mirror of
https://github.com/PiBrewing/craftbeerpi4.git
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66 lines
2.3 KiB
Python
66 lines
2.3 KiB
Python
# This file is dual licensed under the terms of the Apache License, Version
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# 2.0, and the BSD License. See the LICENSE file in the root of this repository
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# for complete details.
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from __future__ import absolute_import, division, print_function
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import warnings
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from cryptography import utils
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from cryptography.hazmat.primitives import hashes
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from cryptography.hazmat.primitives.asymmetric.utils import Prehashed
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def _evp_pkey_derive(backend, evp_pkey, peer_public_key):
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ctx = backend._lib.EVP_PKEY_CTX_new(evp_pkey, backend._ffi.NULL)
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backend.openssl_assert(ctx != backend._ffi.NULL)
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ctx = backend._ffi.gc(ctx, backend._lib.EVP_PKEY_CTX_free)
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res = backend._lib.EVP_PKEY_derive_init(ctx)
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backend.openssl_assert(res == 1)
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res = backend._lib.EVP_PKEY_derive_set_peer(ctx, peer_public_key._evp_pkey)
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backend.openssl_assert(res == 1)
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keylen = backend._ffi.new("size_t *")
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res = backend._lib.EVP_PKEY_derive(ctx, backend._ffi.NULL, keylen)
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backend.openssl_assert(res == 1)
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backend.openssl_assert(keylen[0] > 0)
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buf = backend._ffi.new("unsigned char[]", keylen[0])
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res = backend._lib.EVP_PKEY_derive(ctx, buf, keylen)
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if res != 1:
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raise ValueError("Null shared key derived from public/private pair.")
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return backend._ffi.buffer(buf, keylen[0])[:]
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def _calculate_digest_and_algorithm(backend, data, algorithm):
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if not isinstance(algorithm, Prehashed):
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hash_ctx = hashes.Hash(algorithm, backend)
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hash_ctx.update(data)
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data = hash_ctx.finalize()
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else:
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algorithm = algorithm._algorithm
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if len(data) != algorithm.digest_size:
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raise ValueError(
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"The provided data must be the same length as the hash "
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"algorithm's digest size."
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)
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return (data, algorithm)
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def _check_not_prehashed(signature_algorithm):
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if isinstance(signature_algorithm, Prehashed):
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raise TypeError(
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"Prehashed is only supported in the sign and verify methods. "
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"It cannot be used with signer, verifier or "
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"recover_data_from_signature."
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)
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def _warn_sign_verify_deprecated():
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warnings.warn(
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"signer and verifier have been deprecated. Please use sign "
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"and verify instead.",
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utils.PersistentlyDeprecated2017,
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stacklevel=3,
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)
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