anti
988732f4f9
Some checks failed
CI / Test (pytest) (3.11) (push) Has been cancelled
CI / Test (pytest) (3.12) (push) Has been cancelled
Security / SAST (bandit) (push) Has been cancelled
Security / Dependency audit (pip-audit) (push) Has been cancelled
CI / Lint (ruff) (push) Has been cancelled
108 lines
3.9 KiB
Python
108 lines
3.9 KiB
Python
#!/usr/bin/env python3
|
|
"""
|
|
MySQLserver.
|
|
Sends a realistic MySQL 5.7 server handshake, reads the client login
|
|
packet, extracts username, then closes with Access Denied. Logs auth
|
|
attempts as JSON.
|
|
"""
|
|
|
|
import asyncio
|
|
import os
|
|
import struct
|
|
from decnet_logging import syslog_line, write_syslog_file, forward_syslog
|
|
|
|
NODE_NAME = os.environ.get("NODE_NAME", "dbserver")
|
|
SERVICE_NAME = "mysql"
|
|
LOG_TARGET = os.environ.get("LOG_TARGET", "")
|
|
_MYSQL_VER = os.environ.get("MYSQL_VERSION", "5.7.38-log")
|
|
|
|
# Minimal MySQL server greeting (protocol v10) — version string is configurable
|
|
_GREETING = (
|
|
b"\x0a" # protocol version 10
|
|
+ _MYSQL_VER.encode() + b"\x00" # server version + NUL
|
|
+ b"\x01\x00\x00\x00" # connection id = 1
|
|
+ b"\x70\x76\x21\x6d\x61\x67\x69\x63" # auth-plugin-data part 1
|
|
+ b"\x00" # filler
|
|
+ b"\xff\xf7" # capability flags low
|
|
+ b"\x21" # charset utf8
|
|
+ b"\x02\x00" # status flags
|
|
+ b"\xff\x81" # capability flags high
|
|
+ b"\x15" # auth plugin data length
|
|
+ b"\x00\x00\x00\x00\x00\x00\x00\x00\x00\x00" # reserved (10 bytes)
|
|
+ b"\x21\x4f\x7d\x25\x3e\x55\x4d\x7c\x67\x75\x5e\x31\x00" # auth part 2
|
|
+ b"mysql_native_password\x00" # auth plugin name
|
|
)
|
|
|
|
|
|
def _make_packet(payload: bytes, seq: int = 0) -> bytes:
|
|
length = len(payload)
|
|
return struct.pack("<I", length)[:3] + bytes([seq]) + payload
|
|
|
|
|
|
|
|
|
|
def _log(event_type: str, severity: int = 6, **kwargs) -> None:
|
|
line = syslog_line(SERVICE_NAME, NODE_NAME, event_type, severity, **kwargs)
|
|
print(line, flush=True)
|
|
write_syslog_file(line)
|
|
forward_syslog(line, LOG_TARGET)
|
|
|
|
|
|
class MySQLProtocol(asyncio.Protocol):
|
|
def __init__(self):
|
|
self._transport = None
|
|
self._peer = None
|
|
self._buf = b""
|
|
self._greeted = False
|
|
|
|
def connection_made(self, transport):
|
|
self._transport = transport
|
|
self._peer = transport.get_extra_info("peername", ("?", 0))
|
|
_log("connect", src=self._peer[0], src_port=self._peer[1])
|
|
transport.write(_make_packet(_GREETING, seq=0))
|
|
self._greeted = True
|
|
|
|
def data_received(self, data):
|
|
self._buf += data
|
|
# MySQL packets: 3-byte length + 1-byte seq + payload
|
|
while len(self._buf) >= 4:
|
|
length = struct.unpack("<I", self._buf[:3] + b"\x00")[0]
|
|
if len(self._buf) < 4 + length:
|
|
break
|
|
payload = self._buf[4:4 + length]
|
|
self._buf = self._buf[4 + length:]
|
|
self._handle_packet(payload)
|
|
|
|
def _handle_packet(self, payload: bytes):
|
|
if not payload:
|
|
return
|
|
# Login packet: capability flags (4), max_packet (4), charset (1), reserved (23), username (NUL-terminated)
|
|
if len(payload) > 32:
|
|
try:
|
|
# skip capability(4) + max_pkt(4) + charset(1) + reserved(23) = 32 bytes
|
|
username_start = 32
|
|
nul = payload.index(b"\x00", username_start)
|
|
username = payload[username_start:nul].decode(errors="replace")
|
|
except (ValueError, IndexError):
|
|
username = "<parse_error>"
|
|
_log("auth", src=self._peer[0], username=username)
|
|
# Send Access Denied error
|
|
err = b"\xff" + struct.pack("<H", 1045) + b"#28000Access denied for user\x00"
|
|
self._transport.write(_make_packet(err, seq=2))
|
|
self._transport.close()
|
|
|
|
def connection_lost(self, exc):
|
|
_log("disconnect", src=self._peer[0] if self._peer else "?")
|
|
|
|
|
|
async def main():
|
|
_log("startup", msg=f"MySQL server starting as {NODE_NAME}")
|
|
loop = asyncio.get_running_loop()
|
|
server = await loop.create_server(MySQLProtocol, "0.0.0.0", 3306)
|
|
async with server:
|
|
await server.serve_forever()
|
|
|
|
|
|
if __name__ == "__main__":
|
|
asyncio.run(main())
|