| # Copyright (C) 2010 Google Inc. |
| # |
| # 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. |
| |
| """An OAuth 2.0 client. |
| |
| Tools for interacting with OAuth 2.0 protected resources. |
| """ |
| |
| __author__ = 'jcgregorio@google.com (Joe Gregorio)' |
| |
| import base64 |
| import clientsecrets |
| import copy |
| import datetime |
| import httplib2 |
| import logging |
| import os |
| import sys |
| import time |
| import urllib |
| import urlparse |
| |
| from anyjson import simplejson |
| |
| HAS_OPENSSL = False |
| try: |
| from oauth2client.crypt import Signer |
| from oauth2client.crypt import make_signed_jwt |
| from oauth2client.crypt import verify_signed_jwt_with_certs |
| HAS_OPENSSL = True |
| except ImportError: |
| pass |
| |
| try: |
| from urlparse import parse_qsl |
| except ImportError: |
| from cgi import parse_qsl |
| |
| logger = logging.getLogger(__name__) |
| |
| # Expiry is stored in RFC3339 UTC format |
| EXPIRY_FORMAT = '%Y-%m-%dT%H:%M:%SZ' |
| |
| # Which certs to use to validate id_tokens received. |
| ID_TOKEN_VERIFICATON_CERTS = 'https://www.googleapis.com/oauth2/v1/certs' |
| |
| # Constant to use for the out of band OAuth 2.0 flow. |
| OOB_CALLBACK_URN = 'urn:ietf:wg:oauth:2.0:oob' |
| |
| |
| class Error(Exception): |
| """Base error for this module.""" |
| pass |
| |
| |
| class FlowExchangeError(Error): |
| """Error trying to exchange an authorization grant for an access token.""" |
| pass |
| |
| |
| class AccessTokenRefreshError(Error): |
| """Error trying to refresh an expired access token.""" |
| pass |
| |
| class UnknownClientSecretsFlowError(Error): |
| """The client secrets file called for an unknown type of OAuth 2.0 flow. """ |
| pass |
| |
| |
| class AccessTokenCredentialsError(Error): |
| """Having only the access_token means no refresh is possible.""" |
| pass |
| |
| |
| class VerifyJwtTokenError(Error): |
| """Could on retrieve certificates for validation.""" |
| pass |
| |
| |
| def _abstract(): |
| raise NotImplementedError('You need to override this function') |
| |
| |
| class MemoryCache(object): |
| """httplib2 Cache implementation which only caches locally.""" |
| |
| def __init__(self): |
| self.cache = {} |
| |
| def get(self, key): |
| return self.cache.get(key) |
| |
| def set(self, key, value): |
| self.cache[key] = value |
| |
| def delete(self, key): |
| self.cache.pop(key, None) |
| |
| |
| class Credentials(object): |
| """Base class for all Credentials objects. |
| |
| Subclasses must define an authorize() method that applies the credentials to |
| an HTTP transport. |
| |
| Subclasses must also specify a classmethod named 'from_json' that takes a JSON |
| string as input and returns an instaniated Credentials object. |
| """ |
| |
| NON_SERIALIZED_MEMBERS = ['store'] |
| |
| def authorize(self, http): |
| """Take an httplib2.Http instance (or equivalent) and |
| authorizes it for the set of credentials, usually by |
| replacing http.request() with a method that adds in |
| the appropriate headers and then delegates to the original |
| Http.request() method. |
| """ |
| _abstract() |
| |
| def refresh(self, http): |
| """Forces a refresh of the access_token. |
| |
| Args: |
| http: httplib2.Http, an http object to be used to make the refresh |
| request. |
| """ |
| _abstract() |
| |
| def apply(self, headers): |
| """Add the authorization to the headers. |
| |
| Args: |
| headers: dict, the headers to add the Authorization header to. |
| """ |
| _abstract() |
| |
| def _to_json(self, strip): |
| """Utility function for creating a JSON representation of an instance of Credentials. |
| |
| Args: |
| strip: array, An array of names of members to not include in the JSON. |
| |
| Returns: |
| string, a JSON representation of this instance, suitable to pass to |
| from_json(). |
| """ |
| t = type(self) |
| d = copy.copy(self.__dict__) |
| for member in strip: |
| if member in d: |
| del d[member] |
| if 'token_expiry' in d and isinstance(d['token_expiry'], datetime.datetime): |
| d['token_expiry'] = d['token_expiry'].strftime(EXPIRY_FORMAT) |
| # Add in information we will need later to reconsistitue this instance. |
| d['_class'] = t.__name__ |
| d['_module'] = t.__module__ |
| return simplejson.dumps(d) |
| |
| def to_json(self): |
| """Creating a JSON representation of an instance of Credentials. |
| |
| Returns: |
| string, a JSON representation of this instance, suitable to pass to |
| from_json(). |
| """ |
| return self._to_json(Credentials.NON_SERIALIZED_MEMBERS) |
| |
| @classmethod |
| def new_from_json(cls, s): |
| """Utility class method to instantiate a Credentials subclass from a JSON |
| representation produced by to_json(). |
| |
| Args: |
| s: string, JSON from to_json(). |
| |
| Returns: |
| An instance of the subclass of Credentials that was serialized with |
| to_json(). |
| """ |
| data = simplejson.loads(s) |
| # Find and call the right classmethod from_json() to restore the object. |
| module = data['_module'] |
| try: |
| m = __import__(module) |
| except ImportError: |
| # In case there's an object from the old package structure, update it |
| module = module.replace('.apiclient', '') |
| m = __import__(module) |
| |
| m = __import__(module, fromlist=module.split('.')[:-1]) |
| kls = getattr(m, data['_class']) |
| from_json = getattr(kls, 'from_json') |
| return from_json(s) |
| |
| @classmethod |
| def from_json(cls, s): |
| """Instantiate a Credentials object from a JSON description of it. |
| |
| The JSON should have been produced by calling .to_json() on the object. |
| |
| Args: |
| data: dict, A deserialized JSON object. |
| |
| Returns: |
| An instance of a Credentials subclass. |
| """ |
| return Credentials() |
| |
| |
| class Flow(object): |
| """Base class for all Flow objects.""" |
| pass |
| |
| |
| class Storage(object): |
| """Base class for all Storage objects. |
| |
| Store and retrieve a single credential. This class supports locking |
| such that multiple processes and threads can operate on a single |
| store. |
| """ |
| |
| def acquire_lock(self): |
| """Acquires any lock necessary to access this Storage. |
| |
| This lock is not reentrant. |
| """ |
| pass |
| |
| def release_lock(self): |
| """Release the Storage lock. |
| |
| Trying to release a lock that isn't held will result in a |
| RuntimeError. |
| """ |
| pass |
| |
| def locked_get(self): |
| """Retrieve credential. |
| |
| The Storage lock must be held when this is called. |
| |
| Returns: |
| oauth2client.client.Credentials |
| """ |
| _abstract() |
| |
| def locked_put(self, credentials): |
| """Write a credential. |
| |
| The Storage lock must be held when this is called. |
| |
| Args: |
| credentials: Credentials, the credentials to store. |
| """ |
| _abstract() |
| |
| def locked_delete(self): |
| """Delete a credential. |
| |
| The Storage lock must be held when this is called. |
| """ |
| _abstract() |
| |
| def get(self): |
| """Retrieve credential. |
| |
| The Storage lock must *not* be held when this is called. |
| |
| Returns: |
| oauth2client.client.Credentials |
| """ |
| self.acquire_lock() |
| try: |
| return self.locked_get() |
| finally: |
| self.release_lock() |
| |
| def put(self, credentials): |
| """Write a credential. |
| |
| The Storage lock must be held when this is called. |
| |
| Args: |
| credentials: Credentials, the credentials to store. |
| """ |
| self.acquire_lock() |
| try: |
| self.locked_put(credentials) |
| finally: |
| self.release_lock() |
| |
| def delete(self): |
| """Delete credential. |
| |
| Frees any resources associated with storing the credential. |
| The Storage lock must *not* be held when this is called. |
| |
| Returns: |
| None |
| """ |
| self.acquire_lock() |
| try: |
| return self.locked_delete() |
| finally: |
| self.release_lock() |
| |
| |
| class OAuth2Credentials(Credentials): |
| """Credentials object for OAuth 2.0. |
| |
| Credentials can be applied to an httplib2.Http object using the authorize() |
| method, which then adds the OAuth 2.0 access token to each request. |
| |
| OAuth2Credentials objects may be safely pickled and unpickled. |
| """ |
| |
| def __init__(self, access_token, client_id, client_secret, refresh_token, |
| token_expiry, token_uri, user_agent, id_token=None): |
| """Create an instance of OAuth2Credentials. |
| |
| This constructor is not usually called by the user, instead |
| OAuth2Credentials objects are instantiated by the OAuth2WebServerFlow. |
| |
| Args: |
| access_token: string, access token. |
| client_id: string, client identifier. |
| client_secret: string, client secret. |
| refresh_token: string, refresh token. |
| token_expiry: datetime, when the access_token expires. |
| token_uri: string, URI of token endpoint. |
| user_agent: string, The HTTP User-Agent to provide for this application. |
| id_token: object, The identity of the resource owner. |
| |
| Notes: |
| store: callable, A callable that when passed a Credential |
| will store the credential back to where it came from. |
| This is needed to store the latest access_token if it |
| has expired and been refreshed. |
| """ |
| self.access_token = access_token |
| self.client_id = client_id |
| self.client_secret = client_secret |
| self.refresh_token = refresh_token |
| self.store = None |
| self.token_expiry = token_expiry |
| self.token_uri = token_uri |
| self.user_agent = user_agent |
| self.id_token = id_token |
| |
| # True if the credentials have been revoked or expired and can't be |
| # refreshed. |
| self.invalid = False |
| |
| def authorize(self, http): |
| """Authorize an httplib2.Http instance with these credentials. |
| |
| The modified http.request method will add authentication headers to each |
| request and will refresh access_tokens when a 401 is received on a |
| request. In addition the http.request method has a credentials property, |
| http.request.credentials, which is the Credentials object that authorized |
| it. |
| |
| Args: |
| http: An instance of httplib2.Http |
| or something that acts like it. |
| |
| Returns: |
| A modified instance of http that was passed in. |
| |
| Example: |
| |
| h = httplib2.Http() |
| h = credentials.authorize(h) |
| |
| You can't create a new OAuth subclass of httplib2.Authenication |
| because it never gets passed the absolute URI, which is needed for |
| signing. So instead we have to overload 'request' with a closure |
| that adds in the Authorization header and then calls the original |
| version of 'request()'. |
| """ |
| request_orig = http.request |
| |
| # The closure that will replace 'httplib2.Http.request'. |
| def new_request(uri, method='GET', body=None, headers=None, |
| redirections=httplib2.DEFAULT_MAX_REDIRECTS, |
| connection_type=None): |
| if not self.access_token: |
| logger.info('Attempting refresh to obtain initial access_token') |
| self._refresh(request_orig) |
| |
| # Modify the request headers to add the appropriate |
| # Authorization header. |
| if headers is None: |
| headers = {} |
| self.apply(headers) |
| |
| if self.user_agent is not None: |
| if 'user-agent' in headers: |
| headers['user-agent'] = self.user_agent + ' ' + headers['user-agent'] |
| else: |
| headers['user-agent'] = self.user_agent |
| |
| resp, content = request_orig(uri, method, body, headers, |
| redirections, connection_type) |
| |
| if resp.status == 401: |
| logger.info('Refreshing due to a 401') |
| self._refresh(request_orig) |
| self.apply(headers) |
| return request_orig(uri, method, body, headers, |
| redirections, connection_type) |
| else: |
| return (resp, content) |
| |
| # Replace the request method with our own closure. |
| http.request = new_request |
| |
| # Set credentials as a property of the request method. |
| setattr(http.request, 'credentials', self) |
| |
| return http |
| |
| def refresh(self, http): |
| """Forces a refresh of the access_token. |
| |
| Args: |
| http: httplib2.Http, an http object to be used to make the refresh |
| request. |
| """ |
| self._refresh(http.request) |
| |
| def apply(self, headers): |
| """Add the authorization to the headers. |
| |
| Args: |
| headers: dict, the headers to add the Authorization header to. |
| """ |
| headers['Authorization'] = 'Bearer ' + self.access_token |
| |
| def to_json(self): |
| return self._to_json(Credentials.NON_SERIALIZED_MEMBERS) |
| |
| @classmethod |
| def from_json(cls, s): |
| """Instantiate a Credentials object from a JSON description of it. The JSON |
| should have been produced by calling .to_json() on the object. |
| |
| Args: |
| data: dict, A deserialized JSON object. |
| |
| Returns: |
| An instance of a Credentials subclass. |
| """ |
| data = simplejson.loads(s) |
| if 'token_expiry' in data and not isinstance(data['token_expiry'], |
| datetime.datetime): |
| try: |
| data['token_expiry'] = datetime.datetime.strptime( |
| data['token_expiry'], EXPIRY_FORMAT) |
| except: |
| data['token_expiry'] = None |
| retval = OAuth2Credentials( |
| data['access_token'], |
| data['client_id'], |
| data['client_secret'], |
| data['refresh_token'], |
| data['token_expiry'], |
| data['token_uri'], |
| data['user_agent'], |
| data.get('id_token', None)) |
| retval.invalid = data['invalid'] |
| return retval |
| |
| @property |
| def access_token_expired(self): |
| """True if the credential is expired or invalid. |
| |
| If the token_expiry isn't set, we assume the token doesn't expire. |
| """ |
| if self.invalid: |
| return True |
| |
| if not self.token_expiry: |
| return False |
| |
| now = datetime.datetime.utcnow() |
| if now >= self.token_expiry: |
| logger.info('access_token is expired. Now: %s, token_expiry: %s', |
| now, self.token_expiry) |
| return True |
| return False |
| |
| def set_store(self, store): |
| """Set the Storage for the credential. |
| |
| Args: |
| store: Storage, an implementation of Stroage object. |
| This is needed to store the latest access_token if it |
| has expired and been refreshed. This implementation uses |
| locking to check for updates before updating the |
| access_token. |
| """ |
| self.store = store |
| |
| def _updateFromCredential(self, other): |
| """Update this Credential from another instance.""" |
| self.__dict__.update(other.__getstate__()) |
| |
| def __getstate__(self): |
| """Trim the state down to something that can be pickled.""" |
| d = copy.copy(self.__dict__) |
| del d['store'] |
| return d |
| |
| def __setstate__(self, state): |
| """Reconstitute the state of the object from being pickled.""" |
| self.__dict__.update(state) |
| self.store = None |
| |
| def _generate_refresh_request_body(self): |
| """Generate the body that will be used in the refresh request.""" |
| body = urllib.urlencode({ |
| 'grant_type': 'refresh_token', |
| 'client_id': self.client_id, |
| 'client_secret': self.client_secret, |
| 'refresh_token': self.refresh_token, |
| }) |
| return body |
| |
| def _generate_refresh_request_headers(self): |
| """Generate the headers that will be used in the refresh request.""" |
| headers = { |
| 'content-type': 'application/x-www-form-urlencoded', |
| } |
| |
| if self.user_agent is not None: |
| headers['user-agent'] = self.user_agent |
| |
| return headers |
| |
| def _refresh(self, http_request): |
| """Refreshes the access_token. |
| |
| This method first checks by reading the Storage object if available. |
| If a refresh is still needed, it holds the Storage lock until the |
| refresh is completed. |
| |
| Args: |
| http_request: callable, a callable that matches the method signature of |
| httplib2.Http.request, used to make the refresh request. |
| |
| Raises: |
| AccessTokenRefreshError: When the refresh fails. |
| """ |
| if not self.store: |
| self._do_refresh_request(http_request) |
| else: |
| self.store.acquire_lock() |
| try: |
| new_cred = self.store.locked_get() |
| if (new_cred and not new_cred.invalid and |
| new_cred.access_token != self.access_token): |
| logger.info('Updated access_token read from Storage') |
| self._updateFromCredential(new_cred) |
| else: |
| self._do_refresh_request(http_request) |
| finally: |
| self.store.release_lock() |
| |
| def _do_refresh_request(self, http_request): |
| """Refresh the access_token using the refresh_token. |
| |
| Args: |
| http_request: callable, a callable that matches the method signature of |
| httplib2.Http.request, used to make the refresh request. |
| |
| Raises: |
| AccessTokenRefreshError: When the refresh fails. |
| """ |
| body = self._generate_refresh_request_body() |
| headers = self._generate_refresh_request_headers() |
| |
| logger.info('Refreshing access_token') |
| resp, content = http_request( |
| self.token_uri, method='POST', body=body, headers=headers) |
| if resp.status == 200: |
| # TODO(jcgregorio) Raise an error if loads fails? |
| d = simplejson.loads(content) |
| self.access_token = d['access_token'] |
| self.refresh_token = d.get('refresh_token', self.refresh_token) |
| if 'expires_in' in d: |
| self.token_expiry = datetime.timedelta( |
| seconds=int(d['expires_in'])) + datetime.datetime.utcnow() |
| else: |
| self.token_expiry = None |
| if self.store: |
| self.store.locked_put(self) |
| else: |
| # An {'error':...} response body means the token is expired or revoked, |
| # so we flag the credentials as such. |
| logger.info('Failed to retrieve access token: %s' % content) |
| error_msg = 'Invalid response %s.' % resp['status'] |
| try: |
| d = simplejson.loads(content) |
| if 'error' in d: |
| error_msg = d['error'] |
| self.invalid = True |
| if self.store: |
| self.store.locked_put(self) |
| except: |
| pass |
| raise AccessTokenRefreshError(error_msg) |
| |
| |
| class AccessTokenCredentials(OAuth2Credentials): |
| """Credentials object for OAuth 2.0. |
| |
| Credentials can be applied to an httplib2.Http object using the |
| authorize() method, which then signs each request from that object |
| with the OAuth 2.0 access token. This set of credentials is for the |
| use case where you have acquired an OAuth 2.0 access_token from |
| another place such as a JavaScript client or another web |
| application, and wish to use it from Python. Because only the |
| access_token is present it can not be refreshed and will in time |
| expire. |
| |
| AccessTokenCredentials objects may be safely pickled and unpickled. |
| |
| Usage: |
| credentials = AccessTokenCredentials('<an access token>', |
| 'my-user-agent/1.0') |
| http = httplib2.Http() |
| http = credentials.authorize(http) |
| |
| Exceptions: |
| AccessTokenCredentialsExpired: raised when the access_token expires or is |
| revoked. |
| """ |
| |
| def __init__(self, access_token, user_agent): |
| """Create an instance of OAuth2Credentials |
| |
| This is one of the few types if Credentials that you should contrust, |
| Credentials objects are usually instantiated by a Flow. |
| |
| Args: |
| access_token: string, access token. |
| user_agent: string, The HTTP User-Agent to provide for this application. |
| |
| Notes: |
| store: callable, a callable that when passed a Credential |
| will store the credential back to where it came from. |
| """ |
| super(AccessTokenCredentials, self).__init__( |
| access_token, |
| None, |
| None, |
| None, |
| None, |
| None, |
| user_agent) |
| |
| |
| @classmethod |
| def from_json(cls, s): |
| data = simplejson.loads(s) |
| retval = AccessTokenCredentials( |
| data['access_token'], |
| data['user_agent']) |
| return retval |
| |
| def _refresh(self, http_request): |
| raise AccessTokenCredentialsError( |
| "The access_token is expired or invalid and can't be refreshed.") |
| |
| |
| class AssertionCredentials(OAuth2Credentials): |
| """Abstract Credentials object used for OAuth 2.0 assertion grants. |
| |
| This credential does not require a flow to instantiate because it |
| represents a two legged flow, and therefore has all of the required |
| information to generate and refresh its own access tokens. It must |
| be subclassed to generate the appropriate assertion string. |
| |
| AssertionCredentials objects may be safely pickled and unpickled. |
| """ |
| |
| def __init__(self, assertion_type, user_agent, |
| token_uri='https://accounts.google.com/o/oauth2/token', |
| **unused_kwargs): |
| """Constructor for AssertionFlowCredentials. |
| |
| Args: |
| assertion_type: string, assertion type that will be declared to the auth |
| server |
| user_agent: string, The HTTP User-Agent to provide for this application. |
| token_uri: string, URI for token endpoint. For convenience |
| defaults to Google's endpoints but any OAuth 2.0 provider can be used. |
| """ |
| super(AssertionCredentials, self).__init__( |
| None, |
| None, |
| None, |
| None, |
| None, |
| token_uri, |
| user_agent) |
| self.assertion_type = assertion_type |
| |
| def _generate_refresh_request_body(self): |
| assertion = self._generate_assertion() |
| |
| body = urllib.urlencode({ |
| 'assertion_type': self.assertion_type, |
| 'assertion': assertion, |
| 'grant_type': 'assertion', |
| }) |
| |
| return body |
| |
| def _generate_assertion(self): |
| """Generate the assertion string that will be used in the access token |
| request. |
| """ |
| _abstract() |
| |
| if HAS_OPENSSL: |
| # PyOpenSSL is not a prerequisite for oauth2client, so if it is missing then |
| # don't create the SignedJwtAssertionCredentials or the verify_id_token() |
| # method. |
| |
| class SignedJwtAssertionCredentials(AssertionCredentials): |
| """Credentials object used for OAuth 2.0 Signed JWT assertion grants. |
| |
| This credential does not require a flow to instantiate because it represents |
| a two legged flow, and therefore has all of the required information to |
| generate and refresh its own access tokens. |
| |
| SignedJwtAssertionCredentials requires PyOpenSSL and because of that it does |
| not work on App Engine. For App Engine you may consider using |
| AppAssertionCredentials. |
| """ |
| |
| MAX_TOKEN_LIFETIME_SECS = 3600 # 1 hour in seconds |
| |
| def __init__(self, |
| service_account_name, |
| private_key, |
| scope, |
| private_key_password='notasecret', |
| user_agent=None, |
| token_uri='https://accounts.google.com/o/oauth2/token', |
| **kwargs): |
| """Constructor for SignedJwtAssertionCredentials. |
| |
| Args: |
| service_account_name: string, id for account, usually an email address. |
| private_key: string, private key in P12 format. |
| scope: string or list of strings, scope(s) of the credentials being |
| requested. |
| private_key_password: string, password for private_key. |
| user_agent: string, HTTP User-Agent to provide for this application. |
| token_uri: string, URI for token endpoint. For convenience |
| defaults to Google's endpoints but any OAuth 2.0 provider can be used. |
| kwargs: kwargs, Additional parameters to add to the JWT token, for |
| example prn=joe@xample.org.""" |
| |
| super(SignedJwtAssertionCredentials, self).__init__( |
| 'http://oauth.net/grant_type/jwt/1.0/bearer', |
| user_agent, |
| token_uri=token_uri, |
| ) |
| |
| if type(scope) is list: |
| scope = ' '.join(scope) |
| self.scope = scope |
| |
| # Keep base64 encoded so it can be stored in JSON. |
| self.private_key = base64.b64encode(private_key) |
| |
| self.private_key_password = private_key_password |
| self.service_account_name = service_account_name |
| self.kwargs = kwargs |
| |
| @classmethod |
| def from_json(cls, s): |
| data = simplejson.loads(s) |
| retval = SignedJwtAssertionCredentials( |
| data['service_account_name'], |
| base64.b64decode(data['private_key']), |
| data['scope'], |
| private_key_password=data['private_key_password'], |
| user_agent=data['user_agent'], |
| token_uri=data['token_uri'], |
| **data['kwargs'] |
| ) |
| retval.invalid = data['invalid'] |
| retval.access_token = data['access_token'] |
| return retval |
| |
| def _generate_assertion(self): |
| """Generate the assertion that will be used in the request.""" |
| now = long(time.time()) |
| payload = { |
| 'aud': self.token_uri, |
| 'scope': self.scope, |
| 'iat': now, |
| 'exp': now + SignedJwtAssertionCredentials.MAX_TOKEN_LIFETIME_SECS, |
| 'iss': self.service_account_name |
| } |
| payload.update(self.kwargs) |
| logger.debug(str(payload)) |
| |
| private_key = base64.b64decode(self.private_key) |
| return make_signed_jwt( |
| Signer.from_string(private_key, self.private_key_password), payload) |
| |
| # Only used in verify_id_token(), which is always calling to the same URI |
| # for the certs. |
| _cached_http = httplib2.Http(MemoryCache()) |
| |
| def verify_id_token(id_token, audience, http=None, |
| cert_uri=ID_TOKEN_VERIFICATON_CERTS): |
| """Verifies a signed JWT id_token. |
| |
| This function requires PyOpenSSL and because of that it does not work on |
| App Engine. For App Engine you may consider using AppAssertionCredentials. |
| |
| Args: |
| id_token: string, A Signed JWT. |
| audience: string, The audience 'aud' that the token should be for. |
| http: httplib2.Http, instance to use to make the HTTP request. Callers |
| should supply an instance that has caching enabled. |
| cert_uri: string, URI of the certificates in JSON format to |
| verify the JWT against. |
| |
| Returns: |
| The deserialized JSON in the JWT. |
| |
| Raises: |
| oauth2client.crypt.AppIdentityError if the JWT fails to verify. |
| """ |
| if http is None: |
| http = _cached_http |
| |
| resp, content = http.request(cert_uri) |
| |
| if resp.status == 200: |
| certs = simplejson.loads(content) |
| return verify_signed_jwt_with_certs(id_token, certs, audience) |
| else: |
| raise VerifyJwtTokenError('Status code: %d' % resp.status) |
| |
| |
| def _urlsafe_b64decode(b64string): |
| # Guard against unicode strings, which base64 can't handle. |
| b64string = b64string.encode('ascii') |
| padded = b64string + '=' * (4 - len(b64string) % 4) |
| return base64.urlsafe_b64decode(padded) |
| |
| |
| def _extract_id_token(id_token): |
| """Extract the JSON payload from a JWT. |
| |
| Does the extraction w/o checking the signature. |
| |
| Args: |
| id_token: string, OAuth 2.0 id_token. |
| |
| Returns: |
| object, The deserialized JSON payload. |
| """ |
| segments = id_token.split('.') |
| |
| if (len(segments) != 3): |
| raise VerifyJwtTokenError( |
| 'Wrong number of segments in token: %s' % id_token) |
| |
| return simplejson.loads(_urlsafe_b64decode(segments[1])) |
| |
| def _parse_exchange_token_response(content): |
| """Parses response of an exchange token request. |
| |
| Most providers return JSON but some (e.g. Facebook) return a |
| url-encoded string. |
| |
| Args: |
| content: The body of a response |
| |
| Returns: |
| Content as a dictionary object. Note that the dict could be empty, |
| i.e. {}. That basically indicates a failure. |
| """ |
| resp = {} |
| try: |
| resp = simplejson.loads(content) |
| except StandardError: |
| # different JSON libs raise different exceptions, |
| # so we just do a catch-all here |
| resp = dict(parse_qsl(content)) |
| |
| # some providers respond with 'expires', others with 'expires_in' |
| if resp and 'expires' in resp: |
| resp['expires_in'] = resp.pop('expires') |
| |
| return resp |
| |
| def credentials_from_code(client_id, client_secret, scope, code, |
| redirect_uri = 'postmessage', |
| http=None, user_agent=None, |
| token_uri='https://accounts.google.com/o/oauth2/token'): |
| """Exchanges an authorization code for an OAuth2Credentials object. |
| |
| Args: |
| client_id: string, client identifier. |
| client_secret: string, client secret. |
| scope: string or list of strings, scope(s) to request. |
| code: string, An authroization code, most likely passed down from |
| the client |
| redirect_uri: string, this is generally set to 'postmessage' to match the |
| redirect_uri that the client specified |
| http: httplib2.Http, optional http instance to use to do the fetch |
| token_uri: string, URI for token endpoint. For convenience |
| defaults to Google's endpoints but any OAuth 2.0 provider can be used. |
| Returns: |
| An OAuth2Credentials object. |
| |
| Raises: |
| FlowExchangeError if the authorization code cannot be exchanged for an |
| access token |
| """ |
| flow = OAuth2WebServerFlow(client_id, client_secret, scope, user_agent, |
| 'https://accounts.google.com/o/oauth2/auth', |
| token_uri) |
| |
| # We primarily make this call to set up the redirect_uri in the flow object |
| uriThatWeDontReallyUse = flow.step1_get_authorize_url(redirect_uri) |
| credentials = flow.step2_exchange(code, http) |
| return credentials |
| |
| |
| def credentials_from_clientsecrets_and_code(filename, scope, code, |
| message = None, |
| redirect_uri = 'postmessage', |
| http=None): |
| """Returns OAuth2Credentials from a clientsecrets file and an auth code. |
| |
| Will create the right kind of Flow based on the contents of the clientsecrets |
| file or will raise InvalidClientSecretsError for unknown types of Flows. |
| |
| Args: |
| filename: string, File name of clientsecrets. |
| scope: string or list of strings, scope(s) to request. |
| code: string, An authroization code, most likely passed down from |
| the client |
| message: string, A friendly string to display to the user if the |
| clientsecrets file is missing or invalid. If message is provided then |
| sys.exit will be called in the case of an error. If message in not |
| provided then clientsecrets.InvalidClientSecretsError will be raised. |
| redirect_uri: string, this is generally set to 'postmessage' to match the |
| redirect_uri that the client specified |
| http: httplib2.Http, optional http instance to use to do the fetch |
| |
| Returns: |
| An OAuth2Credentials object. |
| |
| Raises: |
| FlowExchangeError if the authorization code cannot be exchanged for an |
| access token |
| UnknownClientSecretsFlowError if the file describes an unknown kind of Flow. |
| clientsecrets.InvalidClientSecretsError if the clientsecrets file is |
| invalid. |
| """ |
| flow = flow_from_clientsecrets(filename, scope, message) |
| # We primarily make this call to set up the redirect_uri in the flow object |
| uriThatWeDontReallyUse = flow.step1_get_authorize_url(redirect_uri) |
| credentials = flow.step2_exchange(code, http) |
| return credentials |
| |
| |
| class OAuth2WebServerFlow(Flow): |
| """Does the Web Server Flow for OAuth 2.0. |
| |
| OAuth2Credentials objects may be safely pickled and unpickled. |
| """ |
| |
| def __init__(self, client_id, client_secret, scope, user_agent=None, |
| auth_uri='https://accounts.google.com/o/oauth2/auth', |
| token_uri='https://accounts.google.com/o/oauth2/token', |
| **kwargs): |
| """Constructor for OAuth2WebServerFlow. |
| |
| Args: |
| client_id: string, client identifier. |
| client_secret: string client secret. |
| scope: string or list of strings, scope(s) of the credentials being |
| requested. |
| user_agent: string, HTTP User-Agent to provide for this application. |
| auth_uri: string, URI for authorization endpoint. For convenience |
| defaults to Google's endpoints but any OAuth 2.0 provider can be used. |
| token_uri: string, URI for token endpoint. For convenience |
| defaults to Google's endpoints but any OAuth 2.0 provider can be used. |
| **kwargs: dict, The keyword arguments are all optional and required |
| parameters for the OAuth calls. |
| """ |
| self.client_id = client_id |
| self.client_secret = client_secret |
| if type(scope) is list: |
| scope = ' '.join(scope) |
| self.scope = scope |
| self.user_agent = user_agent |
| self.auth_uri = auth_uri |
| self.token_uri = token_uri |
| self.params = { |
| 'access_type': 'offline', |
| } |
| self.params.update(kwargs) |
| self.redirect_uri = None |
| |
| def step1_get_authorize_url(self, redirect_uri=OOB_CALLBACK_URN): |
| """Returns a URI to redirect to the provider. |
| |
| Args: |
| redirect_uri: string, Either the string 'urn:ietf:wg:oauth:2.0:oob' for |
| a non-web-based application, or a URI that handles the callback from |
| the authorization server. |
| |
| If redirect_uri is 'urn:ietf:wg:oauth:2.0:oob' then pass in the |
| generated verification code to step2_exchange, |
| otherwise pass in the query parameters received |
| at the callback uri to step2_exchange. |
| """ |
| |
| self.redirect_uri = redirect_uri |
| query = { |
| 'response_type': 'code', |
| 'client_id': self.client_id, |
| 'redirect_uri': redirect_uri, |
| 'scope': self.scope, |
| } |
| query.update(self.params) |
| parts = list(urlparse.urlparse(self.auth_uri)) |
| query.update(dict(parse_qsl(parts[4]))) # 4 is the index of the query part |
| parts[4] = urllib.urlencode(query) |
| return urlparse.urlunparse(parts) |
| |
| def step2_exchange(self, code, http=None): |
| """Exhanges a code for OAuth2Credentials. |
| |
| Args: |
| code: string or dict, either the code as a string, or a dictionary |
| of the query parameters to the redirect_uri, which contains |
| the code. |
| http: httplib2.Http, optional http instance to use to do the fetch |
| |
| Returns: |
| An OAuth2Credentials object that can be used to authorize requests. |
| |
| Raises: |
| FlowExchangeError if a problem occured exchanging the code for a |
| refresh_token. |
| """ |
| |
| if not (isinstance(code, str) or isinstance(code, unicode)): |
| if 'code' not in code: |
| if 'error' in code: |
| error_msg = code['error'] |
| else: |
| error_msg = 'No code was supplied in the query parameters.' |
| raise FlowExchangeError(error_msg) |
| else: |
| code = code['code'] |
| |
| body = urllib.urlencode({ |
| 'grant_type': 'authorization_code', |
| 'client_id': self.client_id, |
| 'client_secret': self.client_secret, |
| 'code': code, |
| 'redirect_uri': self.redirect_uri, |
| 'scope': self.scope, |
| }) |
| headers = { |
| 'content-type': 'application/x-www-form-urlencoded', |
| } |
| |
| if self.user_agent is not None: |
| headers['user-agent'] = self.user_agent |
| |
| if http is None: |
| http = httplib2.Http() |
| |
| resp, content = http.request(self.token_uri, method='POST', body=body, |
| headers=headers) |
| d = _parse_exchange_token_response(content) |
| if resp.status == 200 and 'access_token' in d: |
| access_token = d['access_token'] |
| refresh_token = d.get('refresh_token', None) |
| token_expiry = None |
| if 'expires_in' in d: |
| token_expiry = datetime.datetime.utcnow() + datetime.timedelta( |
| seconds=int(d['expires_in'])) |
| |
| if 'id_token' in d: |
| d['id_token'] = _extract_id_token(d['id_token']) |
| |
| logger.info('Successfully retrieved access token: %s' % content) |
| return OAuth2Credentials(access_token, self.client_id, |
| self.client_secret, refresh_token, token_expiry, |
| self.token_uri, self.user_agent, |
| id_token=d.get('id_token', None)) |
| else: |
| logger.info('Failed to retrieve access token: %s' % content) |
| if 'error' in d: |
| # you never know what those providers got to say |
| error_msg = unicode(d['error']) |
| else: |
| error_msg = 'Invalid response: %s.' % str(resp.status) |
| raise FlowExchangeError(error_msg) |
| |
| def flow_from_clientsecrets(filename, scope, message=None): |
| """Create a Flow from a clientsecrets file. |
| |
| Will create the right kind of Flow based on the contents of the clientsecrets |
| file or will raise InvalidClientSecretsError for unknown types of Flows. |
| |
| Args: |
| filename: string, File name of client secrets. |
| scope: string or list of strings, scope(s) to request. |
| message: string, A friendly string to display to the user if the |
| clientsecrets file is missing or invalid. If message is provided then |
| sys.exit will be called in the case of an error. If message in not |
| provided then clientsecrets.InvalidClientSecretsError will be raised. |
| |
| Returns: |
| A Flow object. |
| |
| Raises: |
| UnknownClientSecretsFlowError if the file describes an unknown kind of Flow. |
| clientsecrets.InvalidClientSecretsError if the clientsecrets file is |
| invalid. |
| """ |
| try: |
| client_type, client_info = clientsecrets.loadfile(filename) |
| if client_type in [clientsecrets.TYPE_WEB, clientsecrets.TYPE_INSTALLED]: |
| return OAuth2WebServerFlow( |
| client_info['client_id'], |
| client_info['client_secret'], |
| scope, |
| None, # user_agent |
| client_info['auth_uri'], |
| client_info['token_uri']) |
| except clientsecrets.InvalidClientSecretsError: |
| if message: |
| sys.exit(message) |
| else: |
| raise |
| else: |
| raise UnknownClientSecretsFlowError( |
| 'This OAuth 2.0 flow is unsupported: "%s"' * client_type) |