试着学了一下IDA的动调，用一道题目来练了一下，adworld新手区game
0x01
拿到文件先查壳
没有加壳，拖到IDA里
0x02
int __cdecl main_0(int argc, const char **argv, const char **envp)
{
int i; // [esp+DCh] [ebp-20h]
int v5; // [esp+F4h] [ebp-8h] BYREF
sub_45A7BE(&unk_50B110);
sub_45A7BE(&unk_50B158);
sub_45A7BE(&unk_50B1A0);
sub_45A7BE(&unk_50B1E8);
sub_45A7BE(&unk_50B230);
sub_45A7BE(&unk_50B278);
sub_45A7BE(&unk_50B2C0);
sub_45A7BE(&unk_50B308);
sub_45A7BE(&unk_50AFD0);
sub_45A7BE("| by 0x61 |\n");
sub_45A7BE("| |\n");
sub_45A7BE("|------------------------------------------------------|\n");
sub_45A7BE(
"Play a game\n"
"The n is the serial number of the lamp,and m is the state of the lamp\n"
"If m of the Nth lamp is 1,it's on ,if not it's off\n"
"At first all the lights were closed\n");
sub_45A7BE("Now you can input n to change its state\n");
sub_45A7BE(
"But you should pay attention to one thing,if you change the state of the Nth lamp,the state of (N-1)th and (N+1)th w"
"ill be changed too\n");
sub_45A7BE("When all lamps are on,flag will appear\n");
sub_45A7BE("Now,input n \n");
while ( 1 )
{
while ( 1 )
{
sub_45A7BE("input n,n(1-8)\n");
sub_459418();
sub_45A7BE("n=");
sub_4596D4("%d", &v5);
sub_45A7BE("\n");
if ( v5 >= 0 && v5 <= 8 )
break;
sub_45A7BE("sorry,n error,try again\n");
}
if ( v5 )
{
sub_4576D6(v5 - 1);
}
else
{
for ( i = 0; i < 8; ++i )
{
if ( (unsigned int)i >= 9 )
j____report_rangecheckfailure();
byte_532E28[i] = 0;
}
}
j__system("CLS");
sub_458054();
if ( byte_532E28[0] == 1
&& byte_532E28[1] == 1
&& byte_532E28[2] == 1
&& byte_532E28[3] == 1
&& byte_532E28[4] == 1
&& byte_532E28[5] == 1
&& byte_532E28[6] == 1
&& byte_532E28[7] == 1 )
{
sub_457AB4();
}
}
}运行看看
能看出sub_45A7BE这个函数应该是printf，最后有一个if判断，跟进到sub_457AB4()康康
int sub_45E940()
{
int i; // [esp+D0h] [ebp-94h]
char v2[22]; // [esp+DCh] [ebp-88h] BYREF
char v3[32]; // [esp+F2h] [ebp-72h] BYREF
char v4[4]; // [esp+112h] [ebp-52h] BYREF
char v5[64]; // [esp+120h] [ebp-44h]
sub_45A7BE("done!!! the flag is ");
v5[0] = 18;
v5[1] = 64;
v5[2] = 98;
v5[3] = 5;
v5[4] = 2;
v5[5] = 4;
v5[6] = 6;
v5[7] = 3;
v5[8] = 6;
v5[9] = 48;
v5[10] = 49;
v5[11] = 65;
v5[12] = 32;
v5[13] = 12;
v5[14] = 48;
v5[15] = 65;
v5[16] = 31;
v5[17] = 78;
v5[18] = 62;
v5[19] = 32;
v5[20] = 49;
v5[21] = 32;
v5[22] = 1;
v5[23] = 57;
v5[24] = 96;
v5[25] = 3;
v5[26] = 21;
v5[27] = 9;
v5[28] = 4;
v5[29] = 62;
v5[30] = 3;
v5[31] = 5;
v5[32] = 4;
v5[33] = 1;
v5[34] = 2;
v5[35] = 3;
v5[36] = 44;
v5[37] = 65;
v5[38] = 78;
v5[39] = 32;
v5[40] = 16;
v5[41] = 97;
v5[42] = 54;
v5[43] = 16;
v5[44] = 44;
v5[45] = 52;
v5[46] = 32;
v5[47] = 64;
v5[48] = 89;
v5[49] = 45;
v5[50] = 32;
v5[51] = 65;
v5[52] = 15;
v5[53] = 34;
v5[54] = 18;
v5[55] = 16;
v5[56] = 0;
qmemcpy(v2, "{ ", 2);
v2[2] = 18;
v2[3] = 98;
v2[4] = 119;
v2[5] = 108;
v2[6] = 65;
v2[7] = 41;
v2[8] = 124;
v2[9] = 80;
v2[10] = 125;
v2[11] = 38;
v2[12] = 124;
v2[13] = 111;
v2[14] = 74;
v2[15] = 49;
v2[16] = 83;
v2[17] = 108;
v2[18] = 94;
v2[19] = 108;
v2[20] = 84;
v2[21] = 6;
qmemcpy(v3, "`S,yhn _uec{", 12);
v3[12] = 127;
v3[13] = 119;
v3[14] = 96;
v3[15] = 48;
v3[16] = 107;
v3[17] = 71;
v3[18] = 92;
v3[19] = 29;
v3[20] = 81;
v3[21] = 107;
v3[22] = 90;
v3[23] = 85;
v3[24] = 64;
v3[25] = 12;
v3[26] = 43;
v3[27] = 76;
v3[28] = 86;
v3[29] = 13;
v3[30] = 114;
v3[31] = 1;
strcpy(v4, "u~");
for ( i = 0; i < 56; ++i )
{
v2[i] ^= v5[i];
v2[i] ^= 0x13u;
}
return sub_45A7BE("%s\n");
}看来这个就是输出flag的函数，数据都有，加密就是两个异或，很容易就可以拿到flag，不过我们要用动调，
也就是让下面的逻辑成真，
if ( byte_532E28[0] == 1
&& byte_532E28[1] == 1
&& byte_532E28[2] == 1
&& byte_532E28[3] == 1
&& byte_532E28[4] == 1
&& byte_532E28[5] == 1
&& byte_532E28[6] == 1
&& byte_532E28[7] == 1 )0x03
f9动调，断点就下在if上面
主要就是这里，byte_532E28[i]的值在比较之前会保存到寄存器中，所以要让寄存器的值为1
双击它改成1，重复几次，直到运行sub_457AB4()
