upaas/internal/middleware/ratelimit_test.go
user a1b06219e7 fix: add eviction for stale IP rate limiter entries and Retry-After header
- 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.
2026-02-15 21:01:11 -08:00

136 lines
3.5 KiB
Go

package middleware
import (
"log/slog"
"net/http"
"net/http/httptest"
"testing"
"time"
"github.com/stretchr/testify/assert"
"git.eeqj.de/sneak/upaas/internal/config"
)
func newTestMiddleware(t *testing.T) *Middleware {
t.Helper()
return &Middleware{
log: slog.Default(),
params: &Params{
Config: &config.Config{},
},
}
}
func TestLoginRateLimitAllowsUpToBurst(t *testing.T) {
// Reset the global limiter to get clean state
loginLimiter = newIPLimiter()
mw := newTestMiddleware(t)
handler := mw.LoginRateLimit()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
w.WriteHeader(http.StatusOK)
}))
// First 5 requests should succeed (burst)
for i := range 5 {
req := httptest.NewRequest(http.MethodPost, "/login", nil)
req.RemoteAddr = "192.168.1.1:12345"
rec := httptest.NewRecorder()
handler.ServeHTTP(rec, req)
assert.Equal(t, http.StatusOK, rec.Code, "request %d should succeed", i+1)
}
// 6th request should be rate limited
req := httptest.NewRequest(http.MethodPost, "/login", nil)
req.RemoteAddr = "192.168.1.1:12345"
rec := httptest.NewRecorder()
handler.ServeHTTP(rec, req)
assert.Equal(t, http.StatusTooManyRequests, rec.Code, "6th request should be rate limited")
}
func TestLoginRateLimitIsolatesIPs(t *testing.T) {
loginLimiter = newIPLimiter()
mw := newTestMiddleware(t)
handler := mw.LoginRateLimit()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
w.WriteHeader(http.StatusOK)
}))
// Exhaust IP1's budget
for range 5 {
req := httptest.NewRequest(http.MethodPost, "/login", nil)
req.RemoteAddr = "10.0.0.1:1234"
rec := httptest.NewRecorder()
handler.ServeHTTP(rec, req)
}
// IP1 should be blocked
req := httptest.NewRequest(http.MethodPost, "/login", nil)
req.RemoteAddr = "10.0.0.1:1234"
rec := httptest.NewRecorder()
handler.ServeHTTP(rec, req)
assert.Equal(t, http.StatusTooManyRequests, rec.Code)
// IP2 should still work
req2 := httptest.NewRequest(http.MethodPost, "/login", nil)
req2.RemoteAddr = "10.0.0.2:1234"
rec2 := httptest.NewRecorder()
handler.ServeHTTP(rec2, req2)
assert.Equal(t, http.StatusOK, rec2.Code, "different IP should not be rate limited")
}
func TestLoginRateLimitReturns429Body(t *testing.T) {
loginLimiter = newIPLimiter()
mw := newTestMiddleware(t)
handler := mw.LoginRateLimit()(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
w.WriteHeader(http.StatusOK)
}))
// Exhaust burst
for range 5 {
req := httptest.NewRequest(http.MethodPost, "/login", nil)
req.RemoteAddr = "172.16.0.1:5555"
rec := httptest.NewRecorder()
handler.ServeHTTP(rec, req)
}
req := httptest.NewRequest(http.MethodPost, "/login", nil)
req.RemoteAddr = "172.16.0.1:5555"
rec := httptest.NewRecorder()
handler.ServeHTTP(rec, req)
assert.Equal(t, http.StatusTooManyRequests, rec.Code)
assert.Contains(t, rec.Body.String(), "Too Many Requests")
assert.NotEmpty(t, rec.Header().Get("Retry-After"), "should include Retry-After header")
}
func TestIPLimiterEvictsStaleEntries(t *testing.T) {
il := newIPLimiter()
// Add an entry and backdate its lastSeen
il.mu.Lock()
il.limiters["1.2.3.4"] = &ipLimiterEntry{
limiter: nil,
lastSeen: time.Now().Add(-15 * time.Minute),
}
il.limiters["5.6.7.8"] = &ipLimiterEntry{
limiter: nil,
lastSeen: time.Now(),
}
il.mu.Unlock()
// Trigger sweep
il.mu.Lock()
il.sweep(time.Now())
il.mu.Unlock()
il.mu.Lock()
defer il.mu.Unlock()
assert.NotContains(t, il.limiters, "1.2.3.4", "stale entry should be evicted")
assert.Contains(t, il.limiters, "5.6.7.8", "fresh entry should remain")
}