#acsc2021 #good_challenges_2021 #!/usr/bin/env python3 import os import random import string with open('flag.txt', 'rb') as f: FLAG = f.read().strip() assert FLAG.startswith(b'ACSC{') assert FLAG.endswith(b'}') SECRET = FLAG[5:-1] assert l…

#acsc2021 $name, "msg" => $msg, "flag" => "ACSC{" . $KEY . "}" // try to get this flag! ); $iv = openssl_ran…

#acsc2021 import gmpy2 from Crypto.Util.number import long_to_bytes, bytes_to_long, getStrongPrime, inverse from Crypto.Util.Padding import pad from flag import m #m = b"ACSC{<REDACTED>}" # flag! f = open("chal.py","rb").read() # I'll encrypt myself</redacted>…

#acsc2021 import random from Crypto.Util.number import * from Crypto.Util.Padding import pad from flag import flag p = getStrongPrime(512) q = getStrongPrime(512) n = p * q B = getStrongPrime(512) m = flag[0:len(flag)//2] print("flag1_len …

#acsc2021 #!/usr/bin/env python3 import base64 import json import os from Crypto.Cipher import AES from Crypto.Util.Padding import pad, unpad from flag import flag key = os.urandom(16) iv1 = os.urandom(16) iv2 = os.urandom(16) admin_userna…

#acsc2021 from params import p, a, b, flag, y x = int.from_bytes(flag, "big") assert 0 < x < p assert 0 < y < p assert x != y EC = EllipticCurve(GF(p), [a, b]) assert EC(x,y) assert EC(y,x) print("p = {}".format(p)) print("a = {}".format(a…

#acsc2021 import os import string from Crypto.Cipher import AES, ARC4, DES BLOCK = 16 def bxor(a, b): res = [c1 ^ c2 for (c1, c2) in zip(a, b)] return bytes(res) def block_hash(data): data = AES.new(data, AES.MODE_ECB).encrypt(b"\x00" * AE…