from pwn import context, args, process, remote, success, xor

context.update(arch='amd64', os='linux', log_level='info')

URL = 'iaet6burymdllg3rflxg4ym7vk-1024-intro-crypto-1.challenge.cscg.live'
PORT = 443

def start():
    if args.REMOTE:
        return remote(URL, PORT, ssl=True)
    else:
        return process(['python3', './main.py'])

io = start()

payload_len = 512
io.sendlineafter(b"Enter some plaintext (hex): ", (b"00" * payload_len))

keystreams = []
for i in range(256):
    line = io.recvline()
    ks = bytes.fromhex(line.strip().split(b" ")[-1].decode())
    keystreams.append(ks)

io.recvuntil(b"Flag: ")
flag_enc = bytes.fromhex(io.recvline().strip().decode())

io.close()

for ks in keystreams:
    candidate = xor(flag_enc, ks[:len(flag_enc)])
    if b"CSCG{" in candidate or b"flag{" in candidate:
        success(f"Found Flag: {candidate.decode()}")
        break