcAddress(GetModuleHandleA("user32.dll"), "DialogBoxParamA") If VirtualProtect(ByVal pFunc, 6, PAGE_EXECUTE_READWRITE, OriginProtect) <> 0 Then MoveMemory ByVal VarPtr(TmpBytes(0)), ByVal pFunc, 6 If TmpBytes(0) <> &H68 Then MoveMemory ByVal VarPtr(OriginBytes(0)), ByVal pFunc, 6 p = GetPtr(AddressOf MyDialogBoxParam) HookBytes(0) = &H68 MoveMemory ByVal VarPtr(HookBytes(1)), ByVal VarPtr(p), 4 HookBytes(5) = &HC3 MoveMemory ByVal pFunc, ByVal VarPtr(HookBytes(0)), 6 Flag = True Hook = True End If End If
End Function
Private Function MyDialogBoxParam(ByVal hInstance As Long, ByVal pTemplateName As Long, ByVal hWndParent As Long, ByVal lpDialogFunc As Long, ByVal dwInitParam As Long) As Integer
If pTemplateName = 4070 Then
MyDialogBoxParam = 1
Else
RecoverBytes
MyDialogBoxParam = DialogBoxParam(hInstance, pTemplateName, _
hWndParent, lpDialogFunc, dwInitParam)
Hook
End If
End Function
Public Sub unprotected()
If Hook Then
MsgBox "VBA Project is unprotected!", vbInformation, "*"
End If
End Sub

Option Explicit

Private Const PAGE_EXECUTE_READWRITE = &H40

Private Declare PtrSafe Sub MoveMemory Lib "kernel32" Alias "RtlMoveMemory" (Destination As LongPtr, Source As LongPtr, ByVal Length As LongPtr)
Private Declare PtrSafe Function VirtualProtect Lib "kernel32" (lpAddress As LongPtr, ByVal dwSize As LongPtr, ByVal flNewProtect As LongPtr, lpflOldProtect As LongPtr) As LongPtr
Private Declare PtrSafe Function GetModuleHandleA Lib "kernel32" (ByVal lpModuleName As String) As LongPtr
Private Declare PtrSafe Function GetProcAddress Lib "kernel32" (ByVal hModule As LongPtr, ByVal lpProcName As String) As LongPtr
Private Declare PtrSafe Function DialogBoxParam Lib "user32" Alias "DialogBoxParamA" (ByVal hInstance As LongPtr, ByVal pTemplateName As LongPtr, ByVal hWndParent As LongPtr, ByVal lpDialogFunc As LongPtr, ByVal dwInitParam As LongPtr) As Integer
Dim HookBytes(0 To 5) As Byte
Dim OriginBytes(0 To 5) As Byte
Dim pFunc As LongPtr
Dim Flag As Boolean

Private Function GetPtr(ByVal Value As LongPtr) As LongPtr
  GetPtr = Value
End Function

Private Sub RecoverBytes()
  If Flag Then MoveMemory ByVal pFunc, ByVal VarPtr(OriginBytes(0)), 6
End Sub

Public Function Hook() As Boolean
  Dim TmpBytes(0 To 5) As Byte
  Dim p As LongPtr
  Dim OriginProtect As LongPtr

  Hook = False
  pFunc = GetProcAddress(GetModuleHandleA("user32.dll"), "DialogBoxParamA")
  If VirtualProtect(ByVal pFunc, 6, PAGE_EXECUTE_READWRITE, OriginProtect) <> 0 Then
    MoveMemory ByVal VarPtr(TmpBytes(0)), ByVal pFunc, 6
    If TmpBytes(0) <> &H68 Then
      MoveMemory ByVal VarPtr(OriginBytes(0)), ByVal pFunc, 6
      p = GetPtr(AddressOf MyDialogBoxParam)
      HookBytes(0) = &H68
      MoveMemory ByVal VarPtr(HookBytes(1)), ByVal VarPtr(p), 4
      HookBytes(5) = &HC3
      MoveMemory ByVal pFunc, ByVal VarPtr(HookBytes(0)), 6
      Flag = True
      Hook = True
    End If
  End If
End Function

Private Function MyDialogBoxParam(ByVal hInstance As LongPtr, ByVal pTemplateName As LongPtr, ByVal hWndParent As LongPtr, ByVal lpDialogFunc As LongPtr, ByVal dwInitParam As LongPtr) As Integer
  If pTemplateName = 4070 Then
    MyDialogBoxParam = 1
  Else
    RecoverBytes
    MyDialogBoxParam = DialogBoxParam(hInstance, pTemplateName, hWndParent, lpDialogFunc, dwInitParam)
    Hook
  End If
End Function

Public Sub unprotected()
  If Hook Then
    MsgBox "VBA Project is unprotected!", vbInformation, "*****"
  End If
End Sub