blob: c79c70b4ef86fc1d9985b48fd3ef9dc03dc308e6 [file] [log] [blame]
# Copyright 2019 Google LLC
#
# 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.
"""A client for Google Cloud KMS."""
from tink import aead
from tink import core
from tink.cc.pybind import tink_bindings
GCP_KEYURI_PREFIX = 'gcp-kms://'
class GcpKmsClient:
"""Basic GCP client for AEAD."""
def __init__(self, key_uri: str, credentials_path: str):
"""Creates a new GcpKmsClient that is bound to the key specified in 'key_uri'.
Uses the specified credentials when communicating with the KMS. Either of
arguments can be empty.
If 'key_uri' is empty, then the client is not bound to any particular key.
If 'credential_path' is empty, then default credentials will be used.
Args:
key_uri: Text, URI of the key the client should be bound to.
credentials_path: Text, Path to the file with the access credentials.
Raises:
ValueError: If the path or filename of the credentials is invalid.
TinkError: If the key uri is not valid.
"""
if not key_uri:
self._key_uri = ''
elif key_uri.startswith(GCP_KEYURI_PREFIX):
self._key_uri = key_uri
else:
raise core.TinkError
# Use the C++ GCP KMS client
self.cc_client = tink_bindings.GcpKmsClient(key_uri, credentials_path)
def does_support(self, key_uri: str) -> bool:
"""Returns true iff this client supports KMS key specified in 'key_uri'.
Args:
key_uri: Text, URI of the key to be checked.
Returns:
A boolean value which is true if the key is supported and false otherwise.
"""
return self.cc_client.does_support(key_uri)
@core.use_tink_errors
def get_aead(self, key_uri: str) -> aead.Aead:
"""Returns an Aead-primitive backed by KMS key specified by 'key_uri'.
Args:
key_uri: Text, URI of the key which should be used.
Returns:
The AEAD object...
"""
return aead.AeadCcToPyWrapper(self.cc_client.get_aead(key_uri))
@classmethod
def register_client(cls, key_uri, credentials_path) -> None:
"""Registers the KMS client internally."""
tink_bindings.GcpKmsClient.register_client(key_uri, credentials_path)