28 lines
997 B
Python
28 lines
997 B
Python
################################################################################
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# Copyright 2016 Google LLC.
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#
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# This software is licensed under the terms defined in the Widevine Master
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# License Agreement. For a copy of this agreement, please contact
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# widevine-licensing@google.com.
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################################################################################
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"""Utility functions for cryptography."""
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import logging
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from cryptography.hazmat import backends
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from cryptography.hazmat.primitives import hashes
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from cryptography.hazmat.primitives import serialization
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from cryptography.hazmat.primitives.asymmetric import padding
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def VerifySignature(public_key, signature, data):
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hash_algorithm = hashes.SHA1()
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salt_len = 20
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logging.info('Verying signature.')
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key = serialization.load_der_public_key(
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public_key, backend=backends.default_backend())
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key.verify(signature, data,
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padding.PSS(padding.MGF1(hash_algorithm), salt_len),
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hash_algorithm)
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