鹤城杯

⏳:2021-10-8

Petition

32位无壳

 

shift+f12找字符串 没发现

转换找main函数 没有

只能打开start函数

 

发现函数嵌套函数

 

进入sub_119C 发现函数嵌套函数

 

进入sub_122A 发现函数嵌套函数。。。。

一直循环了下去 且变化的数是

 

初步怀疑两数异或的值

试一下前几个值进行异或:

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print(chr(0x1e^0x78),end='')
print(chr(0x6c^0x00),end='')
print(chr(0x07^0x66),end='')
print(chr(0xa9^0xce),end='')

得出

flag

猜想成立 一直写下去

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print(chr(0x1e^0x78),end='')
print(chr(0x6c^0x00),end='')
print(chr(0x07^0x66),end='')
print(chr(0xa9^0xce),end='')
print(chr(0xf9^0x82),end='')
print(chr(0x8c^0xb5),end='')
print(chr(0x88^0xbe),end='')
print(chr(0xcb^0xa8),end='')
print(chr(0x52^0x64),end='')
print(chr(0xa0^0x99),end='')
print(chr(0x19^0x2f),end='')
print(chr(0x21^0x15),end='')
print(chr(0x66^0x50),end='')
print(chr(0x03^0x2e),end='')
print(chr(0xaf^0x97),end='')
print(chr(0xf6^0xc7),end='')
print(chr(0x43^0x7b),end='')
print(chr(0x18^0x2c),end='')
print(chr(0xc9^0xe4),end='')
print(chr(0xfe^0xca),end='')
print(chr(0x66^0x55),end='')
print(chr(0x9c^0xaa),end='')
print(chr(0x4c^0x7f),end='')
print(chr(0x00^0x2d),end='')
print(chr(0x25^0x1d),end='')
print(chr(0xd6^0xb2),end='')
print(chr(0x9a^0xff),end='')
print(chr(0x7d^0x44),end='')
print(chr(0xbd^0x90),end='')
print(chr(0x45^0x72),end='')
print(chr(0x65^0x56),end='')
print(chr(0x6e^0x08),end='')
print(chr(0x85^0xb2),end='')
print(chr(0x12^0x21),end='')
print(chr(0x7f^0x46),end='')
print(chr(0x2b^0x13),end='')
print(chr(0x24^0x14),end='')
print(chr(0xfc^0xca),end='')
print(chr(0x24^0x12),end='')
print(chr(0x50^0x33),end='')
print(chr(0x12^0x23),end='')
print(chr(0xea^0x97),end='')
print(chr(0xb2^0xb2),end='')

flag{96c69646-8184-4363-8de9-73f7398066c1}