auth.py 10 KB
Newer Older
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
# Copyright 2018 Markus Scheidgen
#
# 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.

"""
Endpoints can use *flask_httpauth* based authentication either with basic HTTP
authentication or access tokens. Currently the authentication is validated against
users and sessions in the NOMAD-coe repository postgres db.

There are two authentication "schemes" to authenticate users. First we use
HTTP Basic Authentication (username, password), which also works with username=token,
password=''. Second, there is a curstom HTTP header 'X-Token' that can be used to
give a token. The first precedes the second. The used tokens are given and stored
by the NOMAD-coe repository GUI.

Authenticated user information is available via FLASK's build in flask.g.user object.
It is set to None, if no user information is available.

There are two decorators for FLASK API endpoints that can be used if endpoints require
authenticated user information for authorization or otherwise.

.. autofunction:: login_if_available
.. autofunction:: login_really_required
"""

36
37
from flask import g, request
from flask_restplus import abort, Resource, fields
38
39
from flask_httpauth import HTTPBasicAuth

40
from nomad import config, processing, files, utils, coe_repo
41
from nomad.coe_repo import User, LoginException
42

43
from .app import app, api
44
45
46
47
48

app.config['SECRET_KEY'] = config.services.api_secret
auth = HTTPBasicAuth()


49
50
51
52
53
54
55
56
57
58
59
60
61
# Authentication scheme definitions, for swagger only.
api.authorizations = {
    'HTTP Basic': {
        'type': 'basic'
    },
    'X-Token': {
        'type': 'apiKey',
        'in': 'header',
        'name': 'X-Token'
    }
}


62
63
@auth.verify_password
def verify_password(username_or_token, password):
64
65
66
67
68
69
70
71
    if username_or_token is None or username_or_token == '':
        g.user = None
        return True

    if password is None or password == '':
        g.user = User.verify_auth_token(username_or_token)
        return g.user is not None
    else:
72
73
        try:
            g.user = User.verify_user_password(username_or_token, password)
74
75
        except Exception as e:
            utils.get_logger(__name__).error('could not verify password', exc_info=e)
76
77
            return False

78
        return g.user is not None
79

80
81
82
83

@auth.error_handler
def auth_error_handler():
    abort(401, 'Could not authenticate user, bad credentials')
84
85
86
87
88
89
90


def login_if_available(func):
    """
    A decorator for API endpoint implementations that might authenticate users, but
    provide limited functionality even without users.
    """
91
92
    @api.response(401, 'Not authorized, some data require authentication and authorization')
    @api.doc(security=list(api.authorizations.keys()))
93
94
95
96
97
98
99
100
    @auth.login_required
    def wrapper(*args, **kwargs):
        # TODO the cutom X-Token based authentication should be replaced by a real
        # Authentication header based token authentication
        if not g.user and 'X-Token' in request.headers:
            token = request.headers['X-Token']
            g.user = User.verify_auth_token(token)
            if not g.user:
101
                abort(401, message='Not authorized, some data require authentication and authorization')
102
103
104
105
106
107
108
109
110
111
112
113
114

        return func(*args, **kwargs)

    wrapper.__name__ = func.__name__
    wrapper.__doc__ = func.__doc__
    return wrapper


def login_really_required(func):
    """
    A decorator for API endpoint implementations that forces user authentication on
    endpoints.
    """
115
116
    @api.response(401, 'Authentication required or not authorized to access requested data')
    @api.doc(security=list(api.authorizations.keys()))
117
118
119
    @login_if_available
    def wrapper(*args, **kwargs):
        if g.user is None:
120
            abort(401, message='Authentication required or not authorized to access requested data')
121
122
123
124
125
126
127
        else:
            return func(*args, **kwargs)
    wrapper.__name__ = func.__name__
    wrapper.__doc__ = func.__doc__
    return wrapper


128
ns = api.namespace(
129
130
    'auth',
    description='Authentication related endpoints.')
131
132


133
134
135
136
137
user_model = api.model('User', {
    'first_name': fields.String(description='The user\'s first name'),
    'last_name': fields.String(description='The user\'s last name'),
    'email': fields.String(description='Guess what, the user\'s email'),
    'affiliation': fields.String(description='The user\'s affiliation'),
138
    'password': fields.String(description='The bcrypt 2y-indented password for initial and changed password'),
139
140
141
142
143
144
145
    'token': fields.String(
        description='The access token that authenticates the user with the API. '
        'User the HTTP header "X-Token" to provide it in API requests.')
})


@ns.route('/user')
146
class UserResource(Resource):
147
148
    @api.doc('get_user')
    @api.marshal_with(user_model, skip_none=True, code=200, description='User data send')
149
150
151
    @login_really_required
    def get(self):
        """
152
        Get user information including a long term access token for the authenticated user.
153
154
155
156
157
158

        You can use basic authentication to access this endpoint and receive a
        token for further api access. This token will expire at some point and presents
        a more secure method of authentication.
        """
        try:
159
            return g.user
160
161
162
        except LoginException:
            abort(
                401,
163
                message='User not logged in, provide credentials via Basic HTTP authentication.')
164

165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
    @api.doc('create_user')
    @api.expect(user_model)
    @api.marshal_with(user_model, skip_none=True, code=200, description='User created')
    @login_really_required
    def put(self):
        """
        Creates a new user account. Currently only the admin user is allows. The
        NOMAD-CoE repository GUI should be used to create user accounts for now.
        Passwords have to be encrypted by the client with bcrypt and 2y indent.
        """
        if not g.user.is_admin:
            abort(401, message='Only the admin user can perform create user.')

        data = request.get_json()
        if data is None:
            data = {}

        for required_key in ['last_name', 'first_name', 'password', 'email']:
            if required_key not in data:
                abort(400, message='The %s is missing' % required_key)

        user = coe_repo.User.create_user(
            email=data['email'], password=data.get('password', None), crypted=True,
            first_name=data['first_name'], last_name=data['last_name'],
            affiliation=data.get('affiliation', None))

        return user, 200

    @api.doc('update_user')
    @api.expect(user_model)
    @api.marshal_with(user_model, skip_none=True, code=200, description='User updated')
    @login_really_required
    def post(self):
        """
        Allows to edit the authenticated user and change his password. Password
        have to be encrypted by the client with bcrypt and 2y indent.
        """
        data = request.get_json()
        if data is None:
            data = {}

        if 'email' in data:
            abort(400, message='Cannot change the users email.')

        g.user.update(crypted=True, **data)

        return g.user, 200

213

214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
token_model = api.model('Token', {
    'user': fields.Nested(user_model),
    'token': fields.String(description='The short term token to sign URLs'),
    'experies_at': fields.DateTime(desription='The time when the token expires')
})


signature_token_argument = dict(
    name='token', type=str, help='Token that signs the URL and authenticates the user',
    location='args')


@ns.route('/token')
class TokenResource(Resource):
    @api.doc('get_token')
    @api.marshal_with(token_model, skip_none=True, code=200, description='Token send')
    @login_really_required
    def get(self):
        """
        Generates a short (10s) term JWT token that can be used to authenticate the user in
        URLs towards most API get request, e.g. for file downloads on the
        raw or archive api endpoints. Use the token query parameter to sign URLs.
        """
        token, expires_at = g.user.get_signature_token()
        return {
            'user': g.user,
            'token': token,
            'expires_at': expires_at.isoformat()
        }


def with_signature_token(func):
    """
    A decorator for API endpoint implementations that validates signed URLs.
    """
    @api.response(401, 'Invalid or expired signature token')
    def wrapper(*args, **kwargs):
        token = request.args.get('token', None)
        if token is not None:
            try:
                g.user = coe_repo.User.verify_signature_token(token)
            except LoginException:
                abort(401, 'Invalid or expired signature token')

        return func(*args, **kwargs)
    wrapper.__name__ = func.__name__
    wrapper.__doc__ = func.__doc__
    return wrapper


264
def create_authorization_predicate(upload_id, calc_id=None):
265
266
267
268
269
270
271
272
273
274
    """
    Returns a predicate that determines if the logged in user has the authorization
    to access the given upload and calculation.
    """
    def func():
        if g.user is None:
            # guest users don't have authorized access to anything
            return False

        # look in repository
275
        upload = coe_repo.Upload.from_upload_id(upload_id)
276
277
278
279
        if upload is not None:
            return upload.user_id == g.user.user_id

        # look in staging
280
        staging_upload = processing.Upload.get(upload_id)
281
282
283
284
        if staging_upload is not None:
            return str(g.user.user_id) == str(staging_upload.user_id)

        # There are no db entries for the given resource
285
        if files.UploadFiles.get(upload_id) is not None:
286
            logger = utils.get_logger(__name__, upload_id=upload_id, calc_id=calc_id)
287
288
289
290
            logger.error('Upload files without respective db entry')

        raise KeyError
    return func