mirror of
https://github.com/avatao-content/baseimage-tutorial-framework
synced 2024-11-05 23:11:22 +00:00
48 lines
1.4 KiB
Python
48 lines
1.4 KiB
Python
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# Copyright (C) 2018 Avatao.com Innovative Learning Kft.
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# All Rights Reserved. See LICENSE file for details.
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from functools import wraps
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from cryptography.hazmat.backends import default_backend
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from cryptography.hazmat.primitives.hashes import SHA256
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from cryptography.hazmat.primitives.hmac import HMAC as _HMAC
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from cryptography.exceptions import InvalidSignature
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class HMAC:
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def __init__(self, key, message):
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self.key = key
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self.message = message
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self._hmac = _HMAC(
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key=key,
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algorithm=SHA256(),
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backend=default_backend()
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)
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def _reload_if_finalized(f):
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# pylint: disable=no-self-argument,not-callable
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@wraps(f)
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def wrapped(instance, *args, **kwargs):
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if getattr(instance, '_finalized', False):
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instance.__init__(instance.key, instance.message)
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ret_val = f(instance, *args, **kwargs)
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setattr(instance, '_finalized', True)
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return ret_val
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return wrapped
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@property
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@_reload_if_finalized
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def signature(self):
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self._hmac.update(self.message)
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signature = self._hmac.finalize()
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return signature
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@_reload_if_finalized
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def verify(self, signature):
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self._hmac.update(self.message)
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try:
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self._hmac.verify(signature)
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return True
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except InvalidSignature:
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return False
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