まあこれはやらなくていい
from ptrlib import Socket, xor, chunks sock = Socket("nc crypto.zh3r0.cf 1111") sock.sendlineafter(">>> ", "2") sock.sendlineafter("hex:", b'hello world! Lets get going'.hex()) sock.sendlineafter(">>> ", "2") sock.sendlineafter("hex:", b'Nothing fancy, just standard bytes_to_int'.hex()) # flag = bytes.fromhex(sock.recvlineafter("flag: ").decode()) # # plaintext = bytes([i for i in range(256)]) # sock.sendlineafter(">>> ", "1") # sock.sendlineafter("hex:", plaintext.hex()) # ciphertext = bytes.fromhex(sock.recvline().decode()) # plain_flag = bytes([plaintext[ciphertext.find(f)] for f in flag]) plain_flag = b'mono substitutions arent that creative' sock.sendlineafter(">>> ", "2") sock.sendlineafter("hex:", plain_flag.hex()) # flag_hex = sock.recvlineafter("flag: ").decode() # known = list(b'creating different substitutions for each char') # # from tqdm import tqdm # while len(known) < len(flag_hex) // 2: # for c in tqdm(range(0x20, 0x7f)): # sock.sendlineafter(">>> ", "1") # sock.sendlineafter("hex:", bytes(known + [c]).hex()) # res = sock.recvline().decode() # if flag_hex.startswith(res): # known.append(c) # print(bytes(known)) # break plain_flag = b'creating different substitutions for each char' sock.sendlineafter(">>> ", "2") sock.sendlineafter("hex:", plain_flag.hex()) flag = b"Glad that you figured out the invariant" sock.sendlineafter(">>> ", "2") sock.sendlineafter("hex:", flag.hex()) # flag_hex = sock.recvlineafter("flag: ").decode() # # plaintext = "".join([bytes([x]).hex() * 200 for x in range(0x20, 0x7f)]) # sock.sendlineafter(">>> ", "1") # sock.sendlineafter("hex:", plaintext) # res = chunks(sock.recvline().decode(), 4) # table = {} # p = 0 # for c in range(0x20, 0x7f): # for i in range(200): # table[res[200*p+i]] = c # p += 1 # # flag_chunks = chunks(flag_hex, 4) # for c in flag_chunks: # if c in table: # print(chr(table[c])) # else: # print("[!]" + c) flag = b'Here we append the key with your shit, please dont tell anyone' sock.sendlineafter(">>> ", "2") sock.sendlineafter("hex:", flag.hex()) sock.interactive()
