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# 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.
from __future__ import absolute_import, division, print_function
import abc
import six
@six.add_metaclass(abc.ABCMeta)
class CipherBackend(object):
@abc.abstractmethod
def cipher_supported(self, cipher, mode):
"""
Return True if the given cipher and mode are supported.
"""
@abc.abstractmethod
def create_symmetric_encryption_ctx(self, cipher, mode):
"""
Get a CipherContext that can be used for encryption.
"""
@abc.abstractmethod
def create_symmetric_decryption_ctx(self, cipher, mode):
"""
Get a CipherContext that can be used for decryption.
"""
@six.add_metaclass(abc.ABCMeta)
class HashBackend(object):
@abc.abstractmethod
def hash_supported(self, algorithm):
"""
Return True if the hash algorithm is supported by this backend.
"""
@abc.abstractmethod
def create_hash_ctx(self, algorithm):
"""
Create a HashContext for calculating a message digest.
"""
@six.add_metaclass(abc.ABCMeta)
class HMACBackend(object):
@abc.abstractmethod
def hmac_supported(self, algorithm):
"""
Return True if the hash algorithm is supported for HMAC by this
backend.
"""
@abc.abstractmethod
def create_hmac_ctx(self, key, algorithm):
"""
Create a HashContext for calculating a message authentication code.
"""
@six.add_metaclass(abc.ABCMeta)
class PBKDF2HMACBackend(object):
@abc.abstractmethod
def pbkdf2_hmac_supported(self, algorithm):
"""
Return True if the hash algorithm is supported for PBKDF2 by this
backend.
"""
@abc.abstractmethod
def derive_pbkdf2_hmac(self, algorithm, length, salt, iterations,
key_material):
"""
Return length bytes derived from provided PBKDF2 parameters.
"""
@six.add_metaclass(abc.ABCMeta)
class RSABackend(object):
@abc.abstractmethod
def generate_rsa_private_key(self, public_exponent, key_size):
"""
Generate an RSAPrivateKey instance with public_exponent and a modulus
of key_size bits.
"""
@abc.abstractmethod
def create_rsa_signature_ctx(self, private_key, padding, algorithm):
"""
Returns an object conforming to the AsymmetricSignatureContext
interface.
"""
@abc.abstractmethod
def create_rsa_verification_ctx(self, public_key, signature, padding,
algorithm):
"""
Returns an object conforming to the AsymmetricVerificationContext
interface.
"""
@abc.abstractmethod
def mgf1_hash_supported(self, algorithm):
"""
Return True if the hash algorithm is supported for MGF1 in PSS.
"""
@abc.abstractmethod
def decrypt_rsa(self, private_key, ciphertext, padding):
"""
Returns decrypted bytes.
"""
@abc.abstractmethod
def encrypt_rsa(self, public_key, plaintext, padding):
"""
Returns encrypted bytes.
"""
@six.add_metaclass(abc.ABCMeta)
class DSABackend(object):
@abc.abstractmethod
def generate_dsa_parameters(self, key_size):
"""
Generate a DSAParameters instance with a modulus of key_size bits.
"""
@abc.abstractmethod
def generate_dsa_private_key(self, parameters):
"""
Generate an DSAPrivateKey instance with parameters as
a DSAParameters object.
"""
@six.add_metaclass(abc.ABCMeta)
class TraditionalOpenSSLSerializationBackend(object):
@abc.abstractmethod
def load_traditional_openssl_pem_private_key(self, data, password):
"""
Load a private key from PEM encoded data, using password if the data
is encrypted.
"""
@six.add_metaclass(abc.ABCMeta)
class CMACBackend(object):
@abc.abstractmethod
def cmac_algorithm_supported(self, algorithm):
"""
Returns True if the block cipher is supported for CMAC by this backend
"""
@abc.abstractmethod
def create_cmac_ctx(self, algorithm):
"""
Create a CMACContext for calculating a message authentication code.
"""
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