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 
    21from google.auth import exceptions 
    22 
    23 
    24def from_dict(data, require=None, use_rsa_signer=True): 
    25    """Validates a dictionary containing Google service account data. 
    26 
    27    Creates and returns a :class:`google.auth.crypt.Signer` instance from the 
    28    private key specified in the data. 
    29 
    30    Args: 
    31        data (Mapping[str, str]): The service account data 
    32        require (Sequence[str]): List of keys required to be present in the 
    33            info. 
    34        use_rsa_signer (Optional[bool]): Whether to use RSA signer or EC signer. 
    35            We use RSA signer by default. 
    36 
    37    Returns: 
    38        google.auth.crypt.Signer: A signer created from the private key in the 
    39            service account file. 
    40 
    41    Raises: 
    42        MalformedError: if the data was in the wrong format, or if one of the 
    43            required keys is missing. 
    44    """ 
    45    keys_needed = set(require if require is not None else []) 
    46 
    47    missing = keys_needed.difference(data.keys()) 
    48 
    49    if missing: 
    50        raise exceptions.MalformedError( 
    51            "Service account info was not in the expected format, missing " 
    52            "fields {}.".format(", ".join(missing)) 
    53        ) 
    54 
    55    # Create a signer. 
    56    if use_rsa_signer: 
    57        signer = crypt.RSASigner.from_service_account_info(data) 
    58    else: 
    59        signer = crypt.ES256Signer.from_service_account_info(data) 
    60 
    61    return signer 
    62 
    63 
    64def from_filename(filename, require=None, use_rsa_signer=True): 
    65    """Reads a Google service account JSON file and returns its parsed info. 
    66 
    67    Args: 
    68        filename (str): The path to the service account .json file. 
    69        require (Sequence[str]): List of keys required to be present in the 
    70            info. 
    71        use_rsa_signer (Optional[bool]): Whether to use RSA signer or EC signer. 
    72            We use RSA signer by default. 
    73 
    74    Returns: 
    75        Tuple[ Mapping[str, str], google.auth.crypt.Signer ]: The verified 
    76            info and a signer instance. 
    77    """ 
    78    with io.open(filename, "r", encoding="utf-8") as json_file: 
    79        data = json.load(json_file) 
    80        return data, from_dict(data, require=require, use_rsa_signer=use_rsa_signer)