Skill: risky-module-review

Risky Modules in This Repo

File	Risk	What to check
admin_auth.py	Session auth, admin identity	No secret leaks, session fixation prevention, proper expiry
key_store.py	API key persistence	Keys hashed before storage, no plaintext in logs, file permissions
agent/tools.py	Filesystem write surface	Path traversal prevention, content sanitization
proxy.py (auth middleware)	Bearer token validation	No bypass paths, rate limit correctness
agent/loop.py (_local_safety_check)	Security guardrail	Not weakened or removed

Instructions

Step 1 — Read the module's CLAUDE.md

• agent/ → agent/CLAUDE.md
• router/ → router/CLAUDE.md
• No module CLAUDE.md? Read the file header docstring carefully.

Step 2 — Checklist by module

admin_auth.py checklist

• Admin password is read from environment — never hardcoded
• Sessions expire (check max_age or SESSION_MAX_AGE)
• AdminIdentity is validated before any state-mutating action
• No print() or log.debug() exposes the admin password or session token
• CSRF protection present for state-mutating routes

key_store.py checklist

• API keys are stored hashed (SHA-256 or stronger) — never plaintext
• keys.json is never committed (it is in .gitignore)
• Key comparison uses constant-time comparison (hmac.compare_digest)
• No key value appears in any log line
• issue_new_api_key returns the plaintext key exactly once, immediately

agent/tools.py checklist

• apply_diff resolves paths with Path.resolve() and validates they stay within self.root
• No .. traversal path accepted without rejection
• File content is not eval()-ed or exec()-ed
• search_code does not expose .env or keys.json content

proxy.py auth middleware checklist

• verify_api_key() cannot be bypassed by setting a header to empty string
• Rate limit is per-key, not per-IP (IP can be spoofed)
• VALID_API_KEYS from env is populated — empty set should reject all requests

Step 3 — Run targeted tests

pytest -x tests/test_agent_api.py tests/test_agent_tools.py

Step 4 — Write a security note in the PR description

## Security note
- Changed: <what changed>
- Risk: <what could go wrong>
- Mitigation: <how it is addressed>
- Verified by: risky-module-review skill

Acceptance Checks

• All relevant checklist items above checked
• No secrets in source
• Path traversal not possible in file-write code
• Tests pass for affected module
• Security note included in PR description or commit message
• Changelog entry under ### Security added if applicable

Escalation

If a change would weaken an existing security check (e.g., remove path validation,
make auth optional), stop and document the risk explicitly before proceeding.
Prefer to add a feature flag rather than weaken a hard check.