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挖掘MSVBVM60.DLL内的API （2）
作者:JiaJia 日期:2008-01-24
引用内容Option Explicit
'
' Undocumented Memory Functions
' -----------------------------
'
' There are 2 undocumented "memory functions" in msvbvm60.dll -> __vbaCopyBytes and __vbaCopyBytesZero.
'
' __vbaCopyBytes -> this function copies bytes from one memory location to another memory location
' __vbaCopyBytesZero -> this function copies bytes from one memory location to another memory location and then source memory is filled with zeros
'
' Both functions have 3 parameters
' 1.param -> number of bytes to copy
' 2.param -> pointer to the destination memory
' 3.param -> pointer to the source memory
'
' That's all you need to know ;-)
' btw if you know ASM and want to know how __vbaCopyBytes and __vbaCopyBytesZero work, then check their ASM code below.
'
' Enjoy,
' Libor
'
'
' ---> __vbaCopyBytes <---
'
'public __vbaCopyBytes
'.text:660D9B6B __vbaCopyBytes proc near
'.text:660D9B6B
'.text:660D9B6B arg_0 = dword ptr 4 ;1.param - number of bytes to copy
'.text:660D9B6B arg_4 = dword ptr 8 ;2.param - pointer to the destination memory
'.text:660D9B6B arg_8 = dword ptr 0Ch ;3.param - pointer to the source memory
'.text:660D9B6B
'.text:660D9B6B mov ecx, [esp+arg_0] ;ecx = 1.param
'.text:660D9B6F push esi ;save esi
'.text:660D9B70 mov esi, [esp+4+arg_8] ;esi = 3.param
'.text:660D9B74 push edi ;save edi
'.text:660D9B75 mov edi, [esp+8+arg_4] ;edi = 2.param
'.text:660D9B79 mov eax, ecx ;eax = ecx
'.text:660D9B7B mov edx, edi ;edx = edi
'.text:660D9B7D shr ecx, 2 ;ecx = ecx/2
'.text:660D9B80 rep movsd ;perform dword copy
'.text:660D9B82 mov ecx, eax ;ecx = eax
'.text:660D9B84 mov eax, edx ;eax = edx
'.text:660D9B86 and ecx, 3 ;ecx = ecx mod 4
'.text:660D9B89 rep movsb ;perform byte copy
'.text:660D9B8B pop edi ;restore edi
'.text:660D9B8C pop esi ;restore esi
'.text:660D9B8D retn 0Ch ;return
'.text:660D9B8D
'.text:660D9B8D __vbaCopyBytes endp
'
'
' ---> __vbaCopyBytesZero <---
'
'public __vbaCopyBytesZero
'.text:660D9B90 __vbaCopyBytesZero proc near
'.text:660D9B90
'.text:660D9B90 arg_0 = dword ptr 8 ;1.param - number of bytes to copy
'.text:660D9B90 arg_4 = dword ptr 0Ch ;2.param - pointer to the destination memory
'.text:660D9B90 arg_8 = dword ptr 10h ;3.param - pointer to the source memory
'.text:660D9B90
'.text:660D9B90 push ebp ;save ebp
'.text:660D9B91 mov ebp, esp ;ebp = esp
'.text:660D9B93 mov ecx, [ebp+arg_0] ;ecx = 1.param
'.text:660D9B96 push esi ;save edi
'.text:660D9B97 mov esi, [ebp+arg_8] ;esi = 3.param
'.text:660D9B9A mov eax, ecx ;eax = ecx
'.text:660D9B9C push edi ;save edi
'.text:660D9B9D mov edi, [ebp+arg_4] ;edi = 2.param
'.text:660D9BA0 shr ecx, 2 ;ecx = ecx/4
'.text:660D9BA3 rep movsd ;perform dword copy
'.text:660D9BA5 mov ecx, eax ;ecx = eax
'.text:660D9BA7 and ecx, 3 ;ecx = ecx mod 4
'.text:660D9BAA rep movsb ;perform byte copy
'.text:660D9BAC mov edi, [ebp+arg_8] ;edi = 3.param
'.text:660D9BAF mov ecx, eax ;ecx = eax
'.text:660D9BB1 mov edx, ecx ;edx = ecx
'.text:660D9BB3 xor eax, eax ;eax = 0
'.text:660D9BB5 shr ecx, 2 ;ecx = ecx/4
'.text:660D9BB8 rep stosd ;store eax to [edi]
'.text:660D9BBA mov ecx, edx ;ecx = edx
'.text:660D9BBC and ecx, 3 ;ecx = ecx mod 4
'.text:660D9BBF rep stosb ;store eax to [edi]
'.text:660D9BC1 mov eax, [ebp+arg_4] ;eax = 2.param
'.text:660D9BC4 pop edi ;restore edi
'.text:660D9BC5 pop esi ;restore esi
'.text:660D9BC6 pop ebp ;restore ebp
'.text:660D9BC7 retn 0Ch ;return
'.text:660D9BC7
'.text:660D9BC7 __vbaCopyBytesZero endp
'
'declare the undoc functions
Private Declare Sub vbaCopyBytes Lib "msvbvm60.dll" Alias "__vbaCopyBytes" (ByVal Length As Long, Destination As Any, Source As Any)
Private Declare Sub vbaCopyBytesZero Lib "msvbvm60.dll" Alias "__vbaCopyBytesZero" (ByVal Length As Long, Destination As Any, Source As Any)
'test __vbaCopyBytesZero
Private Sub cmdvbaCopyBytesZero_Click()
Dim a(1 To 15) As Byte 'source
Dim b(1 To 15) As Byte 'destination
Dim s As String, i As Long
'fill the first array
For i = LBound(a) To UBound(a)
a(i) = i
s = s & vbCrLf & i & ". a = " & a(i) & " ; b = " & b(i)
Next i
MsgBox "Before __vbaCopyBytes" & s
vbaCopyBytesZero LenB(a(1)) * 15, b(1), a(1)
s = ""
'check the second array
For i = LBound(a) To UBound(a)
s = s & vbCrLf & i & ". a = " & a(i) & " ; b = " & b(i)
Next i
MsgBox "After __vbaCopyBytesZero" & s
End Sub
'test __vbaCopyBytes
Private Sub cmdvbaCopyBytes_Click()
Dim a(1 To 15) As Byte 'source
Dim b(1 To 15) As Byte 'destination
Dim s As String, i As Long
'fill the first array
For i = LBound(a) To UBound(a)
a(i) = i
s = s & vbCrLf & i & ". a = " & a(i) & " ; b = " & b(i)
Next i
MsgBox "Before __vbaCopyBytes" & s
vbaCopyBytes LenB(a(1)) * 15, b(1), a(1)
s = ""
'check the second array
For i = LBound(a) To UBound(a)
s = s & vbCrLf & i & ". a = " & a(i) & " ; b = " & b(i)
Next i
MsgBox "After __vbaCopyBytes" & s
End Sub
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