[原创] 对Light Image Resizer v6.1.9.0逆向分析和注册破解

程序为32位程序，（程序对提示字符串进行了加密处理），采用 Delphi编制，这样的程序特点明显。所以我们从特定字符串切入。

1、用OllyDbg载入程序，F8一路执行，当程序跑起来时记住调用的Call下断，Ctrl+F2重新载入，F9运行断在下断的Call处，F7进入；

010DFA9C  /$  55                 push ebp
010DFA9D  |.  8BEC               mov ebp,esp
010DFA9F  |.  51                 push ecx                                 ;  Resize.014B07A0
010DFAA0  |.  B9 0E000000        mov ecx,0xE
010DFAA5  |>  6A 00              /push 0x0
010DFAA7  |.  6A 00              |push 0x0
010DFAA9  |.  49                 |dec ecx                                 ;  Resize.014B07A0
010DFAAA  |.^ 75 F9              \jnz short Resize.010DFAA5
010DFAAC  |.  51                 push ecx                                 ;  Resize.014B07A0
010DFAAD  |.  874D FC            xchg [local.1],ecx                       ;  Resize.014B07A0
010DFAB0  |.  53                 push ebx
010DFAB1  |.  56                 push esi                                 ;  Resize.<ModuleEntryPoint>
010DFAB2  |.  57                 push edi                                 ;  Resize.<ModuleEntryPoint>
010DFAB3  |.  884D FB            mov byte ptr ss:[ebp-0x5],cl
010DFAB6  |.  8955 FC            mov [local.1],edx                        ;  Resize.011A2964
010DFAB9  |.  8BF0               mov esi,eax
010DFABB  |.  33C0               xor eax,eax
010DFABD  |.  55                 push ebp
010DFABE  |.  68 5CFE0D01        push Resize.010DFE5C
010DFAC3  |.  64:FF30            push dword ptr fs:[eax]                  ;  Resize.005F9CC1
010DFAC6  |.  64:8920            mov dword ptr fs:[eax],esp
010DFAC9  |.  B8 78FE0D01        mov eax,Resize.010DFE78                  ;  TfrmTrial.Execute Begin
010DFACE  |.  E8 199EBEFF        call Resize.00CC98EC

来自  011BA435, 011C5623 这两处，分别转到这两处分析。

【011BA435处】：

011BA3F1   .  80B8 35090000 00   cmp byte ptr ds:[eax+0x935],0x0
011BA3F8   .  74 40              je short Resize.011BA43A
011BA3FA   .  E8 A5FCB0FF        call Resize.00CCA0A4
011BA3FF   .  D1F8               sar eax,1
011BA401   .  79 03              jns short Resize.011BA406
011BA403   .  83D0 00            adc eax,0x0
011BA406   >  83F8 03            cmp eax,0x3
011BA409   .  7F 05              jg short Resize.011BA410
011BA40B   .  B8 03000000        mov eax,0x3
011BA410   >  83F8 14            cmp eax,0x14
011BA413   .  7D 08              jge short Resize.011BA41D
011BA415   .  8985 D8FDFFFF      mov dword ptr ss:[ebp-0x228],eax
011BA41B   .  EB 0A              jmp short Resize.011BA427
011BA41D   >  C785 D8FDFFFF 1400>mov dword ptr ss:[ebp-0x228],0x14
011BA427   >  8BCB               mov ecx,ebx
011BA429   .  8B95 D8FDFFFF      mov edx,dword ptr ss:[ebp-0x228]
011BA42F   .  8B85 FCFDFFFF      mov eax,dword ptr ss:[ebp-0x204]
011BA435   .  E8 6256F2FF        call Resize.010DFA9C                     ;  》此处调用试用窗体
011BA43A   >  33C0               xor eax,eax

【011C5623处】：

011C5613   .  80B8 35090000 00   cmp byte ptr ds:[eax+0x935],0x0
011C561A   .  74 1A              je short Resize.011C5636
011C561C   .  33C9               xor ecx,ecx                              ;  Resize.014B07A0
011C561E   .  33D2               xor edx,edx                              ;  Resize.011A2964
011C5620   .  8B45 D4            mov eax,dword ptr ss:[ebp-0x2C]
011C5623   .  E8 74A4F1FF        call Resize.010DFA9C                     ;  》此处调用试用窗体
011C5628   .  84C0               test al,al
011C562A   .  75 0A              jnz short Resize.011C5636
011C562C   .  E8 C72824FF        call Resize.00407EF8
011C5631   .  E9 EA240000        jmp Resize.011C7B20
011C5636   >  33C0               xor eax,eax

此两处都有跳转je，都有相同的比较语句 cmp byte ptr ds:[eax+0x935],0x0 所以只要 ds:[eax+0x935]=0，je跳转实现，跳过试用窗体，ds:[eax+0x935]≠0，je不跳转，出现提示窗体，这不，基本思路就有了：就是找到何处给 ds:[eax+0x935]赋值不为 0。

4、在 cmp byte ptr ds:[eax+0x935],0x0 上 右键 — 查找参考 — 地址常量，得到以下比较和赋值语句：

00CCD22C   cmp byte ptr ds:[eax+0x935],0x0
00F63CD0   cmp byte ptr ds:[eax+0x935],0x0
011AF79D   movzx edx,byte ptr ds:[eax+0x935]
011BA110   cmp byte ptr ds:[eax+0x935],0x0
011BA3F1   cmp byte ptr ds:[eax+0x935],0x0
011BD98B   cmp byte ptr ds:[eax+0x935],0x0           》*
011C55B3   cmp byte ptr ds:[eax+0x935],0x0
011C55E8   cmp byte ptr ds:[eax+0x935],0x0
011C5613   cmp byte ptr ds:[eax+0x935],0x0           (初始 CPU 选择)
011CCE59   mov byte ptr ds:[ebx+0x935],al
011D597D   cmp byte ptr ds:[esi+0x935],0x0
011D7EFB   movzx eax,byte ptr ds:[eax+0x935]
011D9CB6   cmp byte ptr ds:[eax+0x935],0x0
011DBFFF   mov byte ptr ds:[eax+0x935],0x0
011DC06D   mov byte ptr ds:[eax+0x935],0x1
011DC07C   mov byte ptr ds:[eax+0x935],0x1           》*
011DC093   mov byte ptr ds:[ebx+0x935],0x1

5、挨个下断，重新载入，运行调试此处是关键：

011DC07C   mov byte ptr ds:[eax+0x935],0x1           》*

赋值修改为 0，接着运行，来到此处：

011BD98B      80B8 35090000 00   cmp byte ptr ds:[eax+0x935],0x0          ;  》*
011BD992   .  0F85 E2000000      jnz Resize.011BDA7A
011BD998   .  A1 B82C2C01        mov eax,dword ptr ds:[0x12C2CB8]
011BD99D   .  0FB600             movzx eax,byte ptr ds:[eax]
011BD9A0   .  2C 01              sub al,0x1                               ;  Switch (cases 0..4)
011BD9A2   .  72 0D              jb short Resize.011BD9B1
011BD9A4   .  2C 03              sub al,0x3
011BD9A6   .  0F84 8A000000      je Resize.011BDA36
011BD9AC   .  E9 C9000000        jmp Resize.011BDA7A
011BD9B1   >  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]         ;  Case 0 of switch 011BD9A0
011BD9B7   .  83B8 940A0000 00   cmp dword ptr ds:[eax+0xA94],0x0
011BD9BE   .  74 42              je short Resize.011BDA02
011BD9C0   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BD9C6   .  8B80 940A0000      mov eax,dword ptr ds:[eax+0xA94]
011BD9CC   .  83B8 E0000000 00   cmp dword ptr ds:[eax+0xE0],0x0
011BD9D3   .  74 2D              je short Resize.011BDA02
011BD9D5   .  6A 00              push 0x0
011BD9D7   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BD9DD   .  8B88 40090000      mov ecx,dword ptr ds:[eax+0x940]
011BD9E3   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BD9E9   .  8B80 940A0000      mov eax,dword ptr ds:[eax+0xA94]
011BD9EF   .  8B90 E0000000      mov edx,dword ptr ds:[eax+0xE0]
011BD9F5   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BD9FB   .  E8 84320000        call Resize.011C0C84
011BDA00   .  EB 1B              jmp short Resize.011BDA1D
011BDA02   >  6A 00              push 0x0
011BDA04   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BDA0A   .  8B88 40090000      mov ecx,dword ptr ds:[eax+0x940]
011BDA10   .  33D2               xor edx,edx
011BDA12   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BDA18   .  E8 67320000        call Resize.011C0C84
011BDA1D   >  A1 B82C2C01        mov eax,dword ptr ds:[0x12C2CB8]
011BDA22   .  8038 00            cmp byte ptr ds:[eax],0x0
011BDA25   .  75 53              jnz short Resize.011BDA7A
011BDA27   .  B2 01              mov dl,0x1
011BDA29   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BDA2F   .  E8 04F40000        call Resize.011CCE38
011BDA34   .  EB 44              jmp short Resize.011BDA7A
011BDA36   >  6A 01              push 0x1                                 ;  Case 4 of switch 011BD9A0
011BDA38   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BDA3E   .  8B88 40090000      mov ecx,dword ptr ds:[eax+0x940]
011BDA44   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BDA4A   .  8B80 940A0000      mov eax,dword ptr ds:[eax+0xA94]
011BDA50   .  8B90 E0000000      mov edx,dword ptr ds:[eax+0xE0]
011BDA56   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BDA5C   .  E8 23320000        call Resize.011C0C84
011BDA61   .  A1 B82C2C01        mov eax,dword ptr ds:[0x12C2CB8]
011BDA66   .  8038 04            cmp byte ptr ds:[eax],0x4
011BDA69   .  75 51              jnz short Resize.011BDABC
011BDA6B   .  B2 01              mov dl,0x1
011BDA6D   .  8B85 08FEFFFF      mov eax,dword ptr ss:[ebp-0x1F8]
011BDA73   .  E8 C0F30000        call Resize.011CCE38
011BDA78   .  EB 42              jmp short Resize.011BDABC
011BDA7A   >  E8 25C6B0FF        call Resize.00CCA0A4                     ;  Default case of switch

经逐步分析，此处 011BDA2F call Resize.011CCE38 调用“试用版本”标题，加密字符串为“%#xp{ 't#$x~}”，所以只需要 011BD992   .  jnz Resize.011BDA7A 跳转实现即可，刚才我们已经把 数据堆栈 ds:[eax+0x935] 赋值为 0 了，因此，只要把 011BD98B cmp byte ptr ds:[eax+0x935],0x0 改为与 1 比较，下面一行的 jnz就会跳转实现。

6、总结

所以需要破解的地方有两处

011DC07C mov byte ptr ds:[eax+0x935],0x1 改为  011DC07C mov byte ptr ds:[eax+0x935],0x0
011BD98B cmp byte ptr ds:[eax+0x935],0x0 改为  011BD98B cmp byte ptr ds:[eax+0x935],0x1

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