Extracting binary data with Poasm

[Vortex]

Simple method to extract binary executable data with Poasm. The procedure WriteFileToDisc saves the code between the two labels, MsgBox and start. This method is useful to call assembly code from languages like RapidQ Basic with no inline assembly support.

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.386
.model flat,stdcall
option casemap:none

ExitProcess PROTO :DWORD

WriteFileToDisc PROTO :DWORD,:DWORD,:DWORD

.data

fname       db 'MsgBox.bin',0

.code

MsgBox:

    call    delta

delta:

    pop     edx
    mov     eax,OFFSET delta
    sub     edx,eax
    lea     eax,[edx+capt]
    lea     ecx,[edx+msg]

;   call    MessageBox

    push    0
    push    eax
    push    ecx
    push    0
    call    DWORD PTR [esp+20]
   
    retn    16

capt    db 'Hello',0
msg     db 'This is a test.',0

start:

ProcLen EQU start-MsgBox

    invoke  WriteFileToDisc,ADDR fname,\
            MsgBox,ProcLen
           
    invoke  ExitProcess,0

END start

Running the executable, it creates the file MsgBox.bin

RapidQ Basic code calling the embedded binary data :

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$APPTYPE GUI

DIM s AS STRING

DIM pMessageBox as INTEGER

DECLARE FUNCTION CallWindowProc LIB "user32" ALIAS "CallWindowProcA" _
                 (Proc AS LONG, p1 AS LONG, p2 AS LONG, p3 AS LONG, _
                 p4 AS LONG) AS LONG

DECLARE FUNCTION GetProcAddress LIB "kernel32" ALIAS "GetProcAddress" (hModule AS LONG, lpProcName AS STRING) AS LONG
DECLARE FUNCTION LoadLibrary LIB "kernel32" ALIAS "LoadLibraryA" (lpFileName AS STRING) AS LONG

DefInt ptrMsgBox

FUNCTION MsgBox1(pointer As Long) As Long
    Result=CallWindowProc(ptrMsgBox,pointer,0,0,0)
END FUNCTION

$RESOURCE ResourceName AS "MsgBox.bin"

DIM Mem AS QMEMORYSTREAM

Mem.ExtractRes(Resource(0))
Mem.Position=0
s=Mem.ReadBinStr(Mem.Size)

ptrMsgBox=varptr(s)

pMessageBox = GetProcAddress(LoadLibrary("user32.dll"), "MessageBoxA")

MsgBox1(pMessageBox)

Compiling the RapidQ code :

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RC.EXE -LC:\Rapidq\lib MBox.bas