| # This file is dual licensed under the terms of the Apache License, Version |
| # 2.0, and the BSD License. See the LICENSE file in the root of this repository |
| # for complete details. |
| |
| from __future__ import absolute_import, division, print_function |
| |
| import abc |
| |
| import six |
| |
| from cryptography import utils |
| from cryptography.exceptions import ( |
| AlreadyFinalized, |
| UnsupportedAlgorithm, |
| _Reasons, |
| ) |
| from cryptography.hazmat.backends import _get_backend |
| from cryptography.hazmat.backends.interfaces import HashBackend |
| |
| |
| @six.add_metaclass(abc.ABCMeta) |
| class HashAlgorithm(object): |
| @abc.abstractproperty |
| def name(self): |
| """ |
| A string naming this algorithm (e.g. "sha256", "md5"). |
| """ |
| |
| @abc.abstractproperty |
| def digest_size(self): |
| """ |
| The size of the resulting digest in bytes. |
| """ |
| |
| |
| @six.add_metaclass(abc.ABCMeta) |
| class HashContext(object): |
| @abc.abstractproperty |
| def algorithm(self): |
| """ |
| A HashAlgorithm that will be used by this context. |
| """ |
| |
| @abc.abstractmethod |
| def update(self, data): |
| """ |
| Processes the provided bytes through the hash. |
| """ |
| |
| @abc.abstractmethod |
| def finalize(self): |
| """ |
| Finalizes the hash context and returns the hash digest as bytes. |
| """ |
| |
| @abc.abstractmethod |
| def copy(self): |
| """ |
| Return a HashContext that is a copy of the current context. |
| """ |
| |
| |
| @six.add_metaclass(abc.ABCMeta) |
| class ExtendableOutputFunction(object): |
| """ |
| An interface for extendable output functions. |
| """ |
| |
| |
| @utils.register_interface(HashContext) |
| class Hash(object): |
| def __init__(self, algorithm, backend=None, ctx=None): |
| backend = _get_backend(backend) |
| if not isinstance(backend, HashBackend): |
| raise UnsupportedAlgorithm( |
| "Backend object does not implement HashBackend.", |
| _Reasons.BACKEND_MISSING_INTERFACE, |
| ) |
| |
| if not isinstance(algorithm, HashAlgorithm): |
| raise TypeError("Expected instance of hashes.HashAlgorithm.") |
| self._algorithm = algorithm |
| |
| self._backend = backend |
| |
| if ctx is None: |
| self._ctx = self._backend.create_hash_ctx(self.algorithm) |
| else: |
| self._ctx = ctx |
| |
| algorithm = utils.read_only_property("_algorithm") |
| |
| def update(self, data): |
| if self._ctx is None: |
| raise AlreadyFinalized("Context was already finalized.") |
| utils._check_byteslike("data", data) |
| self._ctx.update(data) |
| |
| def copy(self): |
| if self._ctx is None: |
| raise AlreadyFinalized("Context was already finalized.") |
| return Hash( |
| self.algorithm, backend=self._backend, ctx=self._ctx.copy() |
| ) |
| |
| def finalize(self): |
| if self._ctx is None: |
| raise AlreadyFinalized("Context was already finalized.") |
| digest = self._ctx.finalize() |
| self._ctx = None |
| return digest |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA1(object): |
| name = "sha1" |
| digest_size = 20 |
| block_size = 64 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA512_224(object): # noqa: N801 |
| name = "sha512-224" |
| digest_size = 28 |
| block_size = 128 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA512_256(object): # noqa: N801 |
| name = "sha512-256" |
| digest_size = 32 |
| block_size = 128 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA224(object): |
| name = "sha224" |
| digest_size = 28 |
| block_size = 64 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA256(object): |
| name = "sha256" |
| digest_size = 32 |
| block_size = 64 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA384(object): |
| name = "sha384" |
| digest_size = 48 |
| block_size = 128 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA512(object): |
| name = "sha512" |
| digest_size = 64 |
| block_size = 128 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA3_224(object): # noqa: N801 |
| name = "sha3-224" |
| digest_size = 28 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA3_256(object): # noqa: N801 |
| name = "sha3-256" |
| digest_size = 32 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA3_384(object): # noqa: N801 |
| name = "sha3-384" |
| digest_size = 48 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class SHA3_512(object): # noqa: N801 |
| name = "sha3-512" |
| digest_size = 64 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| @utils.register_interface(ExtendableOutputFunction) |
| class SHAKE128(object): |
| name = "shake128" |
| |
| def __init__(self, digest_size): |
| if not isinstance(digest_size, six.integer_types): |
| raise TypeError("digest_size must be an integer") |
| |
| if digest_size < 1: |
| raise ValueError("digest_size must be a positive integer") |
| |
| self._digest_size = digest_size |
| |
| digest_size = utils.read_only_property("_digest_size") |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| @utils.register_interface(ExtendableOutputFunction) |
| class SHAKE256(object): |
| name = "shake256" |
| |
| def __init__(self, digest_size): |
| if not isinstance(digest_size, six.integer_types): |
| raise TypeError("digest_size must be an integer") |
| |
| if digest_size < 1: |
| raise ValueError("digest_size must be a positive integer") |
| |
| self._digest_size = digest_size |
| |
| digest_size = utils.read_only_property("_digest_size") |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class MD5(object): |
| name = "md5" |
| digest_size = 16 |
| block_size = 64 |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class BLAKE2b(object): |
| name = "blake2b" |
| _max_digest_size = 64 |
| _min_digest_size = 1 |
| block_size = 128 |
| |
| def __init__(self, digest_size): |
| |
| if digest_size != 64: |
| raise ValueError("Digest size must be 64") |
| |
| self._digest_size = digest_size |
| |
| digest_size = utils.read_only_property("_digest_size") |
| |
| |
| @utils.register_interface(HashAlgorithm) |
| class BLAKE2s(object): |
| name = "blake2s" |
| block_size = 64 |
| _max_digest_size = 32 |
| _min_digest_size = 1 |
| |
| def __init__(self, digest_size): |
| |
| if digest_size != 32: |
| raise ValueError("Digest size must be 32") |
| |
| self._digest_size = digest_size |
| |
| digest_size = utils.read_only_property("_digest_size") |