text: # Copyright (C) 2015-2021 Virgil Security, Inc.
  #
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  #     notice, this list of conditions and the following disclaimer.
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  #     (2) Redistributions in binary form must reproduce the above copyright
  #     notice, this list of conditions and the following disclaimer in
  #     the documentation and/or other materials provided with the
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  #     contributors may be used to endorse or promote products derived from
  #     this software without specific prior written permission.
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  # THIS SOFTWARE IS PROVIDED BY THE AUTHOR ''AS IS'' AND ANY EXPRESS OR
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  # Lead Maintainer: Virgil Security Inc. <support@virgilsecurity.com>
  
  
  from ctypes import *
  from abc import *
  
  
  class EntropySource(object):
      """Defines generic interface for the entropy source."""
      __metaclass__ = ABCMeta
  
      @abstractmethod
      def is_strong(self):
          """Defines that implemented source is strong."""
          raise NotImplementedError()
  
      @abstractmethod
      def gather(self, len):
          """Gather entropy of the requested length."""
          raise NotImplementedError()
  