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
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
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
213
214
215
|
#!/usr/bin/env python3
# noinspection PyUnresolvedReferences
import falcon
import os
import logging
import json
import sqlalchemy as sa
import patatt
DB_VERSION = 1
logger = logging.getLogger('b4-send-receive')
# noinspection PyBroadException, PyMethodMayBeStatic
class SendReceiveListener(object):
def __init__(self, _engine):
self._engine = _engine
# You shouldn't use this in production
if self._engine.driver == 'pysqlite':
self._init_sa_db()
def _init_sa_db(self):
logger.info('Creating tables')
conn = self._engine.connect()
md = sa.MetaData()
meta = sa.Table('meta', md,
sa.Column('version', sa.Integer())
)
auth = sa.Table('auth', md,
sa.Column('auth_id', sa.Integer(), primary_key=True),
sa.Column('created', sa.DateTime(), nullable=False, server_default=sa.sql.func.now()),
sa.Column('identity', sa.Text(), nullable=False),
sa.Column('selector', sa.Text(), nullable=False),
sa.Column('pubkey', sa.Text(), nullable=False),
sa.Column('challenge', sa.Text(), nullable=True),
sa.Column('verified', sa.Integer(), nullable=False),
)
sa.Index('idx_identity_selector', auth.c.identity, auth.c.selector, unique=True)
md.create_all(self._engine)
q = sa.insert(meta).values(version=DB_VERSION)
conn.execute(q)
def on_get(self, req, resp): # noqa
resp.status = falcon.HTTP_200
resp.content_type = falcon.MEDIA_TEXT
resp.text = "We don't serve GETs here\n"
def send_error(self, resp, message):
resp.status = falcon.HTTP_500
resp.text = json.dumps({'result': 'error', 'message': message})
def send_success(self, resp, message):
resp.status = falcon.HTTP_200
resp.text = json.dumps({'result': 'success', 'message': message})
def auth_new(self, jdata, resp):
# Is it already authorized?
conn = self._engine.connect()
md = sa.MetaData()
identity = jdata.get('identity')
selector = jdata.get('selector')
pubkey = jdata.get('pubkey')
t_auth = sa.Table('auth', md, autoload=True, autoload_with=self._engine)
q = sa.select([t_auth.c.auth_id]).where(t_auth.c.identity == identity, t_auth.c.selector == selector,
t_auth.c.verified == 1)
rp = conn.execute(q)
if len(rp.fetchall()):
self.send_error(resp, message='i=%s;s=%s is already authorized' % (identity, selector))
return
# delete any existing challenges for this and create a new one
q = sa.delete(t_auth).where(t_auth.c.identity == identity, t_auth.c.selector == selector,
t_auth.c.verified == 0)
conn.execute(q)
# create new challenge
import uuid
cstr = str(uuid.uuid4())
q = sa.insert(t_auth).values(identity=identity, selector=selector, pubkey=pubkey, challenge=cstr,
verified=0)
conn.execute(q)
# TODO: Actual mail sending
logger.info('Challenge: %s', cstr)
self.send_success(resp, message='Challenge generated')
def validate_message(self, conn, t_auth, bdata, verified=1):
# Returns auth_id of the matching record
pm = patatt.PatattMessage(bdata)
if not pm.signed:
return None
auth_id = identity = pubkey = None
for ds in pm.get_sigs():
selector = 'default'
identity = ''
i = ds.get_field('i')
if i:
identity = i.decode()
s = ds.get_field('s')
if s:
selector = s.decode()
logger.debug('i=%s; s=%s', identity, selector)
q = sa.select([t_auth.c.auth_id, t_auth.c.pubkey]).where(t_auth.c.identity == identity,
t_auth.c.selector == selector,
t_auth.c.verified == verified)
rp = conn.execute(q)
res = rp.fetchall()
if res:
auth_id, pubkey = res[0]
break
logger.debug('auth_id=%s', auth_id)
if not auth_id:
return None
try:
pm.validate(identity, pubkey.encode())
except Exception as ex:
logger.debug('Validation failed: %s', ex)
return None
return auth_id
def auth_verify(self, jdata, resp):
msg = jdata.get('msg')
if msg.find('\nverify:') < 0:
self.send_error(resp, message='Invalid verification message')
return
conn = self._engine.connect()
md = sa.MetaData()
t_auth = sa.Table('auth', md, autoload=True, autoload_with=self._engine)
bdata = msg.encode()
auth_id = self.validate_message(conn, t_auth, bdata, verified=0)
if auth_id is None:
self.send_error(resp, message='Signature validation failed')
return
# Now compare the challenge to what we received
q = sa.select([t_auth.c.challenge]).where(t_auth.c.auth_id == auth_id)
rp = conn.execute(q)
res = rp.fetchall()
challenge = res[0][0]
if msg.find(f'\nverify:{challenge}') < 0:
self.send_error(resp, message='Invalid verification string')
return
q = sa.update(t_auth).where(t_auth.c.auth_id == auth_id).values(challenge=None, verified=1)
conn.execute(q)
self.send_success(resp, message='Challenge verified')
def auth_delete(self, jdata, resp):
msg = jdata.get('msg')
if msg.find('\nauth-delete') < 0:
self.send_error(resp, message='Invalid key delete message')
return
conn = self._engine.connect()
md = sa.MetaData()
t_auth = sa.Table('auth', md, autoload=True, autoload_with=self._engine)
bdata = msg.encode()
auth_id = self.validate_message(conn, t_auth, bdata)
if auth_id is None:
self.send_error(resp, message='Signature validation failed')
return
q = sa.delete(t_auth).where(t_auth.c.auth_id == auth_id)
conn.execute(q)
self.send_success(resp, message='Authentication deleted')
def on_post(self, req, resp):
if not req.content_length:
resp.status = falcon.HTTP_500
resp.content_type = falcon.MEDIA_TEXT
resp.text = 'Payload required\n'
return
raw = req.bounded_stream.read()
try:
jdata = json.loads(raw)
except:
resp.status = falcon.HTTP_500
resp.content_type = falcon.MEDIA_TEXT
resp.text = 'Failed to parse the request\n'
return
action = jdata.get('action')
if action == 'auth-new':
self.auth_new(jdata, resp)
return
if action == 'auth-verify':
self.auth_verify(jdata, resp)
return
if action == 'auth-delete':
self.auth_delete(jdata, resp)
return
resp.status = falcon.HTTP_500
resp.content_type = falcon.MEDIA_TEXT
resp.text = 'Unknown action: %s\n' % action
app = falcon.App()
dburl = os.getenv('DB_URL', 'sqlite:///:memory:')
engine = sa.create_engine(dburl)
srl = SendReceiveListener(engine)
mp = os.getenv('MOUNTPOINT', '/_b4_submit')
app.add_route(mp, srl)
if __name__ == '__main__':
from wsgiref.simple_server import make_server
logger.setLevel(logging.DEBUG)
ch = logging.StreamHandler()
formatter = logging.Formatter('%(message)s')
ch.setFormatter(formatter)
ch.setLevel(logging.DEBUG)
logger.addHandler(ch)
with make_server('', 8000, app) as httpd:
logger.info('Serving on port 8000...')
# Serve until process is killed
httpd.serve_forever()
|