🐛 fall back to system trust store when no custom TLS CA is set (#331)

* 🐛 fall back to system trust store when no custom TLS CA is set

Closes #327.

Until now, configuring `crowdsecLapiScheme=https` forced the operator
to either provide `crowdsecLapiTLSCertificateAuthority` (a custom CA)
or set `crowdsecLapiTLSInsecureVerify=true` — there was no way to rely
on the host's system trust store, which is the expected setup when the
LAPI sits behind a reverse proxy with a publicly trusted (e.g. Let's
Encrypt) certificate.

Two contributing bugs:
  - `validateParamsTLS` rejected an empty CA up-front.
  - `getTLSConfig` always allocated an empty `tls.Config.RootCAs`,
    which silently disabled the standard library's fall-back to
    `x509.SystemCertPool()`.

Fix: drop the validation error for the empty-CA case and only allocate
`RootCAs` when a custom CA is actually provided. Same change applies
symmetrically to the AppSec path since the helper is shared.

Add unit tests covering the four meaningful states (HTTP, HTTPS with
system CA, HTTPS with custom CA, HTTPS with insecure verify) plus the
malformed-PEM rejection. README updated to document the system trust
store as an explicit option for both LAPI and AppSec HTTPS.

* 📝 fix gofmt alignment in TLS test struct

* ✅ update existing test: https without CA is now accepted

* ♻️ tests: hoist shared validPEM to package level, rename cfgGarbage

Address review on #331:
- the self-signed validPEM block was duplicated in two test funcs; declare it
  once at package level and drop both local copies.
- rename cfgGarbage -> cfgInvalidCA (and its test case) for a descriptive name.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

* ✅ e2e mock: add tls-system-ca scenario (HTTPS LAPI via system trust store)

CI regression coverage for this PR: with no custom CA configured, the bouncer
must fall back to the OS/system trust store for an HTTPS LAPI.

In the binary suite the "system trust store" is whatever Go's
x509.SystemCertPool() reads, which honours SSL_CERT_FILE on the Traefik process.
The scenario mints a throwaway CA, serves the mock LAPI over HTTPS with a cert
signed by it, and runs the stack twice:
  - positive: SSL_CERT_FILE = our CA       -> LAPI trusted    -> 200
  - negative: SSL_CERT_FILE = empty bundle  -> not trusted     -> 403 (fail-closed)
The negative run proves the patch still VERIFIES (not an insecure skip).

- mocklapi: optional --lapi-tls-cert/--lapi-tls-key to serve the LAPI over TLS.
- common.sh: opt-in LAPI_TLS_CERT/KEY (HTTPS mock) and TRAEFIK_SSL_CERT_FILE
  (inject SSL_CERT_FILE into Traefik); both default-empty, other scenarios
  unaffected.
- adds openssl as a scenario-only dependency.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.8 <noreply@anthropic.com>

Makefile

@@ -4,7 +4,7 @@ export GO111MODULE=on
 
 # Binary/mock suite (Traefik binary + mock LAPI). This is what CI runs.
 # The local Docker suite (make e2e) lives in a separate PR/branch.
-E2E_MOCK_SCENARIOS := stream-mode live-mode none-mode trusted-ips custom-ban-page captcha appsec
+E2E_MOCK_SCENARIOS := stream-mode live-mode none-mode trusted-ips custom-ban-page captcha appsec tls-system-ca
 
 default: lint test
 

README.md

@@ -362,7 +362,7 @@ make run
 - CrowdsecAppsecTlsCertificateAuthority
   - string
   - default: ""
-  - PEM-encoded Certificate Authority of Appsec
+  - PEM-encoded Certificate Authority used to verify Appsec's server certificate. When empty (and `crowdsecAppsecTlsInsecureVerify` is `false`), the host's system trust store is used.
 - CrowdsecAppsecScheme
   - string
   - default: value of `CrowdsecLapiScheme`, expected values are: `http`, `https`
@@ -408,7 +408,7 @@ make run
 - CrowdsecLapiTlsCertificateAuthority
   - string
   - default: ""
-  - PEM-encoded Certificate Authority of the Crowdsec LAPI
+  - PEM-encoded Certificate Authority used to verify the LAPI's server certificate. When empty (and `crowdsecLapiTlsInsecureVerify` is `false`), the host's system trust store is used.
 - CrowdsecLapiTlsCertificateBouncer
   - string
   - default: ""
@@ -727,16 +727,18 @@ A script is available to generate certificates in `examples/tls-auth/gencerts.sh
 
 #### Use HTTPS to communicate with the LAPI
 
-To communicate with the LAPI in HTTPS you need to either accept any certificates by setting the `crowdsecLapiTLSInsecureVerify` to true or add the CA used by the server certificate of Crowdsec using `crowdsecLapiTLSCertificateAuthority` or `crowdsecLapiTLSCertificateAuthorityFile`.
+Set `crowdsecLapiScheme` to `https`. The plugin then validates Crowdsec's server certificate. Three options:
-Set the `crowdsecLapiScheme` to https.
+
+- **Publicly trusted certificate** (e.g. Let's Encrypt behind a reverse proxy): leave `crowdsecLapiTLSCertificateAuthority` empty and `crowdsecLapiTLSInsecureVerify` `false`. The plugin falls back to the host's system trust store (the `traefik` image ships `ca-certificates`).
+- **Private/self-signed CA**: set `crowdsecLapiTLSCertificateAuthority` (or `…File`) to the PEM-encoded CA that signed Crowdsec's server cert.
+- **Skip verification entirely** (not recommended for production): set `crowdsecLapiTLSInsecureVerify` to `true`.
 
 Crowdsec must be listening in HTTPS for this to work.
 Please see the [tls-auth example](https://github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin/blob/main/examples/tls-auth/README.md) or the official documentation: [docs.crowdsec.net/docs/local_api/tls_auth/](https://docs.crowdsec.net/docs/local_api/tls_auth/)
 
 #### Use HTTPS to communicate with the Appsec
 
-To communicate with the Appsec in HTTPS you need to either accept any certificates by setting the `crowdsecAppsecTLSInsecureVerify` to true or add the CA used by the server certificate of Crowdsec using `crowdsecAppsecTLSCertificateAuthority` or `crowdsecAppsecTLSCertificateAuthorityFile`.
+Set `crowdsecAppsecScheme` to `https`. Same three options as for the LAPI, prefixed `crowdsecAppsec…` instead of `crowdsecLapi…`: empty CA + secure verify falls back to the system trust store, a custom CA pins to your private PKI, and `crowdsecAppsecTLSInsecureVerify=true` skips verification altogether.
-Set the `crowdsecAppsecScheme` to https.
 
 Currently AppSec does not support mTLS authentication for the AppSec Component.
 

pkg/configuration/configuration.go

@@ -361,7 +361,8 @@ func validateParamsTLS(config *Config) error {
 		return err
 	}
 	if certAuth == "" {
-		return errors.New("CrowdsecLapiTLSCertificateAuthority must be specified when CrowdsecLapiScheme='https' and CrowdsecLapiTLSInsecureVerify=false")
+		// No custom CA — runtime will fall back to the system trust store.
+		return nil
 	}
 	tlsConfig := new(tls.Config)
 	tlsConfig.RootCAs = x509.NewCertPool()
@@ -453,29 +454,31 @@ func validateParamsRequired(config *Config) error {
 
 func getTLSConfig(config *Config, log *slog.Logger, prefix, scheme string, insecureVerify bool) (*tls.Config, error) {
 	tlsConfig := new(tls.Config)
-	tlsConfig.RootCAs = x509.NewCertPool()
 	if scheme != HTTPS {
 		log.Debug("getTLSConfig:" + prefix + "Scheme https:no")
 		return tlsConfig, nil
 	}
+	// RootCAs is intentionally left nil unless a custom CA is provided:
+	// crypto/tls then falls back to x509.SystemCertPool(), which is what we
+	// want when the LAPI is exposed behind a reverse proxy with a publicly
+	// trusted certificate (e.g. Let's Encrypt).
 	//nolint:nestif
 	if insecureVerify {
 		tlsConfig.InsecureSkipVerify = true
 		log.Debug("getTLSConfig:" + prefix + "TLSInsecureVerify tlsInsecure:true")
-		// If we return here and still want to use client auth this won't work
-		// return tlsConfig, nil
 	} else {
 		certAuthority, err := GetVariable(config, prefix+"TLSCertificateAuthority")
 		if err != nil {
 			return nil, err
 		}
 		if len(certAuthority) > 0 {
+			tlsConfig.RootCAs = x509.NewCertPool()
 			if !tlsConfig.RootCAs.AppendCertsFromPEM([]byte(certAuthority)) {
-				// here we return because if CrowdsecLapiTLSInsecureVerify is false
-				// and CA not load, we can't communicate with https
 				return nil, errors.New("getTLSConfig:" + prefix + " cannot load CA and verify cert is enabled")
 			}
 			log.Debug("getTLSConfig:" + prefix + "TLSCertificateAuthority CA added successfully")
+		} else {
+			log.Debug("getTLSConfig:" + prefix + " no CA provided, using system trust store")
 		}
 	}
 	certBouncer, err := GetVariable(config, prefix+"TLSCertificateBouncer")

pkg/configuration/configuration_test.go

@@ -1,13 +1,25 @@
 package configuration
 
 import (
-	"crypto/tls"
-	"reflect"
 	"testing"
 
 	logger "github.com/maxlerebourg/crowdsec-bouncer-traefik-plugin/pkg/logger"
 )
 
+// validPEM is a minimal self-signed certificate accepted by AppendCertsFromPEM,
+// shared by the TLS tests below.
+const validPEM = `-----BEGIN CERTIFICATE-----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+-----END CERTIFICATE-----`
+
 func getMinimalConfig() *Config {
 	cfg := New()
 	cfg.CrowdsecLapiKey = "test"
@@ -111,7 +123,7 @@ func Test_ValidateParams(t *testing.T) {
 		{name: "Not validate a bad clients ips", args: args{config: cfg5}, wantErr: true},
 		// HTTPS enabled
 		{name: "Validate https config with insecure verify", args: args{config: cfg6}, wantErr: false},
-		{name: "Not validate https without cert authority", args: args{config: cfg7}, wantErr: true},
+		{name: "Validate https without cert authority (falls back to system trust store)", args: args{config: cfg7}, wantErr: false},
 		{name: "Valid log level uppercase INFO", args: args{config: cfg8}, wantErr: false},
 		{name: "Valid log level lowercase info", args: args{config: cfg9}, wantErr: false},
 		{name: "Invalid log level Warning", args: args{config: cfg10}, wantErr: true},
@@ -126,19 +138,24 @@ func Test_ValidateParams(t *testing.T) {
 }
 
 func Test_validateParamsTLS(t *testing.T) {
-	type args struct {
+	cfgEmpty := getMinimalConfig()
-		config *Config
+	cfgValid := getMinimalConfig()
-	}
+	cfgValid.CrowdsecLapiTLSCertificateAuthority = validPEM
+	cfgInvalidCA := getMinimalConfig()
+	cfgInvalidCA.CrowdsecLapiTLSCertificateAuthority = "not a pem"
+
 	tests := []struct {
 		name    string
-		args    args
+		config  *Config
 		wantErr bool
 	}{
-		// TODO: Add test cases.
+		{name: "Empty CA is accepted (system trust store used at runtime)", config: cfgEmpty, wantErr: false},
+		{name: "Valid PEM CA is accepted", config: cfgValid, wantErr: false},
+		{name: "Invalid CA is rejected", config: cfgInvalidCA, wantErr: true},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			if err := validateParamsTLS(tt.args.config); (err != nil) != tt.wantErr {
+			if err := validateParamsTLS(tt.config); (err != nil) != tt.wantErr {
 				t.Errorf("validateParamsTLS() error = %v, wantErr %v", err, tt.wantErr)
 			}
 		})
@@ -233,26 +250,53 @@ func Test_validateParamsAPIKey(t *testing.T) {
 
 func Test_GetTLSConfigCrowdsec(t *testing.T) {
 	log := logger.New("INFO", "")
-	type args struct {
+
-		config *Config
+	httpCfg := getMinimalConfig()
-	}
+	httpCfg.CrowdsecLapiScheme = HTTP
+
+	httpsSystemCA := getMinimalConfig()
+	httpsSystemCA.CrowdsecLapiScheme = HTTPS
+
+	httpsCustomCA := getMinimalConfig()
+	httpsCustomCA.CrowdsecLapiScheme = HTTPS
+	httpsCustomCA.CrowdsecLapiTLSCertificateAuthority = validPEM
+
+	httpsInsecure := getMinimalConfig()
+	httpsInsecure.CrowdsecLapiScheme = HTTPS
+	httpsInsecure.CrowdsecLapiTLSInsecureVerify = true
+
+	httpsBadCA := getMinimalConfig()
+	httpsBadCA.CrowdsecLapiScheme = HTTPS
+	httpsBadCA.CrowdsecLapiTLSCertificateAuthority = "not a pem"
+
 	tests := []struct {
-		name    string
+		name             string
-		args    args
+		config           *Config
-		want    *tls.Config
+		wantErr          bool
-		wantErr bool
+		wantRootCAsNil   bool
+		wantInsecureSkip bool
 	}{
-		// TODO: Add test cases.
+		{name: "HTTP scheme returns empty tls.Config", config: httpCfg, wantRootCAsNil: true},
+		{name: "HTTPS without CA leaves RootCAs nil (system trust store)", config: httpsSystemCA, wantRootCAsNil: true},
+		{name: "HTTPS with custom CA populates RootCAs", config: httpsCustomCA, wantRootCAsNil: false},
+		{name: "HTTPS with insecure verify sets InsecureSkipVerify", config: httpsInsecure, wantRootCAsNil: true, wantInsecureSkip: true},
+		{name: "HTTPS with garbage CA is rejected", config: httpsBadCA, wantErr: true},
 	}
 	for _, tt := range tests {
 		t.Run(tt.name, func(t *testing.T) {
-			got, err := GetTLSConfigCrowdsec(tt.args.config, log, false)
+			got, err := GetTLSConfigCrowdsec(tt.config, log, false)
 			if (err != nil) != tt.wantErr {
-				t.Errorf("getTLSConfigCrowdsec() error = %v, wantErr %v", err, tt.wantErr)
+				t.Errorf("GetTLSConfigCrowdsec() error = %v, wantErr %v", err, tt.wantErr)
 				return
 			}
-			if !reflect.DeepEqual(got, tt.want) {
+			if tt.wantErr {
-				t.Errorf("getTLSConfigCrowdsec() = %v, want %v", got, tt.want)
+				return
+			}
+			if (got.RootCAs == nil) != tt.wantRootCAsNil {
+				t.Errorf("GetTLSConfigCrowdsec() RootCAs nil = %v, want nil = %v", got.RootCAs == nil, tt.wantRootCAsNil)
+			}
+			if got.InsecureSkipVerify != tt.wantInsecureSkip {
+				t.Errorf("GetTLSConfigCrowdsec() InsecureSkipVerify = %v, want %v", got.InsecureSkipVerify, tt.wantInsecureSkip)
 			}
 		})
 	}

tests/e2e/mock/README.md

@@ -30,7 +30,7 @@ that lives upstream in Crowdsec.
 |-----------|-----|
 | Traefik   | Binary `v3.7.1`, downloaded into `.cache/` (reused across local runs; re-downloaded on fresh CI runners) |
 | Plugin    | Loaded via `experimental.localPlugins` from the repo root (symlinked into `plugins-local/`) |
-| LAPI      | `mocklapi` — a stdlib-only Go command (its own nested module), compiled and cached under `.cache/`, driven through `/admin` endpoints instead of `cscli` |
+| LAPI      | `mocklapi` — a stdlib-only Go command (its own nested module), compiled and cached under `.cache/`, driven through `/admin` endpoints instead of `cscli`. Serves plain HTTP, or HTTPS when `--lapi-tls-cert/--lapi-tls-key` are passed (the `tls-system-ca` scenario) |
 | AppSec    | WAF stand-in built into the mock — blocks URIs containing `rpc2`, allows the rest |
 | Backend   | A plain HTTP responder built into the mock |
 
@@ -39,9 +39,16 @@ backend `8091`, AppSec `8092`.
 
 ## Running locally
 
-Prerequisites: `bash`, `curl`, `go`, `tar`. On first use the Traefik binary is
+Prerequisites: `bash`, `curl`, `go`, `tar` (plus `openssl` for the
-fetched and the mock is compiled into `.cache/`. That cache is reused across
+`tls-system-ca` scenario, which mints a throwaway CA at runtime). On first use
-local runs; CI runs on fresh runners, so both are recreated on every CI run.
+the Traefik binary is fetched and the mock is compiled into `.cache/`. That
+cache is reused across local runs; CI runs on fresh runners, so both are
+recreated on every CI run.
+
+The `tls-system-ca` scenario verifies that, with no custom CA configured, the
+bouncer falls back to the OS/system trust store for an HTTPS LAPI: it serves the
+mock over TLS and points the Traefik process's `SSL_CERT_FILE` at the test CA
+(trusted → 200) or an empty bundle (untrusted → 403, proving it still verifies).
 
 ```bash
 # one scenario

tests/e2e/mock/lib/common.sh

@@ -190,16 +190,29 @@ start_stack() {
     -e "s|@@SCENARIO_DIR@@|${scenario_dir}|g" \
     "$scenario_dir/dynamic.yml" > "$WORKDIR/dynamic.yml"
 
+  # Opt-in HTTPS LAPI: a scenario exports LAPI_TLS_CERT/LAPI_TLS_KEY to serve the
+  # LAPI over TLS (used by tls-system-ca). Default empty -> plaintext as before.
+  local mock_tls_args=() lapi_scheme=http lapi_curl=()
+  if [[ -n "${LAPI_TLS_CERT:-}" && -n "${LAPI_TLS_KEY:-}" ]]; then
+    mock_tls_args=(--lapi-tls-cert "$LAPI_TLS_CERT" --lapi-tls-key "$LAPI_TLS_KEY")
+    lapi_scheme=https
+    lapi_curl=(-k) # the readiness probe ignores trust; the bouncer's trust is what we test
+  fi
+
   "$mock_bin" \
     --lapi-addr "127.0.0.1:${LAPI_PORT}" \
     --backend-addr "127.0.0.1:${BACKEND_PORT}" \
-    --appsec-addr "127.0.0.1:${APPSEC_PORT}" >"$WORKDIR/mock.log" 2>&1 &
+    --appsec-addr "127.0.0.1:${APPSEC_PORT}" \
+    "${mock_tls_args[@]}" >"$WORKDIR/mock.log" 2>&1 &
   MOCK_PID=$!
 
-  ( cd "$WORKDIR" && exec "$traefik_bin" --configfile=traefik.yml ) >"$WORKDIR/traefik.log" 2>&1 &
+  # Opt-in trust store for the Traefik process: a scenario exports
+  # TRAEFIK_SSL_CERT_FILE to point Go's x509.SystemCertPool() at a specific CA
+  # bundle. Empty -> Go's default system store (unchanged behaviour).
+  ( cd "$WORKDIR" && SSL_CERT_FILE="${TRAEFIK_SSL_CERT_FILE:-}" exec "$traefik_bin" --configfile=traefik.yml ) >"$WORKDIR/traefik.log" 2>&1 &
   TRAEFIK_PID=$!
 
-  wait_for_status "http://127.0.0.1:${LAPI_PORT}/health" 200 30
+  wait_for_status "${lapi_scheme}://127.0.0.1:${LAPI_PORT}/health" 200 30 "${lapi_curl[@]}"
   # AppSec stand-in: a bare GET carries no "rpc2" URI, so it answers 200 (allow).
   wait_for_status "http://127.0.0.1:${APPSEC_PORT}/" 200 30
   # /ping is served by Traefik itself once it is up (plugin compilation included).

tests/e2e/mock/mocklapi/main.go

@@ -52,6 +52,11 @@ func main() {
 	backendAddr := flag.String("backend-addr", "127.0.0.1:8091", "address for the stub upstream service")
 	// AppSec WAF stand-in (the real engine listens on :7422). Not a CRS engine.
 	appsecAddr := flag.String("appsec-addr", "127.0.0.1:8092", "address for the AppSec mock")
+	// Optional TLS for the LAPI: when both are set the LAPI is served over HTTPS
+	// (cert signed by the scenario's throwaway CA) so the suite can exercise the
+	// bouncer's system-trust-store path. Backend and AppSec stay plaintext.
+	lapiTLSCert := flag.String("lapi-tls-cert", "", "PEM cert to serve the LAPI over HTTPS (optional)")
+	lapiTLSKey := flag.String("lapi-tls-key", "", "PEM key for --lapi-tls-cert")
 	flag.Parse()
 
 	go func() {
@@ -130,6 +135,10 @@ func main() {
 		}
 	})
 
+	if *lapiTLSCert != "" && *lapiTLSKey != "" {
+		log.Printf("mocklapi: LAPI on %s (TLS), backend on %s, appsec on %s", *lapiAddr, *backendAddr, *appsecAddr)
+		log.Fatal(http.ListenAndServeTLS(*lapiAddr, *lapiTLSCert, *lapiTLSKey, mux))
+	}
 	log.Printf("mocklapi: LAPI on %s, backend on %s, appsec on %s", *lapiAddr, *backendAddr, *appsecAddr)
 	log.Fatal(http.ListenAndServe(*lapiAddr, mux))
 }

tests/e2e/mock/scenarios/tls-system-ca/dynamic.yml

@@ -0,0 +1,28 @@
+http:
+  routers:
+    r:
+      rule: "PathPrefix(`/foo`)"
+      entryPoints:
+        - web
+      service: backend
+      middlewares:
+        - bouncer
+  services:
+    backend:
+      loadBalancer:
+        servers:
+          - url: "@@BACKEND_URL@@"
+  middlewares:
+    bouncer:
+      plugin:
+        bouncer:
+          enabled: "true"
+          crowdsecMode: live
+          defaultDecisionSeconds: "2"
+          # HTTPS LAPI with NO custom CA configured: the bouncer must fall back to
+          # the OS/system trust store (which the scenario controls via SSL_CERT_FILE).
+          crowdsecLapiScheme: https
+          crowdsecLapiHost: "@@LAPI_HOST@@"
+          crowdsecLapiKey: "@@APIKEY@@"
+          forwardedHeadersTrustedIps:
+            - "127.0.0.1/32"

tests/e2e/mock/scenarios/tls-system-ca/run.sh

@@ -0,0 +1,66 @@
+#!/usr/bin/env bash
+# Scenario: HTTPS LAPI with no custom CA configured -> the bouncer must fall back
+# to the OS/system trust store (PR #331). In the binary suite the "system trust
+# store" is whatever Go's x509.SystemCertPool() reads, which honours SSL_CERT_FILE
+# on the Traefik process. We mint a throwaway CA, serve the mock LAPI over HTTPS
+# with a cert signed by it, and run the stack twice:
+#
+#   positive: SSL_CERT_FILE = our CA      -> LAPI trusted        -> 200
+#   negative: SSL_CERT_FILE = empty bundle -> LAPI not trusted    -> 403
+#
+# live mode is fail-closed, so a TLS error becomes a 403. The negative run proves
+# the patch still VERIFIES (it is not an insecure skip).
+#
+# Extra dependency vs other scenarios: openssl.
+set -euo pipefail
+
+HERE="$(cd "$(dirname "$0")" && pwd)"
+# shellcheck source=../../lib/common.sh
+source "$HERE/../../lib/common.sh"
+
+SCENARIO=tls-system-ca
+SCENARIO_NAME="$SCENARIO"
+SCENARIO_LOG="/tmp/e2e-mock-${SCENARIO}.log"
+CERT_DIR="$(mktemp -d)"
+
+cleanup() {
+  local rc=$?
+  if (( rc != 0 )); then
+    dump_diagnostics > "$SCENARIO_LOG" 2>&1 || true
+    echo "[$SCENARIO] failed. Logs written to $SCENARIO_LOG" >&2
+  fi
+  stop_stack
+  rm -rf "$CERT_DIR"
+  exit $rc
+}
+trap cleanup EXIT
+
+echo "[$SCENARIO] minting throwaway CA + LAPI cert (SAN=IP:127.0.0.1)..."
+openssl ecparam -name prime256v1 -genkey -noout -out "$CERT_DIR/ca.key" 2>/dev/null
+openssl req -x509 -new -key "$CERT_DIR/ca.key" -sha256 -days 3650 \
+  -subj "/CN=crowdsec-bouncer e2e test CA" -out "$CERT_DIR/ca.crt" 2>/dev/null
+openssl ecparam -name prime256v1 -genkey -noout -out "$CERT_DIR/lapi.key" 2>/dev/null
+openssl req -new -key "$CERT_DIR/lapi.key" -subj "/CN=lapi" -out "$CERT_DIR/lapi.csr" 2>/dev/null
+openssl x509 -req -in "$CERT_DIR/lapi.csr" -CA "$CERT_DIR/ca.crt" -CAkey "$CERT_DIR/ca.key" \
+  -CAcreateserial -days 3650 -sha256 -out "$CERT_DIR/lapi.crt" \
+  -extfile <(printf "subjectAltName=IP:127.0.0.1\nbasicConstraints=CA:FALSE\nkeyUsage=digitalSignature,keyEncipherment\nextendedKeyUsage=serverAuth") 2>/dev/null
+: > "$CERT_DIR/empty.crt" # an empty bundle = a system store that trusts nothing
+
+# The mock serves the same CA-signed cert in both runs; only Traefik's trust differs.
+export LAPI_TLS_CERT="$CERT_DIR/lapi.crt" LAPI_TLS_KEY="$CERT_DIR/lapi.key"
+
+echo "[$SCENARIO] === positive: CA in the system trust store ==="
+export TRAEFIK_SSL_CERT_FILE="$CERT_DIR/ca.crt"
+start_stack "$HERE"
+echo "[$SCENARIO] HTTPS LAPI verifies via system trust store -> request passes (200)"
+assert_status "http://127.0.0.1:${WEB_PORT}/foo" 200 -H "X-Forwarded-For: 1.2.3.4"
+stop_stack
+
+echo "[$SCENARIO] === negative: CA absent from the system trust store ==="
+export TRAEFIK_SSL_CERT_FILE="$CERT_DIR/empty.crt"
+start_stack "$HERE"
+echo "[$SCENARIO] LAPI cert not trusted -> TLS fails, fail-closed (403)"
+assert_status "http://127.0.0.1:${WEB_PORT}/foo" 403 -H "X-Forwarded-For: 1.2.3.4"
+stop_stack
+
+echo "[$SCENARIO] OK"