Created
August 10, 2020 08:52
-
-
Save soreatu/591a87dd2af6fc41045ea2e603143f68 to your computer and use it in GitHub Desktop.
Scripts for `idiot box` in WMCTF2020
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import itertools | |
| from binascii import hexlify, unhexlify | |
| import Crypto.Random.random as random | |
| from collections import Counter | |
| from Crypto.Util.number import bytes_to_long, long_to_bytes, getRandomNBitInteger | |
| sbox = [[11, 10, 1, 3, 8, 3, 14, 13, 0, 3, 9, 2, 4, 2, 11, 4, 6, 1, 6, 13, 6, 7, 7, 0, 10, 5, 4, 5, 9, 5, 10, 10, 6, 7, 15, 4, 7, 9, 15, 12, 1, 15, 14, 11, 14, 13, 1, 13, 8, 8, 9, 2, 12, 2, 0, 12, 8, 3, 0, 15, 11, 12, 5, 14], [0, 15, 2, 8, 3, 8, 12, 12, 9, 10, 14, 13, 4, 13, 14, 14, 2, 1, 15, 1, 1, 7, 3, 1, 10, 15, 6, 4, 6, 8, 5, 15, 4, 5, 7, 11, 7, 2, 5, 9, 11, 7, 11, 14, 6, 2, 11, 3, 12, 13, 9, 3, 9, 12, 4, 8, 10, 0, 5, 0, 0, 10, 6, 13], [5, 10, 3, 12, 3, 0, 6, 15, 13, 2, 0, 15, 8, 2, 3, 13, 9, 11, 0, 6, 14, 11, 2, 10, 1, 4, 12, 1, 7, 4, 7, 15, 5, 8, 7, 12, 5, 11, 0, 12, 14, 6, 9, 8, 14, 6, 9, 3, 4, 10, 1, 2, 10, 8, 7, 13, 15, 13, 4, 1, 5, 9, 14, 11], [4, 0, 7, 7, 7, 5, 4, 1, 10, 12, 11, 11, 11, 10, 15, 3, 12, 8, 3, 0, 2, 14, 14, 13, 2, 10, 6, 4, 6, 10, 2, 3, 14, 15, 8, 15, 9, 1, 11, 7, 5, 5, 6, 13, 6, 8, 0, 1, 3, 14, 0, 2, 9, 15, 8, 12, 1, 4, 9, 13, 9, 13, 5, 12], [ | |
| 9, 10, 3, 4, 2, 10, 12, 4, 5, 12, 5, 11, 5, 9, 13, 10, 7, 11, 7, 11, 1, 3, 2, 3, 3, 7, 1, 5, 15, 13, 9, 7, 12, 8, 8, 15, 0, 6, 0, 14, 15, 8, 8, 1, 0, 1, 0, 10, 14, 2, 14, 9, 13, 11, 6, 12, 15, 13, 14, 6, 4, 6, 4, 2], [0, 8, 12, 15, 0, 8, 3, 6, 7, 15, 9, 9, 2, 15, 9, 9, 1, 12, 13, 10, 5, 10, 12, 14, 5, 7, 14, 6, 4, 7, 5, 2, 1, 6, 4, 12, 0, 1, 14, 4, 3, 13, 11, 7, 3, 6, 11, 10, 1, 14, 2, 13, 13, 8, 15, 11, 11, 0, 5, 10, 2, 4, 8, 3], [9, 15, 3, 1, 15, 1, 7, 15, 10, 4, 0, 1, 0, 0, 3, 6, 9, 10, 12, 3, 3, 1, 12, 7, 8, 5, 2, 14, 2, 9, 2, 14, 6, 12, 13, 10, 11, 13, 9, 8, 6, 8, 5, 4, 11, 8, 14, 4, 12, 7, 13, 2, 10, 7, 13, 14, 6, 5, 5, 11, 4, 0, 15, 11], [13, 3, 1, 7, 1, 12, 10, 3, 14, 12, 14, 7, 10, 15, 5, 0, 2, 4, 13, 4, 13, 0, 8, 9, 11, 9, 10, 15, 3, 9, 12, 9, 11, 2, 8, 6, 10, 14, 11, 6, 2, 0, 6, 15, 12, 15, 6, 14, 7, 4, 13, 11, 0, 4, 7, 3, 2, 5, 1, 1, 5, 8, 8, 5]] | |
| pbox = [19, 14, 15, 3, 10, 25, 26, 20, 23, 24, 7, 2, 18, 6, 30, | |
| 29, 1, 4, 9, 8, 27, 5, 13, 0, 21, 16, 17, 22, 12, 31, 11, 28] | |
| keys = [] | |
| pc_key = [2, 13, 16, 37, 34, 32, 21, 29, 15, 25, 44, 42, 18, 35, 5, 38, 39, 12, 30, 11, 7, 20, | |
| 17, 22, 14, 10, 26, 1, 33, 46, 45, 6, 40, 41, 43, 24, 9, 47, 4, 0, 19, 28, 27, 3, 31, 36, 8, 23] | |
| def gen_key(): | |
| global keys | |
| key = getRandomNBitInteger(49) & ((1 << 48) - 1) | |
| key_bin = bin(key)[2:].rjust(48, '0') | |
| for i in range(6): | |
| key_bin = ''.join([key_bin[pc_key[j]] for j in range(48)]) | |
| sub_key = int(key_bin, 2) | |
| keys.append(sub_key) | |
| def s(x, i): | |
| row = ((x & 0b100000) >> 4) + (x & 1) | |
| col = (x & 0b011110) >> 1 | |
| return sbox[i][(row << 4) + col] | |
| def p(x): | |
| x_bin = [int(_) for _ in bin(x)[2:].rjust(32, '0')] | |
| y_bin = [x_bin[pbox[i]] for i in range(32)] | |
| y = int(''.join([str(_) for _ in y_bin]), 2) | |
| return y | |
| def e(x): | |
| x_bin = bin(x)[2:].rjust(32, '0') | |
| y_bin = '' | |
| idx = -1 | |
| for i in range(8): | |
| for j in range(idx, idx + 6): | |
| y_bin += x_bin[j % 32] | |
| idx += 4 | |
| return int(y_bin, 2) | |
| def F(x, k): | |
| x_in = bin(e(x) ^ k)[2:].rjust(48, '0') | |
| y_out = '' | |
| for i in range(0, 48, 6): | |
| x_in_i = int(x_in[i:i+6], 2) | |
| y_out += bin(s(x_in_i, i // 6))[2:].rjust(4, '0') | |
| y_out = int(y_out, 2) | |
| y = p(y_out) | |
| return y | |
| #-------------------------- | |
| def gen_diff_output(diff): | |
| p1 = getRandomNBitInteger(32) | |
| p2 = p1 ^ diff | |
| k = getRandomNBitInteger(48) | |
| c1, c2 = F(p1, k), F(p2, k) | |
| return c1^c2, (p1,p2,c1,c2) | |
| counter = Counter() | |
| for i in range(10000): | |
| P_ = 0x00000040 | |
| X_, _ = gen_diff_output(P_) | |
| counter[X_] += 1 | |
| X_, freq = counter.most_common(1)[0] | |
| print(hex(X_)[2:].rjust(8,'0'), freq / 10000) | |
| # 0x00000002 -> 0x00000002 0.217 | |
| # 0x00000040 -> 0x00000000 0.2534 | |
| # 0x00000400 -> 0x00000000 0.251 | |
| # 0x00000000 -> 0x00000000 1 | |
| # 0x00002000 -> 0x00000000 0.25 | |
| # 0x00004000 -> 0x00000040 0.22 | |
| # 0x00020000 -> 0x00020000 0.18 |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import re | |
| from json import dump | |
| from tqdm import tqdm | |
| from Crypto.Util.number import long_to_bytes, getRandomNBitInteger | |
| from pwn import * | |
| def gen_diff_input(diff): | |
| p1 = getRandomNBitInteger(64) | |
| p2 = p1 ^ diff | |
| return p1, p2 | |
| r = remote("81.68.174.63", 34129) | |
| # context.log_level = "debug" | |
| rec = r.recvuntil(b"required").decode() | |
| cipher_flag = re.findall(r"\n([0-9a-f]{80})\n", rec)[0] | |
| print(cipher_flag) | |
| r.recvline() | |
| pairs = [] | |
| for i in tqdm(range(10000)): | |
| p1, p2 = gen_diff_input(0x0000000000000040) | |
| r.sendline(long_to_bytes(p1).hex().encode()) | |
| c1 = int(r.recvline(keepends=False), 16) | |
| r.sendline(long_to_bytes(p2).hex().encode()) | |
| c2 = int(r.recvline(keepends=False), 16) | |
| pairs.append(((p1,p2), (c1,c2))) | |
| r.close() | |
| dump([cipher_flag, pairs], open("data", "w")) |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import itertools | |
| from binascii import hexlify, unhexlify | |
| import Crypto.Random.random as random | |
| from collections import Counter | |
| from Crypto.Util.number import bytes_to_long, long_to_bytes, getRandomNBitInteger | |
| from json import load | |
| from tqdm import tqdm | |
| cipher_flag, pairs = load(open("data", "r")) | |
| sbox = [[11, 10, 1, 3, 8, 3, 14, 13, 0, 3, 9, 2, 4, 2, 11, 4, 6, 1, 6, 13, 6, 7, 7, 0, 10, 5, 4, 5, 9, 5, 10, 10, 6, 7, 15, 4, 7, 9, 15, 12, 1, 15, 14, 11, 14, 13, 1, 13, 8, 8, 9, 2, 12, 2, 0, 12, 8, 3, 0, 15, 11, 12, 5, 14], [0, 15, 2, 8, 3, 8, 12, 12, 9, 10, 14, 13, 4, 13, 14, 14, 2, 1, 15, 1, 1, 7, 3, 1, 10, 15, 6, 4, 6, 8, 5, 15, 4, 5, 7, 11, 7, 2, 5, 9, 11, 7, 11, 14, 6, 2, 11, 3, 12, 13, 9, 3, 9, 12, 4, 8, 10, 0, 5, 0, 0, 10, 6, 13], [5, 10, 3, 12, 3, 0, 6, 15, 13, 2, 0, 15, 8, 2, 3, 13, 9, 11, 0, 6, 14, 11, 2, 10, 1, 4, 12, 1, 7, 4, 7, 15, 5, 8, 7, 12, 5, 11, 0, 12, 14, 6, 9, 8, 14, 6, 9, 3, 4, 10, 1, 2, 10, 8, 7, 13, 15, 13, 4, 1, 5, 9, 14, 11], [4, 0, 7, 7, 7, 5, 4, 1, 10, 12, 11, 11, 11, 10, 15, 3, 12, 8, 3, 0, 2, 14, 14, 13, 2, 10, 6, 4, 6, 10, 2, 3, 14, 15, 8, 15, 9, 1, 11, 7, 5, 5, 6, 13, 6, 8, 0, 1, 3, 14, 0, 2, 9, 15, 8, 12, 1, 4, 9, 13, 9, 13, 5, 12], [ | |
| 9, 10, 3, 4, 2, 10, 12, 4, 5, 12, 5, 11, 5, 9, 13, 10, 7, 11, 7, 11, 1, 3, 2, 3, 3, 7, 1, 5, 15, 13, 9, 7, 12, 8, 8, 15, 0, 6, 0, 14, 15, 8, 8, 1, 0, 1, 0, 10, 14, 2, 14, 9, 13, 11, 6, 12, 15, 13, 14, 6, 4, 6, 4, 2], [0, 8, 12, 15, 0, 8, 3, 6, 7, 15, 9, 9, 2, 15, 9, 9, 1, 12, 13, 10, 5, 10, 12, 14, 5, 7, 14, 6, 4, 7, 5, 2, 1, 6, 4, 12, 0, 1, 14, 4, 3, 13, 11, 7, 3, 6, 11, 10, 1, 14, 2, 13, 13, 8, 15, 11, 11, 0, 5, 10, 2, 4, 8, 3], [9, 15, 3, 1, 15, 1, 7, 15, 10, 4, 0, 1, 0, 0, 3, 6, 9, 10, 12, 3, 3, 1, 12, 7, 8, 5, 2, 14, 2, 9, 2, 14, 6, 12, 13, 10, 11, 13, 9, 8, 6, 8, 5, 4, 11, 8, 14, 4, 12, 7, 13, 2, 10, 7, 13, 14, 6, 5, 5, 11, 4, 0, 15, 11], [13, 3, 1, 7, 1, 12, 10, 3, 14, 12, 14, 7, 10, 15, 5, 0, 2, 4, 13, 4, 13, 0, 8, 9, 11, 9, 10, 15, 3, 9, 12, 9, 11, 2, 8, 6, 10, 14, 11, 6, 2, 0, 6, 15, 12, 15, 6, 14, 7, 4, 13, 11, 0, 4, 7, 3, 2, 5, 1, 1, 5, 8, 8, 5]] | |
| pbox = [19, 14, 15, 3, 10, 25, 26, 20, 23, 24, 7, 2, 18, 6, 30, | |
| 29, 1, 4, 9, 8, 27, 5, 13, 0, 21, 16, 17, 22, 12, 31, 11, 28] | |
| keys = [] | |
| pc_key = [2, 13, 16, 37, 34, 32, 21, 29, 15, 25, 44, 42, 18, 35, 5, 38, 39, 12, 30, 11, 7, 20, | |
| 17, 22, 14, 10, 26, 1, 33, 46, 45, 6, 40, 41, 43, 24, 9, 47, 4, 0, 19, 28, 27, 3, 31, 36, 8, 23] | |
| def gen_key(): | |
| global keys | |
| keys = [] | |
| key = getRandomNBitInteger(49) & ((1 << 48) - 1) | |
| key_bin = bin(key)[2:].rjust(48, '0') | |
| for i in range(6): | |
| key_bin = ''.join([key_bin[pc_key[j]] for j in range(48)]) | |
| sub_key = int(key_bin, 2) | |
| keys.append(sub_key) | |
| def inv_key(key): | |
| inv_key = [0]*48 | |
| key_bin = bin(key)[2:].rjust(48, '0') | |
| for j in range(48): | |
| inv_key[pc_key[j]] = key_bin[j] | |
| return int(''.join(inv_key), 2) | |
| def inv_keys(k6): | |
| keys = [0]*6 | |
| keys[-1] = k6 | |
| for i in range(4,-1,-1): | |
| keys[i] = inv_key(keys[i+1]) | |
| return keys | |
| def s(x, i): | |
| row = ((x & 0b100000) >> 4) + (x & 1) | |
| col = (x & 0b011110) >> 1 | |
| return sbox[i][(row << 4) + col] | |
| def p(x): | |
| x_bin = [int(_) for _ in bin(x)[2:].rjust(32, '0')] | |
| y_bin = [x_bin[pbox[i]] for i in range(32)] | |
| y = int(''.join([str(_) for _ in y_bin]), 2) | |
| return y | |
| def e(x): | |
| x_bin = bin(x)[2:].rjust(32, '0') | |
| y_bin = '' | |
| idx = -1 | |
| for i in range(8): | |
| for j in range(idx, idx + 6): | |
| y_bin += x_bin[j % 32] | |
| idx += 4 | |
| return int(y_bin, 2) | |
| def F(x, k): | |
| x_in = bin(e(x) ^ k)[2:].rjust(48, '0') | |
| y_out = '' | |
| for i in range(0, 48, 6): | |
| x_in_i = int(x_in[i:i+6], 2) | |
| y_out += bin(s(x_in_i, i // 6))[2:].rjust(4, '0') | |
| y_out = int(y_out, 2) | |
| y = p(y_out) | |
| return y | |
| def enc_block(x): | |
| x_bin = bin(x)[2:].rjust(64, '0') | |
| l, r = int(x_bin[:32], 2), int(x_bin[32:], 2) | |
| for i in range(6): | |
| l, r = r, l ^ F(r, keys[i]) | |
| y = (l + (r << 32)) & ((1 << 64) - 1) | |
| return y | |
| def enc(pt): | |
| pad_len = (8 - len(pt) % 8) % 8 | |
| pt += b'\x00' * pad_len | |
| ct = b'' | |
| for i in range(0, len(pt), 8): | |
| ct_block = long_to_bytes(enc_block(bytes_to_long(pt[i:i+8]))).rjust(8, b'\x00') | |
| ct += ct_block | |
| return ct | |
| #-------------------------- | |
| def inv_p(x): | |
| x_bin = [int(_) for _ in bin(x)[2:].rjust(32, '0')] | |
| y_bin = [0]*32 | |
| for i in range(32): | |
| y_bin[pbox[i]] = x_bin[i] | |
| y = int(''.join([str(_) for _ in y_bin]), 2) | |
| return y | |
| candidate_keys = [Counter() for _ in range(8)] | |
| for _, cs in tqdm(pairs): | |
| c1, c2 = cs | |
| if c1 ^ c2 == 0x0000004000000000: | |
| continue | |
| l1, l2 = c1 >> 32, c2 >> 32 | |
| r1, r2 = c1 & 0xffffffff, c2 & 0xffffffff | |
| # print(r1, r2) | |
| F_ = l1^l2^0x00000040 | |
| F_ = inv_p(F_) # xor of the two outputs of sbox, 32bit | |
| Ep1 = e(r1) # 48bit | |
| Ep2 = e(r2) # 48bit | |
| for i in range(8): | |
| inp1 = (Ep1 >> (7-i)*6) & 0b111111 # 6bit | |
| inp2 = (Ep2 >> (7-i)*6) & 0b111111 # 6bit | |
| out_xor = (F_ >> (7-i)*4) & 0b1111 # 4bit | |
| for key in range(64): | |
| if s(inp1^key, i) ^ s(inp2^key, i) == out_xor: | |
| candidate_keys[i][key] += 1 | |
| print(candidate_keys) | |
| # ---------------------- | |
| key6 = [] | |
| for c in candidate_keys: | |
| print(c.most_common(2)) | |
| key6.append(c.most_common(1)[0][0]) | |
| print(key6) | |
| # key6 = [53, 44, 38, 7, 7, 30, 29, 52] | |
| k6 = sum(key6[i]<<(7-i)*6 for i in range(8)) | |
| # k6 = 236161043654516 | |
| keys = inv_keys(k6) | |
| print(keys) | |
| ps, cs = pairs[0] | |
| p1, c1 = ps[0], cs[0] | |
| assert enc_block(p1) == c1 | |
| # Ok! key is right! | |
| # To decrypt, reverse the keys. | |
| keys = keys[::-1] | |
| print(enc(bytes.fromhex(cipher_flag))) | |
| # b'WMCTF{D1ff3r3nti@1_w1th_1di0t_B0X3s}\x00\x00\x00\x00' |
This file contains bidirectional Unicode text that may be interpreted or compiled differently than what appears below. To review, open the file in an editor that reveals hidden Unicode characters.
Learn more about bidirectional Unicode characters
| import itertools | |
| from binascii import hexlify, unhexlify | |
| import Crypto.Random.random as random | |
| from Crypto.Util.number import bytes_to_long, long_to_bytes, getRandomNBitInteger | |
| # from secret import flag | |
| banner = ''' | |
| __ __ _ _ __ ____ __ ____ _____ _____ | |
| \ \ / /__| | ___ ___ _ __ ___ ___ | |_ ___ \ \ / / \/ |/ ___|_ _| ___| | |
| \ \ /\ / / _ \ |/ __/ _ \| '_ ` _ \ / _ \ | __/ _ \ \ \ /\ / /| |\/| | | | | | | | |
| \ V V / __/ | (_| (_) | | | | | | __/ | || (_) | \ V V / | | | | |___ | | | _| | |
| \_/\_/ \___|_|\___\___/|_| |_| |_|\___| \__\___/ \_/\_/ |_| |_|\____| |_| |_| | |
| ''' | |
| sbox = [[11, 10, 1, 3, 8, 3, 14, 13, 0, 3, 9, 2, 4, 2, 11, 4, 6, 1, 6, 13, 6, 7, 7, 0, 10, 5, 4, 5, 9, 5, 10, 10, 6, 7, 15, 4, 7, 9, 15, 12, 1, 15, 14, 11, 14, 13, 1, 13, 8, 8, 9, 2, 12, 2, 0, 12, 8, 3, 0, 15, 11, 12, 5, 14], [0, 15, 2, 8, 3, 8, 12, 12, 9, 10, 14, 13, 4, 13, 14, 14, 2, 1, 15, 1, 1, 7, 3, 1, 10, 15, 6, 4, 6, 8, 5, 15, 4, 5, 7, 11, 7, 2, 5, 9, 11, 7, 11, 14, 6, 2, 11, 3, 12, 13, 9, 3, 9, 12, 4, 8, 10, 0, 5, 0, 0, 10, 6, 13], [5, 10, 3, 12, 3, 0, 6, 15, 13, 2, 0, 15, 8, 2, 3, 13, 9, 11, 0, 6, 14, 11, 2, 10, 1, 4, 12, 1, 7, 4, 7, 15, 5, 8, 7, 12, 5, 11, 0, 12, 14, 6, 9, 8, 14, 6, 9, 3, 4, 10, 1, 2, 10, 8, 7, 13, 15, 13, 4, 1, 5, 9, 14, 11], [4, 0, 7, 7, 7, 5, 4, 1, 10, 12, 11, 11, 11, 10, 15, 3, 12, 8, 3, 0, 2, 14, 14, 13, 2, 10, 6, 4, 6, 10, 2, 3, 14, 15, 8, 15, 9, 1, 11, 7, 5, 5, 6, 13, 6, 8, 0, 1, 3, 14, 0, 2, 9, 15, 8, 12, 1, 4, 9, 13, 9, 13, 5, 12], [ | |
| 9, 10, 3, 4, 2, 10, 12, 4, 5, 12, 5, 11, 5, 9, 13, 10, 7, 11, 7, 11, 1, 3, 2, 3, 3, 7, 1, 5, 15, 13, 9, 7, 12, 8, 8, 15, 0, 6, 0, 14, 15, 8, 8, 1, 0, 1, 0, 10, 14, 2, 14, 9, 13, 11, 6, 12, 15, 13, 14, 6, 4, 6, 4, 2], [0, 8, 12, 15, 0, 8, 3, 6, 7, 15, 9, 9, 2, 15, 9, 9, 1, 12, 13, 10, 5, 10, 12, 14, 5, 7, 14, 6, 4, 7, 5, 2, 1, 6, 4, 12, 0, 1, 14, 4, 3, 13, 11, 7, 3, 6, 11, 10, 1, 14, 2, 13, 13, 8, 15, 11, 11, 0, 5, 10, 2, 4, 8, 3], [9, 15, 3, 1, 15, 1, 7, 15, 10, 4, 0, 1, 0, 0, 3, 6, 9, 10, 12, 3, 3, 1, 12, 7, 8, 5, 2, 14, 2, 9, 2, 14, 6, 12, 13, 10, 11, 13, 9, 8, 6, 8, 5, 4, 11, 8, 14, 4, 12, 7, 13, 2, 10, 7, 13, 14, 6, 5, 5, 11, 4, 0, 15, 11], [13, 3, 1, 7, 1, 12, 10, 3, 14, 12, 14, 7, 10, 15, 5, 0, 2, 4, 13, 4, 13, 0, 8, 9, 11, 9, 10, 15, 3, 9, 12, 9, 11, 2, 8, 6, 10, 14, 11, 6, 2, 0, 6, 15, 12, 15, 6, 14, 7, 4, 13, 11, 0, 4, 7, 3, 2, 5, 1, 1, 5, 8, 8, 5]] | |
| pbox = [19, 14, 15, 3, 10, 25, 26, 20, 23, 24, 7, 2, 18, 6, 30, | |
| 29, 1, 4, 9, 8, 27, 5, 13, 0, 21, 16, 17, 22, 12, 31, 11, 28] | |
| keys = [] | |
| pc_key = [2, 13, 16, 37, 34, 32, 21, 29, 15, 25, 44, 42, 18, 35, 5, 38, 39, 12, 30, 11, 7, 20, | |
| 17, 22, 14, 10, 26, 1, 33, 46, 45, 6, 40, 41, 43, 24, 9, 47, 4, 0, 19, 28, 27, 3, 31, 36, 8, 23] | |
| def gen_key(): | |
| global keys | |
| key = getRandomNBitInteger(49) & ((1 << 48) - 1) | |
| key_bin = bin(key)[2:].rjust(48, '0') | |
| for i in range(6): | |
| key_bin = ''.join([key_bin[pc_key[j]] for j in range(48)]) | |
| sub_key = int(key_bin, 2) | |
| keys.append(sub_key) | |
| def s(x, i): | |
| row = ((x & 0b100000) >> 4) + (x & 1) | |
| col = (x & 0b011110) >> 1 | |
| return sbox[i][(row << 4) + col] | |
| def p(x): | |
| x_bin = [int(_) for _ in bin(x)[2:].rjust(32, '0')] | |
| y_bin = [x_bin[pbox[i]] for i in range(32)] | |
| y = int(''.join([str(_) for _ in y_bin]), 2) | |
| return y | |
| def e(x): | |
| x_bin = bin(x)[2:].rjust(32, '0') | |
| y_bin = '' | |
| idx = -1 | |
| for i in range(8): | |
| for j in range(idx, idx + 6): | |
| y_bin += x_bin[j % 32] | |
| idx += 4 | |
| print(y_bin) | |
| return int(y_bin, 2) | |
| def F(x, k): | |
| x_in = bin(e(x) ^ k)[2:].rjust(48, '0') | |
| y_out = '' | |
| for i in range(0, 48, 6): | |
| x_in_i = int(x_in[i:i+6], 2) | |
| y_out += bin(s(x_in_i, i // 6))[2:].rjust(4, '0') | |
| y_out = int(y_out, 2) | |
| y = p(y_out) | |
| return y | |
| def enc_block(x): | |
| x_bin = bin(x)[2:].rjust(64, '0') | |
| l, r = int(x_bin[:32], 2), int(x_bin[32:], 2) | |
| for i in range(6): | |
| l, r = r, l ^ F(r, keys[i]) | |
| y = (l + (r << 32)) & ((1 << 64) - 1) | |
| return y | |
| def enc(pt): | |
| pad_len = (8 - len(pt) % 8) % 8 | |
| pt += b'\x00' * pad_len | |
| ct = b'' | |
| for i in range(0, len(pt), 8): | |
| ct_block = long_to_bytes(enc_block(bytes_to_long(pt[i:i+8]))).rjust(8, b'\x00') | |
| ct += ct_block | |
| return ct | |
| if __name__ == '__main__': | |
| print(banner) | |
| gen_key() | |
| print(keys) | |
| cipher = hexlify(enc(flag)).decode('utf8') | |
| print('[++++++++++++++++] FLAG [++++++++++++++++]') | |
| print(cipher) | |
| print('[+] You have up to 65537 chances to obtain the ct corresponding to the pt your input(<= 64 bits and hex required).') | |
| for i in range(65537): | |
| pt = input() | |
| try: | |
| pt = unhexlify(pt) | |
| assert(len(pt) <= 8) | |
| ct = enc(pt) | |
| print(hexlify(ct).decode('utf8')) | |
| except: | |
| print('[*] Read the above carefully!') | |
| break |
Sign up for free
to join this conversation on GitHub.
Already have an account?
Sign in to comment
six six six