z0mbie's CRC32

Код (Text):

1. .386
2. .model flat,stdcall
3. option casemap:none
4.  
5. include \masm32\include\windows.inc                        
6. include \masm32\include\user32.inc
7. include \masm32\include\kernel32.inc
8.  
9. includelib \masm32\lib\user32.lib
10. includelib \masm32\lib\kernel32.lib
11.  
12. S macro pdata:VARARG
13.     LOCAL Buff
14. .data
15.     ifidni <pdata>,<>            
16.         Buff db 0        
17.     else            
18.         Buff db pdata,0
19.     endif
20. .code
21.     exitm <OFFSET Buff>
22. endm
23.  
24. .data
25.     TempBuf     DB 64 dup(0)
26. .code
27. z0mbie_Crc32 proc uses ebx ecx edx pData:dword,tSize:dword
28. ; input:  EDX=data, ECX=size, EAX=crc
29. ; output: EAX=crc, EDX+=ECX, ECX=BL=0
30.     mov edx,pData
31.     mov ecx,tSize
32. xcrc32:
33.     jecxz   @@4
34.         not     eax
35. @@1:                    
36.     xor     al, [edx]
37.         inc     edx
38.         mov     bl, 8
39. @@2:                    
40.     shr     eax, 1
41.         jnc     @@3
42.         xor     eax, 0EDB88320h
43. @@3:                    
44.     dec     bl
45.         jnz     @@2
46.         loop    @@1
47.         not     eax
48. @@4:            
49.     ret
50. z0mbie_Crc32 endp
51. start: 
52.         invoke  RtlZeroMemory,addr TempBuf,64
53.     invoke  lstrlen,S("i'm a foolisher")
54.     mov ecx,eax
55.     mov edx,S("i'm a foolisher")
56.     invoke  z0mbie_Crc32,edx,ecx
57.     invoke  wsprintf,addr TempBuf,S("%X"),EAX
58.     invoke  MessageBox,NULL,addr TempBuf,S("TEST_111"),MB_OK
59.     invoke  ExitProcess, 0 
60. end start

the crc32 value "ED481EB3" is used by other way.
the z0mbie's CRC32 value is "B9C0DD2E".

what' wrong i used the z0mbie's CRC32?

 

hmmm... are you sure about your result? i've used this algo and got ED481EB3. Try to look in debugger what's goes wrong

 

dcskm4200
Something wrong, look at:

z0mbie_Crc32 proc uses ebx ecx edx pData:dword,tSize:dword
; input: EDX=data, ECX=size, EAX=crc

and reg eax used in proc body:

 

input eax=crc=0xDB710641
but this algo glitches on data - e.g. [A] 1 byte long (without brackets of course). Tested with winrar) and online crc32 calc.

 

thanks you who answered the question, especially thanks crypto.
the z0mbie's crc32 arithmetic is powerful.