强网拟态预选赛

from pwn import *
def run(n: int, m: int, a1: list):
    sign = []
    minn = []
    summary = 0
    sum1 = 0
    sum2 = 0
    for i in range(m):
        a = int(a1[i])
        sign.append(1)
        if a < 0:
            sign[i] *= -1
            a *= -1
        summary += a
        minn.append(a)
    for i in range(n-m):
        a = int(a1[i+m])
        if a < 0:
            sign[i % m] *= -1
            a *= -1
        summary += a
        if a < minn[i % m]:
            minn[i % m] = a
    for i in range(m):
        if sign[i] > 0:
            sum1 += minn[i]
        else:
            sum2 += minn[i]
    return summary-2*min(sum1, sum2)
pro = remote('172.52.4.26', 9999)
for i in range(100):
    print(f'round: {i}')
    b = pro.recvuntil(b'Give me your output:\n').decode().split('\n')[-4:-2]
    print(b)
    _len = int(b[0].split()[0])
    k = int(b[0].split()[1])
    a1 = b[1].split()
    print(_len, k, len(a1))
    answer = run(_len, k, a1)
    print(answer)
    pro.sendline(str(answer).encode())
pro.interactive()

from pwn import *
from pwnlib.util.iters import mbruteforce
from hashlib import sha256

def proof_of_work(sh):
    sh.recvuntil("XXXX + ")
    suffix = sh.recvuntil(')').decode("utf8")[:-1]
    log.success(suffix)
    sh.recvuntil("== ")
    cipher = sh.recvline().strip().decode("utf8")
    proof = mbruteforce(lambda x: sha256((x + suffix).encode()).hexdigest() ==  cipher, string.ascii_letters + string.digits, length=4, method='fixed')
    sh.sendlineafter("Give me XXXX:", proof)

sh=remote("123.57.1.42","29518")

proof_of_work(sh)
sh.interactive()