Files
bot-bottle/bot_bottle/egress.py
T
didericis 96f5be48a6 fix(egress): emit preserve_auth into the generated routes
The flag from #453 was parsed off the manifest and honored by the
addon, but `_route_to_yaml_fields` never wrote it, so it was dropped on
the way to the proxy and has never worked end to end. Every registry
route silently kept the unconditional Authorization strip.

That is the whole of the Docker Hub / GHCR "unauthorized" blocker in
#392: podman fetched a valid 2658-byte bearer from auth.docker.io, the
proxy stripped it, and registry-1.docker.io answered the resulting
anonymous request with a fresh WWW-Authenticate challenge — which reads
exactly like a credential problem rather than a serializer gap.

Found by diffing a bottle's rendered routes.yaml against its manifest:
preserve_auth was in the manifest and absent from the output.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>
2026-07-21 22:54:26 -04:00

425 lines
14 KiB
Python

"""Per-bottle egress proxy (PRD 0017, PRD 0053).
This module defines the abstract proxy (`Egress`), its plan
dataclass (`EgressPlan`), and the resolved per-route shape
(`EgressRoute`). The gateway's start/stop lifecycle is backend-
specific and lives on concrete subclasses (see
`bot_bottle/backend/docker/egress.py`).
"""
from __future__ import annotations
import dataclasses
import secrets
from abc import ABC
from dataclasses import dataclass
from pathlib import Path
from typing import TYPE_CHECKING
from .egress_addon_core import (
ON_MATCH_REDACT,
HeaderMatch as CoreHeaderMatch,
MatchEntry as CoreMatchEntry,
PathMatch as CorePathMatch,
Route,
)
from .errors import MissingEnvVarError
from .log import die
if TYPE_CHECKING:
from .manifest import ManifestBottle
CODEX_HOST_CREDENTIAL_TOKEN_REF = "BOT_BOTTLE_CODEX_HOST_ACCESS_TOKEN"
CLAUDE_HOST_CREDENTIAL_TOKEN_REF = "BOT_BOTTLE_CLAUDE_HOST_ACCESS_TOKEN"
EGRESS_HOSTNAME = "egress"
EGRESS_ROUTES_IN_CONTAINER = "/etc/egress/routes.yaml"
EGRESS_ROUTES_FILENAME = Path(EGRESS_ROUTES_IN_CONTAINER).name
_CANARY_ENV_WORDS = (
"ACCORD",
"ANCHOR",
"ATLAS",
"CANON",
"CIPHER",
"EMBER",
"FALCON",
"HARBOR",
"LANTERN",
"MARBLE",
"NOVA",
"ORBIT",
"PIVOT",
"RADIUS",
"SUMMIT",
"VECTOR",
)
def _random_canary_env() -> str:
first = secrets.choice(_CANARY_ENV_WORDS)
remaining = tuple(word for word in _CANARY_ENV_WORDS if word != first)
second = secrets.choice(remaining)
return f"{first}_{second}_SECRET"
def egress_gateway_env_entries(plan: "EgressPlan") -> tuple[str, ...]:
"""Return gateway env entries needed by egress across all backends."""
env: list[str] = []
if plan.routes:
env.extend(sorted(plan.token_env_map.keys()))
if plan.canary and plan.canary_env:
env.append(f"{plan.canary_env}={plan.canary}")
env.append(f"BOT_BOTTLE_SENSITIVE_PREFIXES={plan.canary_env}")
return tuple(env)
def egress_agent_env_entries(plan: "EgressPlan") -> tuple[str, ...]:
"""Return agent-visible egress env entries shared by all backends."""
if plan.canary and plan.canary_env:
return (f"{plan.canary_env}={plan.canary}",)
return ()
@dataclass(frozen=True)
class EgressRoute(Route):
"""Host-side extension of the addon's `Route`.
Inherits `host`, `matches`, `auth_scheme`, and `token_env`
from `egress_addon_core.Route` — those are the fields that cross the
YAML wire into the gateway. The fields below are host-only and
are never serialised to the addon.
`token_ref` is the host env var the CLI reads at launch and forwards
into the container's environ under `token_env`.
`roles` carries the manifest route's role tuple (reserved for
future use; always empty today)."""
token_ref: str = ""
roles: tuple[str, ...] = ()
@dataclass(frozen=True)
class EgressPlan:
slug: str
routes_path: Path
routes: tuple[EgressRoute, ...]
token_env_map: dict[str, str]
internal_network: str = ""
egress_network: str = ""
mitmproxy_ca_host_path: Path = Path()
mitmproxy_ca_cert_only_host_path: Path = Path()
log: int = 0
canary: str = ""
canary_env: str = ""
def egress_manifest_routes(
bottle: ManifestBottle,
) -> tuple[EgressRoute, ...]:
out: list[EgressRoute] = []
for r in bottle.egress.routes:
core_matches: list[CoreMatchEntry] = []
for m in r.Matches:
core_paths = tuple(
CorePathMatch(type=p.Type, value=p.Value)
for p in m.Paths
)
core_headers = tuple(
CoreHeaderMatch(name=h.Name, value=h.Value, type=h.Type)
for h in m.Headers
)
core_matches.append(CoreMatchEntry(
paths=core_paths,
methods=m.Methods,
headers=core_headers,
))
out.append(EgressRoute(
host=r.Host,
matches=tuple(core_matches),
auth_scheme=r.AuthScheme,
token_ref=r.TokenRef,
roles=r.Role,
git_fetch=r.GitFetch,
outbound_detectors=r.OutboundDetectors,
inbound_detectors=r.InboundDetectors,
outbound_on_match=r.OutboundOnMatch,
preserve_auth=r.PreserveAuth,
))
return tuple(out)
def egress_routes_for_bottle(
bottle: ManifestBottle,
provider_routes: tuple[EgressRoute, ...] = (),
) -> tuple[EgressRoute, ...]:
manifest = egress_manifest_routes(bottle)
provisioned_hosts = {pr.host.lower() for pr in provider_routes}
merged = list(_default_provider_on_match(provider_routes)) + [
r for r in manifest if r.host.lower() not in provisioned_hosts
]
return _assign_token_slots(merged)
def _default_provider_on_match(
provider_routes: tuple[EgressRoute, ...],
) -> tuple[EgressRoute, ...]:
"""Provider routes (the agent talking to its own LLM API) default to the
`redact` on-match policy (PRD 0062): high-volume conversation payloads are
the worst source of token-shaped false positives, so a match is scrubbed
and forwarded rather than hard-blocked or queued for the operator. A
provider that sets `outbound_on_match` explicitly keeps its choice."""
return tuple(
r if r.outbound_on_match
else dataclasses.replace(r, outbound_on_match=ON_MATCH_REDACT)
for r in provider_routes
)
def _assign_token_slots(
routes: list[EgressRoute],
) -> tuple[EgressRoute, ...]:
slot_for_ref: dict[str, str] = {}
out: list[EgressRoute] = []
for r in routes:
if r.auth_scheme and r.token_ref:
slot = slot_for_ref.get(r.token_ref)
if slot is None:
slot = f"EGRESS_TOKEN_{len(slot_for_ref)}"
slot_for_ref[r.token_ref] = slot
out.append(dataclasses.replace(r, token_env=slot))
else:
out.append(r)
return tuple(out)
def egress_token_env_map(
routes: tuple[EgressRoute, ...],
) -> dict[str, str]:
out: dict[str, str] = {}
for r in routes:
if not (r.auth_scheme and r.token_ref and r.token_env):
continue
existing = out.get(r.token_env)
if existing is not None and existing != r.token_ref:
die(
f"egress plan conflict: {r.token_env} maps to both "
f"{existing!r} and {r.token_ref!r}. Two routes sharing a "
f"token slot must reference the same host env var."
)
out[r.token_env] = r.token_ref
return out
def _yaml_str_escape(s: str) -> str:
"""Escape a string for use inside a YAML double-quoted scalar."""
return (
s.replace("\\", "\\\\")
.replace('"', '\\"')
.replace("\n", "\\n")
.replace("\r", "\\r")
.replace("\t", "\\t")
)
def _route_to_yaml_fields(r: Route) -> dict[str, object]:
fields: dict[str, object] = {"host": r.host}
if r.auth_scheme and r.token_env:
fields["auth_scheme"] = r.auth_scheme
fields["token_env"] = r.token_env
if r.matches:
matches_data: list[dict[str, object]] = []
for entry in r.matches:
entry_data: dict[str, object] = {}
if entry.paths:
paths_data: list[dict[str, str]] = []
for pm in entry.paths:
pd: dict[str, str] = {"value": pm.value}
if pm.type != "prefix":
pd["type"] = pm.type
paths_data.append(pd)
entry_data["paths"] = paths_data
if entry.methods:
entry_data["methods"] = list(entry.methods)
if entry.headers:
headers_data: list[dict[str, str]] = []
for hm in entry.headers:
hd: dict[str, str] = {"name": hm.name, "value": hm.value}
if hm.type != "exact":
hd["type"] = hm.type
headers_data.append(hd)
entry_data["headers"] = headers_data
matches_data.append(entry_data)
fields["matches"] = matches_data
if r.git_fetch:
fields["git"] = {"fetch": True}
if r.preserve_auth:
fields["preserve_auth"] = True
if (
r.outbound_detectors is not None
or r.inbound_detectors is not None
or r.outbound_on_match
):
dlp: dict[str, object] = {}
if r.outbound_detectors is not None:
dlp["outbound_detectors"] = (
False if not r.outbound_detectors
else list(r.outbound_detectors)
)
if r.inbound_detectors is not None:
dlp["inbound_detectors"] = (
False if not r.inbound_detectors
else list(r.inbound_detectors)
)
if r.outbound_on_match:
dlp["outbound_on_match"] = r.outbound_on_match
fields["dlp"] = dlp
return fields
def _render_match_entry(entry: dict[str, object]) -> list[str]:
lines: list[str] = []
first_key = True
if "paths" in entry:
lines.append(" - paths:")
first_key = False
for pd in entry["paths"]: # type: ignore[union-attr]
pd_dict: dict[str, str] = pd # type: ignore[assignment]
if "type" in pd_dict:
lines.append(f' - type: "{_yaml_str_escape(pd_dict["type"])}"')
lines.append(f' value: "{_yaml_str_escape(pd_dict["value"])}"')
else:
lines.append(f' - value: "{_yaml_str_escape(pd_dict["value"])}"')
if "methods" in entry:
methods_str = ", ".join(f'"{_yaml_str_escape(m)}"' for m in entry["methods"]) # type: ignore[union-attr]
prefix = " - " if first_key else " "
lines.append(f'{prefix}methods: [{methods_str}]')
first_key = False
if "headers" in entry:
prefix = " - " if first_key else " "
lines.append(f"{prefix}headers:")
first_key = False
for hd in entry["headers"]: # type: ignore[union-attr]
hd_dict: dict[str, str] = hd # type: ignore[assignment]
lines.append(f' - name: "{_yaml_str_escape(hd_dict["name"])}"')
lines.append(f' value: "{_yaml_str_escape(hd_dict["value"])}"')
if first_key:
lines.append(" - {}")
return lines
def egress_render_routes(
routes: tuple[EgressRoute, ...],
*,
log: int = 0,
) -> str:
lines: list[str] = []
if log:
lines.append(f"log: {log}")
lines.append("routes:")
if not routes:
lines[-1] = "routes: []"
return "\n".join(lines) + "\n"
for r in routes:
f = _route_to_yaml_fields(r)
lines.append(f' - host: "{_yaml_str_escape(str(f["host"]))}"')
if "auth_scheme" in f:
lines.append(f' auth_scheme: "{_yaml_str_escape(str(f["auth_scheme"]))}"')
lines.append(f' token_env: "{_yaml_str_escape(str(f["token_env"]))}"')
if "matches" in f:
lines.append(" matches:")
for entry in f["matches"]: # type: ignore[union-attr]
lines.extend(_render_match_entry(entry)) # type: ignore[arg-type]
if "git" in f:
git_dict: dict[str, object] = f["git"] # type: ignore
lines.append(" git:")
if git_dict.get("fetch") is True:
lines.append(" fetch: true")
if f.get("preserve_auth") is True:
lines.append(" preserve_auth: true")
if "dlp" in f:
dlp_dict: dict[str, object] = f["dlp"] # type: ignore
lines.append(" dlp:")
for dk, dv in dlp_dict.items():
if dv is False:
lines.append(f" {dk}: false")
elif isinstance(dv, list):
items_str = ", ".join(f'"{x}"' for x in dv)
lines.append(f" {dk}: [{items_str}]")
elif isinstance(dv, str):
lines.append(f' {dk}: "{_yaml_str_escape(dv)}"')
return "\n".join(lines) + "\n"
def egress_resolve_token_values(
token_env_map: dict[str, str],
host_env: dict[str, str],
) -> dict[str, str]:
out: dict[str, str] = {}
for token_env, token_ref in token_env_map.items():
value = host_env.get(token_ref)
if value is None:
raise MissingEnvVarError(
token_ref,
f"egress: host env var '{token_ref}' is unset. Set it "
f"before launching, or remove the corresponding auth block "
f"from bottle.egress.routes.",
)
if not value:
raise MissingEnvVarError(
token_ref,
f"egress: host env var '{token_ref}' is empty. The "
f"egress will not inject an empty token; set it to "
f"the real value or remove the route's auth block.",
)
out[token_env] = value
return out
class Egress(ABC):
def prepare(
self,
bottle: ManifestBottle,
slug: str,
stage_dir: Path,
provider_routes: tuple[EgressRoute, ...] = (),
) -> EgressPlan:
routes = egress_routes_for_bottle(bottle, provider_routes)
log = bottle.egress.Log
routes_path = stage_dir / EGRESS_ROUTES_FILENAME
routes_path.write_text(egress_render_routes(routes, log=log))
routes_path.chmod(0o600)
# Generate a per-session fake secret under a plausible random env name.
# The gateway marks that exact env name as sensitive for known-secret
# scanning; the agent receives the same name/value as exfil bait.
canary = secrets.token_urlsafe(32)
return EgressPlan(
slug=slug,
routes_path=routes_path,
routes=routes,
token_env_map=egress_token_env_map(routes),
log=log,
canary=canary,
canary_env=_random_canary_env(),
)
__all__ = [
"CLAUDE_HOST_CREDENTIAL_TOKEN_REF",
"CODEX_HOST_CREDENTIAL_TOKEN_REF",
"EGRESS_HOSTNAME",
"EGRESS_ROUTES_FILENAME",
"EGRESS_ROUTES_IN_CONTAINER",
"Egress",
"EgressPlan",
"EgressRoute",
"egress_manifest_routes",
"egress_render_routes",
"egress_resolve_token_values",
"egress_routes_for_bottle",
"egress_agent_env_entries",
"egress_gateway_env_entries",
"egress_token_env_map",
]