63 lines
2 KiB
Python
63 lines
2 KiB
Python
#!/usr/bin/env python
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from hashlib import sha3_256
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from itertools import count
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from Crypto.Cipher import ChaCha20
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from math import floor, ceil
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from time import sleep
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def chacha_bits(input, bit_count):
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zerobyte = (0).to_bytes(length=1, byteorder='big')
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cipher = ChaCha20.new(key=sha3_256(input).digest(), nonce=zerobyte*8)
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i = 0
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while True:
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print('-----------------------------')
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start_bit = bit_count * i
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start_byte = start_bit // 8
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start_padding = start_bit % 8
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print('start_bit', start_bit)
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print('start_byte', start_byte)
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print('start_padding', start_padding)
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end_bit = bit_count * i + bit_count
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end_byte = end_bit // 8
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end_padding = 8 - (end_bit % 8)
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print('end_bit', end_bit)
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print('end_byte', end_byte)
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print('end_padding', end_padding)
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byte_count = (end_byte - start_byte) + 1
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print('byte_count', byte_count)
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cipher.seek(start_byte)
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ciphertext = cipher.encrypt(zerobyte*byte_count)
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print('ciphertext', bin(int.from_bytes(ciphertext, byteorder='big')))
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shifted_ciphertext = int.from_bytes(ciphertext, byteorder='big') >> end_padding
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print('shifted_ciphertext', bin(shifted_ciphertext))
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bit_mask = int('1'*bit_count, 2)
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print('bit_mask', bin(bit_mask))
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masked_ciphertext = shifted_ciphertext & bit_mask
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print('masked_ciphertext', bin(masked_ciphertext))
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yield masked_ciphertext
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i += 1
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def chacha_chracter(input, choices):
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get_bits = chacha_bits(input, len(choices).bit_length())
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while True:
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choice = next(get_bits)
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if choice < len(choices):
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yield choices[choice]
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def derive_string(input, length, choices):
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get_character = chacha_chracter(input, choices)
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return ''.join(next(get_character) for i in range(length))
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print(
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derive_string(b'12345', length=100, choices='abcdefghijklmnopqrstuvwxyz0123456789')
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)
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