106 lines
3.7 KiB
Python
106 lines
3.7 KiB
Python
# Copyright 2020 Google LLC
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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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"""Utilites for mutual TLS."""
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import six
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from google.auth import exceptions
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from google.auth.transport import _mtls_helper
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def has_default_client_cert_source():
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"""Check if default client SSL credentials exists on the device.
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Returns:
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bool: indicating if the default client cert source exists.
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"""
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metadata_path = _mtls_helper._check_dca_metadata_path(
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_mtls_helper.CONTEXT_AWARE_METADATA_PATH
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)
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return metadata_path is not None
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def default_client_cert_source():
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"""Get a callback which returns the default client SSL credentials.
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Returns:
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Callable[[], [bytes, bytes]]: A callback which returns the default
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client certificate bytes and private key bytes, both in PEM format.
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Raises:
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google.auth.exceptions.DefaultClientCertSourceError: If the default
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client SSL credentials don't exist or are malformed.
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"""
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if not has_default_client_cert_source():
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raise exceptions.MutualTLSChannelError(
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"Default client cert source doesn't exist"
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)
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def callback():
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try:
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_, cert_bytes, key_bytes = _mtls_helper.get_client_cert_and_key()
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except (OSError, RuntimeError, ValueError) as caught_exc:
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new_exc = exceptions.MutualTLSChannelError(caught_exc)
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six.raise_from(new_exc, caught_exc)
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return cert_bytes, key_bytes
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return callback
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def default_client_encrypted_cert_source(cert_path, key_path):
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"""Get a callback which returns the default encrpyted client SSL credentials.
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Args:
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cert_path (str): The cert file path. The default client certificate will
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be written to this file when the returned callback is called.
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key_path (str): The key file path. The default encrypted client key will
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be written to this file when the returned callback is called.
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Returns:
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Callable[[], [str, str, bytes]]: A callback which generates the default
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client certificate, encrpyted private key and passphrase. It writes
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the certificate and private key into the cert_path and key_path, and
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returns the cert_path, key_path and passphrase bytes.
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Raises:
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google.auth.exceptions.DefaultClientCertSourceError: If any problem
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occurs when loading or saving the client certificate and key.
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"""
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if not has_default_client_cert_source():
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raise exceptions.MutualTLSChannelError(
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"Default client encrypted cert source doesn't exist"
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)
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def callback():
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try:
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(
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_,
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cert_bytes,
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key_bytes,
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passphrase_bytes,
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) = _mtls_helper.get_client_ssl_credentials(generate_encrypted_key=True)
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with open(cert_path, "wb") as cert_file:
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cert_file.write(cert_bytes)
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with open(key_path, "wb") as key_file:
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key_file.write(key_bytes)
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except (exceptions.ClientCertError, OSError) as caught_exc:
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new_exc = exceptions.MutualTLSChannelError(caught_exc)
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six.raise_from(new_exc, caught_exc)
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return cert_path, key_path, passphrase_bytes
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return callback
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