admin: per-IP rate limit (5/min) on admin key attempts (#66)

2026-09-09 09:15:01 -05:00
parent 03bf327f6b
commit 9811191648
3 changed files with 91 additions and 0 deletions
@@ -0,0 +1,80 @@
+package api
+
+// #66: admin key attempts must be rate limited per IP (5/min), constant-time
+// compared, and failures logged. Hammering bad keys must yield 429s.
+
+import (
+	"net/http/httptest"
+	"strings"
+	"testing"
+)
+
+// TestAdminKeyRateLimited: burst of 5 bad-key attempts allowed (401), the 6th
+// gets 429, and even the correct key is blocked from that IP until refill.
+func TestAdminKeyRateLimited(t *testing.T) {
+	srv := newTestServer(t)
+	h := srv.routes()
+	reqIP := "10.7.7.1:1234"
+
+	var got429, retryAfter bool
+	var lastCode int
+	for i := 0; i < 10; i++ {
+		req := httptest.NewRequest("POST", "/admin/api/settings", nil)
+		req.RemoteAddr = reqIP
+		req.Header.Set("X-Admin-Key", "wrong-key")
+		rec := httptest.NewRecorder()
+		h.ServeHTTP(rec, req)
+		lastCode = rec.Code
+		if rec.Code == 429 {
+			got429 = true
+			retryAfter = rec.Header().Get("Retry-After") != ""
+			break
+		}
+	}
+	if !got429 {
+		t.Fatalf("expected 429 after hammering bad keys, last status %d", lastCode)
+	}
+	if !retryAfter {
+		t.Error("429 missing Retry-After header")
+	}
+
+	// Correct key from the same IP is also locked out.
+	req := httptest.NewRequest("POST", "/admin/api/settings", nil)
+	req.RemoteAddr = reqIP
+	req.Header.Set("X-Admin-Key", srv.adminKey)
+	rec := httptest.NewRecorder()
+	h.ServeHTTP(rec, req)
+	if rec.Code != 429 {
+		t.Errorf("correct key after lockout: got %d, want 429", rec.Code)
+	}
+
+	// A different IP is unaffected.
+	req2 := httptest.NewRequest("POST", "/admin/api/settings", strings.NewReader(`{"rate_limit_burst":5,"rate_limit_per_minute":60,"max_content_bytes":1048576,"custom_slug_reservation_days":30,"burn_viewer_window_minutes":15}`))
+	req2.RemoteAddr = "203.0.113.9:1234"
+	req2.Header.Set("X-Admin-Key", srv.adminKey)
+	rec2 := httptest.NewRecorder()
+	h.ServeHTTP(rec2, req2)
+	if rec2.Code != 200 {
+		t.Errorf("correct key from another IP: got %d, want 200", rec2.Code)
+	}
+}
+
+// TestAdminKeyConstantTimeCompare: sanity check that the comparison is
+// constant-time (uses subtle.ConstantTimeCompare, not ==).
+func TestAdminKeyConstantTimeCompare(t *testing.T) {
+	srv := newTestServer(t)
+	r := httptest.NewRequest("GET", "/", nil)
+	r.Header.Set("X-Admin-Key", "test-admin-key")
+	if !srv.adminKeyOK(r, srv.adminKey) {
+		t.Fatal("correct key rejected")
+	}
+	r.Header.Set("X-Admin-Key", "wrong")
+	if srv.adminKeyOK(r, srv.adminKey) {
+		t.Fatal("wrong key accepted")
+	}
+	// differ in length: must not panic/mismatch unexpectedly
+	r.Header.Set("X-Admin-Key", "test-admin-key-longer")
+	if srv.adminKeyOK(r, srv.adminKey) {
+		t.Fatal("longer wrong key accepted")
+	}
+}