82 lines
2.5 KiB
Python
82 lines
2.5 KiB
Python
# Copyright 2016 Donald Stufft and individual contributors
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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import nacl.exceptions as exc
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from nacl._sodium import ffi, lib
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from nacl.exceptions import ensure
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has_crypto_shorthash_siphashx24 = bool(
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lib.PYNACL_HAS_CRYPTO_SHORTHASH_SIPHASHX24
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)
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BYTES: int = lib.crypto_shorthash_siphash24_bytes()
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KEYBYTES: int = lib.crypto_shorthash_siphash24_keybytes()
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XBYTES = 0
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XKEYBYTES = 0
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if has_crypto_shorthash_siphashx24:
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XBYTES = lib.crypto_shorthash_siphashx24_bytes()
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XKEYBYTES = lib.crypto_shorthash_siphashx24_keybytes()
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def crypto_shorthash_siphash24(data: bytes, key: bytes) -> bytes:
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"""Compute a fast, cryptographic quality, keyed hash of the input data
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:param data:
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:type data: bytes
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:param key: len(key) must be equal to
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:py:data:`.KEYBYTES` (16)
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:type key: bytes
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"""
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if len(key) != KEYBYTES:
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raise exc.ValueError(
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"Key length must be exactly {} bytes".format(KEYBYTES)
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)
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digest = ffi.new("unsigned char[]", BYTES)
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rc = lib.crypto_shorthash_siphash24(digest, data, len(data), key)
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ensure(rc == 0, raising=exc.RuntimeError)
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return ffi.buffer(digest, BYTES)[:]
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def crypto_shorthash_siphashx24(data: bytes, key: bytes) -> bytes:
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"""Compute a fast, cryptographic quality, keyed hash of the input data
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:param data:
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:type data: bytes
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:param key: len(key) must be equal to
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:py:data:`.XKEYBYTES` (16)
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:type key: bytes
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:raises nacl.exceptions.UnavailableError: If called when using a
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minimal build of libsodium.
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"""
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ensure(
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has_crypto_shorthash_siphashx24,
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"Not available in minimal build",
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raising=exc.UnavailableError,
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)
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if len(key) != XKEYBYTES:
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raise exc.ValueError(
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"Key length must be exactly {} bytes".format(XKEYBYTES)
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)
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digest = ffi.new("unsigned char[]", XBYTES)
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rc = lib.crypto_shorthash_siphashx24(digest, data, len(data), key)
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ensure(rc == 0, raising=exc.RuntimeError)
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return ffi.buffer(digest, XBYTES)[:]
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