Welcome to my 21th tutorial !!
How to keygen the Cracking4newies Crackme 3 project
Introduction:
Well , this is project to teach newbies cracking.It is the 3rd project , i didn't
look the others yet , coz i am damn busy...
Anyway , i take time to make one tutor , coz this will help newbies , who want to
learn keygening , and it is good for me to make keygens sometimes , hehe :)
Crackme notes from crackme's readme :
================================================================================
#Cracking4Newbies WEEKLY CRACKING TARGET FOR EVERYONE
--------------------------------------------------------------------------------
Start: 25/08/1999
End: 02/09/1999
Name of target: #Cracking4Newbies CrackMe #3
URL: http://c4nprojects.cjb.net
Size: 12 KB
Objectives: Explain how the serial number is generated ... and if
possible, code a KeyGEN for it.
================================================================================
i will add this :
Level : easy
coded by : ytc and Kwai Lo (thx friends , nice crackme !)
I)lets go !!
ok, now it is time to keygen this bitch , so in soft ice set your favorites BPX used
in name / serial cracking :
bpx getwindowtewta and getdlgitemtexta.
Enter your name and Fake serial.(name : ACiD BuRN / Serial : 12345)
Click on enter , you are now back in Soft ice , press F12 coz you are not in the good
place , but in the lame user32 dll...
now , you can see , you are in the crackme. (i hope u understand all , i am tired as hell ;) )
trace with F10 , until u land here :
* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:004010C6(C)
|
:004010AF 0FBE4415C0 movsx eax, byte ptr [ebp+edx-40] ; put in eax the 1st ascii
value of you name (for ACiD BuRN : A=41)
:004010B4 03F0 add esi, eax /
:004010B6 8D7DC0 lea edi, dword ptr [ebp-40] /
:004010B9 83C9FF or ecx, FFFFFFFF /
:004010BC 33C0 xor eax, eax /
:004010BE 42 inc edx / Loop
:004010BF F2 repnz /
:004010C0 AE scasb /
:004010C1 F7D1 not ecx /
:004010C3 49 dec ecx /
:004010C4 3BD1 cmp edx, ecx /
:004010C6 76E7 jbe 004010AF /
ok , so what does this loop ?! :
movsx eax, byte ptr [ebp+edx-40] <== eax = ascii value of the char at position EDX
add esi, eax <== esi = esi + eax
inc edx <== next char
cmp edx, ecx <== compare length of your name with the counter in edx
jbe 004010AF <== If all chars are not done, loop until edx = length name
so , this loop just take each ascii value and add it in ESI.
the result for ACiD BuRN is : 2A8
41 + 43 + 69 + 44 + 20 + 42 + 75 + 52 + 4E = 2A8
A C i D space B u R N
After this loop , you land here :
:004010C8 897508 mov dword ptr [ebp+08], esi ; [ebp+8] contains ESI value
:004010CB C1650807 shl dword ptr [ebp+08], 07 ; [ebp+8] = shl [ebp+8],7
:004010CF 8D4DF4 lea ecx, dword ptr [ebp-0C]
:004010D2 6A0A push 0000000A
:004010D4 51 push ecx
:004010D5 68E9030000 push 000003E9
:004010DA 53 push ebx
As you can see , the esi value (for me : 2A8) is strored in [ebp+8].
then you see : shl dword ptr [ebp+08], 07
really interesting ;)
well , we have to trace again..
Trace until you land here :
* Referenced by a (U)nconditional or (C)onditional Jump at Address:
|:004010E4(C)
|
:00401102 8D55F4 lea edx, dword ptr [ebp-0C]
:00401105 52 push edx
:00401106 E840010000 call 0040124B
:0040110B 8B4D08 mov ecx, dword ptr [ebp+08] ; ECX = [ebp+8] ([ebp+8]= shl esi,7)
:0040110E 83C404 add esp, 00000004
:00401111 03CE add ecx, esi ; ECX = ECX + ESI (ESI=2A8 for me)
:00401113 3BC8 cmp ecx, eax ; ? eax = fake serial / ? ecx = good
:00401115 6A00 push 00000000
:00401117 751B jne 00401134 ; if not equal jump lame cracker
* Possible StringData Ref from Data Obj ->"Good!"
|
:00401119 685C504000 push 0040505C
* Possible StringData Ref from Data Obj ->"Congratulations!!"
|
:0040111E 6848504000 push 00405048
:00401123 53 push ebx
Nice , now , i think you are able to make a keygen !!!
lemme show u all the algo :
1st part: Add all ascii value of your name and strore it in a variable.(ESI in memory)
2nd part: take the value in ESI and do a shl,7 on it and strore it in a variable.([ebp+8] in memory)
3rd part: take the value of the 1st part and add it to the 2nd part's value.
4th part: take the result in decimal for serial :)
Name : ACiD BuRN
sERiAL : 87720
i gave you all to make your own keygen , but i will show u my source ;)
coz this tut is for newbies , well this is my delphi source...
i coded it very fast at 2 am , but works fine !
II) Delphi keygen sources:
procedure TForm1.Edit1Change(Sender: TObject);
var i,ascii,result: integer;
begin
for i:=1 to length(edit1.text) do
begin
ascii:=ascii + ord(edit1.text[i]);
end;
asm
mov eax,ascii
mov ecx,ascii
shl eax,7
add eax,ecx
mov ascii,eax
end;
result:=ascii;
edit2.text:=inttostr(result);
end;
end.
to make this work , u need to create a new project in delphi 4 and put this text box
edit1.text box = place to enter name
edit2.text box = final serial
click on edit1.text , in events , double click on "on change" and past this code !!
have Fun :)
III) Ending...
I want to thanx my friends ytc and kwai_lo for this cool crackme ;)
Well , this tut is finish , hope u understand all this piece of text , but if you have a
comment or one question, mail me to : [email protected]
Enjoy!
Greetings to my groups : ECLiPSE / CiA
Also greetingz to: (no specific order)
R!SC, ^Inferno^, AB4DS, Cyber Blade, Klefz, , Volatility, TORN@DO, T4D
Jeff, [Virus], JaNe , Appbusta , Duelist , tKC , BuLLeT , Lucifer48 ,
MiZ , DnNuke , Bjanes , Skymarshall , afkayas , elmopio , SiFLyiNG ,
Fire Worx , Crackz , neural_en , WarezPup , _y , SiONIDE , SKORPIEN
Lazarus , Eternal_Bliss , Magic Raphoun , DEZM , Bisoux , Carpathia ,
K17 , theMc , noos , Xmen , TeeJi , JB007 , Arobas , T0AD ,ytc , Kwai_lo....
i want to greets PWA members , i left this group due to not enough time for them :(
sorry Dudes ;) , i will back !!
if your name is not here sorry !!! lot of men to greets !
ACiD BuRN [ECL/CiA]