merge: testing → main (reconcile 2-week divergence)

decnet/templates/mongodb/Dockerfile

@@ -0,0 +1,24 @@
+ARG BASE_IMAGE=debian:bookworm-slim
+FROM ${BASE_IMAGE}
+
+RUN apt-get update && apt-get install -y --no-install-recommends \
+    python3 \
+    && rm -rf /var/lib/apt/lists/*
+
+COPY syslog_bridge.py /opt/syslog_bridge.py
+COPY instance_seed.py /opt/instance_seed.py
+COPY server.py /opt/server.py
+COPY entrypoint.sh /entrypoint.sh
+RUN chmod +x /entrypoint.sh
+
+EXPOSE 27017
+RUN useradd -r -s /bin/false -d /opt logrelay \
+ && apt-get update && apt-get install -y --no-install-recommends libcap2-bin \
+ && rm -rf /var/lib/apt/lists/* \
+ && (find /usr/bin/ -maxdepth 1 -name 'python3*' -type f -exec setcap 'cap_net_bind_service+eip' {} \; 2>/dev/null || true)
+
+HEALTHCHECK --interval=30s --timeout=5s --start-period=10s --retries=3 \
+  CMD kill -0 1 || exit 1
+
+USER logrelay
+ENTRYPOINT ["/entrypoint.sh"]

decnet/templates/mongodb/entrypoint.sh

@@ -0,0 +1,3 @@
+#!/bin/bash
+set -e
+exec python3 /opt/server.py

decnet/templates/mongodb/instance_seed.py

@@ -0,0 +1,120 @@
+#!/usr/bin/env python3
+"""
+Per-instance stealth seeding for honeypot service templates.
+
+The whole decoy fleet looks identical to a scanner unless each decky
+diverges on the boring details: cluster UUIDs, auth salts, uptime, minor
+version strings, etc. This module derives a stable per-instance seed
+from NODE_NAME (+ optional INSTANCE_ID) and exposes helpers that return
+deterministic-per-decky-but-different-across-the-fleet values.
+
+Connection-time jitter is intentionally NOT seeded — two hits to the same
+decky should not replay the same latency curve.
+"""
+
+from __future__ import annotations
+
+import asyncio
+import hashlib
+import os
+import random
+import time
+import uuid
+from typing import Sequence, TypeVar
+
+T = TypeVar("T")
+
+_HOSTNAME = (
+    os.environ.get("NODE_NAME")
+    or os.environ.get("HOSTNAME")
+    or "decky"
+)
+_INSTANCE_ID = os.environ.get("INSTANCE_ID", "")
+_SEED_MATERIAL = f"{_HOSTNAME}:{_INSTANCE_ID}".encode()
+_SEED_INT = int.from_bytes(hashlib.sha256(_SEED_MATERIAL).digest()[:8], "big")
+
+#: Deterministic RNG seeded per decky — use for *persistent* choices
+#: (versions, UUIDs, stored credentials). Never use for timing.
+rng = random.Random(_SEED_INT)
+
+#: Process boot time — real uptime elapsed since container start.
+_PROCESS_START = time.time()
+
+#: Deterministic per-instance fake "has been up for this long at boot"
+#: offset, so every decky pretends to have a different history.
+_BOOT_OFFSET = rng.randint(3600, 45 * 86400)
+
+
+def hostname() -> str:
+    return _HOSTNAME
+
+
+def uptime_seconds() -> int:
+    """Monotonically increasing, unique per instance."""
+    return int(_BOOT_OFFSET + (time.time() - _PROCESS_START))
+
+
+def boot_epoch() -> int:
+    """Fake wall-clock boot time for this instance (seconds since epoch)."""
+    return int(time.time() - uptime_seconds())
+
+
+def instance_uuid(namespace: str = "") -> str:
+    """Deterministic UUID4-looking value for this instance+namespace."""
+    ns = uuid.UUID("00000000-0000-0000-0000-000000000000")
+    return str(uuid.uuid5(ns, f"{_HOSTNAME}:{namespace}"))
+
+
+def instance_hex(nbytes: int, namespace: str = "") -> str:
+    """Deterministic hex token of given byte length."""
+    material = f"{_HOSTNAME}:{namespace}".encode()
+    digest = hashlib.sha256(material).digest()
+    while len(digest) < nbytes:
+        digest += hashlib.sha256(digest).digest()
+    return digest[:nbytes].hex()
+
+
+def pick(choices: Sequence[T]) -> T:
+    """Deterministic choice from a sequence."""
+    return rng.choice(list(choices))
+
+
+def pick_weighted(choices: Sequence[tuple[T, float]]) -> T:
+    """Deterministic weighted choice. Input: [(item, weight), ...]."""
+    total = sum(w for _, w in choices)
+    r = rng.uniform(0, total)
+    acc = 0.0
+    for item, w in choices:
+        acc += w
+        if r <= acc:
+            return item
+    return choices[-1][0]
+
+
+def random_bytes(n: int, namespace: str = "") -> bytes:
+    """Deterministic per-instance byte string of length n."""
+    out = bytearray()
+    i = 0
+    while len(out) < n:
+        out.extend(
+            hashlib.sha256(f"{_HOSTNAME}:{namespace}:{i}".encode()).digest()
+        )
+        i += 1
+    return bytes(out[:n])
+
+
+def fresh_bytes(n: int) -> bytes:
+    """Non-deterministic random bytes — for per-connection nonces/salts."""
+    return os.urandom(n)
+
+
+async def jitter(min_ms: int = 5, max_ms: int = 120) -> None:
+    """Async response-time jitter. Uses unseeded RNG so timing varies
+    across connections to the same decky — seeded jitter would leak
+    predictability."""
+    await asyncio.sleep(random.uniform(min_ms, max_ms) / 1000.0)
+
+
+def jitter_sync(min_ms: int = 5, max_ms: int = 120) -> None:
+    """Blocking jitter for non-asyncio servers."""
+    time.sleep(random.uniform(min_ms, max_ms) / 1000.0)

decnet/templates/mongodb/server.py

@@ -0,0 +1,352 @@
+#!/usr/bin/env python3
+"""
+MongoDBserver.
+Implements the MongoDB wire protocol OP_MSG/OP_QUERY handshake. Responds
+to isMaster/hello, listDatabases, and authenticate commands. Logs all
+received messages as JSON.
+"""
+
+import asyncio
+import base64
+import os
+import struct
+
+import instance_seed as _seed
+from syslog_bridge import syslog_line, write_syslog_file, forward_syslog
+
+
+# ─── Minimal BSON walker ──────────────────────────────────────────────────────
+# Just enough to extract `saslStart` / `saslContinue` command auth fields.
+# Pulls a few BSON type codes; ignores everything else (subdocs returned
+# as raw bytes the caller can re-parse if needed). Hand-rolled rather
+# than pulling pymongo as a runtime dep — we only need 8 type codes and
+# the parser is ~40 LoC.
+
+_BSON_DOUBLE = 0x01
+_BSON_STRING = 0x02
+_BSON_DOC    = 0x03
+_BSON_ARRAY  = 0x04
+_BSON_BINARY = 0x05
+_BSON_BOOL   = 0x08
+_BSON_INT32  = 0x10
+_BSON_INT64  = 0x12
+
+
+def _bson_read(buf: bytes, off: int = 0) -> dict:
+    """Read a single BSON document at ``buf[off]``. Returns a dict of
+    ``{key: value}``. Lossy on unsupported types (silently skipped).
+    Untrusted-input safe: bounds-checked, won't infinite-loop on
+    malformed length fields."""
+    out: dict = {}
+    if off + 4 > len(buf):
+        return out
+    doc_len = struct.unpack_from("<i", buf, off)[0]
+    end = off + doc_len
+    if end > len(buf) or doc_len < 5:
+        return out
+    p = off + 4
+    while p < end - 1:  # last byte is the trailing 0x00
+        t = buf[p]
+        p += 1
+        if t == 0:
+            break
+        # Read NUL-terminated cstring key.
+        nul = buf.find(b"\x00", p, end)
+        if nul < 0:
+            break
+        key = buf[p:nul].decode("utf-8", errors="replace")
+        p = nul + 1
+        if t == _BSON_STRING:
+            if p + 4 > end:
+                break
+            slen = struct.unpack_from("<i", buf, p)[0]
+            p += 4
+            if p + slen > end or slen < 1:
+                break
+            out[key] = buf[p:p + slen - 1].decode("utf-8", errors="replace")
+            p += slen
+        elif t == _BSON_BINARY:
+            if p + 5 > end:
+                break
+            blen = struct.unpack_from("<i", buf, p)[0]
+            p += 4
+            _subtype = buf[p]
+            p += 1
+            if p + blen > end or blen < 0:
+                break
+            out[key] = buf[p:p + blen]  # raw bytes
+            p += blen
+        elif t == _BSON_INT32:
+            if p + 4 > end:
+                break
+            out[key] = struct.unpack_from("<i", buf, p)[0]
+            p += 4
+        elif t == _BSON_INT64:
+            if p + 8 > end:
+                break
+            out[key] = struct.unpack_from("<q", buf, p)[0]
+            p += 8
+        elif t == _BSON_BOOL:
+            if p + 1 > end:
+                break
+            out[key] = buf[p] != 0
+            p += 1
+        elif t == _BSON_DOUBLE:
+            p += 8
+        elif t in (_BSON_DOC, _BSON_ARRAY):
+            if p + 4 > end:
+                break
+            sub_len = struct.unpack_from("<i", buf, p)[0]
+            if p + sub_len > end:
+                break
+            p += sub_len
+        else:
+            # Unsupported type — abort cleanly so we don't misalign.
+            break
+    return out
+
+
+def _scram_kv(payload: bytes) -> dict:
+    """Parse a SCRAM message into key=value pairs. SCRAM separates by
+    commas and uses `name=value` pairs. We strip a leading `n,,` (GS2
+    header) when present so the `n=username` shows up directly."""
+    s = payload.decode("utf-8", errors="replace")
+    if s.startswith("n,,"):
+        s = s[3:]
+    elif s.startswith("y,,"):
+        s = s[3:]
+    out: dict = {}
+    for part in s.split(","):
+        if "=" in part:
+            k, _, v = part.partition("=")
+            out[k.strip()] = v
+    return out
+
+NODE_NAME = os.environ.get("NODE_NAME", "mongodb")
+SERVICE_NAME   = "mongodb"
+LOG_TARGET = os.environ.get("LOG_TARGET", "")
+PORT = int(os.environ.get("PORT", "27017"))
+
+# Per-instance (version, maxWireVersion) — paired per real MongoDB release.
+# Wire version is locked to major/minor per upstream release notes.
+_MONGO_RELEASES = [
+    ("4.4.22", 9),
+    ("5.0.25", 13),
+    ("6.0.5",  17),
+    ("6.0.14", 17),
+    ("7.0.5",  21),
+    ("7.0.8",  21),
+    ("7.0.11", 21),
+]
+_MONGO_VERSION, _MONGO_WIRE = _seed.pick(_MONGO_RELEASES)
+_MONGO_SET_NAME = os.environ.get("MONGO_REPL_SET", "")  # empty = standalone
+
+
+def _new_objectid() -> bytes:
+    """12-byte BSON ObjectId — fresh per call."""
+    return _seed.fresh_bytes(12)
+
+# Minimal BSON helpers
+def _bson_str(key: str, val: str) -> bytes:
+    k = key.encode() + b"\x00"
+    v = val.encode() + b"\x00"
+    return b"\x02" + k + struct.pack("<I", len(v)) + v
+
+def _bson_int32(key: str, val: int) -> bytes:
+    return b"\x10" + key.encode() + b"\x00" + struct.pack("<i", val)
+
+def _bson_bool(key: str, val: bool) -> bytes:
+    return b"\x08" + key.encode() + b"\x00" + (b"\x01" if val else b"\x00")
+
+def _bson_doc(*fields: bytes) -> bytes:
+    body = b"".join(fields) + b"\x00"
+    return struct.pack("<I", len(body) + 4) + body
+
+def _op_reply(request_id: int, doc: bytes) -> bytes:
+    # OP_REPLY header: total_len(4), req_id(4), response_to(4), opcode(4)=1,
+    #                  flags(4), cursor_id(8), starting_from(4), number_returned(4), docs
+    header = struct.pack(
+        "<iiiiiqii",
+        16 + 20 + len(doc),  # total length
+        0,                    # request id
+        request_id,           # response to
+        1,                    # OP_REPLY
+        0,                    # flags
+        0,                    # cursor id (int64)
+        0,                    # starting from
+        1,                    # number returned
+    )
+    return header + doc
+
+def _op_msg(request_id: int, doc: bytes) -> bytes:
+    payload = b"\x00" + doc
+    flag_bits = struct.pack("<I", 0)
+    msg_body = flag_bits + payload
+    header = struct.pack("<iiii",
+        16 + len(msg_body),
+        1,
+        request_id,
+        2013,
+    )
+    return header + msg_body
+
+def _log(event_type: str, severity: int = 6, **kwargs) -> None:
+    line = syslog_line(SERVICE_NAME, NODE_NAME, event_type, severity, **kwargs)
+    write_syslog_file(line)
+    forward_syslog(line, LOG_TARGET)
+
+
+class MongoDBProtocol(asyncio.Protocol):
+    def __init__(self):
+        self._transport = None
+        self._peer = None
+        self._buf = b""
+        # Per-connection SCRAM state: pinned at saslStart so the
+        # subsequent saslContinue's client-proof can carry the username
+        # in the emitted credential row.
+        self._sasl_username: str | None = None
+        self._sasl_mechanism: str | None = None
+
+    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
+        while len(self._buf) >= 16:
+            msg_len = struct.unpack("<I", self._buf[:4])[0]
+            if msg_len < 16 or msg_len > 48 * 1024 * 1024:
+                self._transport.close()
+                self._buf = b""
+                return
+            if len(self._buf) < msg_len:
+                break
+            msg = self._buf[:msg_len]
+            self._buf = self._buf[msg_len:]
+            self._handle_message(msg)
+
+    def _handle_message(self, msg: bytes):
+        if len(msg) < 16:
+            return
+        request_id = struct.unpack("<I", msg[4:8])[0]
+        opcode = struct.unpack("<I", msg[12:16])[0]
+        _log("message", src=self._peer[0], opcode=opcode, length=len(msg))
+
+        # SCRAM cred capture: parse the OP_MSG body BSON looking for
+        # saslStart / saslContinue. Each fires its own log event:
+        # saslStart pins the username + mechanism; saslContinue emits
+        # the credential row with the client-proof as secret_b64.
+        if opcode == 2013 and len(msg) >= 21:
+            # OP_MSG body: 4 bytes flagBits, then sections. We only
+            # parse kind=0 (Body) sections — kind=1 (DocSeq) is for
+            # bulk ops that don't carry SCRAM auth.
+            p = 20  # 16 hdr + 4 flagBits
+            while p < len(msg):
+                kind = msg[p]
+                p += 1
+                if kind == 0:  # Body section
+                    if p + 4 > len(msg):
+                        break
+                    doc_len = struct.unpack_from("<i", msg, p)[0]
+                    if p + doc_len > len(msg):
+                        break
+                    cmd = _bson_read(msg, p)
+                    self._handle_command(cmd)
+                    p += doc_len
+                elif kind == 1:  # DocSeq — skip
+                    if p + 4 > len(msg):
+                        break
+                    seq_len = struct.unpack_from("<i", msg, p)[0]
+                    p += seq_len
+                else:
+                    break
+
+        # Build a generic isMaster-style OK response with this instance's
+        # version pair. Fresh topologyVersion on every reply (matches real
+        # mongod behavior — clients use this to detect failover).
+        fields = [
+            _bson_bool("ismaster", True),
+            _bson_bool("helloOk", True),
+            _bson_int32("maxBsonObjectSize", 16777216),
+            _bson_int32("maxMessageSizeBytes", 48000000),
+            _bson_int32("maxWriteBatchSize", 100000),
+            _bson_int32("maxWireVersion", _MONGO_WIRE),
+            _bson_int32("minWireVersion", 0),
+            _bson_str("version", _MONGO_VERSION),
+            _bson_int32("ok", 1),
+        ]
+        if _MONGO_SET_NAME:
+            fields.insert(1, _bson_str("setName", _MONGO_SET_NAME))
+        reply_doc = _bson_doc(*fields)
+        if opcode == 2013:  # OP_MSG
+            self._transport.write(_op_msg(request_id, reply_doc))
+        else:
+            self._transport.write(_op_reply(request_id, reply_doc))
+
+    def _handle_command(self, cmd: dict) -> None:
+        """Parse a single MongoDB command document for SCRAM auth.
+
+        saslStart  — client-first-message in payload. Extract
+                     `n=<username>` so the next saslContinue inherits it.
+        saslContinue — client-final-message in payload. Extract
+                       `p=<base64 client-proof>` and emit a cred row.
+        """
+        # mongo's command dispatch keys off the FIRST field of the BSON
+        # document. We just check key presence since dict ordering in
+        # CPython 3.7+ matches insertion order.
+        if "saslStart" in cmd:
+            mechanism = cmd.get("mechanism")
+            payload = cmd.get("payload") or b""
+            if isinstance(mechanism, str):
+                self._sasl_mechanism = mechanism
+            if isinstance(payload, (bytes, bytearray)):
+                kv = _scram_kv(bytes(payload))
+                self._sasl_username = kv.get("n")
+                _log("auth_start", src=self._peer[0],
+                     mechanism=mechanism or "?",
+                     username=self._sasl_username or "")
+            return
+
+        if "saslContinue" in cmd:
+            payload = cmd.get("payload") or b""
+            if not isinstance(payload, (bytes, bytearray)):
+                return
+            kv = _scram_kv(bytes(payload))
+            proof_b64 = kv.get("p")
+            if not proof_b64:
+                return
+            try:
+                proof_raw = base64.b64decode(proof_b64, validate=True)
+            except (ValueError, base64.binascii.Error):
+                return
+            mech = (self._sasl_mechanism or "").upper()
+            if "SHA-256" in mech or "SHA256" in mech:
+                kind = "scram_sha256"
+            elif "SHA-1" in mech or "SHA1" in mech:
+                kind = "scram_sha1"
+            else:
+                kind = "scram_unknown"
+            _log("auth", src=self._peer[0],
+                 username=self._sasl_username or "",
+                 principal=self._sasl_username,
+                 mechanism=self._sasl_mechanism or "",
+                 secret_kind=kind,
+                 secret_printable=proof_b64,
+                 secret_b64=base64.b64encode(proof_raw).decode("ascii"))
+            return
+
+    def connection_lost(self, exc):
+        _log("disconnect", src=self._peer[0] if self._peer else "?")
+
+
+async def main():
+    _log("startup", msg=f"MongoDB server starting as {NODE_NAME}")
+    loop = asyncio.get_running_loop()
+    server = await loop.create_server(MongoDBProtocol, "0.0.0.0", PORT)  # nosec B104
+    async with server:
+        await server.serve_forever()
+
+
+if __name__ == "__main__":
+    asyncio.run(main())

decnet/templates/mongodb/syslog_bridge.py

@@ -0,0 +1,261 @@
+#!/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 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, base64.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