# Copyright 2014 Google Inc. All rights reserved.
#
# 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.
"""ADB authentication using the ``cryptography`` package.
.. rubric:: Contents
* :class:`CryptographySigner`
* :meth:`CryptographySigner.GetPublicKey`
* :meth:`CryptographySigner.Sign`
"""
from cryptography.hazmat.backends import default_backend
from cryptography.hazmat.primitives import hashes
from cryptography.hazmat.primitives import serialization
from cryptography.hazmat.primitives.asymmetric import padding
from cryptography.hazmat.primitives.asymmetric import utils
# pylint: disable=abstract-method
class CryptographySigner(object):
"""AuthSigner using cryptography.io.
Parameters
----------
rsa_key_path : str
The path to the private key.
Attributes
----------
public_key : str
The contents of the public key file
rsa_key : cryptography.hazmat.backends.openssl.rsa._RSAPrivateKey
The loaded private key
"""
def __init__(self, rsa_key_path):
with open(rsa_key_path + '.pub', 'rb') as rsa_pub_file:
self.public_key = rsa_pub_file.read()
with open(rsa_key_path, 'rb') as rsa_prv_file:
self.rsa_key = serialization.load_pem_private_key(rsa_prv_file.read(), None, default_backend())
def Sign(self, data):
"""Signs given data using a private key.
Parameters
----------
data : TODO
TODO
Returns
-------
TODO
The signed ``data``
"""
return self.rsa_key.sign(data, padding.PKCS1v15(), utils.Prehashed(hashes.SHA1()))
def GetPublicKey(self):
"""Returns the public key in PEM format without headers or newlines.
Returns
-------
self.public_key : str
The contents of the public key file
"""
return self.public_key
