1# Copyright 2016 Google LLC
2#
3# Licensed under the Apache License, Version 2.0 (the "License");
4# you may not use this file except in compliance with the License.
5# You may obtain a copy of the License at
6#
7# http://www.apache.org/licenses/LICENSE-2.0
8#
9# Unless required by applicable law or agreed to in writing, software
10# distributed under the License is distributed on an "AS IS" BASIS,
11# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12# See the License for the specific language governing permissions and
13# limitations under the License.
14
15"""Helper functions for loading data from a Google service account file."""
16
17import io
18import json
19
20from google.auth import crypt, exceptions
21
22
23def from_dict(data, require=None, use_rsa_signer=True):
24 """Validates a dictionary containing Google service account data.
25
26 Creates and returns a :class:`google.auth.crypt.Signer` instance from the
27 private key specified in the data.
28
29 Args:
30 data (Mapping[str, str]): The service account data
31 require (Sequence[str]): List of keys required to be present in the
32 info.
33 use_rsa_signer (Optional[bool]): Whether to use RSA signer or EC signer.
34 We use RSA signer by default.
35
36 Returns:
37 google.auth.crypt.Signer: A signer created from the private key in the
38 service account file.
39
40 Raises:
41 MalformedError: if the data was in the wrong format, or if one of the
42 required keys is missing.
43 """
44 keys_needed = set(require if require is not None else [])
45
46 missing = keys_needed.difference(data.keys())
47
48 if missing:
49 raise exceptions.MalformedError(
50 "Service account info was not in the expected format, missing "
51 "fields {}.".format(", ".join(missing))
52 )
53
54 # Create a signer.
55 if use_rsa_signer:
56 signer = crypt.RSASigner.from_service_account_info(data)
57 else:
58 signer = crypt.EsSigner.from_service_account_info(data)
59
60 return signer
61
62
63def from_filename(filename, require=None, use_rsa_signer=True):
64 """Reads a Google service account JSON file and returns its parsed info.
65
66 Args:
67 filename (str): The path to the service account .json file.
68 require (Sequence[str]): List of keys required to be present in the
69 info.
70 use_rsa_signer (Optional[bool]): Whether to use RSA signer or EC signer.
71 We use RSA signer by default.
72
73 Returns:
74 Tuple[ Mapping[str, str], google.auth.crypt.Signer ]: The verified
75 info and a signer instance.
76 """
77 with io.open(filename, "r", encoding="utf-8") as json_file:
78 data = json.load(json_file)
79 return data, from_dict(data, require=require, use_rsa_signer=use_rsa_signer)