Files
DECNET/templates/postgres/server.py
anti f583b3d699 fix(services): Resolve protocol realism gaps and update technical debt register
- Add dynamic challenge nonces to Postgres, VNC, and SIP.
- Add basic keyspace lookup and mock data to Redis.
- Correct MSSQL TDS pre-login offset bounds.
- Support MongoDB OP_MSG handshake version checking.
- Suppress Werkzeug HTTP server headers and normalize FTPAnonymousShell response.
- Add tracking for Dynamic Bait Store (DEBT-027) via DEBT.md.
2026-04-10 02:16:42 -04:00

112 lines
3.8 KiB
Python

#!/usr/bin/env python3
"""
PostgreSQLserver.
Reads the startup message, extracts username and database, responds with
an AuthenticationMD5Password challenge, logs the hash sent back, then
returns an error. Logs all interactions 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", "pgserver")
SERVICE_NAME = "postgres"
LOG_TARGET = os.environ.get("LOG_TARGET", "")
def _error_response(message: str) -> bytes:
body = b"S" + b"FATAL\x00" + b"M" + message.encode() + b"\x00\x00"
return b"E" + struct.pack(">I", len(body) + 4) + body
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 PostgresProtocol(asyncio.Protocol):
def __init__(self):
self._transport = None
self._peer = None
self._buf = b""
self._state = "startup"
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])
def data_received(self, data):
self._buf += data
self._process()
def _process(self):
if self._state == "startup":
if len(self._buf) < 4:
return
msg_len = struct.unpack(">I", self._buf[:4])[0]
if len(self._buf) < msg_len:
return
msg = self._buf[:msg_len]
self._buf = self._buf[msg_len:]
self._handle_startup(msg)
elif self._state == "auth":
if len(self._buf) < 5:
return
msg_type = chr(self._buf[0])
msg_len = struct.unpack(">I", self._buf[1:5])[0]
if len(self._buf) < msg_len + 1:
return
payload = self._buf[5:msg_len + 1]
self._buf = self._buf[msg_len + 1:]
if msg_type == "p":
self._handle_password(payload)
def _handle_startup(self, msg: bytes):
# Startup message: length(4) + protocol_version(4) + params (key=value\0 pairs)
if len(msg) < 8:
return
proto = struct.unpack(">I", msg[4:8])[0]
if proto == 80877103: # SSL request
self._transport.write(b"N") # reject SSL
return
params_raw = msg[8:].split(b"\x00")
params = {}
for i in range(0, len(params_raw) - 1, 2):
k = params_raw[i].decode(errors="replace")
v = params_raw[i + 1].decode(errors="replace") if i + 1 < len(params_raw) else ""
if k:
params[k] = v
username = params.get("user", "")
database = params.get("database", "")
_log("startup", src=self._peer[0], username=username, database=database)
self._state = "auth"
salt = os.urandom(4)
auth_md5 = b"R" + struct.pack(">I", 12) + struct.pack(">I", 5) + salt
self._transport.write(auth_md5)
def _handle_password(self, payload: bytes):
pw_hash = payload.rstrip(b"\x00").decode(errors="replace")
_log("auth", src=self._peer[0], pw_hash=pw_hash)
self._transport.write(_error_response("password authentication failed"))
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"PostgreSQL server starting as {NODE_NAME}")
loop = asyncio.get_running_loop()
server = await loop.create_server(PostgresProtocol, "0.0.0.0", 5432) # nosec B104
async with server:
await server.serve_forever()
if __name__ == "__main__":
asyncio.run(main())