realIP() now parses RemoteAddr and checks if the source IP is in
RFC1918 (10/8, 172.16/12, 192.168/16), loopback (127/8), or IPv6
ULA/loopback ranges before trusting X-Real-IP or X-Forwarded-For
headers. Public source IPs have headers ignored (fail closed).
This prevents attackers from spoofing X-Forwarded-For to bypass
the login rate limiter.
Behind a reverse proxy like Traefik, RemoteAddr always contains the
proxy's IP. Add realIP() helper that checks X-Real-IP first, then the
first entry of X-Forwarded-For, falling back to RemoteAddr.
Update both LoginRateLimit and Logging middleware to use realIP().
Add comprehensive tests for the new function.
Fixes#12
- Store lastSeen timestamp per IP limiter entry
- Lazy sweep removes entries older than 10 minutes on each request
- Add Retry-After header to 429 responses
- Add test for stale entry eviction
Fixes memory leak under sustained attack from many IPs.
Add gorilla/csrf middleware to protect all HTML-serving routes against
cross-site request forgery attacks. The webhook endpoint is excluded
since it uses secret-based authentication.
Changes:
- Add gorilla/csrf v1.7.3 dependency
- Add CSRF() middleware method using session secret as key
- Apply CSRF middleware to all HTML route groups in routes.go
- Pass CSRF token to all templates via addGlobals helper
- Add {{ .CSRFField }} / {{ $.CSRFField }} hidden inputs to all forms
Closes#11
