Harden Turnstile verification and CI plugin checks

Author: joecorall

ci/test.go

@@ -18,15 +18,18 @@ func main() {
 	_ = os.Remove("./tmp/state.json")
 
 	fmt.Println("Bringing traefik/nginx online")
-	runCommand("docker", "compose", "up", "-d")
+	runCommand("docker", "compose", "down", "--remove-orphans")
+	runCommand("docker", "compose", "up", "-d", "--force-recreate")
 	waitForService("http://localhost")
 	waitForService("http://localhost/app2")
+	assertTraefikPluginLogsClean()
 
 	fmt.Println("Testing Traefik plugin smoke path...")
 	assertProtectedRoute(rootSmokeIP, "http://localhost", "http://localhost/challenge?destination=%2F")
 	assertNoRedirect(rootSmokeIP, "http://localhost/node/123/manifest")
 	assertNoRedirect(rootSmokeIP, "http://localhost/oai/request?foo=bar")
 	assertProtectedRoute(app2SmokeIP, "http://localhost/app2", "http://localhost/challenge?destination=%2Fapp2")
+	assertTraefikPluginLogsClean()
 
 	_ = os.Remove("./tmp/state.json")
 	fmt.Println("✓ Traefik plugin smoke test passed")
@@ -115,18 +118,58 @@ func httpRequest(ip, url string) (string, error) {
 	return strings.TrimSpace(location.String()), nil
 }
 
+func assertTraefikPluginLogsClean() {
+	output, err := commandOutput("docker", "compose", "logs", "--no-color", "traefik")
+	if err != nil {
+		slog.Error("Failed to inspect Traefik logs", "err", err, "output", output)
+		os.Exit(1)
+	}
+
+	if failure, found := traefikPluginLogFailure(output); found {
+		slog.Error("Traefik plugin load failure detected", "failure", failure, "logs", output)
+		os.Exit(1)
+	}
+}
+
+func traefikPluginLogFailure(output string) (string, bool) {
+	failures := []string{
+		"Plugins are disabled",
+		"failed to create Yaegi interpreter",
+		"failed to import plugin code",
+		"cannot use type",
+		"cannot define new methods",
+	}
+	for _, failure := range failures {
+		if strings.Contains(output, failure) {
+			return failure, true
+		}
+	}
+	return "", false
+}
+
+func commandOutput(name string, args ...string) (string, error) {
+	cmd := exec.Command(name, args...) // #nosec G204 -- CI smoke test invokes fixed docker compose commands.
+	cmd.Env = testCommandEnv()
+	output, err := cmd.CombinedOutput()
+	return string(output), err
+}
+
 func runCommand(name string, args ...string) {
 	cmd := exec.Command(name, args...) // #nosec G204 -- CI smoke test invokes fixed docker compose commands.
 	cmd.Stdout = os.Stdout
 	cmd.Stderr = os.Stderr
-	cmd.Env = append(os.Environ(), fmt.Sprintf("RATE_LIMIT=%d", rateLimit))
-
-	if traefikTag := os.Getenv("TRAEFIK_TAG"); traefikTag != "" {
-		cmd.Env = append(cmd.Env, fmt.Sprintf("TRAEFIK_TAG=%s", traefikTag))
-	}
+	cmd.Env = testCommandEnv()
 
 	if err := cmd.Run(); err != nil {
 		slog.Error("Command failed", "err", err)
 		os.Exit(1)
 	}
 }
+
+func testCommandEnv() []string {
+	env := append(os.Environ(), fmt.Sprintf("RATE_LIMIT=%d", rateLimit))
+	if traefikTag := os.Getenv("TRAEFIK_TAG"); traefikTag != "" {
+		env = append(env, fmt.Sprintf("TRAEFIK_TAG=%s", traefikTag))
+	}
+	return env
+}

ci/test_test.go

@@ -0,0 +1,23 @@
+package main
+
+import "testing"
+
+func TestTraefikPluginLogFailureDetectsYaegiImportErrors(t *testing.T) {
+	logs := `traefik-1  | {"level":"error","plugins":["captcha-protect"],"error":"failed to create Yaegi interpreter: failed to import plugin code \"github.com/libops/captcha-protect\": 1:21: import \"github.com/libops/captcha-protect\" error: plugins-local/src/github.com/libops/captcha-protect/main.go:304:23: cannot use type func(string,[]string) bool as type func(context.Context,string,[]string) bool in struct literal","time":"2026-06-24T09:18:16Z","message":"Plugins are disabled because an error has occurred."}`
+
+	failure, found := traefikPluginLogFailure(logs)
+	if !found {
+		t.Fatal("expected Traefik plugin load failure to be detected")
+	}
+	if failure != "Plugins are disabled" {
+		t.Fatalf("expected first detected failure %q, got %q", "Plugins are disabled", failure)
+	}
+}
+
+func TestTraefikPluginLogFailureAllowsCleanLogs(t *testing.T) {
+	logs := `traefik-1  | {"level":"info","message":"Configuration loaded from flags."}`
+
+	if failure, found := traefikPluginLogFailure(logs); found {
+		t.Fatalf("did not expect clean logs to fail, got %q", failure)
+	}
+}

internal/helper/ip.go

@@ -30,7 +30,11 @@ func ParseCIDR(cidr string) (*net.IPNet, error) {
 	return ipNet, nil
 }
 
-func IsIpGoodBot(ctx context.Context, clientIP string, goodBots []string) bool {
+func IsIpGoodBot(clientIP string, goodBots []string) bool {
+	return IsIpGoodBotContext(context.Background(), clientIP, goodBots)
+}
+
+func IsIpGoodBotContext(ctx context.Context, clientIP string, goodBots []string) bool {
 	if len(goodBots) == 0 {
 		return false
 	}

internal/helper/ip_test.go

@@ -134,7 +134,7 @@ func TestIsIpGoodBot(t *testing.T) {
 		}
 
 		t.Run(tc.name, func(t *testing.T) {
-			result := IsIpGoodBot(context.Background(), tc.clientIP, tc.goodBots)
+			result := IsIpGoodBotContext(context.Background(), tc.clientIP, tc.goodBots)
 			if result != tc.expected {
 				t.Errorf("IsIpGoodBot(%q) = %v; expected %v", tc.clientIP, result, tc.expected)
 			}

internal/helper/uptimerobot.go

@@ -17,11 +17,25 @@ const maxUptimeRobotIPResponseSize = 1 << 20
 var UptimeRobotIPRangeURL = "https://api.uptimerobot.com/meta/ips"
 
 // UptimeRobotIPs is a thread-safe set of UptimeRobot IP ranges.
-type UptimeRobotIPs = GooglebotIPs
+type UptimeRobotIPs struct {
+	ranges *GooglebotIPs
+}
 
 // NewUptimeRobotIPs creates an empty UptimeRobot IP range set.
 func NewUptimeRobotIPs() *UptimeRobotIPs {
-	return NewGooglebotIPs()
+	return &UptimeRobotIPs{
+		ranges: NewGooglebotIPs(),
+	}
+}
+
+// Update parses a slice of CIDR strings and replaces the existing IP ranges with the new ones.
+func (u *UptimeRobotIPs) Update(cidrs []string, log *slog.Logger) {
+	u.ranges.Update(cidrs, log)
+}
+
+// Contains checks if the given IP address is within any stored UptimeRobot IP range.
+func (u *UptimeRobotIPs) Contains(ip net.IP) bool {
+	return u.ranges.Contains(ip)
 }
 
 type uptimeRobotIPsJSON struct {

main.go

@@ -39,6 +39,7 @@ const (
 	DefaultHealthCheckPeriodSeconds    = 0 // How often to check captcha provider health
 	DefaultHealthCheckFailureThreshold = 0 // Number of consecutive health check failures before opening circuit
 	goodBotLookupTimeout               = 2 * time.Second
+	maxCaptchaChallengeAge             = 5 * time.Minute
 )
 
 type circuitState int
@@ -125,7 +126,9 @@ type CaptchaConfig struct {
 }
 
 type captchaResponse struct {
-	Success bool `json:"success"`
+	Success     bool   `json:"success"`
+	Hostname    string `json:"hostname"`
+	ChallengeTS string `json:"challenge_ts"`
 }
 
 type challengeData struct {
@@ -297,7 +300,7 @@ func NewCaptchaProtect(ctx context.Context, next http.Handler, config *Config, n
 		},
 		rateCache:          lru.New(expiration, 1*time.Minute),
 		botCache:           lru.New(expiration, 1*time.Hour),
-		goodBotLookup:      helper.IsIpGoodBot,
+		goodBotLookup:      helper.IsIpGoodBotContext,
 		verifiedCache:      lru.New(expiration, 1*time.Hour),
 		exemptIps:          ips,
 		tmpl:               tmpl,
@@ -357,33 +360,35 @@ func NewCaptchaProtect(ctx context.Context, next http.Handler, config *Config, n
 	if config.EnableUptimeRobotBypass == "true" {
 		log.Info("UptimeRobot bypass enabled")
 		bc.uptimeRobotIPs = helper.NewUptimeRobotIPs()
-		go bc.uptimeRobotIPCheckLoop(ctx)
+		go uptimeRobotIPCheckLoop(ctx, log, bc.httpClient, bc.uptimeRobotIPs)
 	}
 
 	return &bc, nil
 }
 
-func (bc *CaptchaProtect) uptimeRobotIPCheckLoop(ctx context.Context) {
+func uptimeRobotIPCheckLoop(ctx context.Context, log *slog.Logger, httpClient *http.Client, uptimeRobotIPs *helper.UptimeRobotIPs) {
 	ticker := time.NewTicker(24 * time.Hour)
 	defer ticker.Stop()
 
-	refresh := func() {
-		count, err := helper.RefreshUptimeRobotIPs(ctx, bc.log, bc.httpClient, bc.uptimeRobotIPs, helper.UptimeRobotIPRangeURL)
-		if err != nil {
-			bc.log.Error("failed to fetch UptimeRobot IPs", "err", err)
-			return
-		}
-		bc.log.Info("Updated UptimeRobot IPs", "count", count)
-	}
-
 	if ctx.Err() != nil {
 		return
 	}
-	refresh()
+	count, err := helper.RefreshUptimeRobotIPs(ctx, log, httpClient, uptimeRobotIPs, helper.UptimeRobotIPRangeURL)
+	if err != nil {
+		log.Error("failed to fetch UptimeRobot IPs", "err", err)
+	} else {
+		log.Info("Updated UptimeRobot IPs", "count", count)
+	}
+
 	for {
 		select {
 		case <-ticker.C:
-			refresh()
+			count, err := helper.RefreshUptimeRobotIPs(ctx, log, httpClient, uptimeRobotIPs, helper.UptimeRobotIPRangeURL)
+			if err != nil {
+				log.Error("failed to fetch UptimeRobot IPs", "err", err)
+				continue
+			}
+			log.Info("Updated UptimeRobot IPs", "count", count)
 		case <-ctx.Done():
 			return
 		}
@@ -687,6 +692,16 @@ func (bc *CaptchaProtect) verifyChallengePage(rw http.ResponseWriter, req *http.
 		var body = url.Values{}
 		body.Add("secret", bc.config.SecretKey)
 		body.Add("response", response)
+		if activeConfig.key == "cf-turnstile" {
+			idempotencyKey, err := randomUUID()
+			if err != nil {
+				bc.log.Error("unable to create turnstile idempotency key", "err", err)
+				http.Error(rw, "Internal error", http.StatusInternalServerError)
+				return http.StatusInternalServerError
+			}
+			body.Add("remoteip", ip)
+			body.Add("idempotency_key", idempotencyKey)
+		}
 		validationReq, err := http.NewRequestWithContext(req.Context(), http.MethodPost, activeConfig.validate, strings.NewReader(body.Encode()))
 		if err != nil {
 			bc.log.Error("unable to create captcha validation request", "url", activeConfig.validate, "err", err)
@@ -715,6 +730,28 @@ func (bc *CaptchaProtect) verifyChallengePage(rw http.ResponseWriter, req *http.
 		}
 
 		success = captchaResponse.Success
+		if success && activeConfig.key == "cf-turnstile" {
+			expectedHostname := captchaValidationHostname(req)
+			if captchaResponse.Hostname != expectedHostname {
+				bc.log.Warn("captcha hostname mismatch", "hostname", captchaResponse.Hostname, "expectedHostname", expectedHostname)
+				success = false
+			} else {
+				challengeTime, err := time.Parse(time.RFC3339Nano, captchaResponse.ChallengeTS)
+				if err != nil {
+					bc.log.Warn("invalid captcha challenge timestamp", "challenge_ts", captchaResponse.ChallengeTS, "err", err)
+					success = false
+				} else {
+					age := time.Since(challengeTime)
+					if age < 0 {
+						age = 0
+					}
+					if age > maxCaptchaChallengeAge {
+						bc.log.Warn("stale captcha challenge rejected", "challenge_ts", captchaResponse.ChallengeTS, "age", age)
+						success = false
+					}
+				}
+			}
+		}
 	}
 
 	if success {
@@ -731,6 +768,35 @@ func (bc *CaptchaProtect) verifyChallengePage(rw http.ResponseWriter, req *http.
 	return http.StatusForbidden
 }
 
+func captchaValidationHostname(req *http.Request) string {
+	host := req.Host
+	if host == "" {
+		host = req.URL.Host
+	}
+	if hostname, _, err := net.SplitHostPort(host); err == nil {
+		return hostname
+	}
+	return host
+}
+
+func randomUUID() (string, error) {
+	var b [16]byte
+	if _, err := crand.Read(b[:]); err != nil {
+		return "", err
+	}
+
+	b[6] = (b[6] & 0x0f) | 0x40
+	b[8] = (b[8] & 0x3f) | 0x80
+
+	return fmt.Sprintf("%02x%02x%02x%02x-%02x%02x-%02x%02x-%02x%02x-%02x%02x%02x%02x%02x%02x",
+		b[0], b[1], b[2], b[3],
+		b[4], b[5],
+		b[6], b[7],
+		b[8], b[9],
+		b[10], b[11], b[12], b[13], b[14], b[15],
+	), nil
+}
+
 func normalizeDestination(destination string) string {
 	if destination == "" {
 		return "/"