46 lines
1.1 KiB
Python
Executable File
46 lines
1.1 KiB
Python
Executable File
#!python3
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from pwn import *
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import string
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import ast
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#conn = process(["python3", "compress_and_attack.py"])
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conn = remote("mercury.picoctf.net", 2431)
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conn.recvuntil(b": ")
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def encrypt(text):
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conn.sendline(text)
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nonce = ast.literal_eval(conn.recvline().decode())
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encrypted = ast.literal_eval(conn.recvline().decode())
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length = int(conn.recvline())
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conn.recvuntil(b": ")
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return nonce, encrypted, length
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CHARACTERSET = string.ascii_lowercase + string.digits + " }_"
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prefix = "picoCTF{"
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pre_known = "sheriff_you_solved_"
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max_chars = 20
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sol_char = prefix[-1]
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sol_string = prefix+pre_known
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while sol_char != '}':
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P = log.progress("trying characters... ")
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min_char = ""
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min_size = 1000000000000000000000000000000000
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for c in CHARACTERSET:
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P.status(sol_string+c)
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s = 0
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n = 1
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for _ in range(n):
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_, encrypted, _ = encrypt((sol_string+c).encode())
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s += len(encrypted)
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if s < min_size:
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min_char = c
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min_size = s
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sol_char = min_char
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sol_string += min_char
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P.success(sol_string)
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