feat: add HASSHServer and TCP/IP stack fingerprinting to DECNET-PROBER

Extends the prober with two new active probe types alongside JARM:
- HASSHServer: SSH server fingerprinting via KEX_INIT algorithm ordering
  (MD5 hash of kex;enc_s2c;mac_s2c;comp_s2c, pure stdlib)
- TCP/IP stack: OS/tool fingerprinting via SYN-ACK analysis using scapy
  (TTL, window size, DF bit, MSS, TCP options ordering, SHA256 hash)

Worker probe cycle now runs three phases per IP with independent
per-type port tracking. Ingester extracts bounties for all three
fingerprint types.

decnet/cli.py

@@ -324,7 +324,7 @@ def probe(
     timeout: float = typer.Option(5.0, "--timeout", help="Per-probe TCP timeout in seconds"),
     daemon: bool = typer.Option(False, "--daemon", "-d", help="Detach to background (used by deploy, no console output)"),
 ) -> None:
-    """JARM-fingerprint all attackers discovered in the log stream."""
+    """Fingerprint attackers (JARM + HASSH + TCP/IP stack) discovered in the log stream."""
     import asyncio
     from decnet.prober import prober_worker
 

decnet/prober/hassh.py

@@ -0,0 +1,248 @@
+"""
+HASSHServer — SSH server fingerprinting via KEX_INIT algorithm ordering.
+
+Connects to an SSH server, completes the version exchange, captures the
+server's SSH_MSG_KEXINIT message, and hashes the server-to-client algorithm
+fields (kex, encryption, MAC, compression) into a 32-character MD5 digest.
+
+This is the *server* variant of HASSH (HASSHServer). It fingerprints what
+the server *offers*, which identifies the SSH implementation (OpenSSH,
+Paramiko, libssh, Cobalt Strike SSH, etc.).
+
+Stdlib only (socket, struct, hashlib). No DECNET imports.
+"""
+
+from __future__ import annotations
+
+import hashlib
+import socket
+import struct
+from typing import Any
+
+# SSH protocol constants
+_SSH_MSG_KEXINIT = 20
+_KEX_INIT_COOKIE_LEN = 16
+_KEX_INIT_NAME_LISTS = 10  # 10 name-list fields in KEX_INIT
+
+# Blend in as a normal OpenSSH client
+_CLIENT_BANNER = b"SSH-2.0-OpenSSH_9.6\r\n"
+
+# Max bytes to read for server banner
+_MAX_BANNER_LEN = 256
+
+# Max bytes for a single SSH packet (KEX_INIT is typically < 2KB)
+_MAX_PACKET_LEN = 35000
+
+
+# ─── SSH connection + KEX_INIT capture ──────────────────────────────────────
+
+def _ssh_connect(
+    host: str,
+    port: int,
+    timeout: float,
+) -> tuple[str, bytes] | None:
+    """
+    TCP connect, exchange version strings, read server's KEX_INIT.
+
+    Returns (server_banner, kex_init_payload) or None on failure.
+    The kex_init_payload starts at the SSH_MSG_KEXINIT type byte.
+    """
+    sock = None
+    try:
+        sock = socket.create_connection((host, port), timeout=timeout)
+        sock.settimeout(timeout)
+
+        # 1. Read server banner (line ending \r\n or \n)
+        banner = _read_banner(sock)
+        if banner is None or not banner.startswith("SSH-"):
+            return None
+
+        # 2. Send our client version string
+        sock.sendall(_CLIENT_BANNER)
+
+        # 3. Read the server's first binary packet (should be KEX_INIT)
+        payload = _read_ssh_packet(sock)
+        if payload is None or len(payload) < 1:
+            return None
+
+        if payload[0] != _SSH_MSG_KEXINIT:
+            return None
+
+        return (banner, payload)
+
+    except (OSError, socket.timeout, TimeoutError, ConnectionError):
+        return None
+    finally:
+        if sock is not None:
+            try:
+                sock.close()
+            except OSError:
+                pass
+
+
+def _read_banner(sock: socket.socket) -> str | None:
+    """Read the SSH version banner line from the socket."""
+    buf = b""
+    while len(buf) < _MAX_BANNER_LEN:
+        try:
+            byte = sock.recv(1)
+        except (OSError, socket.timeout, TimeoutError):
+            return None
+        if not byte:
+            return None
+        buf += byte
+        if buf.endswith(b"\n"):
+            break
+
+    try:
+        return buf.decode("utf-8", errors="replace").rstrip("\r\n")
+    except Exception:
+        return None
+
+
+def _read_ssh_packet(sock: socket.socket) -> bytes | None:
+    """
+    Read a single SSH binary packet and return its payload.
+
+    SSH binary packet format:
+        uint32  packet_length   (not including itself or MAC)
+        byte    padding_length
+        byte[]  payload         (packet_length - padding_length - 1)
+        byte[]  padding
+    """
+    header = _recv_exact(sock, 4)
+    if header is None:
+        return None
+
+    packet_length = struct.unpack("!I", header)[0]
+    if packet_length < 2 or packet_length > _MAX_PACKET_LEN:
+        return None
+
+    rest = _recv_exact(sock, packet_length)
+    if rest is None:
+        return None
+
+    padding_length = rest[0]
+    payload_length = packet_length - padding_length - 1
+    if payload_length < 1 or payload_length > len(rest) - 1:
+        return None
+
+    return rest[1 : 1 + payload_length]
+
+
+def _recv_exact(sock: socket.socket, n: int) -> bytes | None:
+    """Read exactly n bytes from socket, or None on failure."""
+    buf = b""
+    while len(buf) < n:
+        try:
+            chunk = sock.recv(n - len(buf))
+        except (OSError, socket.timeout, TimeoutError):
+            return None
+        if not chunk:
+            return None
+        buf += chunk
+    return buf
+
+
+# ─── KEX_INIT parsing ──────────────────────────────────────────────────────
+
+def _parse_kex_init(payload: bytes) -> dict[str, str] | None:
+    """
+    Parse SSH_MSG_KEXINIT payload and extract the 10 name-list fields.
+
+    Payload layout:
+        byte    SSH_MSG_KEXINIT (20)
+        byte[16] cookie
+        10 × name-list:
+            uint32  length
+            byte[]  utf-8 string (comma-separated algorithm names)
+        bool    first_kex_packet_follows
+        uint32  reserved
+
+    Returns dict with keys: kex_algorithms, server_host_key_algorithms,
+    encryption_client_to_server, encryption_server_to_client,
+    mac_client_to_server, mac_server_to_client,
+    compression_client_to_server, compression_server_to_client,
+    languages_client_to_server, languages_server_to_client.
+    """
+    if len(payload) < 1 + _KEX_INIT_COOKIE_LEN + 4:
+        return None
+
+    offset = 1 + _KEX_INIT_COOKIE_LEN  # skip type byte + cookie
+
+    field_names = [
+        "kex_algorithms",
+        "server_host_key_algorithms",
+        "encryption_client_to_server",
+        "encryption_server_to_client",
+        "mac_client_to_server",
+        "mac_server_to_client",
+        "compression_client_to_server",
+        "compression_server_to_client",
+        "languages_client_to_server",
+        "languages_server_to_client",
+    ]
+
+    fields: dict[str, str] = {}
+    for name in field_names:
+        if offset + 4 > len(payload):
+            return None
+        length = struct.unpack("!I", payload[offset : offset + 4])[0]
+        offset += 4
+        if offset + length > len(payload):
+            return None
+        fields[name] = payload[offset : offset + length].decode(
+            "utf-8", errors="replace"
+        )
+        offset += length
+
+    return fields
+
+
+# ─── HASSH computation ──────────────────────────────────────────────────────
+
+def _compute_hassh(kex: str, enc: str, mac: str, comp: str) -> str:
+    """
+    Compute HASSHServer hash: MD5 of "kex;enc_s2c;mac_s2c;comp_s2c".
+
+    Returns 32-character lowercase hex digest.
+    """
+    raw = f"{kex};{enc};{mac};{comp}"
+    return hashlib.md5(raw.encode("utf-8")).hexdigest()
+
+
+# ─── Public API ─────────────────────────────────────────────────────────────
+
+def hassh_server(
+    host: str,
+    port: int,
+    timeout: float = 5.0,
+) -> dict[str, Any] | None:
+    """
+    Connect to an SSH server and compute its HASSHServer fingerprint.
+
+    Returns a dict with the hash, banner, and raw algorithm fields,
+    or None if the host is not running an SSH server on the given port.
+    """
+    result = _ssh_connect(host, port, timeout)
+    if result is None:
+        return None
+
+    banner, payload = result
+    fields = _parse_kex_init(payload)
+    if fields is None:
+        return None
+
+    kex = fields["kex_algorithms"]
+    enc = fields["encryption_server_to_client"]
+    mac = fields["mac_server_to_client"]
+    comp = fields["compression_server_to_client"]
+
+    return {
+        "hassh_server": _compute_hassh(kex, enc, mac, comp),
+        "banner": banner,
+        "kex_algorithms": kex,
+        "encryption_s2c": enc,
+        "mac_s2c": mac,
+        "compression_s2c": comp,
+    }

decnet/prober/tcpfp.py

@@ -0,0 +1,223 @@
+"""
+TCP/IP stack fingerprinting via SYN-ACK analysis.
+
+Sends a crafted TCP SYN packet to a target host:port, captures the
+SYN-ACK response, and extracts OS/tool-identifying characteristics:
+TTL, window size, DF bit, MSS, window scale, SACK support, timestamps,
+and TCP options ordering.
+
+Uses scapy for packet crafting and parsing. Requires root/CAP_NET_RAW.
+"""
+
+from __future__ import annotations
+
+import hashlib
+import random
+from typing import Any
+
+# Lazy-import scapy to avoid breaking non-root usage of HASSH/JARM.
+# The actual import happens inside functions that need it.
+
+# ─── TCP option short codes ─────────────────────────────────────────────────
+
+_OPT_CODES: dict[str, str] = {
+    "MSS": "M",
+    "WScale": "W",
+    "SAckOK": "S",
+    "SAck": "S",
+    "Timestamp": "T",
+    "NOP": "N",
+    "EOL": "E",
+    "AltChkSum": "A",
+    "AltChkSumOpt": "A",
+    "UTO": "U",
+}
+
+
+# ─── Packet construction ───────────────────────────────────────────────────
+
+def _send_syn(
+    host: str,
+    port: int,
+    timeout: float,
+) -> Any | None:
+    """
+    Craft a TCP SYN with common options and send it. Returns the
+    SYN-ACK response packet or None on timeout/failure.
+    """
+    from scapy.all import IP, TCP, conf, sr1
+
+    # Suppress scapy's noisy output
+    conf.verb = 0
+
+    src_port = random.randint(49152, 65535)
+
+    pkt = (
+        IP(dst=host)
+        / TCP(
+            sport=src_port,
+            dport=port,
+            flags="S",
+            options=[
+                ("MSS", 1460),
+                ("NOP", None),
+                ("WScale", 7),
+                ("NOP", None),
+                ("NOP", None),
+                ("Timestamp", (0, 0)),
+                ("SAckOK", b""),
+                ("EOL", None),
+            ],
+        )
+    )
+
+    try:
+        resp = sr1(pkt, timeout=timeout, verbose=0)
+    except (OSError, PermissionError):
+        return None
+
+    if resp is None:
+        return None
+
+    # Verify it's a SYN-ACK (flags == 0x12)
+    from scapy.all import TCP as TCPLayer
+    if not resp.haslayer(TCPLayer):
+        return None
+    if resp[TCPLayer].flags != 0x12:  # SYN-ACK
+        return None
+
+    # Send RST to clean up half-open connection
+    _send_rst(host, port, src_port, resp)
+
+    return resp
+
+
+def _send_rst(
+    host: str,
+    dport: int,
+    sport: int,
+    resp: Any,
+) -> None:
+    """Send RST to clean up the half-open connection."""
+    try:
+        from scapy.all import IP, TCP, send
+        rst = (
+            IP(dst=host)
+            / TCP(
+                sport=sport,
+                dport=dport,
+                flags="R",
+                seq=resp.ack,
+            )
+        )
+        send(rst, verbose=0)
+    except Exception:
+        pass  # Best-effort cleanup
+
+
+# ─── Response parsing ───────────────────────────────────────────────────────
+
+def _parse_synack(resp: Any) -> dict[str, Any]:
+    """
+    Extract fingerprint fields from a scapy SYN-ACK response packet.
+    """
+    from scapy.all import IP, TCP
+
+    ip_layer = resp[IP]
+    tcp_layer = resp[TCP]
+
+    # IP fields
+    ttl = ip_layer.ttl
+    df_bit = 1 if (ip_layer.flags & 0x2) else 0  # DF = bit 1
+    ip_id = ip_layer.id
+
+    # TCP fields
+    window_size = tcp_layer.window
+
+    # Parse TCP options
+    mss = 0
+    window_scale = -1
+    sack_ok = 0
+    timestamp = 0
+    options_order = _extract_options_order(tcp_layer.options)
+
+    for opt_name, opt_value in tcp_layer.options:
+        if opt_name == "MSS":
+            mss = opt_value
+        elif opt_name == "WScale":
+            window_scale = opt_value
+        elif opt_name in ("SAckOK", "SAck"):
+            sack_ok = 1
+        elif opt_name == "Timestamp":
+            timestamp = 1
+
+    return {
+        "ttl": ttl,
+        "window_size": window_size,
+        "df_bit": df_bit,
+        "ip_id": ip_id,
+        "mss": mss,
+        "window_scale": window_scale,
+        "sack_ok": sack_ok,
+        "timestamp": timestamp,
+        "options_order": options_order,
+    }
+
+
+def _extract_options_order(options: list[tuple[str, Any]]) -> str:
+    """
+    Map scapy TCP option tuples to a short-code string.
+
+    E.g. [("MSS", 1460), ("NOP", None), ("WScale", 7)] → "M,N,W"
+    """
+    codes = []
+    for opt_name, _ in options:
+        code = _OPT_CODES.get(opt_name, "?")
+        codes.append(code)
+    return ",".join(codes)
+
+
+# ─── Fingerprint computation ───────────────────────────────────────────────
+
+def _compute_fingerprint(fields: dict[str, Any]) -> tuple[str, str]:
+    """
+    Compute fingerprint raw string and SHA256 hash from parsed fields.
+
+    Returns (raw_string, hash_hex_32).
+    """
+    raw = (
+        f"{fields['ttl']}:{fields['window_size']}:{fields['df_bit']}:"
+        f"{fields['mss']}:{fields['window_scale']}:{fields['sack_ok']}:"
+        f"{fields['timestamp']}:{fields['options_order']}"
+    )
+    h = hashlib.sha256(raw.encode("utf-8")).hexdigest()[:32]
+    return raw, h
+
+
+# ─── Public API ─────────────────────────────────────────────────────────────
+
+def tcp_fingerprint(
+    host: str,
+    port: int,
+    timeout: float = 5.0,
+) -> dict[str, Any] | None:
+    """
+    Send a TCP SYN to host:port and fingerprint the SYN-ACK response.
+
+    Returns a dict with the hash, raw fingerprint string, and individual
+    fields, or None if no SYN-ACK was received.
+
+    Requires root/CAP_NET_RAW.
+    """
+    resp = _send_syn(host, port, timeout)
+    if resp is None:
+        return None
+
+    fields = _parse_synack(resp)
+    raw, h = _compute_fingerprint(fields)
+
+    return {
+        "tcpfp_hash": h,
+        "tcpfp_raw": raw,
+        **fields,
+    }

decnet/prober/worker.py

@@ -2,7 +2,11 @@
 DECNET-PROBER standalone worker.
 
 Runs as a detached host-level process. Discovers attacker IPs by tailing the
-collector's JSON log file, then JARM-probes them on common C2/TLS ports.
+collector's JSON log file, then fingerprints them via multiple active probes:
+- JARM (TLS server fingerprinting)
+- HASSHServer (SSH server fingerprinting)
+- TCP/IP stack fingerprinting (OS/tool identification)
+
 Results are written as RFC 5424 syslog + JSON to the same log files.
 
 Target discovery is fully automatic — every unique attacker IP seen in the
@@ -23,17 +27,25 @@ from pathlib import Path
 from typing import Any
 
 from decnet.logging import get_logger
+from decnet.prober.hassh import hassh_server
 from decnet.prober.jarm import JARM_EMPTY_HASH, jarm_hash
+from decnet.prober.tcpfp import tcp_fingerprint
 
 logger = get_logger("prober")
 
-# ─── Default ports to JARM-probe on each attacker IP ─────────────────────────
+# ─── Default ports per probe type ───────────────────────────────────────────
-# Common C2 callback / TLS server ports (Cobalt Strike, Sliver, Metasploit, etc.)
 
+# JARM: common C2 callback / TLS server ports
 DEFAULT_PROBE_PORTS: list[int] = [
     443, 8443, 8080, 4443, 50050, 2222, 993, 995, 8888, 9001,
 ]
 
+# HASSHServer: common SSH server ports
+DEFAULT_SSH_PORTS: list[int] = [22, 2222, 22222, 2022]
+
+# TCP/IP stack: probe on common service ports
+DEFAULT_TCPFP_PORTS: list[int] = [80, 443]
+
 # ─── RFC 5424 formatting (inline, mirrors templates/*/decnet_logging.py) ─────
 
 _FACILITY_LOCAL0 = 16
@@ -208,38 +220,58 @@ def _discover_attackers(json_path: Path, position: int) -> tuple[set[str], int]:
 
 def _probe_cycle(
     targets: set[str],
-    probed: dict[str, set[int]],
+    probed: dict[str, dict[str, set[int]]],
-    ports: list[int],
+    jarm_ports: list[int],
+    ssh_ports: list[int],
+    tcpfp_ports: list[int],
     log_path: Path,
     json_path: Path,
     timeout: float = 5.0,
 ) -> None:
     """
-    Probe all known attacker IPs on the configured ports.
+    Probe all known attacker IPs with JARM, HASSH, and TCP/IP fingerprinting.
 
     Args:
         targets: set of attacker IPs to probe
-        probed: dict mapping IP -> set of ports already successfully probed
+        probed: dict mapping IP -> {probe_type -> set of ports already probed}
-        ports: list of ports to probe on each IP
+        jarm_ports: TLS ports for JARM fingerprinting
+        ssh_ports: SSH ports for HASSHServer fingerprinting
+        tcpfp_ports: ports for TCP/IP stack fingerprinting
         log_path: RFC 5424 log file
         json_path: JSON log file
         timeout: per-probe TCP timeout
     """
     for ip in sorted(targets):
-        already_done = probed.get(ip, set())
+        ip_probed = probed.setdefault(ip, {})
-        ports_to_probe = [p for p in ports if p not in already_done]
 
-        if not ports_to_probe:
+        # Phase 1: JARM (TLS fingerprinting)
+        _jarm_phase(ip, ip_probed, jarm_ports, log_path, json_path, timeout)
+
+        # Phase 2: HASSHServer (SSH fingerprinting)
+        _hassh_phase(ip, ip_probed, ssh_ports, log_path, json_path, timeout)
+
+        # Phase 3: TCP/IP stack fingerprinting
+        _tcpfp_phase(ip, ip_probed, tcpfp_ports, log_path, json_path, timeout)
+
+
+def _jarm_phase(
+    ip: str,
+    ip_probed: dict[str, set[int]],
+    ports: list[int],
+    log_path: Path,
+    json_path: Path,
+    timeout: float,
+) -> None:
+    """JARM-fingerprint an IP on the given TLS ports."""
+    done = ip_probed.setdefault("jarm", set())
+    for port in ports:
+        if port in done:
             continue
-
-        for port in ports_to_probe:
         try:
             h = jarm_hash(ip, port, timeout=timeout)
+            done.add(port)
             if h == JARM_EMPTY_HASH:
-                    # No TLS server on this port — don't log, don't reprobed
-                    probed.setdefault(ip, set()).add(port)
                 continue
-
             _write_event(
                 log_path, json_path,
                 "jarm_fingerprint",
@@ -249,9 +281,8 @@ def _probe_cycle(
                 msg=f"JARM {ip}:{port} = {h}",
             )
             logger.info("prober: JARM %s:%d = %s", ip, port, h)
-                probed.setdefault(ip, set()).add(port)
-
         except Exception as exc:
+            done.add(port)
             _write_event(
                 log_path, json_path,
                 "prober_error",
@@ -262,8 +293,102 @@ def _probe_cycle(
                 msg=f"JARM probe failed for {ip}:{port}: {exc}",
             )
             logger.warning("prober: JARM probe failed %s:%d: %s", ip, port, exc)
-                # Mark as probed to avoid infinite retries
+
-                probed.setdefault(ip, set()).add(port)
+
+def _hassh_phase(
+    ip: str,
+    ip_probed: dict[str, set[int]],
+    ports: list[int],
+    log_path: Path,
+    json_path: Path,
+    timeout: float,
+) -> None:
+    """HASSHServer-fingerprint an IP on the given SSH ports."""
+    done = ip_probed.setdefault("hassh", set())
+    for port in ports:
+        if port in done:
+            continue
+        try:
+            result = hassh_server(ip, port, timeout=timeout)
+            done.add(port)
+            if result is None:
+                continue
+            _write_event(
+                log_path, json_path,
+                "hassh_fingerprint",
+                target_ip=ip,
+                target_port=str(port),
+                hassh_server_hash=result["hassh_server"],
+                ssh_banner=result["banner"],
+                kex_algorithms=result["kex_algorithms"],
+                encryption_s2c=result["encryption_s2c"],
+                mac_s2c=result["mac_s2c"],
+                compression_s2c=result["compression_s2c"],
+                msg=f"HASSH {ip}:{port} = {result['hassh_server']}",
+            )
+            logger.info("prober: HASSH %s:%d = %s", ip, port, result["hassh_server"])
+        except Exception as exc:
+            done.add(port)
+            _write_event(
+                log_path, json_path,
+                "prober_error",
+                severity=_SEVERITY_WARNING,
+                target_ip=ip,
+                target_port=str(port),
+                error=str(exc),
+                msg=f"HASSH probe failed for {ip}:{port}: {exc}",
+            )
+            logger.warning("prober: HASSH probe failed %s:%d: %s", ip, port, exc)
+
+
+def _tcpfp_phase(
+    ip: str,
+    ip_probed: dict[str, set[int]],
+    ports: list[int],
+    log_path: Path,
+    json_path: Path,
+    timeout: float,
+) -> None:
+    """TCP/IP stack fingerprint an IP on the given ports."""
+    done = ip_probed.setdefault("tcpfp", set())
+    for port in ports:
+        if port in done:
+            continue
+        try:
+            result = tcp_fingerprint(ip, port, timeout=timeout)
+            done.add(port)
+            if result is None:
+                continue
+            _write_event(
+                log_path, json_path,
+                "tcpfp_fingerprint",
+                target_ip=ip,
+                target_port=str(port),
+                tcpfp_hash=result["tcpfp_hash"],
+                tcpfp_raw=result["tcpfp_raw"],
+                ttl=str(result["ttl"]),
+                window_size=str(result["window_size"]),
+                df_bit=str(result["df_bit"]),
+                mss=str(result["mss"]),
+                window_scale=str(result["window_scale"]),
+                sack_ok=str(result["sack_ok"]),
+                timestamp=str(result["timestamp"]),
+                options_order=result["options_order"],
+                msg=f"TCPFP {ip}:{port} = {result['tcpfp_hash']}",
+            )
+            logger.info("prober: TCPFP %s:%d = %s", ip, port, result["tcpfp_hash"])
+        except Exception as exc:
+            done.add(port)
+            _write_event(
+                log_path, json_path,
+                "prober_error",
+                severity=_SEVERITY_WARNING,
+                target_ip=ip,
+                target_port=str(port),
+                error=str(exc),
+                msg=f"TCPFP probe failed for {ip}:{port}: {exc}",
+            )
+            logger.warning("prober: TCPFP probe failed %s:%d: %s", ip, port, exc)
 
 
 # ─── Main worker ─────────────────────────────────────────────────────────────
@@ -273,41 +398,52 @@ async def prober_worker(
     interval: int = 300,
     timeout: float = 5.0,
     ports: list[int] | None = None,
+    ssh_ports: list[int] | None = None,
+    tcpfp_ports: list[int] | None = None,
 ) -> None:
     """
     Main entry point for the standalone prober process.
 
     Discovers attacker IPs automatically by tailing the JSON log file,
-    then JARM-probes each IP on common C2 ports.
+    then fingerprints each IP via JARM, HASSH, and TCP/IP stack probes.
 
     Args:
         log_file: base path for log files (RFC 5424 to .log, JSON to .json)
         interval: seconds between probe cycles
         timeout: per-probe TCP timeout
-        ports: list of ports to probe (defaults to DEFAULT_PROBE_PORTS)
+        ports: JARM TLS ports (defaults to DEFAULT_PROBE_PORTS)
+        ssh_ports: HASSH SSH ports (defaults to DEFAULT_SSH_PORTS)
+        tcpfp_ports: TCP fingerprint ports (defaults to DEFAULT_TCPFP_PORTS)
     """
-    probe_ports = ports or DEFAULT_PROBE_PORTS
+    jarm_ports = ports or DEFAULT_PROBE_PORTS
+    hassh_ports = ssh_ports or DEFAULT_SSH_PORTS
+    tcp_ports = tcpfp_ports or DEFAULT_TCPFP_PORTS
+
+    all_ports_str = (
+        f"jarm={','.join(str(p) for p in jarm_ports)} "
+        f"ssh={','.join(str(p) for p in hassh_ports)} "
+        f"tcpfp={','.join(str(p) for p in tcp_ports)}"
+    )
 
     log_path = Path(log_file)
     json_path = log_path.with_suffix(".json")
     log_path.parent.mkdir(parents=True, exist_ok=True)
 
     logger.info(
-        "prober started interval=%ds ports=%s log=%s",
+        "prober started interval=%ds %s log=%s",
-        interval, ",".join(str(p) for p in probe_ports), log_path,
+        interval, all_ports_str, log_path,
     )
 
     _write_event(
         log_path, json_path,
         "prober_startup",
         interval=str(interval),
-        probe_ports=",".join(str(p) for p in probe_ports),
+        probe_ports=all_ports_str,
-        msg=f"DECNET-PROBER started, interval {interval}s, "
+        msg=f"DECNET-PROBER started, interval {interval}s, {all_ports_str}",
-            f"ports {','.join(str(p) for p in probe_ports)}",
     )
 
     known_attackers: set[str] = set()
-    probed: dict[str, set[int]] = {}  # IP -> set of ports already probed
+    probed: dict[str, dict[str, set[int]]] = {}  # IP -> {type -> ports}
     log_position: int = 0
 
     while True:
@@ -326,7 +462,8 @@ async def prober_worker(
 
         if known_attackers:
             await asyncio.to_thread(
-                _probe_cycle, known_attackers, probed, probe_ports,
+                _probe_cycle, known_attackers, probed,
+                jarm_ports, hassh_ports, tcp_ports,
                 log_path, json_path, timeout,
             )
 

decnet/web/ingester.py

@@ -218,3 +218,49 @@ async def _extract_bounty(repo: BaseRepository, log_data: dict[str, Any]) -> Non
                 "target_port": _fields.get("target_port"),
             },
         })
+
+    # 10. HASSHServer fingerprint from active prober
+    _hassh = _fields.get("hassh_server_hash")
+    if _hassh and log_data.get("service") == "prober":
+        await repo.add_bounty({
+            "decky": log_data.get("decky"),
+            "service": "prober",
+            "attacker_ip": _fields.get("target_ip", "Unknown"),
+            "bounty_type": "fingerprint",
+            "payload": {
+                "fingerprint_type": "hassh_server",
+                "hash": _hassh,
+                "target_ip": _fields.get("target_ip"),
+                "target_port": _fields.get("target_port"),
+                "ssh_banner": _fields.get("ssh_banner"),
+                "kex_algorithms": _fields.get("kex_algorithms"),
+                "encryption_s2c": _fields.get("encryption_s2c"),
+                "mac_s2c": _fields.get("mac_s2c"),
+                "compression_s2c": _fields.get("compression_s2c"),
+            },
+        })
+
+    # 11. TCP/IP stack fingerprint from active prober
+    _tcpfp = _fields.get("tcpfp_hash")
+    if _tcpfp and log_data.get("service") == "prober":
+        await repo.add_bounty({
+            "decky": log_data.get("decky"),
+            "service": "prober",
+            "attacker_ip": _fields.get("target_ip", "Unknown"),
+            "bounty_type": "fingerprint",
+            "payload": {
+                "fingerprint_type": "tcpfp",
+                "hash": _tcpfp,
+                "raw": _fields.get("tcpfp_raw"),
+                "target_ip": _fields.get("target_ip"),
+                "target_port": _fields.get("target_port"),
+                "ttl": _fields.get("ttl"),
+                "window_size": _fields.get("window_size"),
+                "df_bit": _fields.get("df_bit"),
+                "mss": _fields.get("mss"),
+                "window_scale": _fields.get("window_scale"),
+                "sack_ok": _fields.get("sack_ok"),
+                "timestamp": _fields.get("timestamp"),
+                "options_order": _fields.get("options_order"),
+            },
+        })

tests/test_prober_bounty.py

@@ -1,8 +1,9 @@
 """
-Tests for JARM bounty extraction in the ingester.
+Tests for prober bounty extraction in the ingester.
 
-Verifies that _extract_bounty() correctly identifies and stores JARM
+Verifies that _extract_bounty() correctly identifies and stores JARM,
-fingerprints from prober events, and ignores JARM fields from other services.
+HASSH, and TCP/IP fingerprints from prober events, and ignores these
+fields when they come from other services.
 """
 
 from __future__ import annotations
@@ -112,3 +113,131 @@ async def test_jarm_bounty_missing_fields_dict():
     for call in repo.add_bounty.call_args_list:
         payload = call[0][0].get("payload", {})
         assert payload.get("fingerprint_type") != "jarm"
+
+
+# ─── HASSH bounty extraction ───────────────────────────────────────────────
+
+@pytest.mark.asyncio
+async def test_hassh_bounty_extracted():
+    """Prober event with hassh_server_hash should create a fingerprint bounty."""
+    repo = _make_repo()
+    log_data = {
+        "decky": "decnet-prober",
+        "service": "prober",
+        "event_type": "hassh_fingerprint",
+        "attacker_ip": "Unknown",
+        "fields": {
+            "target_ip": "10.0.0.1",
+            "target_port": "22",
+            "hassh_server_hash": "a" * 32,
+            "ssh_banner": "SSH-2.0-OpenSSH_8.9p1",
+            "kex_algorithms": "curve25519-sha256",
+            "encryption_s2c": "aes256-gcm@openssh.com",
+            "mac_s2c": "hmac-sha2-256-etm@openssh.com",
+            "compression_s2c": "none",
+        },
+        "msg": "HASSH 10.0.0.1:22 = ...",
+    }
+
+    await _extract_bounty(repo, log_data)
+
+    # Find the HASSH bounty call
+    hassh_calls = [
+        c for c in repo.add_bounty.call_args_list
+        if c[0][0].get("payload", {}).get("fingerprint_type") == "hassh_server"
+    ]
+    assert len(hassh_calls) == 1
+    payload = hassh_calls[0][0][0]["payload"]
+    assert payload["hash"] == "a" * 32
+    assert payload["ssh_banner"] == "SSH-2.0-OpenSSH_8.9p1"
+    assert payload["kex_algorithms"] == "curve25519-sha256"
+    assert payload["encryption_s2c"] == "aes256-gcm@openssh.com"
+    assert payload["mac_s2c"] == "hmac-sha2-256-etm@openssh.com"
+    assert payload["compression_s2c"] == "none"
+
+
+@pytest.mark.asyncio
+async def test_hassh_bounty_not_extracted_from_other_services():
+    """A non-prober event with hassh_server_hash should NOT trigger extraction."""
+    repo = _make_repo()
+    log_data = {
+        "decky": "decky-01",
+        "service": "ssh",
+        "event_type": "login_attempt",
+        "attacker_ip": "192.168.1.50",
+        "fields": {
+            "hassh_server_hash": "fake_hash",
+        },
+        "msg": "",
+    }
+
+    await _extract_bounty(repo, log_data)
+
+    for call in repo.add_bounty.call_args_list:
+        payload = call[0][0].get("payload", {})
+        assert payload.get("fingerprint_type") != "hassh_server"
+
+
+# ─── TCP/IP fingerprint bounty extraction ──────────────────────────────────
+
+@pytest.mark.asyncio
+async def test_tcpfp_bounty_extracted():
+    """Prober event with tcpfp_hash should create a fingerprint bounty."""
+    repo = _make_repo()
+    log_data = {
+        "decky": "decnet-prober",
+        "service": "prober",
+        "event_type": "tcpfp_fingerprint",
+        "attacker_ip": "Unknown",
+        "fields": {
+            "target_ip": "10.0.0.1",
+            "target_port": "443",
+            "tcpfp_hash": "d" * 32,
+            "tcpfp_raw": "64:65535:1:1460:7:1:1:M,N,W,N,N,T,S,E",
+            "ttl": "64",
+            "window_size": "65535",
+            "df_bit": "1",
+            "mss": "1460",
+            "window_scale": "7",
+            "sack_ok": "1",
+            "timestamp": "1",
+            "options_order": "M,N,W,N,N,T,S,E",
+        },
+        "msg": "TCPFP 10.0.0.1:443 = ...",
+    }
+
+    await _extract_bounty(repo, log_data)
+
+    tcpfp_calls = [
+        c for c in repo.add_bounty.call_args_list
+        if c[0][0].get("payload", {}).get("fingerprint_type") == "tcpfp"
+    ]
+    assert len(tcpfp_calls) == 1
+    payload = tcpfp_calls[0][0][0]["payload"]
+    assert payload["hash"] == "d" * 32
+    assert payload["raw"] == "64:65535:1:1460:7:1:1:M,N,W,N,N,T,S,E"
+    assert payload["ttl"] == "64"
+    assert payload["window_size"] == "65535"
+    assert payload["options_order"] == "M,N,W,N,N,T,S,E"
+
+
+@pytest.mark.asyncio
+async def test_tcpfp_bounty_not_extracted_from_other_services():
+    """A non-prober event with tcpfp_hash should NOT trigger extraction."""
+    repo = _make_repo()
+    log_data = {
+        "decky": "decky-01",
+        "service": "sniffer",
+        "event_type": "something",
+        "attacker_ip": "192.168.1.50",
+        "fields": {
+            "tcpfp_hash": "fake_hash",
+        },
+        "msg": "",
+    }
+
+    await _extract_bounty(repo, log_data)
+
+    for call in repo.add_bounty.call_args_list:
+        payload = call[0][0].get("payload", {})
+        assert payload.get("fingerprint_type") != "tcpfp"

tests/test_prober_hassh.py

@@ -0,0 +1,357 @@
+"""
+Unit tests for the HASSHServer SSH fingerprinting module.
+
+Tests cover KEX_INIT parsing, HASSH hash computation, SSH connection
+handling, and end-to-end hassh_server() with mocked sockets.
+"""
+
+from __future__ import annotations
+
+import hashlib
+import socket
+import struct
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from decnet.prober.hassh import (
+    _CLIENT_BANNER,
+    _SSH_MSG_KEXINIT,
+    _compute_hassh,
+    _parse_kex_init,
+    _read_banner,
+    _read_ssh_packet,
+    hassh_server,
+)
+
+
+# ─── Helpers ────────────────────────────────────────────────────────────────
+
+def _build_name_list(value: str) -> bytes:
+    """Encode a single SSH name-list (uint32 length + utf-8 string)."""
+    encoded = value.encode("utf-8")
+    return struct.pack("!I", len(encoded)) + encoded
+
+
+def _build_kex_init(
+    kex: str = "curve25519-sha256,diffie-hellman-group14-sha256",
+    host_key: str = "ssh-ed25519,rsa-sha2-512",
+    enc_c2s: str = "aes256-gcm@openssh.com,aes128-gcm@openssh.com",
+    enc_s2c: str = "aes256-gcm@openssh.com,chacha20-poly1305@openssh.com",
+    mac_c2s: str = "hmac-sha2-256-etm@openssh.com",
+    mac_s2c: str = "hmac-sha2-256-etm@openssh.com,hmac-sha2-512-etm@openssh.com",
+    comp_c2s: str = "none,zlib@openssh.com",
+    comp_s2c: str = "none,zlib@openssh.com",
+    lang_c2s: str = "",
+    lang_s2c: str = "",
+    cookie: bytes | None = None,
+) -> bytes:
+    """Build a complete SSH_MSG_KEXINIT payload for testing."""
+    if cookie is None:
+        cookie = b"\x00" * 16
+
+    payload = struct.pack("B", _SSH_MSG_KEXINIT) + cookie
+    for value in [kex, host_key, enc_c2s, enc_s2c, mac_c2s, mac_s2c,
+                  comp_c2s, comp_s2c, lang_c2s, lang_s2c]:
+        payload += _build_name_list(value)
+    # first_kex_packet_follows (bool) + reserved (uint32)
+    payload += struct.pack("!BI", 0, 0)
+    return payload
+
+
+def _wrap_ssh_packet(payload: bytes) -> bytes:
+    """Wrap payload into an SSH binary packet (header only, no MAC)."""
+    # Padding to 8-byte boundary (minimum 4 bytes)
+    block_size = 8
+    padding_needed = block_size - ((1 + len(payload)) % block_size)
+    if padding_needed < 4:
+        padding_needed += block_size
+    padding = b"\x00" * padding_needed
+    packet_length = 1 + len(payload) + len(padding)  # padding_length(1) + payload + padding
+    return struct.pack("!IB", packet_length, padding_needed) + payload + padding
+
+
+def _make_socket_with_data(data: bytes) -> MagicMock:
+    """Create a mock socket that yields data byte-by-byte or in chunks."""
+    sock = MagicMock()
+    pos = [0]
+
+    def recv(n):
+        if pos[0] >= len(data):
+            return b""
+        chunk = data[pos[0] : pos[0] + n]
+        pos[0] += n
+        return chunk
+
+    sock.recv = recv
+    return sock
+
+
+# ─── _parse_kex_init ────────────────────────────────────────────────────────
+
+class TestParseKexInit:
+
+    def test_parses_all_ten_fields(self):
+        payload = _build_kex_init()
+        result = _parse_kex_init(payload)
+        assert result is not None
+        assert len(result) == 10
+
+    def test_extracts_correct_field_values(self):
+        payload = _build_kex_init(
+            kex="curve25519-sha256",
+            enc_s2c="chacha20-poly1305@openssh.com",
+            mac_s2c="hmac-sha2-512-etm@openssh.com",
+            comp_s2c="none",
+        )
+        result = _parse_kex_init(payload)
+        assert result["kex_algorithms"] == "curve25519-sha256"
+        assert result["encryption_server_to_client"] == "chacha20-poly1305@openssh.com"
+        assert result["mac_server_to_client"] == "hmac-sha2-512-etm@openssh.com"
+        assert result["compression_server_to_client"] == "none"
+
+    def test_extracts_hassh_server_fields_at_correct_indices(self):
+        """HASSHServer uses indices 0(kex), 3(enc_s2c), 5(mac_s2c), 7(comp_s2c)."""
+        payload = _build_kex_init(
+            kex="KEX_FIELD",
+            host_key="HOSTKEY_FIELD",
+            enc_c2s="ENC_C2S_FIELD",
+            enc_s2c="ENC_S2C_FIELD",
+            mac_c2s="MAC_C2S_FIELD",
+            mac_s2c="MAC_S2C_FIELD",
+            comp_c2s="COMP_C2S_FIELD",
+            comp_s2c="COMP_S2C_FIELD",
+        )
+        result = _parse_kex_init(payload)
+        # Indices used by HASSHServer
+        assert result["kex_algorithms"] == "KEX_FIELD"               # index 0
+        assert result["encryption_server_to_client"] == "ENC_S2C_FIELD"  # index 3
+        assert result["mac_server_to_client"] == "MAC_S2C_FIELD"     # index 5
+        assert result["compression_server_to_client"] == "COMP_S2C_FIELD"  # index 7
+
+    def test_empty_name_lists(self):
+        payload = _build_kex_init(
+            kex="", host_key="", enc_c2s="", enc_s2c="",
+            mac_c2s="", mac_s2c="", comp_c2s="", comp_s2c="",
+        )
+        result = _parse_kex_init(payload)
+        assert result is not None
+        assert result["kex_algorithms"] == ""
+
+    def test_truncated_payload_returns_none(self):
+        # Just the type byte and cookie, no name-lists
+        payload = struct.pack("B", _SSH_MSG_KEXINIT) + b"\x00" * 16
+        assert _parse_kex_init(payload) is None
+
+    def test_truncated_name_list_returns_none(self):
+        # Type + cookie + length says 100 but only 2 bytes follow
+        payload = struct.pack("B", _SSH_MSG_KEXINIT) + b"\x00" * 16
+        payload += struct.pack("!I", 100) + b"ab"
+        assert _parse_kex_init(payload) is None
+
+    def test_too_short_returns_none(self):
+        assert _parse_kex_init(b"") is None
+        assert _parse_kex_init(b"\x14") is None
+
+    def test_large_algorithm_lists(self):
+        long_kex = ",".join(f"algo-{i}" for i in range(50))
+        payload = _build_kex_init(kex=long_kex)
+        result = _parse_kex_init(payload)
+        assert result is not None
+        assert result["kex_algorithms"] == long_kex
+
+
+# ─── _compute_hassh ─────────────────────────────────────────────────────────
+
+class TestComputeHashh:
+
+    def test_md5_correctness(self):
+        kex = "curve25519-sha256"
+        enc = "aes256-gcm@openssh.com"
+        mac = "hmac-sha2-256-etm@openssh.com"
+        comp = "none"
+        raw = f"{kex};{enc};{mac};{comp}"
+        expected = hashlib.md5(raw.encode("utf-8")).hexdigest()
+        assert _compute_hassh(kex, enc, mac, comp) == expected
+
+    def test_hash_length_is_32(self):
+        result = _compute_hassh("a", "b", "c", "d")
+        assert len(result) == 32
+
+    def test_deterministic(self):
+        r1 = _compute_hassh("kex1", "enc1", "mac1", "comp1")
+        r2 = _compute_hassh("kex1", "enc1", "mac1", "comp1")
+        assert r1 == r2
+
+    def test_different_inputs_different_hashes(self):
+        r1 = _compute_hassh("kex1", "enc1", "mac1", "comp1")
+        r2 = _compute_hassh("kex2", "enc2", "mac2", "comp2")
+        assert r1 != r2
+
+    def test_empty_fields(self):
+        result = _compute_hassh("", "", "", "")
+        expected = hashlib.md5(b";;;").hexdigest()
+        assert result == expected
+
+    def test_semicolon_delimiter(self):
+        """The delimiter is semicolon, not comma."""
+        result = _compute_hassh("a", "b", "c", "d")
+        expected = hashlib.md5(b"a;b;c;d").hexdigest()
+        assert result == expected
+
+
+# ─── _read_banner ───────────────────────────────────────────────────────────
+
+class TestReadBanner:
+
+    def test_reads_banner_with_crlf(self):
+        sock = _make_socket_with_data(b"SSH-2.0-OpenSSH_8.9p1\r\n")
+        result = _read_banner(sock)
+        assert result == "SSH-2.0-OpenSSH_8.9p1"
+
+    def test_reads_banner_with_lf(self):
+        sock = _make_socket_with_data(b"SSH-2.0-OpenSSH_8.9p1\n")
+        result = _read_banner(sock)
+        assert result == "SSH-2.0-OpenSSH_8.9p1"
+
+    def test_empty_data_returns_none(self):
+        sock = _make_socket_with_data(b"")
+        result = _read_banner(sock)
+        assert result is None
+
+    def test_no_newline_within_limit(self):
+        # 256 bytes with no newline — should stop at limit
+        sock = _make_socket_with_data(b"A" * 256)
+        result = _read_banner(sock)
+        assert result == "A" * 256
+
+
+# ─── _read_ssh_packet ───────────────────────────────────────────────────────
+
+class TestReadSSHPacket:
+
+    def test_reads_valid_packet(self):
+        payload = b"\x14" + b"\x00" * 20  # type 20 + some data
+        packet_data = _wrap_ssh_packet(payload)
+        sock = _make_socket_with_data(packet_data)
+        result = _read_ssh_packet(sock)
+        assert result is not None
+        assert result[0] == 0x14  # SSH_MSG_KEXINIT
+
+    def test_empty_socket_returns_none(self):
+        sock = _make_socket_with_data(b"")
+        assert _read_ssh_packet(sock) is None
+
+    def test_truncated_header_returns_none(self):
+        sock = _make_socket_with_data(b"\x00\x00")
+        assert _read_ssh_packet(sock) is None
+
+    def test_oversized_packet_returns_none(self):
+        # packet_length = 40000 (over limit)
+        sock = _make_socket_with_data(struct.pack("!I", 40000))
+        assert _read_ssh_packet(sock) is None
+
+    def test_zero_length_returns_none(self):
+        sock = _make_socket_with_data(struct.pack("!I", 0))
+        assert _read_ssh_packet(sock) is None
+
+
+# ─── hassh_server (end-to-end with mocked sockets) ─────────────────────────
+
+class TestHasshServerE2E:
+
+    @patch("decnet.prober.hassh._ssh_connect")
+    def test_success(self, mock_connect: MagicMock):
+        payload = _build_kex_init(
+            kex="curve25519-sha256",
+            enc_s2c="aes256-gcm@openssh.com",
+            mac_s2c="hmac-sha2-256-etm@openssh.com",
+            comp_s2c="none",
+        )
+        mock_connect.return_value = ("SSH-2.0-OpenSSH_8.9p1", payload)
+
+        result = hassh_server("10.0.0.1", 22, timeout=1.0)
+        assert result is not None
+        assert len(result["hassh_server"]) == 32
+        assert result["banner"] == "SSH-2.0-OpenSSH_8.9p1"
+        assert result["kex_algorithms"] == "curve25519-sha256"
+        assert result["encryption_s2c"] == "aes256-gcm@openssh.com"
+        assert result["mac_s2c"] == "hmac-sha2-256-etm@openssh.com"
+        assert result["compression_s2c"] == "none"
+
+    @patch("decnet.prober.hassh._ssh_connect")
+    def test_connection_failure_returns_none(self, mock_connect: MagicMock):
+        mock_connect.return_value = None
+        assert hassh_server("10.0.0.1", 22, timeout=1.0) is None
+
+    @patch("decnet.prober.hassh._ssh_connect")
+    def test_truncated_kex_init_returns_none(self, mock_connect: MagicMock):
+        # Payload too short to parse
+        payload = struct.pack("B", _SSH_MSG_KEXINIT) + b"\x00" * 16
+        mock_connect.return_value = ("SSH-2.0-OpenSSH_8.9p1", payload)
+        assert hassh_server("10.0.0.1", 22, timeout=1.0) is None
+
+    @patch("decnet.prober.hassh._ssh_connect")
+    def test_hash_is_deterministic(self, mock_connect: MagicMock):
+        payload = _build_kex_init()
+        mock_connect.return_value = ("SSH-2.0-OpenSSH_8.9p1", payload)
+
+        r1 = hassh_server("10.0.0.1", 22)
+        r2 = hassh_server("10.0.0.1", 22)
+        assert r1["hassh_server"] == r2["hassh_server"]
+
+    @patch("decnet.prober.hassh._ssh_connect")
+    def test_different_servers_different_hashes(self, mock_connect: MagicMock):
+        p1 = _build_kex_init(kex="curve25519-sha256", enc_s2c="aes256-gcm@openssh.com")
+        p2 = _build_kex_init(kex="diffie-hellman-group14-sha1", enc_s2c="aes128-cbc")
+
+        mock_connect.return_value = ("SSH-2.0-OpenSSH_8.9p1", p1)
+        r1 = hassh_server("10.0.0.1", 22)
+
+        mock_connect.return_value = ("SSH-2.0-Paramiko_3.0", p2)
+        r2 = hassh_server("10.0.0.2", 22)
+
+        assert r1["hassh_server"] != r2["hassh_server"]
+
+    @patch("decnet.prober.hassh.socket.create_connection")
+    def test_full_socket_mock(self, mock_create: MagicMock):
+        """Full integration: mock at socket level, verify banner exchange."""
+        kex_payload = _build_kex_init()
+        kex_packet = _wrap_ssh_packet(kex_payload)
+
+        banner_bytes = b"SSH-2.0-OpenSSH_8.9p1\r\n"
+        all_data = banner_bytes + kex_packet
+
+        mock_sock = _make_socket_with_data(all_data)
+        mock_sock.sendall = MagicMock()
+        mock_sock.settimeout = MagicMock()
+        mock_sock.close = MagicMock()
+        mock_create.return_value = mock_sock
+
+        result = hassh_server("10.0.0.1", 22, timeout=2.0)
+        assert result is not None
+        assert result["banner"] == "SSH-2.0-OpenSSH_8.9p1"
+        assert len(result["hassh_server"]) == 32
+
+        # Verify we sent our client banner
+        mock_sock.sendall.assert_called_once_with(_CLIENT_BANNER)
+
+    @patch("decnet.prober.hassh.socket.create_connection")
+    def test_non_ssh_banner_returns_none(self, mock_create: MagicMock):
+        mock_sock = _make_socket_with_data(b"HTTP/1.1 200 OK\r\n")
+        mock_sock.sendall = MagicMock()
+        mock_sock.settimeout = MagicMock()
+        mock_sock.close = MagicMock()
+        mock_create.return_value = mock_sock
+
+        assert hassh_server("10.0.0.1", 80, timeout=1.0) is None
+
+    @patch("decnet.prober.hassh.socket.create_connection")
+    def test_connection_refused(self, mock_create: MagicMock):
+        mock_create.side_effect = ConnectionRefusedError
+        assert hassh_server("10.0.0.1", 22, timeout=1.0) is None
+
+    @patch("decnet.prober.hassh.socket.create_connection")
+    def test_timeout(self, mock_create: MagicMock):
+        mock_create.side_effect = socket.timeout("timed out")
+        assert hassh_server("10.0.0.1", 22, timeout=1.0) is None

tests/test_prober_tcpfp.py

@@ -0,0 +1,349 @@
+"""
+Unit tests for the TCP/IP stack fingerprinting module.
+
+Tests cover SYN-ACK parsing, options extraction, fingerprint computation,
+and end-to-end tcp_fingerprint() with mocked scapy packets.
+"""
+
+from __future__ import annotations
+
+import hashlib
+from types import SimpleNamespace
+from unittest.mock import MagicMock, patch
+
+import pytest
+
+from decnet.prober.tcpfp import (
+    _compute_fingerprint,
+    _extract_options_order,
+    _parse_synack,
+    tcp_fingerprint,
+)
+
+
+# ─── Helpers ────────────────────────────────────────────────────────────────
+
+def _make_synack(
+    ttl: int = 64,
+    flags: int = 0x02,  # IP flags (DF = 0x02)
+    ip_id: int = 0,
+    window: int = 65535,
+    tcp_flags: int = 0x12,  # SYN-ACK
+    options: list | None = None,
+    ack: int = 1,
+) -> SimpleNamespace:
+    """Build a fake scapy-like SYN-ACK packet for testing."""
+    if options is None:
+        options = [
+            ("MSS", 1460),
+            ("NOP", None),
+            ("WScale", 7),
+            ("NOP", None),
+            ("NOP", None),
+            ("Timestamp", (12345, 0)),
+            ("SAckOK", b""),
+            ("EOL", None),
+        ]
+
+    tcp_layer = SimpleNamespace(
+        flags=tcp_flags,
+        window=window,
+        options=options,
+        dport=12345,
+        ack=ack,
+    )
+    ip_layer = SimpleNamespace(
+        ttl=ttl,
+        flags=flags,
+        id=ip_id,
+    )
+
+    class FakePacket:
+        def __init__(self):
+            self._layers = {"IP": ip_layer, "TCP": tcp_layer}
+            self.ack = ack
+
+        def __getitem__(self, key):
+            # Support both class and string access
+            name = key.__name__ if hasattr(key, "__name__") else str(key)
+            return self._layers[name]
+
+        def haslayer(self, key):
+            name = key.__name__ if hasattr(key, "__name__") else str(key)
+            return name in self._layers
+
+    return FakePacket()
+
+
+# ─── _extract_options_order ─────────────────────────────────────────────────
+
+class TestExtractOptionsOrder:
+
+    def test_standard_linux_options(self):
+        options = [
+            ("MSS", 1460), ("NOP", None), ("WScale", 7),
+            ("NOP", None), ("NOP", None), ("Timestamp", (0, 0)),
+            ("SAckOK", b""), ("EOL", None),
+        ]
+        assert _extract_options_order(options) == "M,N,W,N,N,T,S,E"
+
+    def test_windows_options(self):
+        options = [
+            ("MSS", 1460), ("NOP", None), ("WScale", 8),
+            ("NOP", None), ("NOP", None), ("SAckOK", b""),
+        ]
+        assert _extract_options_order(options) == "M,N,W,N,N,S"
+
+    def test_empty_options(self):
+        assert _extract_options_order([]) == ""
+
+    def test_mss_only(self):
+        assert _extract_options_order([("MSS", 536)]) == "M"
+
+    def test_unknown_option(self):
+        options = [("MSS", 1460), ("UnknownOpt", 42)]
+        assert _extract_options_order(options) == "M,?"
+
+    def test_sack_variant(self):
+        options = [("SAck", (100, 200))]
+        assert _extract_options_order(options) == "S"
+
+
+# ─── _parse_synack ──────────────────────────────────────────────────────────
+
+class TestParseSynack:
+
+    def test_linux_64_ttl(self):
+        resp = _make_synack(ttl=64)
+        result = _parse_synack(resp)
+        assert result["ttl"] == 64
+
+    def test_windows_128_ttl(self):
+        resp = _make_synack(ttl=128)
+        result = _parse_synack(resp)
+        assert result["ttl"] == 128
+
+    def test_df_bit_set(self):
+        resp = _make_synack(flags=0x02)  # DF set
+        result = _parse_synack(resp)
+        assert result["df_bit"] == 1
+
+    def test_df_bit_unset(self):
+        resp = _make_synack(flags=0x00)
+        result = _parse_synack(resp)
+        assert result["df_bit"] == 0
+
+    def test_window_size(self):
+        resp = _make_synack(window=29200)
+        result = _parse_synack(resp)
+        assert result["window_size"] == 29200
+
+    def test_mss_extraction(self):
+        resp = _make_synack(options=[("MSS", 1460)])
+        result = _parse_synack(resp)
+        assert result["mss"] == 1460
+
+    def test_window_scale(self):
+        resp = _make_synack(options=[("WScale", 7)])
+        result = _parse_synack(resp)
+        assert result["window_scale"] == 7
+
+    def test_sack_ok(self):
+        resp = _make_synack(options=[("SAckOK", b"")])
+        result = _parse_synack(resp)
+        assert result["sack_ok"] == 1
+
+    def test_no_sack(self):
+        resp = _make_synack(options=[("MSS", 1460)])
+        result = _parse_synack(resp)
+        assert result["sack_ok"] == 0
+
+    def test_timestamp_present(self):
+        resp = _make_synack(options=[("Timestamp", (12345, 0))])
+        result = _parse_synack(resp)
+        assert result["timestamp"] == 1
+
+    def test_no_timestamp(self):
+        resp = _make_synack(options=[("MSS", 1460)])
+        result = _parse_synack(resp)
+        assert result["timestamp"] == 0
+
+    def test_options_order(self):
+        resp = _make_synack(options=[
+            ("MSS", 1460), ("NOP", None), ("WScale", 7),
+            ("SAckOK", b""), ("Timestamp", (0, 0)),
+        ])
+        result = _parse_synack(resp)
+        assert result["options_order"] == "M,N,W,S,T"
+
+    def test_ip_id(self):
+        resp = _make_synack(ip_id=12345)
+        result = _parse_synack(resp)
+        assert result["ip_id"] == 12345
+
+    def test_empty_options(self):
+        resp = _make_synack(options=[])
+        result = _parse_synack(resp)
+        assert result["mss"] == 0
+        assert result["window_scale"] == -1
+        assert result["sack_ok"] == 0
+        assert result["timestamp"] == 0
+        assert result["options_order"] == ""
+
+    def test_full_linux_fingerprint(self):
+        """Typical Linux 5.x+ SYN-ACK."""
+        resp = _make_synack(
+            ttl=64, flags=0x02, window=65535,
+            options=[
+                ("MSS", 1460), ("NOP", None), ("WScale", 7),
+                ("NOP", None), ("NOP", None), ("Timestamp", (0, 0)),
+                ("SAckOK", b""), ("EOL", None),
+            ],
+        )
+        result = _parse_synack(resp)
+        assert result["ttl"] == 64
+        assert result["df_bit"] == 1
+        assert result["window_size"] == 65535
+        assert result["mss"] == 1460
+        assert result["window_scale"] == 7
+        assert result["sack_ok"] == 1
+        assert result["timestamp"] == 1
+        assert result["options_order"] == "M,N,W,N,N,T,S,E"
+
+
+# ─── _compute_fingerprint ──────────────────────────────────────────────────
+
+class TestComputeFingerprint:
+
+    def test_hash_length_is_32(self):
+        fields = {
+            "ttl": 64, "window_size": 65535, "df_bit": 1,
+            "mss": 1460, "window_scale": 7, "sack_ok": 1,
+            "timestamp": 1, "options_order": "M,N,W,N,N,T,S,E",
+        }
+        raw, h = _compute_fingerprint(fields)
+        assert len(h) == 32
+
+    def test_deterministic(self):
+        fields = {
+            "ttl": 64, "window_size": 65535, "df_bit": 1,
+            "mss": 1460, "window_scale": 7, "sack_ok": 1,
+            "timestamp": 1, "options_order": "M,N,W,S,T",
+        }
+        _, h1 = _compute_fingerprint(fields)
+        _, h2 = _compute_fingerprint(fields)
+        assert h1 == h2
+
+    def test_different_inputs_different_hashes(self):
+        f1 = {
+            "ttl": 64, "window_size": 65535, "df_bit": 1,
+            "mss": 1460, "window_scale": 7, "sack_ok": 1,
+            "timestamp": 1, "options_order": "M,N,W,S,T",
+        }
+        f2 = {
+            "ttl": 128, "window_size": 8192, "df_bit": 1,
+            "mss": 1460, "window_scale": 8, "sack_ok": 1,
+            "timestamp": 0, "options_order": "M,N,W,N,N,S",
+        }
+        _, h1 = _compute_fingerprint(f1)
+        _, h2 = _compute_fingerprint(f2)
+        assert h1 != h2
+
+    def test_raw_format(self):
+        fields = {
+            "ttl": 64, "window_size": 65535, "df_bit": 1,
+            "mss": 1460, "window_scale": 7, "sack_ok": 1,
+            "timestamp": 1, "options_order": "M,N,W",
+        }
+        raw, _ = _compute_fingerprint(fields)
+        assert raw == "64:65535:1:1460:7:1:1:M,N,W"
+
+    def test_sha256_correctness(self):
+        fields = {
+            "ttl": 64, "window_size": 65535, "df_bit": 1,
+            "mss": 1460, "window_scale": 7, "sack_ok": 1,
+            "timestamp": 1, "options_order": "M,N,W",
+        }
+        raw, h = _compute_fingerprint(fields)
+        expected = hashlib.sha256(raw.encode("utf-8")).hexdigest()[:32]
+        assert h == expected
+
+
+# ─── tcp_fingerprint (end-to-end with mocked scapy) ────────────────────────
+
+class TestTcpFingerprintE2E:
+
+    @patch("decnet.prober.tcpfp._send_syn")
+    def test_success(self, mock_send: MagicMock):
+        mock_send.return_value = _make_synack(
+            ttl=64, flags=0x02, window=65535,
+            options=[
+                ("MSS", 1460), ("NOP", None), ("WScale", 7),
+                ("SAckOK", b""), ("Timestamp", (0, 0)),
+            ],
+        )
+        result = tcp_fingerprint("10.0.0.1", 443, timeout=1.0)
+        assert result is not None
+        assert len(result["tcpfp_hash"]) == 32
+        assert result["ttl"] == 64
+        assert result["window_size"] == 65535
+        assert result["df_bit"] == 1
+        assert result["mss"] == 1460
+        assert result["window_scale"] == 7
+        assert result["sack_ok"] == 1
+        assert result["timestamp"] == 1
+        assert result["options_order"] == "M,N,W,S,T"
+
+    @patch("decnet.prober.tcpfp._send_syn")
+    def test_no_response_returns_none(self, mock_send: MagicMock):
+        mock_send.return_value = None
+        assert tcp_fingerprint("10.0.0.1", 443, timeout=1.0) is None
+
+    @patch("decnet.prober.tcpfp._send_syn")
+    def test_windows_fingerprint(self, mock_send: MagicMock):
+        mock_send.return_value = _make_synack(
+            ttl=128, flags=0x02, window=8192,
+            options=[
+                ("MSS", 1460), ("NOP", None), ("WScale", 8),
+                ("NOP", None), ("NOP", None), ("SAckOK", b""),
+            ],
+        )
+        result = tcp_fingerprint("10.0.0.1", 443, timeout=1.0)
+        assert result is not None
+        assert result["ttl"] == 128
+        assert result["window_size"] == 8192
+        assert result["window_scale"] == 8
+
+    @patch("decnet.prober.tcpfp._send_syn")
+    def test_embedded_device_fingerprint(self, mock_send: MagicMock):
+        """Embedded devices often have TTL=255, small window, no options."""
+        mock_send.return_value = _make_synack(
+            ttl=255, flags=0x00, window=4096,
+            options=[("MSS", 536)],
+        )
+        result = tcp_fingerprint("10.0.0.1", 80, timeout=1.0)
+        assert result is not None
+        assert result["ttl"] == 255
+        assert result["df_bit"] == 0
+        assert result["window_size"] == 4096
+        assert result["mss"] == 536
+        assert result["window_scale"] == -1
+        assert result["sack_ok"] == 0
+
+    @patch("decnet.prober.tcpfp._send_syn")
+    def test_result_contains_raw_and_hash(self, mock_send: MagicMock):
+        mock_send.return_value = _make_synack()
+        result = tcp_fingerprint("10.0.0.1", 443)
+        assert "tcpfp_hash" in result
+        assert "tcpfp_raw" in result
+        assert ":" in result["tcpfp_raw"]
+
+    @patch("decnet.prober.tcpfp._send_syn")
+    def test_deterministic(self, mock_send: MagicMock):
+        pkt = _make_synack(ttl=64, window=65535)
+        mock_send.return_value = pkt
+
+        r1 = tcp_fingerprint("10.0.0.1", 443)
+        r2 = tcp_fingerprint("10.0.0.1", 443)
+        assert r1["tcpfp_hash"] == r2["tcpfp_hash"]
+        assert r1["tcpfp_raw"] == r2["tcpfp_raw"]

tests/test_prober_worker.py

@@ -1,6 +1,6 @@
 """
 Tests for the prober worker — target discovery from the log stream and
-probe cycle behavior.
+probe cycle behavior (JARM, HASSH, TCP/IP fingerprinting).
 """
 
 from __future__ import annotations
@@ -14,6 +14,8 @@ import pytest
 from decnet.prober.jarm import JARM_EMPTY_HASH
 from decnet.prober.worker import (
     DEFAULT_PROBE_PORTS,
+    DEFAULT_SSH_PORTS,
+    DEFAULT_TCPFP_PORTS,
     _discover_attackers,
     _probe_cycle,
     _write_event,
@@ -103,86 +105,357 @@ class TestDiscoverAttackers:
         assert "10.0.0.1" in ips
 
 
-# ─── _probe_cycle ────────────────────────────────────────────────────────────
+# ─── _probe_cycle: JARM phase ──────────────────────────────────────────────
 
-class TestProbeCycle:
+class TestProbeCycleJARM:
 
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
     @patch("decnet.prober.worker.jarm_hash")
-    def test_probes_new_ips(self, mock_jarm: MagicMock, tmp_path: Path):
+    def test_probes_new_ips(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                            mock_tcpfp: MagicMock, tmp_path: Path):
         mock_jarm.return_value = "c0c" * 10 + "a" * 32  # fake 62-char hash
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = None
         log_path = tmp_path / "decnet.log"
         json_path = tmp_path / "decnet.json"
 
         targets = {"10.0.0.1"}
-        probed: dict[str, set[int]] = {}
+        probed: dict[str, dict[str, set[int]]] = {}
 
-        _probe_cycle(targets, probed, [443, 8443], log_path, json_path, timeout=1.0)
+        _probe_cycle(targets, probed, [443, 8443], [], [], log_path, json_path, timeout=1.0)
 
         assert mock_jarm.call_count == 2  # two ports
-        assert 443 in probed["10.0.0.1"]
+        assert 443 in probed["10.0.0.1"]["jarm"]
-        assert 8443 in probed["10.0.0.1"]
+        assert 8443 in probed["10.0.0.1"]["jarm"]
 
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
     @patch("decnet.prober.worker.jarm_hash")
-    def test_skips_already_probed_ports(self, mock_jarm: MagicMock, tmp_path: Path):
+    def test_skips_already_probed_ports(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                        mock_tcpfp: MagicMock, tmp_path: Path):
         mock_jarm.return_value = "c0c" * 10 + "a" * 32
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = None
         log_path = tmp_path / "decnet.log"
         json_path = tmp_path / "decnet.json"
 
         targets = {"10.0.0.1"}
-        probed: dict[str, set[int]] = {"10.0.0.1": {443}}
+        probed: dict[str, dict[str, set[int]]] = {"10.0.0.1": {"jarm": {443}}}
 
-        _probe_cycle(targets, probed, [443, 8443], log_path, json_path, timeout=1.0)
+        _probe_cycle(targets, probed, [443, 8443], [], [], log_path, json_path, timeout=1.0)
 
         # Should only probe 8443 (443 already done)
         assert mock_jarm.call_count == 1
         mock_jarm.assert_called_once_with("10.0.0.1", 8443, timeout=1.0)
 
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
     @patch("decnet.prober.worker.jarm_hash")
-    def test_empty_hash_not_logged(self, mock_jarm: MagicMock, tmp_path: Path):
+    def test_empty_hash_not_logged(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
-        """All-zeros JARM hash (no TLS server) should not be written as a jarm_fingerprint event."""
+                                    mock_tcpfp: MagicMock, tmp_path: Path):
         mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = None
         log_path = tmp_path / "decnet.log"
         json_path = tmp_path / "decnet.json"
 
         targets = {"10.0.0.1"}
-        probed: dict[str, set[int]] = {}
+        probed: dict[str, dict[str, set[int]]] = {}
 
-        _probe_cycle(targets, probed, [443], log_path, json_path, timeout=1.0)
+        _probe_cycle(targets, probed, [443], [], [], log_path, json_path, timeout=1.0)
 
-        # Port should be marked as probed
+        assert 443 in probed["10.0.0.1"]["jarm"]
-        assert 443 in probed["10.0.0.1"]
-        # But no jarm_fingerprint event should be written
         if json_path.exists():
             content = json_path.read_text()
             assert "jarm_fingerprint" not in content
 
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
     @patch("decnet.prober.worker.jarm_hash")
-    def test_exception_marks_port_probed(self, mock_jarm: MagicMock, tmp_path: Path):
+    def test_exception_marks_port_probed(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                          mock_tcpfp: MagicMock, tmp_path: Path):
         mock_jarm.side_effect = OSError("Connection refused")
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = None
         log_path = tmp_path / "decnet.log"
         json_path = tmp_path / "decnet.json"
 
         targets = {"10.0.0.1"}
-        probed: dict[str, set[int]] = {}
+        probed: dict[str, dict[str, set[int]]] = {}
 
-        _probe_cycle(targets, probed, [443], log_path, json_path, timeout=1.0)
+        _probe_cycle(targets, probed, [443], [], [], log_path, json_path, timeout=1.0)
 
-        # Port marked as probed to avoid infinite retries
+        assert 443 in probed["10.0.0.1"]["jarm"]
-        assert 443 in probed["10.0.0.1"]
 
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
     @patch("decnet.prober.worker.jarm_hash")
-    def test_skips_ip_with_all_ports_done(self, mock_jarm: MagicMock, tmp_path: Path):
+    def test_skips_ip_with_all_ports_done(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                           mock_tcpfp: MagicMock, tmp_path: Path):
         log_path = tmp_path / "decnet.log"
         json_path = tmp_path / "decnet.json"
 
         targets = {"10.0.0.1"}
-        probed: dict[str, set[int]] = {"10.0.0.1": {443, 8443}}
+        probed: dict[str, dict[str, set[int]]] = {
+            "10.0.0.1": {"jarm": {443, 8443}, "hassh": set(), "tcpfp": set()},
+        }
 
-        _probe_cycle(targets, probed, [443, 8443], log_path, json_path, timeout=1.0)
+        _probe_cycle(targets, probed, [443, 8443], [], [], log_path, json_path, timeout=1.0)
 
         assert mock_jarm.call_count == 0
 
 
+# ─── _probe_cycle: HASSH phase ─────────────────────────────────────────────
+
+class TestProbeCycleHASSH:
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_probes_ssh_ports(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                               mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = {
+            "hassh_server": "a" * 32,
+            "banner": "SSH-2.0-OpenSSH_8.9p1",
+            "kex_algorithms": "curve25519-sha256",
+            "encryption_s2c": "aes256-gcm@openssh.com",
+            "mac_s2c": "hmac-sha2-256-etm@openssh.com",
+            "compression_s2c": "none",
+        }
+        mock_tcpfp.return_value = None
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        _probe_cycle(targets, probed, [], [22, 2222], [], log_path, json_path, timeout=1.0)
+
+        assert mock_hassh.call_count == 2
+        assert 22 in probed["10.0.0.1"]["hassh"]
+        assert 2222 in probed["10.0.0.1"]["hassh"]
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_hassh_writes_event(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                 mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = {
+            "hassh_server": "b" * 32,
+            "banner": "SSH-2.0-Paramiko_3.0",
+            "kex_algorithms": "diffie-hellman-group14-sha1",
+            "encryption_s2c": "aes128-cbc",
+            "mac_s2c": "hmac-sha1",
+            "compression_s2c": "none",
+        }
+        mock_tcpfp.return_value = None
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        _probe_cycle(targets, probed, [], [22], [], log_path, json_path, timeout=1.0)
+
+        assert json_path.exists()
+        content = json_path.read_text()
+        assert "hassh_fingerprint" in content
+        record = json.loads(content.strip())
+        assert record["fields"]["hassh_server_hash"] == "b" * 32
+        assert record["fields"]["ssh_banner"] == "SSH-2.0-Paramiko_3.0"
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_hassh_none_not_logged(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                    mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = None  # No SSH server
+        mock_tcpfp.return_value = None
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        _probe_cycle(targets, probed, [], [22], [], log_path, json_path, timeout=1.0)
+
+        assert 22 in probed["10.0.0.1"]["hassh"]
+        if json_path.exists():
+            content = json_path.read_text()
+            assert "hassh_fingerprint" not in content
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_hassh_skips_already_probed(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                         mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_tcpfp.return_value = None
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {"10.0.0.1": {"hassh": {22}}}
+
+        _probe_cycle(targets, probed, [], [22, 2222], [], log_path, json_path, timeout=1.0)
+
+        assert mock_hassh.call_count == 1  # only 2222
+        mock_hassh.assert_called_once_with("10.0.0.1", 2222, timeout=1.0)
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_hassh_exception_marks_probed(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                           mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.side_effect = OSError("Connection refused")
+        mock_tcpfp.return_value = None
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        _probe_cycle(targets, probed, [], [22], [], log_path, json_path, timeout=1.0)
+
+        assert 22 in probed["10.0.0.1"]["hassh"]
+
+
+# ─── _probe_cycle: TCPFP phase ─────────────────────────────────────────────
+
+class TestProbeCycleTCPFP:
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_probes_tcpfp_ports(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                 mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = {
+            "tcpfp_hash": "d" * 32,
+            "tcpfp_raw": "64:65535:1:1460:7:1:1:M,N,W,N,N,T,S,E",
+            "ttl": 64, "window_size": 65535, "df_bit": 1,
+            "mss": 1460, "window_scale": 7, "sack_ok": 1,
+            "timestamp": 1, "options_order": "M,N,W,N,N,T,S,E",
+        }
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        _probe_cycle(targets, probed, [], [], [80, 443], log_path, json_path, timeout=1.0)
+
+        assert mock_tcpfp.call_count == 2
+        assert 80 in probed["10.0.0.1"]["tcpfp"]
+        assert 443 in probed["10.0.0.1"]["tcpfp"]
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_tcpfp_writes_event_with_all_fields(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                                  mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = {
+            "tcpfp_hash": "e" * 32,
+            "tcpfp_raw": "128:8192:1:1460:8:1:0:M,N,W,N,N,S",
+            "ttl": 128, "window_size": 8192, "df_bit": 1,
+            "mss": 1460, "window_scale": 8, "sack_ok": 1,
+            "timestamp": 0, "options_order": "M,N,W,N,N,S",
+        }
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        _probe_cycle(targets, probed, [], [], [443], log_path, json_path, timeout=1.0)
+
+        content = json_path.read_text()
+        assert "tcpfp_fingerprint" in content
+        record = json.loads(content.strip())
+        assert record["fields"]["tcpfp_hash"] == "e" * 32
+        assert record["fields"]["ttl"] == "128"
+        assert record["fields"]["window_size"] == "8192"
+        assert record["fields"]["options_order"] == "M,N,W,N,N,S"
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_tcpfp_none_not_logged(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                    mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = None
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        _probe_cycle(targets, probed, [], [], [443], log_path, json_path, timeout=1.0)
+
+        assert 443 in probed["10.0.0.1"]["tcpfp"]
+        if json_path.exists():
+            content = json_path.read_text()
+            assert "tcpfp_fingerprint" not in content
+
+
+# ─── Probe type isolation ───────────────────────────────────────────────────
+
+class TestProbeTypeIsolation:
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_jarm_does_not_mark_hassh(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                       mock_tcpfp: MagicMock, tmp_path: Path):
+        """JARM probing port 2222 should not mark HASSH port 2222 as done."""
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = None
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        # Probe with JARM on 2222 and HASSH on 2222
+        _probe_cycle(targets, probed, [2222], [2222], [], log_path, json_path, timeout=1.0)
+
+        # Both should be called
+        assert mock_jarm.call_count == 1
+        assert mock_hassh.call_count == 1
+        assert 2222 in probed["10.0.0.1"]["jarm"]
+        assert 2222 in probed["10.0.0.1"]["hassh"]
+
+    @patch("decnet.prober.worker.tcp_fingerprint")
+    @patch("decnet.prober.worker.hassh_server")
+    @patch("decnet.prober.worker.jarm_hash")
+    def test_all_three_probes_run(self, mock_jarm: MagicMock, mock_hassh: MagicMock,
+                                   mock_tcpfp: MagicMock, tmp_path: Path):
+        mock_jarm.return_value = JARM_EMPTY_HASH
+        mock_hassh.return_value = None
+        mock_tcpfp.return_value = None
+        log_path = tmp_path / "decnet.log"
+        json_path = tmp_path / "decnet.json"
+
+        targets = {"10.0.0.1"}
+        probed: dict[str, dict[str, set[int]]] = {}
+
+        _probe_cycle(targets, probed, [443], [22], [80], log_path, json_path, timeout=1.0)
+
+        assert mock_jarm.call_count == 1
+        assert mock_hassh.call_count == 1
+        assert mock_tcpfp.call_count == 1
+
+
 # ─── _write_event ────────────────────────────────────────────────────────────
 
 class TestWriteEvent: