summaryrefslogtreecommitdiff
path: root/service/pixelated/bitmask_libraries/leap_srp.py
blob: 05e27a94345b4be31e93ab4cdd0930dd4de1f114 (plain)
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
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
#
# Copyright (c) 2014 ThoughtWorks, Inc.
#
# Pixelated is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Pixelated is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with Pixelated. If not, see <http://www.gnu.org/licenses/>.
import binascii
import json
import requests

from requests import Session
from srp import User, srp, create_salted_verification_key
from requests.exceptions import HTTPError, SSLError, Timeout
from config import SYSTEM_CA_BUNDLE

REGISTER_USER_LOGIN_KEY = 'user[login]'
REGISTER_USER_VERIFIER_KEY = 'user[password_verifier]'
REGISTER_USER_SALT_KEY = 'user[password_salt]'


class LeapAuthException(Exception):
    def __init__(self, *args, **kwargs):
        super(LeapAuthException, self).__init__(*args, **kwargs)


class LeapSRPSession(object):
    def __init__(self, user_name, api_server_name, uuid, token, session_id, api_version='1'):
        self.user_name = user_name
        self.api_server_name = api_server_name
        self.uuid = uuid
        self.token = token
        self.session_id = session_id
        self.api_version = api_version

    def __str__(self):
        return 'LeapSRPSession(%s, %s, %s, %s, %s, %s)' % (self.user_name, self.api_server_name, self.uuid, self.token, self.session_id, self.api_version)


class LeapSecureRemotePassword(object):
    def __init__(self, hash_alg=srp.SHA256, ng_type=srp.NG_1024, ca_bundle=SYSTEM_CA_BUNDLE, timeout_in_s=15,
                 leap_api_version='1'):

        self.hash_alg = hash_alg
        self.ng_type = ng_type
        self.timeout_in_s = timeout_in_s
        self.ca_bundle = ca_bundle
        self.leap_api_version = leap_api_version

    def authenticate(self, api_uri, username, password):
        session = Session()
        try:
            return self._authenticate_with_session(session, api_uri, username, password)
        except Timeout, e:
            raise LeapAuthException(e)
        finally:
            session.close()

    def _authenticate_with_session(self, http_session, api_uri, username, password):
        try:
            srp_user = User(username.encode('utf-8'), password.encode('utf-8'), self.hash_alg, self.ng_type)

            salt, B_challenge = self._begin_authentication(srp_user, http_session, api_uri)
            M2_verfication_code, leap_session = self._process_challenge(srp_user, http_session, api_uri, salt,
                                                                        B_challenge)
            self._verify_session(srp_user, M2_verfication_code)

            return leap_session
        except (HTTPError, SSLError), e:
            raise LeapAuthException(e)

    def _begin_authentication(self, user, session, api_uri):
        _, A = user.start_authentication()

        auth_data = {
            "login": user.get_username(),
            "A": binascii.hexlify(A)
        }
        session_url = '%s/%s/sessions' % (api_uri, self.leap_api_version)
        response = session.post(session_url, data=auth_data, verify=self.ca_bundle, timeout=self.timeout_in_s)
        response.raise_for_status()
        json_content = json.loads(response.content)

        salt = _safe_unhexlify(json_content.get('salt'))
        B = _safe_unhexlify(json_content.get('B'))

        return salt, B

    def _process_challenge(self, user, session, api_uri, salt, B):
        M = user.process_challenge(salt, B)

        auth_data = {
            "client_auth": binascii.hexlify(M)
        }

        auth_url = '%s/%s/sessions/%s' % (api_uri, self.leap_api_version, user.get_username())
        response = session.put(auth_url, data=auth_data, verify=self.ca_bundle, timeout=self.timeout_in_s)
        response.raise_for_status()
        auth_json = json.loads(response.content)

        M2 = _safe_unhexlify(auth_json.get('M2'))
        uuid = auth_json.get('id')
        token = auth_json.get('token')
        session_id = response.cookies.get('_session_id')

        return M2, LeapSRPSession(user.get_username(), api_uri, uuid, token, session_id)

    def _verify_session(self, user, M2):
        user.verify_session(M2)
        if not user.authenticated():
            raise LeapAuthException()

    def register(self, api_uri, username, password):
        try:
            salt, verifier = create_salted_verification_key(username, password, self.hash_alg, self.ng_type)
            return self._post_registration_data(api_uri, username, salt, verifier)
        except (HTTPError, SSLError, Timeout), e:
            raise LeapAuthException(e)

    def _post_registration_data(self, api_uri, username, salt, verifier):
        users_url = '%s/%s/users' % (api_uri, self.leap_api_version)

        user_data = {
            REGISTER_USER_LOGIN_KEY: username,
            REGISTER_USER_SALT_KEY: binascii.hexlify(salt),
            REGISTER_USER_VERIFIER_KEY: binascii.hexlify(verifier)
        }

        response = requests.post(users_url, data=user_data, verify=self.ca_bundle, timeout=self.timeout_in_s)
        response.raise_for_status()
        reg_json = json.loads(response.content)

        return reg_json['ok']


def _safe_unhexlify(hex_str):
    return binascii.unhexlify(hex_str) \
        if (len(hex_str) % 2 == 0) else binascii.unhexlify('0' + hex_str)