* fix(auth): prune expired sessions on every verify to prevent memory leak
The in-memory _sessions dict accumulated expired tokens indefinitely —
entries were only removed when that specific token was verified. Add a
lazy _prune_expired_sessions() call at the top of verify_session() so
all expired entries are swept during normal traffic.
Addresses #192.
* test(auth): add 8 unit tests for session lifecycle and lazy pruning
Tests verify:
- Fresh session creation and validation
- Expired entries are pruned during verify_session() calls
- Valid sessions are never removed by pruning
- Empty dict is safe for pruning
- Session TTL matches expected 24-hour window
- invalidate_session() actually removes the token
- Invalidating non-existent tokens is safe
* security: fix four audit findings -- env race, signing key, upload traversal, password hash
1. Race condition in os.environ (HIGH): Per-session _agent_lock didn't
prevent cross-session env writes from interleaving. Added global
_ENV_LOCK in streaming.py that serializes the entire env save/restore
block across all sessions.
2. Predictable signing key (MEDIUM): sha256(STATE_DIR) was deterministic.
Now generates a random 32-byte key on first startup and persists it to
STATE_DIR/.signing_key (chmod 600). Existing sessions invalidated on
first restart (acceptable for a security fix).
3. Upload path traversal (MEDIUM): Filename '..' survived the regex
sanitization (dots are allowed chars). Added explicit rejection of
dot-only names and safe_resolve_ws() check to verify the resolved
path stays within the workspace.
4. Weak password hashing (MEDIUM): Replaced bare SHA-256 with PBKDF2-
SHA256 (600k iterations per OWASP). Uses stdlib hashlib.pbkdf2_hmac,
no new dependencies. Note: existing passwords must be re-set after
this change (hash format changed).
Closes#106
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
* fix: use random signing key as PBKDF2 salt (replaces predictable STATE_DIR salt)
---------
Co-authored-by: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
'/' and '/index.html' were in PUBLIC_PATHS, so setting a password
and refreshing the root URL would show the app blank (JS loaded
but all API calls returned 401) instead of redirecting to /login.
Root and index.html must be protected paths so the browser gets a
302 -> /login when auth is active and no valid session cookie exists.
Auth system (off by default, zero friction for localhost):
- New api/auth.py module: password hashing (SHA-256 + STATE_DIR salt),
signed HMAC session cookies (24h TTL), auth middleware
- Enable via HERMES_WEBUI_PASSWORD env var or Settings panel
- Minimal dark-themed login page at /login (self-contained HTML)
- POST /api/auth/login, /api/auth/logout, GET /api/auth/status
- Settings panel: "Access Password" field + "Sign Out" button
- password_hash added to settings.json (null = auth disabled)
Security hardening:
- Security headers on all responses: X-Content-Type-Options: nosniff,
X-Frame-Options: DENY, Referrer-Policy: same-origin
- POST body size limit: 20MB cap in read_body() to prevent DoS
Closes#23. 9 new tests. Total: 304 passed, 0 regressions.
Co-Authored-By: Claude Opus 4.6 (1M context) <noreply@anthropic.com>
