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import os
from Crypto.Util.number import *
from typing import Union
from flag import flag
bits = 512
def polar(msg: Union[bytes, bytearray], length: int) -> bytes:
assert length > len(msg), "指定的长度必须大于原始消息长度加 1。"
return bytes(msg) + b'\x00' + os.urandom(length - len(msg) - 1)
def unpolar(msg: Union[bytes, bytearray]) -> bytes:
msg = bytes(msg)
assert b'\x00' in msg, "输入的字节串中不包含分隔符。"
return msg.split(b'\x00')[0]
def getflag1(m):
result = []
for i in range(2):
result.append(getPrime(bits))
p, q = result
if p <= q:
p, q = q, p
e = 0x10001
n = p * q
c = pow(m, e, n)
hint = pow(2024 * p + 2025, q, n)
print('---------- getflag 1 ----------')
print(f'{c = }')
print(f'{n = }')
print(f'{hint = }')
def getflag2(m):
result = []
for i in range(2):
result.append(getPrime(bits))
p, q = result
n = p * q
hint1 = pow(m, p, n)
hint2 = pow(m, q, n)
print('---------- getflag 2 ----------')
print(f'{hint1 = }')
print(f'{hint2 = }')
print(f'{n = }')
def getflag3(m):
result = []
for i in range(2):
result.append(getPrime(bits))
p, q = result
e = 0x10001
n = p * q
g = 20242025
hint = pow(g + p * 1111, e, n)
c = pow(m, e, n)
print('---------- getflag 3 ----------')
print(f'{c = }')
print(f'{n = }')
print(f'{hint = }')
assert len(flag) == 42
mm = []
for i in range(0, 42, 14):
mm.append(bytes_to_long(polar(flag[i:i + 14], bits // 4 - 1)))
m1, m2, m3 = mm
getflag1(m1)
getflag2(m2)
getflag3(m3)
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