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
|
# Copyright 2014-2021 The aiosmtpd Developers
# SPDX-License-Identifier: Apache-2.0
import asyncio
import dns.resolver
import logging
import sqlite3
import sys
from aiosmtpd.controller import Controller
from aiosmtpd.smtp import AuthResult, LoginPassword
from argon2 import PasswordHasher
from functools import lru_cache
from pathlib import Path
from smtplib import SMTP as SMTPCLient
DEST_PORT = 25
DB_AUTH = Path("mail.db~")
class Authenticator:
def __init__(self, auth_database):
self.auth_db = Path(auth_database)
self.ph = PasswordHasher()
def __call__(self, server, session, envelope, mechanism, auth_data):
fail_nothandled = AuthResult(success=False, handled=False)
if mechanism not in ("LOGIN", "PLAIN"):
return fail_nothandled
if not isinstance(auth_data, LoginPassword):
return fail_nothandled
username = auth_data.login
password = auth_data.password
hashpass = self.ph.hash(password)
conn = sqlite3.connect(self.auth_db)
curs = conn.execute(
"SELECT hashpass FROM userauth WHERE username=?", (username,)
)
hash_db = curs.fetchone()
conn.close()
if not hash_db:
return fail_nothandled
if hashpass != hash_db[0]:
return fail_nothandled
return AuthResult(success=True)
@lru_cache(maxsize=256)
def get_mx(domain):
records = dns.resolver.resolve(domain, "MX")
if not records:
return None
records = sorted(records, key=lambda r: r.preference)
return str(records[0].exchange)
class RelayHandler:
def handle_data(self, server, session, envelope, data):
mx_rcpt = {}
for rcpt in envelope.rcpt_tos:
_, _, domain = rcpt.partition("@")
mx = get_mx(domain)
if mx is None:
continue
mx_rcpt.setdefault(mx, []).append(rcpt)
for mx, rcpts in mx_rcpt.items():
with SMTPCLient(mx, 25) as client:
client.sendmail(
from_addr=envelope.mail_from,
to_addrs=rcpts,
msg=envelope.original_content
)
# noinspection PyShadowingNames
async def amain():
handler = RelayHandler()
cont = Controller(
handler,
hostname='',
port=8025,
authenticator=Authenticator(DB_AUTH)
)
try:
cont.start()
finally:
cont.stop()
if __name__ == '__main__':
if not DB_AUTH.exists():
print(f"Please create {DB_AUTH} first using make_user_db.py")
sys.exit(1)
logging.basicConfig(level=logging.DEBUG)
loop = asyncio.get_event_loop()
loop.create_task(amain())
try:
loop.run_forever()
except KeyboardInterrupt:
pass
|
