anti
55896b0caa
- decnet/logging/syslog_formatter.py: RFC 5424 formatter (local0 facility, decnet@55555 SD element ID, full escaping per §6.3.3) - decnet/logging/file_handler.py: rotating file handler (10 MB / 5 backups), path configurable via DECNET_LOG_FILE env var - templates/decnet_logging.py: combined syslog_line / write_syslog_file / forward_syslog helper distributed to all 22 service template dirs - All templates/*/server.py: replaced ad-hoc JSON _forward/_log with RFC 5424 syslog_line + write_syslog_file + forward_syslog - All templates/*/Dockerfile: COPY decnet_logging.py /opt/ - DecnetConfig: added log_file field; CLI: --log-file flag; composer injects DECNET_LOG_FILE env var into service containers - tests/test_syslog_formatter.py + tests/test_file_handler.py: 25 new tests Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
100 lines
3.2 KiB
Python
100 lines
3.2 KiB
Python
#!/usr/bin/env python3
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"""
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VNC (RFB)server.
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Performs the RFB 3.8 handshake, offers VNC authentication, captures the
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24-byte DES-encrypted challenge response, then rejects with "Authentication
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failed". Logs the raw response for offline cracking.
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"""
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import asyncio
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import json
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import os
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import socket
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from datetime import datetime, timezone
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from decnet_logging import syslog_line, write_syslog_file, forward_syslog
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NODE_NAME = os.environ.get("NODE_NAME", "desktop")
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SERVICE_NAME = "vnc"
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LOG_TARGET = os.environ.get("LOG_TARGET", "")
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# RFB challenge — fixed so captured responses are reproducible
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_CHALLENGE = bytes(range(16)) * 1 + b"\x10\x11\x12\x13\x14\x15\x16\x17" # 24 bytes
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def _log(event_type: str, severity: int = 6, **kwargs) -> None:
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line = syslog_line(SERVICE_NAME, NODE_NAME, event_type, severity, **kwargs)
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print(line, flush=True)
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write_syslog_file(line)
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forward_syslog(line, LOG_TARGET)
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class VNCProtocol(asyncio.Protocol):
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def __init__(self):
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self._transport = None
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self._peer = None
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self._buf = b""
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self._state = "version"
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def connection_made(self, transport):
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self._transport = transport
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self._peer = transport.get_extra_info("peername", ("?", 0))
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_log("connect", src=self._peer[0], src_port=self._peer[1])
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# Send RFB version
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transport.write(b"RFB 003.008\n")
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def data_received(self, data):
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self._buf += data
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self._process()
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def _process(self):
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if self._state == "version":
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if b"\n" not in self._buf:
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return
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line, self._buf = self._buf.split(b"\n", 1)
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client_version = line.decode(errors="replace").strip()
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_log("version", src=self._peer[0], client_version=client_version)
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# Send security types: 1 type = VNC Authentication (2)
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self._transport.write(b"\x01\x02")
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self._state = "security_choice"
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elif self._state == "security_choice":
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if len(self._buf) < 1:
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return
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chosen = self._buf[0]
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self._buf = self._buf[1:]
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_log("security_choice", src=self._peer[0], type=chosen)
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# Send 16-byte challenge
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self._transport.write(_CHALLENGE[:16])
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self._state = "auth_response"
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elif self._state == "auth_response":
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if len(self._buf) < 16:
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return
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response = self._buf[:16]
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self._buf = self._buf[16:]
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_log("auth_response", src=self._peer[0], response=response.hex())
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# SecurityResult: 1 = failed
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self._transport.write(b"\x00\x00\x00\x01")
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# Failure reason
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reason = b"Authentication failed"
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import struct
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self._transport.write(struct.pack(">I", len(reason)) + reason)
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self._transport.close()
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def connection_lost(self, exc):
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_log("disconnect", src=self._peer[0] if self._peer else "?")
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async def main():
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_log("startup", msg=f"VNC server starting as {NODE_NAME}")
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loop = asyncio.get_running_loop()
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server = await loop.create_server(VNCProtocol, "0.0.0.0", 5900)
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async with server:
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await server.serve_forever()
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if __name__ == "__main__":
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asyncio.run(main())
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