refactor: move codex_auth into contrib/codex

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
2026-06-04 16:27:57 +00:00
parent eafd1c1fb2
commit 6a2d07d39c
3 changed files with 2 additions and 2 deletions
@@ -0,0 +1,328 @@
+"""Host Codex auth helpers.
+
+Reads the host's Codex ChatGPT/device-login auth state and returns only
+the short-lived access token needed by egress. This module deliberately
+does not expose refresh tokens or raw auth payloads.
+"""
+
+from __future__ import annotations
+
+import base64
+import json
+import os
+from copy import deepcopy
+from datetime import datetime, timezone
+from pathlib import Path
+from typing import cast
+
+from .log import die
+from .util import expand_tilde
+
+
+def codex_auth_path(host_env: dict[str, str] | None = None) -> Path:
+    env = os.environ if host_env is None else host_env
+    home = env.get("CODEX_HOME")
+    if home:
+        return Path(expand_tilde(home)) / "auth.json"
+    return Path.home() / ".codex" / "auth.json"
+
+
+def codex_host_access_token(
+    host_env: dict[str, str] | None = None,
+    *,
+    now: datetime | None = None,
+) -> str:
+    path = codex_auth_path(host_env)
+    if not path.is_file():
+        die(
+            f"codex host credentials: auth file missing at {path}. "
+            "Run `codex login --device-auth` on the host or disable "
+            "agent_provider.forward_host_credentials."
+        )
+    raw = _read_auth_object(path)
+
+    auth_mode = raw.get("auth_mode")
+    if not isinstance(auth_mode, str) or auth_mode == "api_key":
+        die(
+            "codex host credentials: host Codex auth is not user/device "
+            "auth. Run `codex login --device-auth` on the host."
+        )
+
+    tokens = raw.get("tokens")
+    if not isinstance(tokens, dict):
+        die(f"codex host credentials: {path} is missing tokens")
+    tokens_typed = cast(dict[str, object], tokens)
+    access = tokens_typed.get("access_token")
+    if not isinstance(access, str) or not access:
+        die(
+            f"codex host credentials: {path} is missing tokens.access_token. "
+            "Run `codex login --device-auth` on the host."
+        )
+
+    exp = _jwt_exp(access)
+    if exp is None:
+        die("codex host credentials: tokens.access_token is not a JWT with exp")
+    check_now = now or datetime.now(timezone.utc)
+    if exp <= check_now:
+        die(
+            "codex host credentials: host Codex access token is expired. "
+            "Run `codex login --device-auth` on the host and restart the bottle."
+        )
+    return access
+
+
+def codex_dummy_auth_json(
+    host_env: dict[str, str] | None = None,
+    *,
+    now: datetime | None = None,
+) -> str:
+    """Return a non-secret `auth.json` that keeps Codex in the host's
+    auth branch while egress owns the real bearer token.
+
+    The dummy access/id tokens carry the *host* token's real `exp` so
+    Codex's proactive refresh lifecycle (it refreshes when its local
+    access token is at/past expiry) tracks the real token instead of
+    firing after an artificial TTL. Codex cannot refresh inside the
+    bottle — the refresh token is a placeholder and the OpenAI token
+    endpoint is off-route — so a shorter dummy exp would drop Codex to
+    the sign-in screen the moment it lapsed, even while egress still
+    holds a valid bearer."""
+    path = codex_auth_path(host_env)
+    access = codex_host_access_token(host_env, now=now)
+    raw = _read_auth_object(path)
+    host_exp = _jwt_exp(access)
+    exp_ts = int(host_exp.timestamp()) if host_exp is not None else None
+    dummy = _redact_codex_auth(deepcopy(raw), now=now, exp_ts=exp_ts)
+    return json.dumps(dummy, indent=2, sort_keys=True) + "\n"
+
+
+def write_codex_dummy_auth_file(
+    path: Path,
+    host_env: dict[str, str] | None = None,
+    *,
+    now: datetime | None = None,
+) -> None:
+    path.parent.mkdir(parents=True, exist_ok=True)
+    path.write_text(codex_dummy_auth_json(host_env, now=now))
+    path.chmod(0o600)
+
+
+def _read_auth_object(path: Path) -> dict[str, object]:
+    try:
+        raw = json.loads(path.read_text())
+    except (OSError, json.JSONDecodeError) as e:
+        die(f"codex host credentials: could not read valid JSON at {path}: {e}")
+    if not isinstance(raw, dict):
+        die(f"codex host credentials: {path} must contain a JSON object")
+    return cast(dict[str, object], raw)
+
+
+def _dummy_exp(now: datetime | None, exp_ts: int | None) -> int:
+    if exp_ts is not None:
+        return exp_ts
+    check_now = now or datetime.now(timezone.utc)
+    return int(check_now.timestamp()) + 3600
+
+
+def _dummy_timestamp(now: datetime | None = None) -> str:
+    check_now = now or datetime.now(timezone.utc)
+    if check_now.tzinfo is None:
+        check_now = check_now.replace(tzinfo=timezone.utc)
+    check_now = check_now.astimezone(timezone.utc)
+    return check_now.isoformat(timespec="milliseconds").replace("+00:00", "Z")
+
+
+def _dummy_jwt(now: datetime | None = None, *, exp_ts: int | None = None) -> str:
+    return _encode_dummy_jwt({
+        "exp": _dummy_exp(now, exp_ts),
+        "sub": "bot-bottle-placeholder",
+    })
+
+
+def _dummy_jwt_from_host(
+    value: object, *, now: datetime | None = None, exp_ts: int | None = None,
+) -> str:
+    if not isinstance(value, str):
+        return _dummy_jwt(now, exp_ts=exp_ts)
+    parts = value.split(".")
+    if len(parts) < 2:
+        return _dummy_jwt(now, exp_ts=exp_ts)
+    try:
+        payload = json.loads(_b64url_decode(parts[1]))
+    except (ValueError, json.JSONDecodeError):
+        return _dummy_jwt(now, exp_ts=exp_ts)
+    if not isinstance(payload, dict):
+        return _dummy_jwt(now, exp_ts=exp_ts)
+    return _encode_dummy_jwt(_redact_jwt_payload(cast(dict[str, object], payload), now=now, exp_ts=exp_ts))
+
+
+def _encode_dummy_jwt(payload: dict[str, object]) -> str:
+    def enc(obj: dict[str, object]) -> str:
+        raw = json.dumps(obj, separators=(",", ":")).encode()
+        return base64.urlsafe_b64encode(raw).decode().rstrip("=")
+
+    return f"{enc({'alg': 'none', 'typ': 'JWT'})}.{enc(payload)}.placeholder"
+
+
+def _redact_jwt_payload(
+    payload: dict[str, object],
+    *,
+    now: datetime | None = None,
+    exp_ts: int | None = None,
+) -> dict[str, object]:
+    out = _redact_claims(payload)
+    if not isinstance(out, dict):
+        out = {}
+    out_typed: dict[str, object] = cast(dict[str, object], out)
+    out_typed["exp"] = _dummy_exp(now, exp_ts)
+    out_typed.setdefault("sub", "bot-bottle-placeholder")
+    return out_typed
+
+
+def _redact_claims(value: object) -> object:
+    if isinstance(value, dict):
+        out: dict[str, object] = {}
+        for key, inner in cast(dict[str, object], value).items():
+            lower = key.lower()
+            if key == "https://api.openai.com/profile":
+                out[key] = _redact_profile_claim(inner)
+            elif key == "https://api.openai.com/auth":
+                out[key] = _redact_auth_claim(inner)
+            elif lower == "email":
+                out[key] = "bot-bottle@example.invalid"
+            elif lower == "email_verified":
+                out[key] = True
+            elif lower in {"exp", "iat", "nbf", "auth_time", "pwd_auth_time"}:
+                out[key] = inner if isinstance(inner, (int, float)) else 0
+            elif lower in {"aud", "scp", "amr"}:
+                out[key] = inner if isinstance(inner, list) else []
+            elif isinstance(inner, bool):
+                out[key] = inner
+            elif isinstance(inner, dict):
+                out[key] = {}
+            elif isinstance(inner, list):
+                out[key] = []
+            else:
+                out[key] = "bot-bottle-placeholder"
+        return out
+    if isinstance(value, list):
+        return []
+    return "bot-bottle-placeholder"
+
+
+def _redact_profile_claim(value: object) -> dict[str, object]:
+    profile = cast(dict[str, object], value) if isinstance(value, dict) else {}
+    return {
+        "email": "bot-bottle@example.invalid",
+        "email_verified": bool(profile.get("email_verified", True)),
+    }
+
+
+def _redact_auth_claim(value: object) -> dict[str, object]:
+    auth = cast(dict[str, object], value) if isinstance(value, dict) else {}
+    out: dict[str, object] = {}
+    for key, inner in auth.items():
+        lower = key.lower()
+        if lower == "chatgpt_plan_type" and isinstance(inner, str) and inner:
+            out[key] = inner
+        elif lower == "chatgpt_account_id" and isinstance(inner, str) and inner:
+            # Current Codex uses the selected account id when building
+            # ChatGPT requests. Keep that non-secret identifier aligned
+            # with the host while egress owns the real bearer token.
+            out[key] = inner
+        elif lower == "localhost" and isinstance(inner, bool):
+            out[key] = inner
+        elif isinstance(inner, bool):
+            out[key] = inner
+        elif isinstance(inner, list):
+            out[key] = []
+        elif isinstance(inner, dict):
+            out[key] = {}
+        else:
+            out[key] = "bot-bottle-placeholder"
+    out.setdefault("chatgpt_plan_type", "unknown")
+    out.setdefault("user_id", "bot-bottle-placeholder")
+    out.setdefault("chatgpt_user_id", "bot-bottle-placeholder")
+    out.setdefault("chatgpt_account_id", "bot-bottle-placeholder")
+    return out
+
+
+def _redact_codex_auth(
+    value: object, *, now: datetime | None = None, exp_ts: int | None = None,
+) -> object:
+    auth = cast(dict[str, object], value) if isinstance(value, dict) else {}
+    out: dict[str, object] = {}
+    for key, inner in auth.items():
+        lower = key.lower()
+        if lower == "auth_mode" and isinstance(inner, str) and inner:
+            out[key] = inner
+        elif lower == "openai_api_key":
+            out[key] = None
+        elif lower == "last_refresh":
+            # Codex parses this as a timestamp on startup. Keep the
+            # schema valid without copying host-side session metadata.
+            out[key] = _dummy_timestamp(now)
+        elif lower == "tokens":
+            out[key] = _redact_token_block(inner, now=now, exp_ts=exp_ts)
+        else:
+            out[key] = _redact_unknown_auth_value(inner)
+    return out
+
+
+def _redact_token_block(
+    value: object, *, now: datetime | None = None, exp_ts: int | None = None,
+) -> dict[str, object]:
+    tokens = cast(dict[str, object], value) if isinstance(value, dict) else {}
+    out: dict[str, object] = {}
+    for key, inner in tokens.items():
+        lower = key.lower()
+        if lower in {"access_token", "id_token"}:
+            out[key] = _dummy_jwt_from_host(inner, now=now, exp_ts=exp_ts)
+        elif lower == "account_id" and isinstance(inner, str) and inner:
+            # Current Codex uses this non-secret selected account id
+            # while egress owns the real bearer token.
+            out[key] = inner
+        else:
+            out[key] = _redact_unknown_auth_value(inner)
+    return out
+
+
+def _redact_unknown_auth_value(value: object) -> object:
+    if isinstance(value, bool):
+        return value
+    if isinstance(value, dict):
+        return {}
+    if isinstance(value, list):
+        return []
+    if value is None:
+        return None
+    return "bot-bottle-placeholder"
+
+
+def _jwt_exp(token: str) -> datetime | None:
+    parts = token.split(".")
+    if len(parts) < 2:
+        return None
+    try:
+        payload = json.loads(_b64url_decode(parts[1]))
+    except (ValueError, json.JSONDecodeError):
+        return None
+    if not isinstance(payload, dict):
+        return None
+    exp = cast(dict[str, object], payload).get("exp")
+    if not isinstance(exp, (int, float)):
+        return None
+    return datetime.fromtimestamp(exp, timezone.utc)
+
+
+def _b64url_decode(value: str) -> str:
+    padded = value + ("=" * (-len(value) % 4))
+    return base64.urlsafe_b64decode(padded.encode("ascii")).decode("utf-8")
+
+
+__all__ = [
+    "codex_auth_path",
+    "codex_dummy_auth_json",
+    "codex_host_access_token",
+    "write_codex_dummy_auth_file",
+]