[反汇编练习] 160个CrackMe之021.
本系列文章的目的是从一个没有任何经验的新手的角度(其实就是我自己)，一步步尝试将160个CrackMe全部破解，如果可以，通过任何方式写出一个类似于注册机的东西。
其中，文章中按照如下逻辑编排（解决如下问题）：
1、使用什么环境和工具
2、程序分析
3、思路分析和破解流程
4、注册机的探索
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提醒各位看客: 如果文章中的逻辑看不明白,那你一定是没有亲手操刀!OD中的跳转提示很强大,只要你跟踪了,不用怎么看代码就理解了!
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1、工具和环境：
WinXP SP3 + 52Pojie六周年纪念版OD + PEID + 汇编金手指。
160个CrackMe的打包文件。
下载地址： http://pan.baidu.com/s/1xUWOY 密码: jbnq
注：
1、Win7系统对于模块和程序开启了随机初始地址的功能，会给分析带来很大的负担，所以不建议使用Win7进行分析。
2、以上工具都是在52PoJie论坛下的原版程序，NOD32不报毒，个人承诺绝对不会进行任何和木马病毒相关内容。
2、程序分析：
想要破解一个程序，必须先了解这个程序。所以，在破解过程中，对最初程序的分析很重要，他可以帮助我们理解作者的目的和意图，特别是对于注册码的处理细节，从而方便我们反向跟踪和推导。
和上一节一样，打开CHM，选择第21个Cabeca.exe，保存下来。运行程序，程序界面如下：
3、思路分析和破解流程
有信息框，老办法。
PEID查看: Borland Delphi 3.0
和以前的一样，直接上步骤：
1、打开OD，将exe拖到OD窗口中，等程序暂停后，直接点击运行按钮(F9)，不用理会。
2、在exe中输入伪码：bbdxf 12345 67890。点击OK按钮，弹出错误信息框，不要关闭。
3、在OD中点击暂停按钮(Ctrl+F12)，再点击堆栈K按钮(Ctrl+K)，可以看到当前堆栈情况。
然后，。。。。。
不对，它是Delphi程序，虽然定位到了位置，但问题是大部分函数和Call根本不知道什么意思。所以，应该是这样子的：
1、使用IDR打开程序分析：
窗口信息： 
按钮事件信息：
Unit1::TForm1.Button1Click 0042D3C4 push ebp 0042D3C5 mov ebp,esp 0042D3C7 xor ecx,ecx 0042D3C9 push ecx 0042D3CA push ecx 0042D3CB push ecx 0042D3CC push ecx 0042D3CD push ebx 0042D3CE mov ebx,eax 0042D3D0 xor eax,eax 0042D3D2 push ebp 0042D3D3 push 42D5AD 0042D3D8 push dword ptr fs:[eax] 0042D3DB mov dword ptr fs:[eax],esp 0042D3DE cmp dword ptr ds:[42F714],0; gvar_0042F714 >0042D3E5 je 0042D42C 0042D3E7 cmp dword ptr ds:[42F718],0; gvar_0042F718 >0042D3EE je 0042D42C 0042D3F0 lea edx,[ebp-4] 0042D3F3 mov eax,dword ptr [ebx+1E0]; TForm1.Edit1:TEdit 0042D3F9 call TControl.GetText 0042D3FE cmp dword ptr [ebp-4],0 >0042D402 je 0042D42C 0042D404 lea edx,[ebp-8] 0042D407 mov eax,dword ptr [ebx+1E4]; TForm1.Edit2:TEdit 0042D40D call TControl.GetText 0042D412 cmp dword ptr [ebp-8],0 >0042D416 je 0042D42C 0042D418 lea edx,[ebp-0C] 0042D41B mov eax,dword ptr [ebx+1EC]; TForm1.Edit3:TEdit 0042D421 call TControl.GetText 0042D426 cmp dword ptr [ebp-0C],0 >0042D42A jne 0042D470 0042D42C mov eax,42D5C4; ‘Fill all boxes first dumb!‘ 0042D431 call ShowMessage 0042D436 xor eax,eax 0042D438 mov [0042F714],eax; gvar_0042F714 0042D43D xor eax,eax 0042D43F mov [0042F718],eax; gvar_0042F718 0042D444 xor edx,edx 0042D446 mov eax,dword ptr [ebx+1E0]; TForm1.Edit1:TEdit 0042D44C call TControl.SetText 0042D451 xor edx,edx 0042D453 mov eax,dword ptr [ebx+1E4]; TForm1.Edit2:TEdit 0042D459 call TControl.SetText 0042D45E xor edx,edx 0042D460 mov eax,dword ptr [ebx+1EC]; TForm1.Edit3:TEdit 0042D466 call TControl.SetText >0042D46B jmp 0042D58A 0042D470 cmp dword ptr ds:[42F714],0; gvar_0042F714 >0042D477 je 0042D4E5 0042D479 cmp dword ptr ds:[42F718],0; gvar_0042F718 >0042D480 je 0042D4E5 0042D482 lea edx,[ebp-10] 0042D485 mov eax,[0042F714]; 0x0 gvar_0042F714 0042D48A call IntToStr 0042D48F mov eax,dword ptr [ebp-10] 0042D492 push eax 0042D493 lea edx,[ebp-4] 0042D496 mov eax,dword ptr [ebx+1E4]; TForm1.Edit2:TEdit 0042D49C call TControl.GetText 0042D4A1 mov edx,dword ptr [ebp-4] 0042D4A4 pop eax 0042D4A5 call @LStrCmp >0042D4AA jne 0042D4E5 0042D4AC lea edx,[ebp-10] 0042D4AF mov eax,[0042F718]; 0x0 gvar_0042F718 0042D4B4 call IntToStr 0042D4B9 mov eax,dword ptr [ebp-10] 0042D4BC push eax 0042D4BD lea edx,[ebp-4] 0042D4C0 mov eax,dword ptr [ebx+1EC]; TForm1.Edit3:TEdit 0042D4C6 call TControl.GetText 0042D4CB mov edx,dword ptr [ebp-4] 0042D4CE pop eax 0042D4CF call @LStrCmp >0042D4D4 jne 0042D4E5 0042D4D6 mov eax,42D5E8; ‘Hmmm.... Cracked... Congratulations idiot! :-)‘ 0042D4DB call ShowMessage >0042D4E0 jmp 0042D58A 0042D4E5 cmp dword ptr ds:[42F714],0; gvar_0042F714 >0042D4EC je 0042D521 0042D4EE cmp dword ptr ds:[42F718],0; gvar_0042F718 >0042D4F5 je 0042D521 0042D4F7 lea edx,[ebp-10] 0042D4FA mov eax,[0042F714]; 0x0 gvar_0042F714 0042D4FF call IntToStr 0042D504 mov eax,dword ptr [ebp-10] 0042D507 push eax 0042D508 lea edx,[ebp-4] 0042D50B mov eax,dword ptr [ebx+1E4]; TForm1.Edit2:TEdit 0042D511 call TControl.GetText 0042D516 mov edx,dword ptr [ebp-4] 0042D519 pop eax 0042D51A call @LStrCmp >0042D51F jne 0042D54B 0042D521 lea edx,[ebp-10] 0042D524 mov eax,[0042F718]; 0x0 gvar_0042F718 0042D529 call IntToStr 0042D52E mov eax,dword ptr [ebp-10] 0042D531 push eax 0042D532 lea edx,[ebp-4] 0042D535 mov eax,dword ptr [ebx+1EC]; TForm1.Edit3:TEdit 0042D53B call TControl.GetText 0042D540 mov edx,dword ptr [ebp-4] 0042D543 pop eax 0042D544 call @LStrCmp >0042D549 je 0042D58A 0042D54B mov eax,42D620; ‘Nice try... but is incorrect... Dumb..‘ 0042D550 call ShowMessage 0042D555 xor eax,eax 0042D557 mov [0042F714],eax; gvar_0042F714 0042D55C xor eax,eax 0042D55E mov [0042F718],eax; gvar_0042F718 0042D563 xor edx,edx 0042D565 mov eax,dword ptr [ebx+1E0]; TForm1.Edit1:TEdit 0042D56B call TControl.SetText 0042D570 xor edx,edx 0042D572 mov eax,dword ptr [ebx+1E4]; TForm1.Edit2:TEdit 0042D578 call TControl.SetText 0042D57D xor edx,edx 0042D57F mov eax,dword ptr [ebx+1EC]; TForm1.Edit3:TEdit 0042D585 call TControl.SetText 0042D58A xor eax,eax 0042D58C pop edx 0042D58D pop ecx 0042D58E pop ecx 0042D58F mov dword ptr fs:[eax],edx 0042D592 push 42D5B4 0042D597 lea eax,[ebp-10] 0042D59A call @LStrClr 0042D59F lea eax,[ebp-0C] 0042D5A2 mov edx,3 0042D5A7 call @LStrArrayClr 0042D5AC ret <0042D5AD jmp @HandleFinally <0042D5B2 jmp 0042D597 0042D5B4 pop ebx 0042D5B5 mov esp,ebp 0042D5B7 pop ebp 0042D5B8 ret
我们在OD中进行分析：
0042D3C4 /. 55 push ebp ; // Try按钮点击 0042D3C5 |. 8BEC mov ebp,esp 0042D3C7 |. 33C9 xor ecx,ecx 0042D3C9 |. 51 push ecx 0042D3CA |. 51 push ecx 0042D3CB |. 51 push ecx 0042D3CC |. 51 push ecx 0042D3CD |. 53 push ebx 0042D3CE |. 8BD8 mov ebx,eax 0042D3D0 |. 33C0 xor eax,eax 0042D3D2 |. 55 push ebp 0042D3D3 |. 68 ADD54200 push 0042D5AD 0042D3D8 |. 64:FF30 push dword ptr fs:[eax] 0042D3DB |. 64:8920 mov dword ptr fs:[eax],esp 0042D3DE |. 833D 14F74200>cmp dword ptr ds:[0x42F714],0x0 0042D3E5 |. 74 45 je short 0042D42C 0042D3E7 |. 833D 18F74200>cmp dword ptr ds:[0x42F718],0x0 0042D3EE |. 74 3C je short 0042D42C 0042D3F0 |. 8D55 FC lea edx,[local.1] 0042D3F3 |. 8B83 E0010000 mov eax,dword ptr ds:[ebx+0x1E0] ; TForm1.Edit1:TEdit 0042D3F9 |. E8 E2C9FEFF call 00419DE0 ; TControl.GetText 0042D3FE |. 837D FC 00 cmp [local.1],0x0 ; // "bbdxf" 0042D402 |. 74 28 je short 0042D42C 0042D404 |. 8D55 F8 lea edx,[local.2] 0042D407 |. 8B83 E4010000 mov eax,dword ptr ds:[ebx+0x1E4] ; TForm1.Edit2:TEdit 0042D40D |. E8 CEC9FEFF call 00419DE0 ; TControl.GetText 0042D412 |. 837D F8 00 cmp [local.2],0x0 ; // "12345" 0042D416 |. 74 14 je short 0042D42C 0042D418 |. 8D55 F4 lea edx,[local.3] 0042D41B |. 8B83 EC010000 mov eax,dword ptr ds:[ebx+0x1EC] ; TForm1.Edit3:TEdit 0042D421 |. E8 BAC9FEFF call 00419DE0 ; TControl.GetText 0042D426 |. 837D F4 00 cmp [local.3],0x0 ; // "67890" 0042D42A |. 75 44 jnz short 0042D470 0042D42C |> B8 C4D54200 mov eax,0042D5C4 ; ASCII 46,"ill all boxes first dumb!" 0042D431 |. E8 56F6FFFF call 0042CA8C 0042D436 |. 33C0 xor eax,eax 0042D438 |. A3 14F74200 mov dword ptr ds:[0x42F714],eax 0042D43D |. 33C0 xor eax,eax 0042D43F |. A3 18F74200 mov dword ptr ds:[0x42F718],eax 0042D444 |. 33D2 xor edx,edx 0042D446 |. 8B83 E0010000 mov eax,dword ptr ds:[ebx+0x1E0] ; TForm1.Edit1:TEdit 0042D44C |. E8 BFC9FEFF call 00419E10 ; TControl.SetText 0042D451 |. 33D2 xor edx,edx 0042D453 |. 8B83 E4010000 mov eax,dword ptr ds:[ebx+0x1E4] ; TForm1.Edit2:TEdit 0042D459 |. E8 B2C9FEFF call 00419E10 ; TControl.SetText 0042D45E |. 33D2 xor edx,edx 0042D460 |. 8B83 EC010000 mov eax,dword ptr ds:[ebx+0x1EC] ; TForm1.Edit3:TEdit 0042D466 |. E8 A5C9FEFF call 00419E10 ; TControl.SetText 0042D46B |. E9 1A010000 jmp 0042D58A 0042D470 |> 833D 14F74200>cmp dword ptr ds:[0x42F714],0x0 ; ds:[0042F714]=00005F2A 0042D477 |. 74 6C je short 0042D4E5 0042D479 |. 833D 18F74200>cmp dword ptr ds:[0x42F718],0x0 ; ds:[0042F718]=0000040B 0042D480 |. 74 63 je short 0042D4E5 0042D482 |. 8D55 F0 lea edx,[local.4] ; // edx = 0x0012F9A0 0042D485 |. A1 14F74200 mov eax,dword ptr ds:[0x42F714] ; ds:[0042F714]=00005F2A 0042D48A |. E8 C190FDFF call 00406550 ; IntToStr 0042D48F |. 8B45 F0 mov eax,[local.4] ; 0x5F2A 转换为 (ASCII "24362") 0042D492 |. 50 push eax 0042D493 |. 8D55 FC lea edx,[local.1] ; // "bbdxf" 0042D496 |. 8B83 E4010000 mov eax,dword ptr ds:[ebx+0x1E4] ; TForm1.Edit2:TEdit 0042D49C |. E8 3FC9FEFF call 00419DE0 ; TControl.GetText 0042D4A1 |. 8B55 FC mov edx,[local.1] ; // "12345" 0042D4A4 |. 58 pop eax ; // eax = "24362" 0042D4A5 |. E8 2664FDFF call 004038D0 ; @LStrCmp 0042D4AA 90 nop ; // 第一个关键跳转 0042D4AB 90 nop 0042D4AC |. 8D55 F0 lea edx,[local.4] ; // "24362" 0042D4AF |. A1 18F74200 mov eax,dword ptr ds:[0x42F718] ; [0042F718]=0000040B = 1035 0042D4B4 |. E8 9790FDFF call 00406550 ; IntToStr 0042D4B9 |. 8B45 F0 mov eax,[local.4] ; // eax = (ASCII "1035") 0042D4BC |. 50 push eax 0042D4BD |. 8D55 FC lea edx,[local.1] ; // "12345" 0042D4C0 |. 8B83 EC010000 mov eax,dword ptr ds:[ebx+0x1EC] ; TForm1.Edit3:TEdit 0042D4C6 |. E8 15C9FEFF call 00419DE0 ; TControl.GetText 0042D4CB |. 8B55 FC mov edx,[local.1] ; // edx = "67890" 0042D4CE |. 58 pop eax ; // eax = "1035" 0042D4CF |. E8 FC63FDFF call 004038D0 ; @LStrCmp 0042D4D4 |. 75 0F jnz short 0042D4E5 ; // 第二个关键跳转 0042D4D6 |. B8 E8D54200 mov eax,0042D5E8 ; ASCII 48,"mmm.... Cracked... Congratulations idiot! :-)" 0042D4DB |. E8 ACF5FFFF call 0042CA8C ; ShowMessage
发现，文本比较的位置是：
0042D51A call @LStrCmp
0042D544 call @LStrCmp
之后有两个关键跳转，我们如果爆破就很简单，修改两个关键跳转，使用NOP填充：
jnz short 0042D4E5
jnz short 0042D4E5
4、注册机的探索
在OD分析的时候其实已经把注册码的生成算法弄出来了，但是我们发现，其中涉及到好几个【常量值】，但是这些【常量】都很特殊，当我们将Name改变时，这些【常量值】也发生了变化，SO，说明【常量】也不是固定的，应该是通过Name算出来的。
继续查看IDR分析，找到了一个Name的事件：
Unit1::TForm1.Edit1KeyPress 0042CE30 xor edx,edx 0042CE32 mov dl,byte ptr [ecx] 0042CE34 add edx,0FFFFFFF8 0042CE37 cmp edx,72 >0042CE3A ja 0042D3C0 0042CE40 mov dl,byte ptr [edx+42CE4D] 0042CE46 jmp dword ptr [edx*4+42CEC0] 0042CE4D db 53 0042CE4E db 0 0042CE4F db 0 0042CE50 db 0 0042CE51 db 0 0042CE52 db 0 0042CE53 db 0 0042CE54 db 0 0042CE55 db 0 0042CE56 db 0 0042CE57 db 0 0042CE58 db 0 0042CE59 db 0 0042CE5A db 0 0042CE5B db 0 0042CE5C db 0 0042CE5D db 0 0042CE5E db 0 0042CE5F db 0 0042CE60 db 0 0042CE61 db 0 0042CE62 db 0 0042CE63 db 0 0042CE64 db 0 0042CE65 db 0 0042CE66 db 0 0042CE67 db 0 0042CE68 db 0 0042CE69 db 0 0042CE6A db 0 0042CE6B db 0 0042CE6C db 0 0042CE6D db 0 0042CE6E db 0 0042CE6F db 0 0042CE70 db 0 0042CE71 db 0 0042CE72 db 0 0042CE73 db 0 0042CE74 db 0 0042CE75 db 0 0042CE76 db 0 0042CE77 db 0 0042CE78 db 0 0042CE79 db 0 0042CE7A db 0 0042CE7B db 0 0042CE7C db 0 0042CE7D db 0 0042CE7E db 0 0042CE7F db 0 0042CE80 db 0 0042CE81 db 0 0042CE82 db 0 0042CE83 db 0 0042CE84 db 0 0042CE85 db 0 0042CE86 db 27 0042CE87 db 28 0042CE88 db 29 0042CE89 db 30 0042CE8A db 31 0042CE8B db 32 0042CE8C db 33 0042CE8D db 34 0042CE8E db 35 0042CE8F db 36 0042CE90 db 37 0042CE91 db 38 0042CE92 db 39 0042CE93 db 40 0042CE94 db 41 0042CE95 db 42 0042CE96 db 43 0042CE97 db 44 0042CE98 db 45 0042CE99 db 46 0042CE9A db 47 0042CE9B db 48 0042CE9C db 50 0042CE9D db 49 0042CE9E db 51 0042CE9F db 52 0042CEA0 db 0 0042CEA1 db 0 0042CEA2 db 0 0042CEA3 db 0 0042CEA4 db 0 0042CEA5 db 0 0042CEA6 db 1 0042CEA7 db 2 0042CEA8 db 3 0042CEA9 db 4 0042CEAA db 5 0042CEAB db 6 0042CEAC db 7 0042CEAD db 8 0042CEAE db 9 0042CEAF db 10 0042CEB0 db 11 0042CEB1 db 12 0042CEB2 db 13 0042CEB3 db 14 0042CEB4 db 15 0042CEB5 db 16 0042CEB6 db 17 0042CEB7 db 18 0042CEB8 db 19 0042CEB9 db 20 0042CEBA db 21 0042CEBB db 22 0042CEBC db 24 0042CEBD db 23 0042CEBE db 25 0042CEBF db 26 0042CEC0 dd 42D3C0 0042CEC4 dd 42CF98 0042CEC8 dd 42CFAA 0042CECC dd 42CFBC 0042CED0 dd 42CFD1 0042CED4 dd 42CFE6 0042CED8 dd 42CFF8 0042CEDC dd 42D00A 0042CEE0 dd 42D01C 0042CEE4 dd 42D02E 0042CEE8 dd 42D040 0042CEEC dd 42D055 0042CEF0 dd 42D067 0042CEF4 dd 42D07C 0042CEF8 dd 42D08E 0042CEFC dd 42D0A0 0042CF00 dd 42D0B5 0042CF04 dd 42D0CA 0042CF08 dd 42D0DF 0042CF0C dd 42D0F4 0042CF10 dd 42D105 0042CF14 dd 42D117 0042CF18 dd 42D129 0042CF1C dd 42D13B 0042CF20 dd 42D14D 0042CF24 dd 42D15F 0042CF28 dd 42D171 0042CF2C dd 42D186 0042CF30 dd 42D19B 0042CF34 dd 42D1AD 0042CF38 dd 42D1C2 0042CF3C dd 42D1D7 0042CF40 dd 42D1EC 0042CF44 dd 42D201 0042CF48 dd 42D216 0042CF4C dd 42D22B 0042CF50 dd 42D240 0042CF54 dd 42D255 0042CF58 dd 42D26A 0042CF5C dd 42D27F 0042CF60 dd 42D294 0042CF64 dd 42D2A9 0042CF68 dd 42D2BE 0042CF6C dd 42D2D3 0042CF70 dd 42D2E8 0042CF74 dd 42D2FD 0042CF78 dd 42D312 0042CF7C dd 42D327 0042CF80 dd 42D33C 0042CF84 dd 42D351 0042CF88 dd 42D366 0042CF8C dd 42D37B 0042CF90 dd 42D390 0042CF94 dd 42D3A5 0042CF98 add dword ptr ds:[42F714],427; gvar_0042F714 0042CFA2 add dword ptr ds:[42F718],79; gvar_0042F718 0042CFA9 ret 0042CFAA add dword ptr ds:[42F714],6BC; gvar_0042F714 0042CFB4 add dword ptr ds:[42F718],6F; gvar_0042F718 0042CFBB ret 0042CFBC add dword ptr ds:[42F714],491; gvar_0042F714 0042CFC6 add dword ptr ds:[42F718],2E2; gvar_0042F718 0042CFD0 ret 0042CFD1 add dword ptr ds:[42F714],474D; gvar_0042F714 0042CFDB add dword ptr ds:[42F718],2FA; gvar_0042F718 0042CFE5 ret 0042CFE6 add dword ptr ds:[42F714],400; gvar_0042F714 0042CFF0 add dword ptr ds:[42F718],0E; gvar_0042F718 0042CFF7 ret 0042CFF8 add dword ptr ds:[42F714],6D0; gvar_0042F714 0042D002 add dword ptr ds:[42F718],0D; gvar_0042F718 0042D009 ret 0042D00A add dword ptr ds:[42F714],67D; gvar_0042F714 0042D014 add dword ptr ds:[42F718],0C; gvar_0042F718 0042D01B ret 0042D01C add dword ptr ds:[42F714],750; gvar_0042F714 0042D026 add dword ptr ds:[42F718],0B; gvar_0042F718 0042D02D ret 0042D02E add dword ptr ds:[42F714],43C; gvar_0042F714 0042D038 add dword ptr ds:[42F718],63; gvar_0042F718 0042D03F ret 0042D040 add dword ptr ds:[42F714],764; gvar_0042F714 0042D04A add dword ptr ds:[42F718],378; gvar_0042F718 0042D054 ret 0042D055 add dword ptr ds:[42F714],0C0; gvar_0042F714 0042D05F add dword ptr ds:[42F718],4D; gvar_0042F718 0042D066 ret 0042D067 add dword ptr ds:[42F714],277D; gvar_0042F714 0042D071 add dword ptr ds:[42F718],22B; gvar_0042F718 0042D07B ret 0042D07C add dword ptr ds:[42F714],81E; gvar_0042F714 0042D086 add dword ptr ds:[42F718],5A; gvar_0042F718 0042D08D ret 0042D08E add dword ptr ds:[42F714],0E07; gvar_0042F714 0042D098 add dword ptr ds:[42F718],62; gvar_0042F718 0042D09F ret 0042D0A0 add dword ptr ds:[42F714],8E; gvar_0042F714 0042D0AA add dword ptr ds:[42F718],1D2C; gvar_0042F718 0042D0B4 ret 0042D0B5 add dword ptr ds:[42F714],9A670; gvar_0042F714 0042D0BF add dword ptr ds:[42F718],8C7F3; gvar_0042F718 0042D0C9 ret 0042D0CA add dword ptr ds:[42F714],0D57; gvar_0042F714 0042D0D4 add dword ptr ds:[42F718],288; gvar_0042F718 0042D0DE ret 0042D0DF add dword ptr ds:[42F714],5FEB; gvar_0042F714 0042D0E9 add dword ptr ds:[42F718],21A; gvar_0042F718 0042D0F3 ret 0042D0F4 add dword ptr ds:[42F714],8B0; gvar_0042F714 0042D0FE inc dword ptr ds:[42F718]; gvar_0042F718 0042D104 ret 0042D105 add dword ptr ds:[42F714],4BB; gvar_0042F714 0042D10F add dword ptr ds:[42F718],40; gvar_0042F718 0042D116 ret 0042D117 add dword ptr ds:[42F714],8C2; gvar_0042F714 0042D121 add dword ptr ds:[42F718],4B; gvar_0042F718 0042D128 ret 0042D129 add dword ptr ds:[42F714],1CA6; gvar_0042F714 0042D133 add dword ptr ds:[42F718],4E; gvar_0042F718 0042D13A ret 0042D13B add dword ptr ds:[42F714],395; gvar_0042F714 0042D145 add dword ptr ds:[42F718],26; gvar_0042F718 0042D14C ret 0042D14D add dword ptr ds:[42F714],251E; gvar_0042F714 0042D157 add dword ptr ds:[42F718],5; gvar_0042F718 0042D15E ret 0042D15F add dword ptr ds:[42F714],2D13; gvar_0042F714 0042D169 add dword ptr ds:[42F718],8; gvar_0042F718 0042D170 ret 0042D171 add dword ptr ds:[42F714],1900; gvar_0042F714 0042D17B add dword ptr ds:[42F718],1C8; gvar_0042F718 0042D185 ret 0042D186 add dword ptr ds:[42F714],428; gvar_0042F714 0042D190 add dword ptr ds:[42F718],1610; gvar_0042F718 0042D19A ret 0042D19B add dword ptr ds:[42F714],0B1630; gvar_0042F714 0042D1A5 add dword ptr ds:[42F718],2; gvar_0042F718 0042D1AC ret 0042D1AD add dword ptr ds:[42F714],0D86; gvar_0042F714 0042D1B7 add dword ptr ds:[42F718],270F; gvar_0042F718 0042D1C1 ret 0042D1C2 add dword ptr ds:[42F714],11A4; gvar_0042F714 0042D1CC add dword ptr ds:[42F718],46FF33C; gvar_0042F718 0042D1D6 ret 0042D1D7 add dword ptr ds:[42F714],11F0A; gvar_0042F714 0042D1E1 add dword ptr ds:[42F718],8B3C; gvar_0042F718 0042D1EB ret 0042D1EC add dword ptr ds:[42F714],3CC2; gvar_0042F714 0042D1F6 add dword ptr ds:[42F718],8618; gvar_0042F718 0042D200 ret 0042D201 add dword ptr ds:[42F714],3E1A8; gvar_0042F714 0042D20B add dword ptr ds:[42F718],6C81C; gvar_0042F718 0042D215 ret 0042D216 add dword ptr ds:[42F714],91E4; gvar_0042F714 0042D220 add dword ptr ds:[42F718],27E945; gvar_0042F718 0042D22A ret 0042D22B add dword ptr ds:[42F714],6B42; gvar_0042F714 0042D235 add dword ptr ds:[42F718],2FC7C3; gvar_0042F718 0042D23F ret 0042D240 add dword ptr ds:[42F714],516A4; gvar_0042F714 0042D24A add dword ptr ds:[42F718],0B8F47C; gvar_0042F718 0042D254 ret 0042D255 add dword ptr ds:[42F714],4345A; gvar_0042F714 0042D25F add dword ptr ds:[42F718],115C7; gvar_0042F718 0042D269 ret 0042D26A add dword ptr ds:[42F714],1BFDD9; gvar_0042F714 0042D274 add dword ptr ds:[42F718],12B54; gvar_0042F718 0042D27E ret 0042D27F add dword ptr ds:[42F714],286D; gvar_0042F714 0042D289 add dword ptr ds:[42F718],0B348C; gvar_0042F718 0042D293 ret 0042D294 add dword ptr ds:[42F714],401; gvar_0042F714 0042D29E add dword ptr ds:[42F718],357CE174; gvar_0042F718 0042D2A8 ret 0042D2A9 add dword ptr ds:[42F714],674; gvar_0042F714 0042D2B3 add dword ptr ds:[42F718],317CD7; gvar_0042F718 0042D2BD ret 0042D2BE add dword ptr ds:[42F714],9C; gvar_0042F714 0042D2C8 add dword ptr ds:[42F718],7DD834; gvar_0042F718 0042D2D2 ret 0042D2D3 add dword ptr ds:[42F714],156; gvar_0042F714 0042D2DD add dword ptr ds:[42F718],39CD0; gvar_0042F718 0042D2E7 ret 0042D2E8 add dword ptr ds:[42F714],8627; gvar_0042F714 0042D2F2 add dword ptr ds:[42F718],0BF44A; gvar_0042F718 0042D2FC ret 0042D2FD add dword ptr ds:[42F714],748190; gvar_0042F714 0042D307 add dword ptr ds:[42F718],854686; gvar_0042F718 0042D311 ret 0042D312 add dword ptr ds:[42F714],0A568; gvar_0042F714 0042D31C add dword ptr ds:[42F718],13220; gvar_0042F718 0042D326 ret 0042D327 add dword ptr ds:[42F714],15592; gvar_0042F714 0042D331 add dword ptr ds:[42F718],302E; gvar_0042F718 0042D33B ret 0042D33C add dword ptr ds:[42F714],1DD9; gvar_0042F714 0042D346 add dword ptr ds:[42F718],1C43; gvar_0042F718 0042D350 ret 0042D351 add dword ptr ds:[42F714],266A; gvar_0042F714 0042D35B add dword ptr ds:[42F718],2BA96C08; gvar_0042F718 0042D365 ret 0042D366 add dword ptr ds:[42F714],3CC0; gvar_0042F714 0042D370 add dword ptr ds:[42F718],4EFC8; gvar_0042F718 0042D37A ret 0042D37B add dword ptr ds:[42F714],8311; gvar_0042F714 0042D385 add dword ptr ds:[42F718],1C46; gvar_0042F718 0042D38F ret 0042D390 add dword ptr ds:[42F714],0CE1B; gvar_0042F714 0042D39A add dword ptr ds:[42F718],0B1664; gvar_0042F718 0042D3A4 ret 0042D3A5 xor edx,edx 0042D3A7 mov eax,dword ptr [eax+1E0]; TForm1.Edit1:TEdit 0042D3AD call TControl.SetText 0042D3B2 xor eax,eax 0042D3B4 mov [0042F714],eax; gvar_0042F714 0042D3B9 xor eax,eax 0042D3BB mov [0042F718],eax; gvar_0042F718 0042D3C0 ret
这看起来很乱，不管他，到OD中分析一下：
0042CE30 . 33D2 xor edx,edx ; // 每输入一个字符就进行处理 0042CE32 . 8A11 mov dl,byte ptr ds:[ecx] ; // dl 存放字符的ANSII 0042CE34 . 83C2 F8 add edx,-0x8 ; Switch (cases 8..7A) 0042CE37 . 83FA 72 cmp edx,0x72 0042CE3A . 0F87 80050000 ja 0042D3C0 ; // ANSII码值大于0x80则直接返回 0042CE40 . 8A92 4DCE4200 mov dl,byte ptr ds:[edx+0x42CE4D] 0042CE46 . FF2495 C0CE42>jmp dword ptr ds:[edx*4+0x42CEC0] ; Cabeca.0042CFF8
头部，进行了一个Switch(),然后跟踪[edx+0x42CE4D]的指针，对应不同的操作，edx范围从8到0x7A，看下0x42CE4D的内容：
db 0x42ce4d
db 0x42cebf
0042CE4D 35 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 5...............
0042CE5D 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0042CE6D 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 ................
0042CE7D 00 00 00 00 00 00 00 00 00 1B 1C 1D 1E 1F 20 21 ......... !
0042CE8D 22 23 24 25 26 27 28 29 2A 2B 2C 2D 2E 2F 30 32 "#$%&‘()*+,-./02
0042CE9D 31 33 34 00 00 00 00 00 00 01 02 03 04 05 06 07 134......
0042CEAD 08 09 0A 0B 0C 0D 0E 0F 10 11 12 13 14 15 16 18 .. ..
0042CEBD 17 19 1A
这些应该是一个数组，存放着递增的值，然后根据计算后的指针，指向下面的跳转：
0042CEC0 . /C0D34200 dd Cabeca.0042D3C0 ; Switch table used at 0042CE46 0042CEC4 . |98CF4200 dd Cabeca.0042CF98 0042CEC8 . |AACF4200 dd Cabeca.0042CFAA 0042CECC . |BCCF4200 dd Cabeca.0042CFBC 0042CED0 . |D1CF4200 dd Cabeca.0042CFD1 0042CED4 . |E6CF4200 dd Cabeca.0042CFE6 0042CED8 . |F8CF4200 dd Cabeca.0042CFF8 0042CEDC . |0AD04200 dd Cabeca.0042D00A 0042CEE0 . |1CD04200 dd Cabeca.0042D01C 0042CEE4 . |2ED04200 dd Cabeca.0042D02E 0042CEE8 . |40D04200 dd Cabeca.0042D040 0042CEEC . |55D04200 dd Cabeca.0042D055 0042CEF0 . |67D04200 dd Cabeca.0042D067 0042CEF4 . |7CD04200 dd Cabeca.0042D07C 0042CEF8 . |8ED04200 dd Cabeca.0042D08E 0042CEFC . |A0D04200 dd Cabeca.0042D0A0 0042CF00 . |B5D04200 dd Cabeca.0042D0B5 0042CF04 . |CAD04200 dd Cabeca.0042D0CA 0042CF08 . |DFD04200 dd Cabeca.0042D0DF 0042CF0C . |F4D04200 dd Cabeca.0042D0F4 0042CF10 . |05D14200 dd Cabeca.0042D105 0042CF14 . |17D14200 dd Cabeca.0042D117 0042CF18 . |29D14200 dd Cabeca.0042D129 0042CF1C . |3BD14200 dd Cabeca.0042D13B 0042CF20 . |4DD14200 dd Cabeca.0042D14D 0042CF24 . |5FD14200 dd Cabeca.0042D15F 0042CF28 . |71D14200 dd Cabeca.0042D171 0042CF2C . |86D14200 dd Cabeca.0042D186 0042CF30 . |9BD14200 dd Cabeca.0042D19B 0042CF34 . |ADD14200 dd Cabeca.0042D1AD 0042CF38 . |C2D14200 dd Cabeca.0042D1C2 0042CF3C . |D7D14200 dd Cabeca.0042D1D7 0042CF40 . |ECD14200 dd Cabeca.0042D1EC 0042CF44 . |01D24200 dd Cabeca.0042D201 0042CF48 . |16D24200 dd Cabeca.0042D216 0042CF4C . |2BD24200 dd Cabeca.0042D22B 0042CF50 . |40D24200 dd Cabeca.0042D240 0042CF54 . |55D24200 dd Cabeca.0042D255 0042CF58 . |6AD24200 dd Cabeca.0042D26A 0042CF5C . |7FD24200 dd Cabeca.0042D27F 0042CF60 . |94D24200 dd Cabeca.0042D294 0042CF64 . |A9D24200 dd Cabeca.0042D2A9 0042CF68 . |BED24200 dd Cabeca.0042D2BE 0042CF6C . |D3D24200 dd Cabeca.0042D2D3 0042CF70 . |E8D24200 dd Cabeca.0042D2E8 0042CF74 . |FDD24200 dd Cabeca.0042D2FD 0042CF78 . |12D34200 dd Cabeca.0042D312 0042CF7C . |27D34200 dd Cabeca.0042D327 0042CF80 . |3CD34200 dd Cabeca.0042D33C 0042CF84 . |51D34200 dd Cabeca.0042D351 0042CF88 . |66D34200 dd Cabeca.0042D366 0042CF8C . |7BD34200 dd Cabeca.0042D37B 0042CF90 . |90D34200 dd Cabeca.0042D390 0042CF94 . |A5D34200 dd Cabeca.0042D3A5 0042CF98 > \8105 14F74200>add dword ptr ds:[0x42F714],0x427 ; Case 61 of switch 0042CE34 0042CFA2 . 8305 18F74200>add dword ptr ds:[0x42F718],0x79 0042CFA9 . C3 retn 0042CFAA > 8105 14F74200>add dword ptr ds:[0x42F714],0x6BC ; Case 62 of switch 0042CE34 0042CFB4 . 8305 18F74200>add dword ptr ds:[0x42F718],0x6F 0042CFBB . C3 retn 0042CFBC > 8105 14F74200>add dword ptr ds:[0x42F714],0x491 ; Case 63 of switch 0042CE34 0042CFC6 . 8105 18F74200>add dword ptr ds:[0x42F718],0x2E2 0042CFD0 . C3 retn 0042CFD1 > 8105 14F74200>add dword ptr ds:[0x42F714],0x474D ; Case 64 of switch 0042CE34 0042CFDB . 8105 18F74200>add dword ptr ds:[0x42F718],0x2FA 0042CFE5 . C3 retn 0042CFE6 > 8105 14F74200>add dword ptr ds:[0x42F714],0x400 ; Case 65 of switch 0042CE34 0042CFF0 . 8305 18F74200>add dword ptr ds:[0x42F718],0xE 0042CFF7 . C3 retn 0042CFF8 > 8105 14F74200>add dword ptr ds:[0x42F714],0x6D0 ; Case 66 of switch 0042CE34 0042D002 . 8305 18F74200>add dword ptr ds:[0x42F718],0xD 0042D009 . C3 retn 0042D00A > 8105 14F74200>add dword ptr ds:[0x42F714],0x67D ; Case 67 of switch 0042CE34 0042D014 . 8305 18F74200>add dword ptr ds:[0x42F718],0xC 0042D01B . C3 retn 0042D01C > 8105 14F74200>add dword ptr ds:[0x42F714],0x750 ; Case 68 of switch 0042CE34 0042D026 . 8305 18F74200>add dword ptr ds:[0x42F718],0xB 0042D02D . C3 retn 0042D02E > 8105 14F74200>add dword ptr ds:[0x42F714],0x43C ; Case 69 of switch 0042CE34 0042D038 . 8305 18F74200>add dword ptr ds:[0x42F718],0x63 0042D03F . C3 retn 0042D040 > 8105 14F74200>add dword ptr ds:[0x42F714],0x764 ; Case 6A of switch 0042CE34 0042D04A . 8105 18F74200>add dword ptr ds:[0x42F718],0x378 0042D054 . C3 retn 0042D055 > 8105 14F74200>add dword ptr ds:[0x42F714],0xC0 ; Case 6B of switch 0042CE34 0042D05F . 8305 18F74200>add dword ptr ds:[0x42F718],0x4D 0042D066 . C3 retn 0042D067 > 8105 14F74200>add dword ptr ds:[0x42F714],0x277D ; Case 6C of switch 0042CE34 0042D071 . 8105 18F74200>add dword ptr ds:[0x42F718],0x22B 0042D07B . C3 retn 0042D07C > 8105 14F74200>add dword ptr ds:[0x42F714],0x81E ; Case 6D of switch 0042CE34 0042D086 . 8305 18F74200>add dword ptr ds:[0x42F718],0x5A 0042D08D . C3 retn 0042D08E > 8105 14F74200>add dword ptr ds:[0x42F714],0xE07 ; Case 6E of switch 0042CE34 0042D098 . 8305 18F74200>add dword ptr ds:[0x42F718],0x62 0042D09F . C3 retn 0042D0A0 > 8105 14F74200>add dword ptr ds:[0x42F714],0x8E ; Case 6F of switch 0042CE34 0042D0AA . 8105 18F74200>add dword ptr ds:[0x42F718],0x1D2C 0042D0B4 . C3 retn 0042D0B5 > 8105 14F74200>add dword ptr ds:[0x42F714],0x9A670 ; Case 70 of switch 0042CE34 0042D0BF . 8105 18F74200>add dword ptr ds:[0x42F718],0x8C7F3 0042D0C9 . C3 retn 0042D0CA > 8105 14F74200>add dword ptr ds:[0x42F714],0xD57 ; Case 71 of switch 0042CE34 0042D0D4 . 8105 18F74200>add dword ptr ds:[0x42F718],0x288 0042D0DE . C3 retn 0042D0DF > 8105 14F74200>add dword ptr ds:[0x42F714],0x5FEB ; Case 72 of switch 0042CE34 0042D0E9 . 8105 18F74200>add dword ptr ds:[0x42F718],0x21A 0042D0F3 . C3 retn 0042D0F4 > 8105 14F74200>add dword ptr ds:[0x42F714],0x8B0 ; Case 73 of switch 0042CE34 0042D0FE . FF05 18F74200 inc dword ptr ds:[0x42F718] 0042D104 . C3 retn 0042D105 > 8105 14F74200>add dword ptr ds:[0x42F714],0x4BB ; Case 74 of switch 0042CE34 0042D10F . 8305 18F74200>add dword ptr ds:[0x42F718],0x40 0042D116 . C3 retn 0042D117 > 8105 14F74200>add dword ptr ds:[0x42F714],0x8C2 ; Case 75 of switch 0042CE34 0042D121 . 8305 18F74200>add dword ptr ds:[0x42F718],0x4B 0042D128 . C3 retn 0042D129 > 8105 14F74200>add dword ptr ds:[0x42F714],0x1CA6 ; Case 76 of switch 0042CE34 0042D133 . 8305 18F74200>add dword ptr ds:[0x42F718],0x4E 0042D13A . C3 retn 0042D13B > 8105 14F74200>add dword ptr ds:[0x42F714],0x395 ; Case 78 of switch 0042CE34 0042D145 . 8305 18F74200>add dword ptr ds:[0x42F718],0x26 0042D14C . C3 retn 0042D14D > 8105 14F74200>add dword ptr ds:[0x42F714],0x251E ; Case 77 of switch 0042CE34 0042D157 . 8305 18F74200>add dword ptr ds:[0x42F718],0x5 0042D15E . C3 retn 0042D15F > 8105 14F74200>add dword ptr ds:[0x42F714],0x2D13 ; Case 79 of switch 0042CE34 0042D169 . 8305 18F74200>add dword ptr ds:[0x42F718],0x8 0042D170 . C3 retn 0042D171 > 8105 14F74200>add dword ptr ds:[0x42F714],0x1900 ; Case 7A of switch 0042CE34 0042D17B . 8105 18F74200>add dword ptr ds:[0x42F718],0x1C8 0042D185 . C3 retn 0042D186 > 8105 14F74200>add dword ptr ds:[0x42F714],0x428 ; Case 41 of switch 0042CE34 0042D190 . 8105 18F74200>add dword ptr ds:[0x42F718],0x1610 0042D19A . C3 retn 0042D19B > 8105 14F74200>add dword ptr ds:[0x42F714],0xB1630 ; Case 42 of switch 0042CE34 0042D1A5 . 8305 18F74200>add dword ptr ds:[0x42F718],0x2 0042D1AC . C3 retn 0042D1AD > 8105 14F74200>add dword ptr ds:[0x42F714],0xD86 ; Case 43 of switch 0042CE34 0042D1B7 . 8105 18F74200>add dword ptr ds:[0x42F718],0x270F 0042D1C1 . C3 retn 0042D1C2 > 8105 14F74200>add dword ptr ds:[0x42F714],0x11A4 ; Case 44 of switch 0042CE34 0042D1CC . 8105 18F74200>add dword ptr ds:[0x42F718],0x46FF33C 0042D1D6 . C3 retn 0042D1D7 > 8105 14F74200>add dword ptr ds:[0x42F714],0x11F0A ; Case 45 of switch 0042CE34 0042D1E1 . 8105 18F74200>add dword ptr ds:[0x42F718],0x8B3C 0042D1EB . C3 retn 0042D1EC > 8105 14F74200>add dword ptr ds:[0x42F714],0x3CC2 ; Case 46 of switch 0042CE34 0042D1F6 . 8105 18F74200>add dword ptr ds:[0x42F718],0x8618 0042D200 . C3 retn 0042D201 > 8105 14F74200>add dword ptr ds:[0x42F714],0x3E1A8 ; Case 47 of switch 0042CE34 0042D20B . 8105 18F74200>add dword ptr ds:[0x42F718],0x6C81C 0042D215 . C3 retn 0042D216 > 8105 14F74200>add dword ptr ds:[0x42F714],0x91E4 ; Case 48 of switch 0042CE34 0042D220 . 8105 18F74200>add dword ptr ds:[0x42F718],0x27E945 0042D22A . C3 retn 0042D22B > 8105 14F74200>add dword ptr ds:[0x42F714],0x6B42 ; Case 49 of switch 0042CE34 0042D235 . 8105 18F74200>add dword ptr ds:[0x42F718],0x2FC7C3 0042D23F . C3 retn 0042D240 > 8105 14F74200>add dword ptr ds:[0x42F714],0x516A4 ; Case 4A of switch 0042CE34 0042D24A . 8105 18F74200>add dword ptr ds:[0x42F718],0xB8F47C 0042D254 . C3 retn 0042D255 > 8105 14F74200>add dword ptr ds:[0x42F714],0x4345A ; Case 4B of switch 0042CE34 0042D25F . 8105 18F74200>add dword ptr ds:[0x42F718],0x115C7 0042D269 . C3 retn 0042D26A > 8105 14F74200>add dword ptr ds:[0x42F714],0x1BFDD9 ; Case 4C of switch 0042CE34 0042D274 . 8105 18F74200>add dword ptr ds:[0x42F718],0x12B54 0042D27E . C3 retn 0042D27F > 8105 14F74200>add dword ptr ds:[0x42F714],0x286D ; Case 4D of switch 0042CE34 0042D289 . 8105 18F74200>add dword ptr ds:[0x42F718],0xB348C 0042D293 . C3 retn 0042D294 > 8105 14F74200>add dword ptr ds:[0x42F714],0x401 ; Case 4E of switch 0042CE34 0042D29E . 8105 18F74200>add dword ptr ds:[0x42F718],0x357CE174 0042D2A8 . C3 retn 0042D2A9 > 8105 14F74200>add dword ptr ds:[0x42F714],0x674 ; Case 4F of switch 0042CE34 0042D2B3 . 8105 18F74200>add dword ptr ds:[0x42F718],0x317CD7 0042D2BD . C3 retn 0042D2BE > 8105 14F74200>add dword ptr ds:[0x42F714],0x9C ; Case 50 of switch 0042CE34 0042D2C8 . 8105 18F74200>add dword ptr ds:[0x42F718],0x7DD834 0042D2D2 . C3 retn 0042D2D3 > 8105 14F74200>add dword ptr ds:[0x42F714],0x156 ; Case 51 of switch 0042CE34 0042D2DD . 8105 18F74200>add dword ptr ds:[0x42F718],0x39CD0 0042D2E7 . C3 retn 0042D2E8 > 8105 14F74200>add dword ptr ds:[0x42F714],0x8627 ; Case 52 of switch 0042CE34 0042D2F2 . 8105 18F74200>add dword ptr ds:[0x42F718],0xBF44A 0042D2FC . C3 retn 0042D2FD > 8105 14F74200>add dword ptr ds:[0x42F714],0x748190 ; Case 53 of switch 0042CE34 0042D307 . 8105 18F74200>add dword ptr ds:[0x42F718],0x854686 0042D311 . C3 retn 0042D312 > 8105 14F74200>add dword ptr ds:[0x42F714],0xA568 ; Case 54 of switch 0042CE34 0042D31C . 8105 18F74200>add dword ptr ds:[0x42F718],0x13220 0042D326 . C3 retn 0042D327 > 8105 14F74200>add dword ptr ds:[0x42F714],0x15592 ; Case 55 of switch 0042CE34 0042D331 . 8105 18F74200>add dword ptr ds:[0x42F718],0x302E 0042D33B . C3 retn 0042D33C > 8105 14F74200>add dword ptr ds:[0x42F714],0x1DD9 ; Case 56 of switch 0042CE34 0042D346 . 8105 18F74200>add dword ptr ds:[0x42F718],0x1C43 0042D350 . C3 retn 0042D351 > 8105 14F74200>add dword ptr ds:[0x42F714],0x266A ; Case 58 of switch 0042CE34 0042D35B . 8105 18F74200>add dword ptr ds:[0x42F718],0x2BA96C08 0042D365 . C3 retn 0042D366 > 8105 14F74200>add dword ptr ds:[0x42F714],0x3CC0 ; Case 57 of switch 0042CE34 0042D370 . 8105 18F74200>add dword ptr ds:[0x42F718],0x4EFC8 0042D37A . C3 retn 0042D37B > 8105 14F74200>add dword ptr ds:[0x42F714],0x8311 ; Case 59 of switch 0042CE34 0042D385 . 8105 18F74200>add dword ptr ds:[0x42F718],0x1C46 0042D38F . C3 retn 0042D390 > 8105 14F74200>add dword ptr ds:[0x42F714],0xCE1B ; Case 5A of switch 0042CE34 0042D39A . 8105 18F74200>add dword ptr ds:[0x42F718],0xB1664 0042D3A4 . C3 retn 0042D3A5 > 33D2 xor edx,edx ; Case 8 of switch 0042CE34 0042D3A7 . 8B80 E0010000 mov eax,dword ptr ds:[eax+0x1E0] 0042D3AD . E8 5ECAFEFF call 00419E10 0042D3B2 . 33C0 xor eax,eax 0042D3B4 . A3 14F74200 mov dword ptr ds:[0x42F714],eax 0042D3B9 . 33C0 xor eax,eax 0042D3BB . A3 18F74200 mov dword ptr ds:[0x42F718],eax 0042D3C0 > C3 retn ; Default case of switch 0042CE34
到这里就悲剧了！这么多case,虽然每个都执行的加法，但是每个加的值都不同，然后将计算后的值作为后面那个算法的常量值处理。
它大概就是这样的：
int na,nb;
char cInput = xx;
swith( cInput )
{
case 8:
na+=10;
nb+=34;
break;
....
case 0x71:
na+=10;
nb+=34;
break;
default
break;
}
大概就是这样了，又被耍了！
BY 笨笨D幸福
[反汇编练习] 160个CrackMe之021,布布扣,bubuko.com
原文：http://www.cnblogs.com/bbdxf/p/3813869.html