This will allow you to protect or unprotct all worksheets in a workbook at once. It doesn't allow you to input a password; however, if you run the unprotect_all macro and there are worksheets that are password protected, it will prompt you to input the password in order to unprotect the worksheet and will do so for every worksheet that is password protected.
Sub Protect_All()
For i = 1 To Sheets.Count
Sheets(i).Protect
Next i
End Sub
Sub Unprotect_All()
For i = 1 To Sheets.Count
Sheets(i).Unprotect
Next i
End Sub