Files
skills/hub/kvb_hub/approving.py
T
Kevin Veen-BirkenbachandClaude Opus 5.5 8ba45efd04 feat(hub): kvb-hub review hub with passkey-signed approvals
The kvb-hub is a local review hub in a container bound to 127.0.0.1: one page, JSON APIs and an MCP endpoint for the operator's inbox, asks, decisions, staged-commit reviews, the radio stream, the agent graph, the worktree tree, push-to-talk and read-aloud radio (Piper, whisper.cpp) and an optional LLM command line. The hub is only a relay. The host executors in hub/client (the runner user service, the PermissionRequest hook and the approval CLI the commit skills call) verify a WebAuthn passkey signature against keys pinned outside every sandbox, refuse replays and fail closed. scripts/hub.sh with make hub-install, hub-check, hub-pin, hub-runner and hub-hook installs and checks the hub; hub-hook writes ~/.claude/settings.json after a backup. make watch-check shows a stuck watch hook. The new kvb-git-diff skill and the commit skills route reviews through the hub; the test_hub_* suites replace test_hub.py.

Security review (kvb-think-criticize, three skeptics) fixed four holes: signed rules auto-approved chained shell commands; the client and LLM openers followed redirects, the LLM one with its bearer key; the worktree scan ran git fsmonitor and filter commands from agent-writable repos; compose set no memory, pids or health limits. Documented until core requirement 093, on the operator's word: the hub page is trusted while signing and pinning, local processes can forge the unsigned operator actions, and the container reads the host /tmp. Committed on the operator's word despite the gate: the passkey path is not yet verified live.

Accepted MEDUSA false positives (137 findings on 115 lines, rows in security-accepted.jsonl): EXA002 x17, MEDUSA-MM-SCAN-058 x12, B603 x8, MEDUSA-FTSC-SCAN-089 x7, MEDUSA-PRIV-SCAN-762 x6, AIC-EXFIL-005 x5, EXA006 x5, MEDUSA-FTSCAN-231 x5, WEB-SSRF x5, MEDUSA-INF-SCAN-2057 x3, RH005 x3, TC001 x3, LO002 x2, MEDUSA-AEXP-SCAN-096 x2, MEDUSA-CGS-SCAN-028 x2, MEDUSA-INF-SCAN-1350 x2, MEDUSA-INF-SCAN-2369 x2, MEDUSA-INF-SCAN-2440 x2, MEDUSA-INF-SCAN-2638 x2, MLSC-SERIAL-002 x2, PL002 x2, PQC005 x2, SAST-PATH-001 x2, TC004 x2, TC005 x2, TC006 x2, TC007 x2, AA-146, EXA007, FINE-050, GB-ENCODE-001, GB-ENCODE-003, MEDUSA-CGS-SCAN-029, MEDUSA-CGS-SCAN-103, MEDUSA-DP-SCAN-1034, MEDUSA-DP-SCAN-1916, MEDUSA-DP-SCAN-954, MEDUSA-EXF26-TOOL-004, MEDUSA-FT-TRIGGER-005, MEDUSA-INF-SCAN-2206, MEDUSA-INF-SCAN-2457, MEDUSA-INF-WEB-003, MEDUSA-INFRA-SCAN-030, MEDUSA-MP-SCAN-1135, MEDUSA-RLHF-POISON-002, MEDUSA-RT-SCAN-006, MM-ENCODE-001, MP-124, PQC001, PQC002, PQC006, RP001, TC009, TC010, WEB-FLASK-004.

🎯 Fix: 80 %
💥 Break: 4 %
💸 Cost: 129 %
⏱️ Time: –
🛡️ Security: 100 %
💰 Value: ?
🏆 Score: 60
🚦 Gate: ⛔ fix 80 % < 90; cost 129 % > 100: ask the operator before the commit

```
/home/kevinveenbirkenbach/Repositories/github.com/kevinveenbirkenbach/skills/.worktrees/feature/kvb-hub
```

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
2026-11-06 18:46:40 +00:00

164 lines
9.4 KiB
Python

from __future__ import annotations
import secrets
import time
from .asking import ask_state
from .errors import Conflict, Missing, ToolError
from .fields import decode, expect, field
from .records import digest, shown
from .register import REGISTER, operator_rows, read_register, runnable
from .rules import rule_matches
from .signed import ask_signed, operator_signed, review_signed, signing
BATCH_LIMIT = 100
INBOX_KINDS = ("review", "ask", "decision", "operator")
VERBS = ("approve", "reject")
class Approving:
def keys(self) -> list[dict]:
try:
entries = signing.load_pinned(self.approvers)
except signing.Refused:
return []
return [{"id": entry["id"], "alg": signing.ALGORITHMS[entry["alg"]]} for entry in entries]
def covered(self, proof: object, signed: list[dict], now: float) -> dict | None:
"""Args:
proof: {"payload", "assertion"} from the page, or None.
signed: the executor items the approval must list.
now: the current time in epoch seconds.
Returns:
The proof to relay, None when nothing needs a signature. The hub
checks the shape only; the executors verify the signature.
"""
if not signed:
if proof is not None:
raise ToolError("proof must be null when no item needs a signature")
return None
if not isinstance(proof, dict):
raise ToolError("nicht signiert: an approval of an ask, review or operator command needs the passkey signature")
expect(proof, ("payload", "assertion"))
try:
payload = signing.checked_approval(proof["payload"], now)
except signing.Refused as error:
raise ToolError(f"proof: {error}") from None
if not isinstance(proof["assertion"], dict) or any(signing.item_hash(item) not in payload["items"] for item in signed):
raise ToolError("proof must carry the assertion and list every approved item")
return {"payload": payload, "assertion": proof["assertion"]}
def automate(self, kind_name: str, record: dict, subject: dict) -> None:
now = time.time()
rule = next((rule for rule in self.rules.listed() if rule_matches(rule, kind_name, subject, now)), None)
if rule is None:
return
title = {"review": record.get("title"), "ask": f"{record.get('tool')} {record.get('command')}", "decision": record.get("question")}[kind_name]
signed = None if kind_name == "decision" else subject["item"]
item = {"kind": kind_name, "id": record["id"], "verb": "approve", "label": record.get("recommended", ""), "sha256": "", "title": shown(title)[:200], "gate": record.get("gate", ""), "signed": signed}
batch = self.batches.add([item], f"rule:{rule['id']}", rule.get("proof"), self.apply)
words = f"{rule['kind']} {rule['tool']} {rule['pattern']}".replace(" ", " ")
self.log.add({"kind": "rule", "title": f"Regel gibt frei: {item['title']}", "text": words, "ref": {"rule": rule["id"], "batch": batch["id"], "item": item["id"]}})
def apply(self, batch: dict) -> None:
for item in batch["items"]:
try:
outcome = self.settle_item(item, batch["proof"] if item["signed"] is not None else None)
except (OSError, ToolError) as error:
outcome = f"fehlgeschlagen: {error}"
verb = "Freigabe" if item["verb"] == "approve" else "Ablehnung"
label = f" → {item['label']}" if item["label"] else ""
ref = {"kind": item["kind"], "id": item["id"], "verb": item["verb"], "source": batch["source"], "outcome": outcome}
self.log.add({"kind": "approval", "title": f"{verb} {item['kind']}: {item['title']}{label}", "text": f"{outcome} ({batch['source']})", "ref": ref})
def settle_item(self, item: dict, proof: dict | None) -> str:
approve = item["verb"] == "approve"
if item["kind"] == "operator":
return self.queue_job(item, proof)
if item["kind"] == "ask":
record = self.asks.get(item["id"])
if record is None or ask_state(record, time.time())["status"] == "expired":
return "abgelaufen"
record, changed = self.asks.decide(item["id"], {"status": "allowed" if approve else "denied", "proof": proof})
elif item["kind"] == "review":
record, changed = self.reviews.decide(item["id"], {"status": "approved" if approve else "rejected", "proof": proof})
else:
record, changed = self.decisions.decide(item["id"], {"status": "decided", "choice": item["label"]})
if record is None:
return "unbekannt"
return record["status"] if changed else f"schon {record['status']}"
def item_of(self, raw: object, tasks: dict[str, dict]) -> dict:
if not isinstance(raw, dict):
raise ToolError("every item must be an object with kind, id, verb, label and sha256")
expect(raw, ("kind", "id", "verb", "label", "sha256"))
kind_name, verb = raw["kind"], raw["verb"]
if kind_name not in INBOX_KINDS or verb not in VERBS or not isinstance(raw["label"], str) or not isinstance(raw["sha256"], str):
raise ToolError(f"kind must be one of {', '.join(INBOX_KINDS)}, verb approve or reject, label and sha256 text")
if kind_name == "operator":
row = next((row for row in operator_rows(tasks) if row["task"] == raw["id"]), None)
if row is None:
raise Missing(str(raw["id"]))
if verb != "approve" or not runnable(row):
raise ToolError("an operator row is approved only, and only when it holds a directory and a command")
if digest(row["command"]) != raw["sha256"]:
raise Conflict({"id": row["task"], "status": "changed"})
if row["task"] in self.open_jobs():
raise Conflict({"id": row["task"], "status": "queued"})
return {"kind": kind_name, "id": row["task"], "verb": verb, "label": "", "sha256": raw["sha256"], "title": row["command"][:200], "gate": "", "signed": operator_signed(row)}
item_id = field(raw, "id")
record = {"review": self.reviews, "ask": self.asks, "decision": self.decisions}[kind_name].get(item_id)
if record is None:
raise Missing(item_id)
status = ask_state(record, time.time())["status"] if kind_name == "ask" else record["status"]
if status != "pending":
raise Conflict({"id": item_id, "status": status})
label = ""
if kind_name == "decision":
if verb != "approve" or raw["label"] not in [option["label"] for option in record["options"]]:
raise ToolError("a decision is approved with one of its option labels")
label = raw["label"]
title = {"review": record.get("title"), "ask": f"{record.get('tool')} {record.get('command')}", "decision": record.get("question")}[kind_name]
signed = None
if verb == "approve" and kind_name != "decision":
signed = ask_signed(record) if kind_name == "ask" else review_signed(record)
return {"kind": kind_name, "id": item_id, "verb": verb, "label": label, "sha256": "", "title": shown(title)[:200], "gate": record.get("gate", ""), "signed": signed}
def checked(self, raw: object) -> list[dict]:
if not isinstance(raw, list) or not 1 <= len(raw) <= BATCH_LIMIT:
raise ToolError(f"items must be a list of 1 to {BATCH_LIMIT} objects")
tasks = read_register(self.council / REGISTER)
items = [self.item_of(entry, tasks) for entry in raw]
keys = [(item["kind"], item["id"]) for item in items]
if len(set(keys)) != len(keys):
raise ToolError("items must be distinct")
if len(items) > 1 and any(item["kind"] == "review" and item["verb"] == "approve" and item["gate"] != "pass" for item in items):
raise ToolError("a review whose gate is not green is approved only on its own")
if any(self.batches.holds(kind_name, item_id) for kind_name, item_id in keys):
raise Conflict({"status": "held"})
return items
def sign(self, body: bytes) -> dict:
payload = decode(body)
expect(payload, ("items",))
hashes = [signing.item_hash(item["signed"]) for item in self.checked(payload["items"]) if item["signed"] is not None]
credentials = [key["id"] for key in self.keys()]
if not hashes:
return {"payload": None, "challenge": None, "credentials": credentials}
request = signing.approval_payload(hashes, secrets.token_hex(16), int(time.time()) + signing.LIFETIME)
return {"payload": request, "challenge": signing.challenge(request), "credentials": credentials}
def approve(self, body: bytes) -> dict:
payload = decode(body)
expect(payload, ("items", "proof"))
items = self.checked(payload["items"])
proof = self.covered(payload["proof"], [item["signed"] for item in items if item["signed"] is not None], time.time())
return self.batches.add(items, "operator", proof, self.apply)
def undo(self, batch_id: str) -> dict:
batch = self.batches.undo(batch_id)
titles = ", ".join(item["title"][:80] for item in batch["items"])
self.log.add({"kind": "approval", "title": f"Rückgängig: {titles}", "text": batch["source"], "ref": {"batch": batch_id}})
return {"id": batch_id, "status": "undone"}