43 lines
1020 B
Python
43 lines
1020 B
Python
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# standard imports
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import os
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import logging
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import hashlib
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from Crypto.Cipher import AES
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from Crypto.Util import Counter
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from .base import Encrypter
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logg = logging.getLogger(__name__)
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class AESCTREncrypt(Encrypter):
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aes_block_size = 1 << 7
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counter_bytes = int(128 / 8)
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def __init__(self, db_dir, secret):
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self.secret = secret
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def key_to_iv(self, k):
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h = hashlib.sha256()
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h.update(k.encode('utf-8'))
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h.update(self.secret)
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z = h.digest()
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return int.from_bytes(z[:self.counter_bytes], 'big')
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def encrypt(self, k, v):
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iv = self.key_to_iv(k)
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ctr = Counter.new(self.aes_block_size, initial_value=iv)
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cipher = AES.new(self.secret, AES.MODE_CTR, counter=ctr)
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return cipher.encrypt(v)
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def decrypt(self, k, v):
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iv = self.key_to_iv(k)
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ctr = Counter.new(self.aes_block_size, initial_value=iv)
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cipher = AES.new(self.secret, AES.MODE_CTR, counter=ctr)
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return cipher.decrypt(v)
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