didericis-claude
784e49239d
test / integration-docker (pull_request) Successful in 14s
test / unit (pull_request) Successful in 40s
lint / lint (push) Successful in 57s
test / integration-firecracker (pull_request) Successful in 3m51s
test / coverage (pull_request) Successful in 21s
test / publish-infra (pull_request) Has been skipped
tracker-policy-pr / check-pr (pull_request) Successful in 12s
Address review on #482: drop the generic "credential boundary" framing in the PRD and docstrings and talk about the specific services — the orchestrator holds the control-plane key; the host controller (#468) gets a separate key the orchestrator never holds, so the orchestrator can't mint the credentials it uses to talk to the host controller that owns its lifecycle. Lead with that concrete win. No code behaviour change. Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
107 lines
4.3 KiB
Python
107 lines
4.3 KiB
Python
"""Role-scoped control-plane credentials (issue #469 review follow-up).
|
|
|
|
The control plane no longer trusts a single shared bearer secret for every
|
|
route. Instead the orchestrator holds a *signing key* and issues short,
|
|
HMAC-signed tokens (compact HS256 JWTs) that embed a **role** naming the kind
|
|
of caller:
|
|
|
|
* ``gateway`` — the data plane (egress / git-gate / supervise). Restricted to
|
|
the agent-facing routes it actually needs (``/resolve``,
|
|
``/supervise/propose``, ``/supervise/poll``).
|
|
* ``cli`` — the host operator / launcher. Full access to the mutating and
|
|
operator routes (launch/teardown, policy, ``/supervise/respond``, …).
|
|
|
|
Only the orchestrator (and the host CLI, which shares the host trust domain)
|
|
holds the signing key; the gateway is handed a pre-minted ``gateway`` token it
|
|
cannot rewrite into a ``cli`` token. So a compromised data-plane process can no
|
|
longer approve its own supervise proposals or drive operator routes — it can
|
|
only present the ``gateway`` role it was issued (the control plane rejects it
|
|
on operator routes with 403).
|
|
|
|
Stdlib-only (HMAC-SHA256 over a JSON payload); no JWT dependency — the project
|
|
carries no runtime pip deps. Tokens are **signed, not encrypted** (the role is
|
|
not a secret) and **long-lived** (parity with the static token they replace;
|
|
the security win is the unforgeable role claim, not rotation).
|
|
"""
|
|
|
|
from __future__ import annotations
|
|
|
|
import base64
|
|
import binascii
|
|
import hashlib
|
|
import hmac
|
|
import json
|
|
|
|
ROLE_GATEWAY = "gateway"
|
|
ROLE_CLI = "cli"
|
|
ROLES: frozenset[str] = frozenset({ROLE_GATEWAY, ROLE_CLI})
|
|
|
|
_ALG = "HS256"
|
|
|
|
|
|
def _b64url_encode(raw: bytes) -> str:
|
|
return base64.urlsafe_b64encode(raw).rstrip(b"=").decode("ascii")
|
|
|
|
|
|
def _b64url_decode(text: str) -> bytes:
|
|
padded = text + "=" * (-len(text) % 4)
|
|
return base64.urlsafe_b64decode(padded.encode("ascii"))
|
|
|
|
|
|
def _sign(secret: str, signing_input: str) -> str:
|
|
mac = hmac.new(secret.encode("utf-8"), signing_input.encode("ascii"), hashlib.sha256)
|
|
return _b64url_encode(mac.digest())
|
|
|
|
|
|
# The fixed, canonical JOSE header — the same for every token we mint.
|
|
_HEADER_SEGMENT = _b64url_encode(
|
|
json.dumps({"alg": _ALG, "typ": "JWT"}, separators=(",", ":")).encode("utf-8")
|
|
)
|
|
|
|
|
|
def mint(role: str, secret: str, *, roles: frozenset[str] = ROLES) -> str:
|
|
"""A compact HS256 token asserting `role`, signed with `secret`.
|
|
|
|
`roles` is the set the signing key is allowed to sign (default: the
|
|
orchestrator's `{gateway, cli}`). A separate service (e.g. the host
|
|
controller) passes its own key + role set so its tokens can't be forged with
|
|
the orchestrator's key — see `trust_domain.py`, issues #476/#468.
|
|
|
|
Raises ValueError for a role outside `roles`, or an empty signing key (an
|
|
unsigned credential is never valid)."""
|
|
if role not in roles:
|
|
raise ValueError(f"unknown control-plane role {role!r}")
|
|
if not secret:
|
|
raise ValueError("cannot mint a control-plane token without a signing key")
|
|
payload = _b64url_encode(json.dumps({"role": role}, separators=(",", ":")).encode("utf-8"))
|
|
signing_input = f"{_HEADER_SEGMENT}.{payload}"
|
|
return f"{signing_input}.{_sign(secret, signing_input)}"
|
|
|
|
|
|
def verify(token: str, secret: str, *, roles: frozenset[str] = ROLES) -> str | None:
|
|
"""The role a valid `token` carries, or None if it is malformed, wrongly
|
|
signed, or names a role outside `roles` (the verifying trust domain's set —
|
|
default `{gateway, cli}`). Constant-time signature check; rejects any header
|
|
whose alg isn't HS256 (no alg-confusion / `none`)."""
|
|
if not token or not secret:
|
|
return None
|
|
parts = token.split(".")
|
|
if len(parts) != 3:
|
|
return None
|
|
header_b64, payload_b64, sig = parts
|
|
expected = _sign(secret, f"{header_b64}.{payload_b64}")
|
|
if not hmac.compare_digest(sig, expected):
|
|
return None
|
|
try:
|
|
header = json.loads(_b64url_decode(header_b64))
|
|
payload = json.loads(_b64url_decode(payload_b64))
|
|
except (ValueError, binascii.Error):
|
|
return None
|
|
if not isinstance(header, dict) or header.get("alg") != _ALG:
|
|
return None
|
|
role = payload.get("role") if isinstance(payload, dict) else None
|
|
return role if isinstance(role, str) and role in roles else None
|
|
|
|
|
|
__all__ = ["ROLE_GATEWAY", "ROLE_CLI", "ROLES", "mint", "verify"]
|