十六进制编辑器和OllyDbg中的字节

时间:2015-05-03 19:43:46

标签: c windows assembly compiler-construction x86

我正在尝试创建编译器,然后启动了代码生成部分。基于我使用fasm编译的简单可执行文件,我开始使用Python进行导入代码生成。

以下是Assembly中测试程序的源代码:

format PE console
entry start

include 'win32a.inc'

macro import_part1 library, [api]
{ 
  common 
    library#_str: db `library 
  forward 
    if rva $ mod 2 = 0 
     ; db 0
    end if 
    ; When align is right, one byte from previous import name 
    ; is used as byte for next import's hint. 
    api#_str = $-1 
    db 0, `api 
  common 
    db 0
} 

import_part2_first = 0 

macro import_part2 library, [api] 
{ 
  common 
    if import_part2_first = 0 
      align 4 
      import_part2_first = 1 
    else 
      dd 0 
    end if 
    library#_import: 
  forward 
    api dd rva api#_str 
} 

macro import_part3 [library] 
{ 
  common 
    data import 
  forward 
    dd 0, 0, 0, rva library#_str, rva library#_import 
  common 
    rd 5 
    end data 
} 

import_list equ 
import_libraries equ 

macro import library,[api] 
{ 
  common 
    import_list equ import_list import_#library 
    import_#library equ library,api 
    import_libraries equ import_libraries,library 
} 

macro importend 
{ 
  match a, import_list 
  \{ 
    irps b, a \\{ match c, b \\\{ import_part1 c \\\} \\} 
    irps b, a \\{ match c, b \\\{ import_part2 c \\\} \\} 
  \} 
  match =,a,import_libraries \{ import_part3 a \} 
}


start:

         push var
         call  [printf]



         push 0
        call  [ExitProcess]

        var db 'Test', 0


;data import
;
;library kernel32, 'kernel32.dll',  msvcrt, 'msvcrt.dll'
;
;import kernel32, ExitProcess, 'ExitProcess'
;import msvcrt, printf, 'printf'

;end data

 import kernel32.dll, ExitProcess, AttachConsole
 import msvcrt.dll, printf, scanf, puts
 import user32.dll, MessageBoxA
 importend

(OllyDbg)以下是我基于生成导入的部分(我无法发布图片):

CPU Disasm
Address   Hex dump                                       Command                               Comments
00401017   .  006B 65                                    ADD BYTE PTR DS:[EBX+65], CH
0040101A   .  72 6E 65 6C 33 32 2E 64 6C 6C 00           ASCII "rnel32.dll",0                  ; ASCII "rnel32.dll"
00401025   .  45 78 69 74 50 72 6F 63 65 73 73 00        ASCII "ExitProcess",0                 ; ASCII "ExitProcess"
00401031   .  41 74 74 61 63 68 43 6F 6E 73 6F 6C 65 00  ASCII "AttachConsole",0               ; ASCII "AttachConsole"
0040103F   .  6D 73 76 63 72 74 2E 64 6C 6C 00           ASCII "msvcrt.dll",0                  ; ASCII "msvcrt.dll"
0040104A   .  70 72 69 6E 74 66 00                       ASCII "printf",0                      ; ASCII "printf"
00401051   .  73 63 61 6E 66 00                          ASCII "scanf",0                       ; ASCII "scanf"
00401057   .  70 75 74 73 00                             ASCII "puts",0                        ; ASCII "puts"
0040105C   .  75 73 65 72 33 32 2E 64 6C 6C 00           ASCII "user32.dll",0                  ; ASCII "user32.dll"
00401067   .  4D 65 73 73 61 67 65 42 6F 78 41 00        ASCII "MessageBoxA",0                 ; ASCII "MessageBoxA"
00401073      90                                         NOP

Here is the problem:

00401074   .  647FA577                                   DD 77A57F64 -> ExitProcess
00401078   .  1878A577                                   DD 77A57818
0040107C   .  00000000                                   DD 00000000
00401080   .  C4D2B777                                   DD 77B7D2C4
00401084   .  BF16C077                                   DD 77C016BF
00401088   .  9C3BC077                                   DD 77C03B9C
0040108C   .  00000000                                   DD 00000000
00401090   .  9E278B77                                   DD 778B279E



00401094   .  00000000                                   DD 00000000                           ; Struct 'IMAGE_IMPORT_DESCRIPTOR'
00401098   .  00000000                                   DD 00000000
0040109C   .  00000000                                   DD 00000000
004010A0   .  18100000                                   DD 00001018
004010A4   .  74100000                                   DD 00001074
004010A8   .  00000000                                   DD 00000000                           ; Struct 'IMAGE_IMPORT_DESCRIPTOR'
004010AC   .  00000000                                   DD 00000000
004010B0   .  00000000                                   DD 00000000
004010B4   .  3F100000                                   DD 0000103F
004010B8   .  80100000                                   DD 00001080
004010BC   .  00000000                                   DD 00000000                           ; Struct 'IMAGE_IMPORT_DESCRIPTOR'
004010C0   .  00000000                                   DD 00000000
004010C4   .  00000000                                   DD 00000000
004010C8   .  5C100000                                   DD 0000105C
004010CC   .  90100000                                   DD 00001090
004010D0   .  00000000                                   DD 00000000                           ; Struct 'IMAGE_IMPORT_DESCRIPTOR'
004010D4   .  00000000                                   DD 00000000
004010D8   .  00000000                                   DD 00000000
004010DC   .  00000000                                   DD 00000000
004010E0   .  00000000                                   DD 00000000

这是我的程序输出:

kernel32.dll , 0
ExitProcess , 0
AttachConsole , 0
msvcrt.dll , 0
printf , 0
scanf , 0
puts , 0
user32.dll , 0
MessageBoxA , 0
90
-------------------
0x77a57f64
0x77a57818
0x0
0x77b7d2c4
0x77c016bf
0x77c03b9c
0x0
0x778b279e
-------------------
0x0
0x0
0x0
0x1018
0x1074
0x0
0x0
0x0
0x103f
0x1080
0x0
0x0
0x0
0x105c
0x1090
0x0
0x0
0x0
0x0
0x0

生成的文件:

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00000000  6B 65 72 6E 65 6C 33 32 2E 64 6C 6C 00 45 78 69  kernel32.dll.Exi
00000010  74 50 72 6F 63 65 73 73 00 41 74 74 61 63 68 43  tProcess.AttachC
00000020  6F 6E 73 6F 6C 65 00 6D 73 76 63 72 74 2E 64 6C  onsole.msvcrt.dl
00000030  6C 00 70 72 69 6E 74 66 00 73 63 61 6E 66 00 70  l.printf.scanf.p
00000040  75 74 73 00 75 73 65 72 33 32 2E 64 6C 6C 00 4D  uts.user32.dll.M
00000050  65 73 73 61 67 65 42 6F 78 41 00 90 64 7F A5 77  essageBoxA..d.¥w
00000060  18 78 A5 77 00 00 00 00 C4 D2 B7 77 BF 16 C0 77  .x¥w....ÄÒ·w¿.Àw
00000070  9C 3B C0 77 00 00 00 00 9E 27 8B 77 00 00 00 00  œ;Àw....ž'‹w....
00000080  00 00 00 00 00 00 00 00 00 00 00 00 18 10 00 00  ................
00000090  74 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00  t...............
000000A0  3F 10 00 00 80 10 00 00 00 00 00 00 00 00 00 00  ?...€...........
000000B0  00 00 00 00 5C 10 00 00 90 10 00 00 00 00 00 00  ....\...........
000000C0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................

以下是十六进制编辑器中测试程序的导入部分:

Offset(h) 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F

00000210                          6B 65 72 6E 65 6C 33 32          kernel32
00000220  2E 64 6C 6C 00 45 78 69 74 50 72 6F 63 65 73 73  .dll.ExitProcess
00000230  00 41 74 74 61 63 68 43 6F 6E 73 6F 6C 65 00 6D  .AttachConsole.m
00000240  73 76 63 72 74 2E 64 6C 6C 00 70 72 69 6E 74 66  svcrt.dll.printf
00000250  00 73 63 61 6E 66 00 70 75 74 73 00 75 73 65 72  .scanf.puts.user
00000260  33 32 2E 64 6C 6C 00 4D 65 73 73 61 67 65 42 6F  32.dll.MessageBo
00000270  78 41 00 90 23 10 00 00 2F 10 00 00 00 00 00 00  xA..#.../.......
00000280  48 10 00 00 4F 10 00 00 55 10 00 00 00 00 00 00  H...O...U.......
00000290  65 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00  e...............
000002A0  18 10 00 00 74 10 00 00 00 00 00 00 00 00 00 00  ....t...........
000002B0  00 00 00 00 3F 10 00 00 80 10 00 00 00 00 00 00  ....?...€.......
000002C0  00 00 00 00 00 00 00 00 5C 10 00 00 90 10 00 00  ........\.......
000002D0  00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00  ................

我不明白为什么OllyDbg和hex编辑器中的某些字节不同?我还需要做一些计算吗?

1 个答案:

答案 0 :(得分:0)

Here is the problem:

00401074   .  647FA577                                   DD 77A57F64 -> ExitProcess
00401078   .  1878A577                                   DD 77A57818

没有问题。

在左列(转储)中,字节按照它们在内存中的顺序排列。首先是低字节。

最后一列(命令)显示与dword相同的4个字节,但它不会添加通常的前缀 0x 或后缀 h