十、switch语句逆向代码

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 1 #include "stdafx.h"
 2 
 3 
 4 int _tmain(int argc, _TCHAR* argv[])
 5 {
 6 004113B0  push        ebp  
 7 004113B1  mov         ebp,esp 
 8 004113B3  sub         esp,0D0h 
 9 004113B9  push        ebx  
10 004113BA  push        esi  
11 004113BB  push        edi  
12 004113BC  lea         edi,[ebp-0D0h] 
13 004113C2  mov         ecx,34h 
14 004113C7  mov         eax,0CCCCCCCCh 
15 004113CC  rep stos    dword ptr es:[edi] 
16     int c;
17     printf("input number\n");
18 004113CE  mov         esi,esp 
19 004113D0  push        offset string "input number\n" (415770h) 
20 004113D5  call        dword ptr [__imp__printf (4182BCh)] 
21 004113DB  add         esp,4 
22 004113DE  cmp         esi,esp 
23 004113E0  call        @ILT+325(__RTC_CheckEsp) (41114Ah) 
24     scanf("%d",&c);
25 004113E5  mov         esi,esp 
26 004113E7  lea         eax,[c] 
27 004113EA  push        eax  
28 004113EB  push        offset string "%d" (41576Ch) 
29 004113F0  call        dword ptr [__imp__scanf (4182C4h)] 
30 004113F6  add         esp,8 
31 004113F9  cmp         esi,esp 
32 004113FB  call        @ILT+325(__RTC_CheckEsp) (41114Ah) 
33     c=c/10;
34 00411400  mov         eax,dword ptr [c] 
35 00411403  cdq              
36 00411404  mov         ecx,0Ah 
37 00411409  idiv        eax,ecx 
38 0041140B  mov         dword ptr [c],eax 
39     switch(c)
40 0041140E  mov         eax,dword ptr [c] 
41 00411411  mov         dword ptr [ebp-0D0h],eax 
42 00411417  cmp         dword ptr [ebp-0D0h],0 
43 0041141E  je          wmain+7Bh (41142Bh) 
44 00411420  cmp         dword ptr [ebp-0D0h],1 
45 00411427  je          wmain+94h (411444h) 
46 00411429  jmp         wmain+0ADh (41145Dh) 
47     {
48     case 0:
49         printf("c>0 && c<10");
50 0041142B  mov         esi,esp 
51 0041142D  push        offset string "c>0 && c<10" (41575Ch) 
52 00411432  call        dword ptr [__imp__printf (4182BCh)] 
53 00411438  add         esp,4 
54 0041143B  cmp         esi,esp 
55 0041143D  call        @ILT+325(__RTC_CheckEsp) (41114Ah) 
56         break;
57 00411442  jmp         wmain+0C4h (411474h) 
58     case 1:
59         printf("c>10 && c<20");
60 00411444  mov         esi,esp 
61 00411446  push        offset string "c>10 && c<100" (41574Ch) 
62 0041144B  call        dword ptr [__imp__printf (4182BCh)] 
63 00411451  add         esp,4 
64 00411454  cmp         esi,esp 
65 00411456  call        @ILT+325(__RTC_CheckEsp) (41114Ah) 
66         break;
67 0041145B  jmp         wmain+0C4h (411474h) 
68     default:
69         printf("c<0 || c>20");
70 0041145D  mov         esi,esp 
71 0041145F  push        offset string "a<0 || a>100" (41573Ch) 
72 00411464  call        dword ptr [__imp__printf (4182BCh)] 
73 0041146A  add         esp,4 
74 0041146D  cmp         esi,esp 
75 0041146F  call        @ILT+325(__RTC_CheckEsp) (41114Ah) 
76         break;
77     }
78     return 0;
79 00411474  xor         eax,eax 
80 }
81 00411476  push        edx  
82 00411477  mov         ecx,ebp 
83 00411479  push        eax  
84 0041147A  lea         edx,[ (41149Ch)] 
85 00411480  call        @ILT+135(@_RTC_CheckStackVars@8) (41108Ch) 
86 00411485  pop         eax  
87 00411486  pop         edx  
88 00411487  pop         edi  
89 00411488  pop         esi  
90 00411489  pop         ebx  
91 0041148A  add         esp,0D0h 
92 00411490  cmp         ebp,esp 
93 00411492  call        @ILT+325(__RTC_CheckEsp) (41114Ah) 
94 00411497  mov         esp,ebp 
95 00411499  pop         ebp  
96 0041149A  ret   

下面是对应的c++代码：

 1 #include "stdafx.h"
 2 
 3 
 4 int _tmain(int argc, _TCHAR* argv[])
 5 {
 6     int c;
 7     printf("input number\n");
 8     scanf("%d",&c);
 9     c=c/10;
10     switch(c)
11     {
12     case 0:
13         printf("c>0 && c<10");
14         break;
15     case 1:
16         printf("c>10 && c<20");
17         break;
18     default:
19         printf("c<0 || c>20");
20         break;
21     }
22     return 0;
23 }

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