下载附件得到py代码：
#As a freshman starting in 2024, you should know something about XOR, so this task is for you to sign in.
from pwn import xor
#The Python pwntools library has a convenient xor() function that can XOR together data of different types and lengths
from Crypto.Util.number import bytes_to_long
key = b’New_Star_CTF’
flag=’flag{*******************}’
m1 = bytes_to_long(bytes(flag[:13], encoding=’utf-8′))
m2 = flag[13:]
c1 = m1 ^ bytes_to_long(key)
c2 = xor(key, m2)
print(‘c1=’,c1)
print(‘c2=’,c2)
”’
c1= 8091799978721254458294926060841
c2= b’;:\x1c1<\x03>*\x10\x11u;’
”’
首先，我们需要把给定的c1和key进行XOR运算，来还原m1，也就是flag的前13个字符（包括'{‘和前面的字符）。然后，我们再用key和c2进行XOR运算，来还原m2，也就是flag剩下的字符。
接下来是解密脚本：
from pwn import xor
from Crypto.Util.number import bytes_to_long, long_to_bytes
key = b’New_Star_CTF’
c1 = 8091799978721254458294926060841
c2 = b’;:\x1c1<\x03>*\x10\x11u;’
m1 = c1 ^ bytes_to_long(key)
flag_start = long_to_bytes(m1).decode(‘utf-8’)
m2 = xor(key, c2)
flag_end = m2.decode(‘utf-8’)
flag = flag_start + flag_end
print(flag)