Files
DECNET/decnet/templates/tftp/syslog_bridge.py
anti 909913e912 fix(types): P0 mypy — explicit binascii import, drop dead or None in ntlmssp
syslog_bridge.py: base64.binascii is not a public mypy-visible attribute;
import binascii directly and reference binascii.Error at the except clause.
Propagated to all 26 template subdirectory copies (all were drift-free).

ntlmssp.py: `principal = username or None` widened the type to str | None
for no runtime reason — _decode_str() always returns str.  Drop the `or None`.
Propagated to smb/ and rdp/ copies.

762 → 722 mypy errors (-40).
2026-05-01 00:09:00 -04:00

263 lines
8.8 KiB
Python

#!/usr/bin/env python3
"""
Shared RFC 5424 syslog helper used by service containers.
Services call syslog_line() to format an RFC 5424 message, then
write_syslog_file() to emit it to stdout — the container runtime
captures it, and the host-side collector streams it into the log file.
RFC 5424 structure:
<PRI>1 TIMESTAMP HOSTNAME APP-NAME PROCID MSGID [SD-ELEMENT] MSG
Facility: local0 (16). SD element ID uses PEN 55555.
"""
import base64
import binascii
import re
from datetime import datetime, timezone
from typing import Any, Optional
# ─── Constants ────────────────────────────────────────────────────────────────
_FACILITY_LOCAL0 = 16
_SD_ID = "relay@55555"
_NILVALUE = "-"
SEVERITY_EMERG = 0
SEVERITY_ALERT = 1
SEVERITY_CRIT = 2
SEVERITY_ERROR = 3
SEVERITY_WARNING = 4
SEVERITY_NOTICE = 5
SEVERITY_INFO = 6
SEVERITY_DEBUG = 7
_MAX_HOSTNAME = 255
_MAX_APPNAME = 48
_MAX_MSGID = 32
# ─── Formatter ────────────────────────────────────────────────────────────────
def _sd_escape(value: str) -> str:
"""Escape SD-PARAM-VALUE per RFC 5424 §6.3.3."""
return value.replace("\\", "\\\\").replace('"', '\\"').replace("]", "\\]")
def _sd_element(fields: dict[str, Any]) -> str:
if not fields:
return _NILVALUE
params = " ".join(f'{k}="{_sd_escape(str(v))}"' for k, v in fields.items())
return f"[{_SD_ID} {params}]"
def syslog_line(
service: str,
hostname: str,
event_type: str,
severity: int = SEVERITY_INFO,
timestamp: datetime | None = None,
msg: str | None = None,
**fields: Any,
) -> str:
"""
Return a single RFC 5424-compliant syslog line (no trailing newline).
Args:
service: APP-NAME (e.g. "http", "mysql")
hostname: HOSTNAME (node name)
event_type: MSGID (e.g. "request", "login_attempt")
severity: Syslog severity integer (default: INFO=6)
timestamp: UTC datetime; defaults to now
msg: Optional free-text MSG
**fields: Encoded as structured data params
"""
pri = f"<{_FACILITY_LOCAL0 * 8 + severity}>"
ts = (timestamp or datetime.now(timezone.utc)).isoformat()
host = (hostname or _NILVALUE)[:_MAX_HOSTNAME]
appname = (service or _NILVALUE)[:_MAX_APPNAME]
msgid = (event_type or _NILVALUE)[:_MAX_MSGID]
sd = _sd_element(fields)
message = f" {msg}" if msg else ""
return f"{pri}1 {ts} {host} {appname} {_NILVALUE} {msgid} {sd}{message}"
def encode_secret(secret: str) -> dict[str, str]:
"""Standardized credential-secret encoding for the universal SD-block shape.
Returns ``{'secret_printable': ..., 'secret_b64': ...}`` ready to spread
into a :func:`syslog_line` / ``_log`` call::
_log("auth_attempt", principal=user, **encode_secret(password))
``secret_printable`` mirrors auth-helper.c's sd_escape: bytes outside
``[0x20, 0x7f)`` collapse to ``'?'`` so the field is always parser-safe
RFC 5424 ASCII. ``secret_b64`` preserves the *original* utf-8 bytes —
NUL/0xff/control/non-utf8 sequences all survive losslessly, useful as
a fingerprinting signal even when the printable form sanitizes them.
The decnet web ingester's native-shape branch keys off ``secret_b64``
being present, so any service emitter calling this helper lands its
cred attempt directly in the :class:`Credential` table.
"""
raw = secret.encode("utf-8", errors="replace")
printable = "".join(chr(b) if 0x20 <= b < 0x7f else "?" for b in raw)
return {
"secret_printable": printable,
"secret_b64": base64.b64encode(raw).decode("ascii"),
}
_DIGEST_PARAM_RE = re.compile(r'(\w+)\s*=\s*"([^"]*)"|(\w+)\s*=\s*([^,\s]+)')
def classify_authorization(header_value: Optional[str]) -> Optional[dict[str, Any]]:
"""Parse an HTTP Authorization header value into Credential SD fields.
Returns a dict with the universal cred shape ready to spread into a
``_log(...)`` call::
auth = request.headers.get("Authorization")
cred = classify_authorization(auth)
if cred:
_log("auth_attempt", **cred)
Recognised schemes:
* Basic — base64(user:pw); decoded → ``principal=user`` +
``secret_kind="plaintext"`` + ``encode_secret(pw)``.
* Bearer / Token — opaque token; ``principal=None`` +
``secret_kind="http_bearer"`` + ``encode_secret(token)``.
* Digest — ``principal=username`` from header +
``secret_kind="http_digest_md5"`` + ``encode_secret(response)``.
Returns ``None`` for anything unrecognized (AWS4-HMAC-SHA256, NTLM,
Negotiate, …) — callers can still log the raw header value in the
ambient SD-block; we just don't know how to extract a hashable
secret from it.
"""
if not header_value or not isinstance(header_value, str):
return None
parts = header_value.strip().split(None, 1)
if len(parts) < 2:
return None
scheme, rest = parts[0].lower(), parts[1].strip()
if scheme == "basic":
try:
decoded = base64.b64decode(rest, validate=True).decode("utf-8", errors="replace")
except (ValueError, binascii.Error):
return None
if ":" not in decoded:
return None
user, _, pw = decoded.partition(":")
return {
"principal": user,
"secret_kind": "plaintext",
**encode_secret(pw),
}
if scheme in ("bearer", "token"):
return {
"principal": None,
"secret_kind": "http_bearer",
**encode_secret(rest),
}
if scheme == "digest":
params: dict[str, str] = {}
for m in _DIGEST_PARAM_RE.finditer(rest):
k = m.group(1) or m.group(3)
v = m.group(2) if m.group(2) is not None else m.group(4)
if k:
params[k.lower()] = v
response = params.get("response")
if not response:
return None
return {
"principal": params.get("username"),
"secret_kind": "http_digest_md5",
**encode_secret(response),
}
return None
_FORM_PRINCIPAL_KEYS = (
"username", "user", "email", "login", "userid", "account",
"log", # wp-login.php
"user_login", # WordPress alt
"uname", # phpMyAdmin
"pma_username",
)
_FORM_SECRET_KEYS = (
"password", "pass", "pwd", "passwd", "passwort", "mot_de_passe",
"user_password", # WordPress alt
"pma_password", # phpMyAdmin
)
def extract_form_credentials(
body: Optional[str],
content_type: Optional[str],
) -> Optional[dict[str, Any]]:
"""Parse an `application/x-www-form-urlencoded` body for credentials.
Returns the universal cred SD shape ready to spread into a
``_log(...)`` call when both a principal-shaped key and a secret-
shaped key are present in the body. Otherwise returns ``None``.
Field-name detection is case-insensitive and covers the most common
login-form variants (WordPress wp-login.php, phpMyAdmin, Joomla,
etc.). Add more entries to ``_FORM_PRINCIPAL_KEYS`` /
``_FORM_SECRET_KEYS`` as new templates surface them.
"""
if not body or not isinstance(content_type, str):
return None
if not content_type.lower().startswith("application/x-www-form-urlencoded"):
return None
fields: dict[str, str] = {}
for pair in body.split("&"):
if "=" not in pair:
continue
k, _, v = pair.partition("=")
# urllib decode without importing urllib at module scope (the
# template emitters are import-cost-sensitive). Inline the
# tiny percent-decode + plus-decode.
try:
from urllib.parse import unquote_plus
key = unquote_plus(k).lower()
val = unquote_plus(v)
except Exception:
continue
# First-wins so duplicate-key forms don't get clobbered.
fields.setdefault(key, val)
principal: Optional[str] = None
for k in _FORM_PRINCIPAL_KEYS:
if k in fields:
principal = fields[k]
break
secret: Optional[str] = None
for k in _FORM_SECRET_KEYS:
if k in fields:
secret = fields[k]
break
if secret is None:
return None
return {
"principal": principal,
"secret_kind": "plaintext",
**encode_secret(secret),
}
def write_syslog_file(line: str) -> None:
"""Emit a syslog line to stdout for container log capture."""
print(line, flush=True)
def forward_syslog(line: str, log_target: str) -> None:
"""No-op stub. TCP forwarding is handled by rsyslog, not by service containers."""
pass