60 lines
1.8 KiB
ReStructuredText
60 lines
1.8 KiB
ReStructuredText
.. hazmat::
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.. module:: cryptography.hazmat.primitives.keywrap
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Key wrapping
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============
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Key wrapping is a cryptographic construct that uses symmetric encryption to
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encapsulate key material. Key wrapping algorithms are occasionally utilized
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to protect keys at rest or transmit them over insecure networks. Many of the
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protections offered by key wrapping are also offered by using authenticated
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:doc:`symmetric encryption </hazmat/primitives/symmetric-encryption>`.
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.. function:: aes_key_wrap(wrapping_key, key_to_wrap, backend)
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.. versionadded:: 1.1
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This function performs AES key wrap (without padding) as specified in
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:rfc:`3394`.
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:param bytes wrapping_key: The wrapping key.
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:param bytes key_to_wrap: The key to wrap.
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:param backend: A
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:class:`~cryptography.hazmat.backends.interfaces.CipherBackend`
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instance that supports
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:class:`~cryptography.hazmat.primitives.ciphers.algorithms.AES`.
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:return bytes: The wrapped key as bytes.
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.. function:: aes_key_unwrap(wrapping_key, wrapped_key, backend)
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.. versionadded:: 1.1
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This function performs AES key unwrap (without padding) as specified in
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:rfc:`3394`.
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:param bytes wrapping_key: The wrapping key.
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:param bytes wrapped_key: The wrapped key.
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:param backend: A
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:class:`~cryptography.hazmat.backends.interfaces.CipherBackend`
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instance that supports
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:class:`~cryptography.hazmat.primitives.ciphers.algorithms.AES`.
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:return bytes: The unwrapped key as bytes.
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:raises cryptography.hazmat.primitives.keywrap.InvalidUnwrap: This is
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raised if the key is not successfully unwrapped.
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Exceptions
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~~~~~~~~~~
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.. class:: InvalidUnwrap
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This is raised when a wrapped key fails to unwrap. It can be caused by a
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corrupted or invalid wrapped key or an invalid wrapping key.
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