CasperSecurity
# Copyright 2013 Donald Stufft and individual contributors
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
"""
The :mod:`nacl.hash` module exposes one-shot interfaces
for libsodium selected hash primitives and the constants needed
for their usage.
"""
import nacl.bindings
import nacl.encoding
BLAKE2B_BYTES = nacl.bindings.crypto_generichash_BYTES
"""Default digest size for :func:`blake2b` hash"""
BLAKE2B_BYTES_MIN = nacl.bindings.crypto_generichash_BYTES_MIN
"""Minimum allowed digest size for :func:`blake2b` hash"""
BLAKE2B_BYTES_MAX = nacl.bindings.crypto_generichash_BYTES_MAX
"""Maximum allowed digest size for :func:`blake2b` hash"""
BLAKE2B_KEYBYTES = nacl.bindings.crypto_generichash_KEYBYTES
"""Default size of the ``key`` byte array for :func:`blake2b` hash"""
BLAKE2B_KEYBYTES_MIN = nacl.bindings.crypto_generichash_KEYBYTES_MIN
"""Minimum allowed size of the ``key`` byte array for :func:`blake2b` hash"""
BLAKE2B_KEYBYTES_MAX = nacl.bindings.crypto_generichash_KEYBYTES_MAX
"""Maximum allowed size of the ``key`` byte array for :func:`blake2b` hash"""
BLAKE2B_SALTBYTES = nacl.bindings.crypto_generichash_SALTBYTES
"""Maximum allowed length of the ``salt`` byte array for
:func:`blake2b` hash"""
BLAKE2B_PERSONALBYTES = nacl.bindings.crypto_generichash_PERSONALBYTES
"""Maximum allowed length of the ``personalization``
byte array for :func:`blake2b` hash"""
SIPHASH_BYTES = nacl.bindings.crypto_shorthash_siphash24_BYTES
"""Size of the :func:`siphash24` digest"""
SIPHASH_KEYBYTES = nacl.bindings.crypto_shorthash_siphash24_KEYBYTES
"""Size of the secret ``key`` used by the :func:`siphash24` MAC"""
SIPHASHX_AVAILABLE = nacl.bindings.has_crypto_shorthash_siphashx24
"""``True`` if :func:`siphashx24` is available to be called"""
SIPHASHX_BYTES = nacl.bindings.crypto_shorthash_siphashx24_BYTES
"""Size of the :func:`siphashx24` digest"""
SIPHASHX_KEYBYTES = nacl.bindings.crypto_shorthash_siphashx24_KEYBYTES
"""Size of the secret ``key`` used by the :func:`siphashx24` MAC"""
_b2b_hash = nacl.bindings.crypto_generichash_blake2b_salt_personal
_sip_hash = nacl.bindings.crypto_shorthash_siphash24
_sip_hashx = nacl.bindings.crypto_shorthash_siphashx24
def sha256(
message: bytes, encoder: nacl.encoding.Encoder = nacl.encoding.HexEncoder
) -> bytes:
"""
Hashes ``message`` with SHA256.
:param message: The message to hash.
:type message: bytes
:param encoder: A class that is able to encode the hashed message.
:returns: The hashed message.
:rtype: bytes
"""
return encoder.encode(nacl.bindings.crypto_hash_sha256(message))
def sha512(
message: bytes, encoder: nacl.encoding.Encoder = nacl.encoding.HexEncoder
) -> bytes:
"""
Hashes ``message`` with SHA512.
:param message: The message to hash.
:type message: bytes
:param encoder: A class that is able to encode the hashed message.
:returns: The hashed message.
:rtype: bytes
"""
return encoder.encode(nacl.bindings.crypto_hash_sha512(message))
def blake2b(
data: bytes,
digest_size: int = BLAKE2B_BYTES,
key: bytes = b"",
salt: bytes = b"",
person: bytes = b"",
encoder: nacl.encoding.Encoder = nacl.encoding.HexEncoder,
) -> bytes:
"""
Hashes ``data`` with blake2b.
:param data: the digest input byte sequence
:type data: bytes
:param digest_size: the requested digest size; must be at most
:const:`BLAKE2B_BYTES_MAX`;
the default digest size is
:const:`BLAKE2B_BYTES`
:type digest_size: int
:param key: the key to be set for keyed MAC/PRF usage; if set, the key
must be at most :data:`~nacl.hash.BLAKE2B_KEYBYTES_MAX` long
:type key: bytes
:param salt: an initialization salt at most
:const:`BLAKE2B_SALTBYTES` long;
it will be zero-padded if needed
:type salt: bytes
:param person: a personalization string at most
:const:`BLAKE2B_PERSONALBYTES` long;
it will be zero-padded if needed
:type person: bytes
:param encoder: the encoder to use on returned digest
:type encoder: class
:returns: The hashed message.
:rtype: bytes
"""
digest = _b2b_hash(
data, digest_size=digest_size, key=key, salt=salt, person=person
)
return encoder.encode(digest)
generichash = blake2b
def siphash24(
message: bytes,
key: bytes = b"",
encoder: nacl.encoding.Encoder = nacl.encoding.HexEncoder,
) -> bytes:
"""
Computes a keyed MAC of ``message`` using the short-input-optimized
siphash-2-4 construction.
:param message: The message to hash.
:type message: bytes
:param key: the message authentication key for the siphash MAC construct
:type key: bytes(:const:`SIPHASH_KEYBYTES`)
:param encoder: A class that is able to encode the hashed message.
:returns: The hashed message.
:rtype: bytes(:const:`SIPHASH_BYTES`)
"""
digest = _sip_hash(message, key)
return encoder.encode(digest)
shorthash = siphash24
def siphashx24(
message: bytes,
key: bytes = b"",
encoder: nacl.encoding.Encoder = nacl.encoding.HexEncoder,
) -> bytes:
"""
Computes a keyed MAC of ``message`` using the 128 bit variant of the
siphash-2-4 construction.
:param message: The message to hash.
:type message: bytes
:param key: the message authentication key for the siphash MAC construct
:type key: bytes(:const:`SIPHASHX_KEYBYTES`)
:param encoder: A class that is able to encode the hashed message.
:returns: The hashed message.
:rtype: bytes(:const:`SIPHASHX_BYTES`)
:raises nacl.exceptions.UnavailableError: If called when using a
minimal build of libsodium.
.. versionadded:: 1.2
"""
digest = _sip_hashx(message, key)
return encoder.encode(digest)