[management, reverse proxy] Add reverse proxy feature (#5291)

* implement reverse proxy --------- Co-authored-by: Alisdair MacLeod <git@alisdairmacleod.co.uk> Co-authored-by: mlsmaycon <mlsmaycon@gmail.com> Co-authored-by: Eduard Gert <kontakt@eduardgert.de> Co-authored-by: Viktor Liu <viktor@netbird.io> Co-authored-by: Diego Noguês <diego.sure@gmail.com> Co-authored-by: Diego Noguês <49420+diegocn@users.noreply.github.com> Co-authored-by: Bethuel Mmbaga <bethuelmbaga12@gmail.com> Co-authored-by: Zoltan Papp <zoltan.pmail@gmail.com> Co-authored-by: Ashley Mensah <ashleyamo982@gmail.com>
2026-10-26 22:39:07 +01:00 · 2026-02-13 19:37:43 +01:00
parent edce11b34d
commit f53155562f
225 changed files with 35513 additions and 235 deletions
@@ -0,0 +1,660 @@
+package auth
+
+import (
+	"crypto/ed25519"
+	"crypto/rand"
+	"encoding/base64"
+	"net/http"
+	"net/http/httptest"
+	"net/url"
+	"strings"
+	"testing"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/netbirdio/netbird/management/internals/modules/reverseproxy/sessionkey"
+	"github.com/netbirdio/netbird/proxy/auth"
+	"github.com/netbirdio/netbird/proxy/internal/proxy"
+)
+
+func generateTestKeyPair(t *testing.T) *sessionkey.KeyPair {
+	t.Helper()
+	kp, err := sessionkey.GenerateKeyPair()
+	require.NoError(t, err)
+	return kp
+}
+
+// stubScheme is a minimal Scheme implementation for testing.
+type stubScheme struct {
+	method   auth.Method
+	token    string
+	promptID string
+	authFn   func(*http.Request) (string, string, error)
+}
+
+func (s *stubScheme) Type() auth.Method { return s.method }
+
+func (s *stubScheme) Authenticate(r *http.Request) (string, string, error) {
+	if s.authFn != nil {
+		return s.authFn(r)
+	}
+	return s.token, s.promptID, nil
+}
+
+func newPassthroughHandler() http.Handler {
+	return http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("backend"))
+	})
+}
+
+func TestAddDomain_ValidKey(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	err := mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", "")
+	require.NoError(t, err)
+
+	mw.domainsMux.RLock()
+	config, exists := mw.domains["example.com"]
+	mw.domainsMux.RUnlock()
+
+	assert.True(t, exists, "domain should be registered")
+	assert.Len(t, config.Schemes, 1)
+	assert.Equal(t, ed25519.PublicKeySize, len(config.SessionPublicKey))
+	assert.Equal(t, time.Hour, config.SessionExpiration)
+}
+
+func TestAddDomain_EmptyKey(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	err := mw.AddDomain("example.com", []Scheme{scheme}, "", time.Hour, "", "")
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "invalid session public key size")
+
+	mw.domainsMux.RLock()
+	_, exists := mw.domains["example.com"]
+	mw.domainsMux.RUnlock()
+	assert.False(t, exists, "domain must not be registered with an empty session key")
+}
+
+func TestAddDomain_InvalidBase64(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	err := mw.AddDomain("example.com", []Scheme{scheme}, "not-valid-base64!!!", time.Hour, "", "")
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "decode session public key")
+
+	mw.domainsMux.RLock()
+	_, exists := mw.domains["example.com"]
+	mw.domainsMux.RUnlock()
+	assert.False(t, exists, "domain must not be registered with invalid base64 key")
+}
+
+func TestAddDomain_WrongKeySize(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+
+	shortKey := base64.StdEncoding.EncodeToString([]byte("tooshort"))
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	err := mw.AddDomain("example.com", []Scheme{scheme}, shortKey, time.Hour, "", "")
+	require.Error(t, err)
+	assert.Contains(t, err.Error(), "invalid session public key size")
+
+	mw.domainsMux.RLock()
+	_, exists := mw.domains["example.com"]
+	mw.domainsMux.RUnlock()
+	assert.False(t, exists, "domain must not be registered with a wrong-size key")
+}
+
+func TestAddDomain_NoSchemes_NoKeyRequired(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+
+	err := mw.AddDomain("example.com", nil, "", time.Hour, "", "")
+	require.NoError(t, err, "domains with no auth schemes should not require a key")
+
+	mw.domainsMux.RLock()
+	_, exists := mw.domains["example.com"]
+	mw.domainsMux.RUnlock()
+	assert.True(t, exists)
+}
+
+func TestAddDomain_OverwritesPreviousConfig(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp1 := generateTestKeyPair(t)
+	kp2 := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp1.PublicKey, time.Hour, "", ""))
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp2.PublicKey, 2*time.Hour, "", ""))
+
+	mw.domainsMux.RLock()
+	config := mw.domains["example.com"]
+	mw.domainsMux.RUnlock()
+
+	pubKeyBytes, _ := base64.StdEncoding.DecodeString(kp2.PublicKey)
+	assert.Equal(t, ed25519.PublicKey(pubKeyBytes), config.SessionPublicKey, "should use the latest key")
+	assert.Equal(t, 2*time.Hour, config.SessionExpiration)
+}
+
+func TestRemoveDomain(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	mw.RemoveDomain("example.com")
+
+	mw.domainsMux.RLock()
+	_, exists := mw.domains["example.com"]
+	mw.domainsMux.RUnlock()
+	assert.False(t, exists)
+}
+
+func TestProtect_UnknownDomainPassesThrough(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	handler := mw.Protect(newPassthroughHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "http://unknown.com/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "backend", rec.Body.String())
+}
+
+func TestProtect_DomainWithNoSchemesPassesThrough(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	require.NoError(t, mw.AddDomain("example.com", nil, "", time.Hour, "", ""))
+
+	handler := mw.Protect(newPassthroughHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "backend", rec.Body.String())
+}
+
+func TestProtect_UnauthenticatedRequestIsBlocked(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	var backendCalled bool
+	backend := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		backendCalled = true
+		w.WriteHeader(http.StatusOK)
+	})
+	handler := mw.Protect(backend)
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.False(t, backendCalled, "unauthenticated request should not reach backend")
+}
+
+func TestProtect_HostWithPortIsMatched(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	var backendCalled bool
+	backend := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		backendCalled = true
+		w.WriteHeader(http.StatusOK)
+	})
+	handler := mw.Protect(backend)
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com:8443/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.False(t, backendCalled, "host with port should still match the protected domain")
+}
+
+func TestProtect_ValidSessionCookiePassesThrough(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	token, err := sessionkey.SignToken(kp.PrivateKey, "test-user", "example.com", auth.MethodPIN, time.Hour)
+	require.NoError(t, err)
+
+	capturedData := &proxy.CapturedData{}
+	handler := mw.Protect(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
+		cd := proxy.CapturedDataFromContext(r.Context())
+		require.NotNil(t, cd)
+		assert.Equal(t, "test-user", cd.GetUserID())
+		assert.Equal(t, "pin", cd.GetAuthMethod())
+		w.WriteHeader(http.StatusOK)
+		_, _ = w.Write([]byte("authenticated"))
+	}))
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	req = req.WithContext(proxy.WithCapturedData(req.Context(), capturedData))
+	req.AddCookie(&http.Cookie{Name: auth.SessionCookieName, Value: token})
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusOK, rec.Code)
+	assert.Equal(t, "authenticated", rec.Body.String())
+}
+
+func TestProtect_ExpiredSessionCookieIsRejected(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	// Sign a token that expired 1 second ago.
+	token, err := sessionkey.SignToken(kp.PrivateKey, "test-user", "example.com", auth.MethodPIN, -time.Second)
+	require.NoError(t, err)
+
+	var backendCalled bool
+	backend := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		backendCalled = true
+		w.WriteHeader(http.StatusOK)
+	})
+	handler := mw.Protect(backend)
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	req.AddCookie(&http.Cookie{Name: auth.SessionCookieName, Value: token})
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.False(t, backendCalled, "expired session should not reach the backend")
+}
+
+func TestProtect_WrongDomainCookieIsRejected(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	// Token signed for a different domain audience.
+	token, err := sessionkey.SignToken(kp.PrivateKey, "test-user", "other.com", auth.MethodPIN, time.Hour)
+	require.NoError(t, err)
+
+	var backendCalled bool
+	backend := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		backendCalled = true
+		w.WriteHeader(http.StatusOK)
+	})
+	handler := mw.Protect(backend)
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	req.AddCookie(&http.Cookie{Name: auth.SessionCookieName, Value: token})
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.False(t, backendCalled, "cookie for wrong domain should be rejected")
+}
+
+func TestProtect_WrongKeyCookieIsRejected(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp1 := generateTestKeyPair(t)
+	kp2 := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp1.PublicKey, time.Hour, "", ""))
+
+	// Token signed with a different private key.
+	token, err := sessionkey.SignToken(kp2.PrivateKey, "test-user", "example.com", auth.MethodPIN, time.Hour)
+	require.NoError(t, err)
+
+	var backendCalled bool
+	backend := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		backendCalled = true
+		w.WriteHeader(http.StatusOK)
+	})
+	handler := mw.Protect(backend)
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	req.AddCookie(&http.Cookie{Name: auth.SessionCookieName, Value: token})
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.False(t, backendCalled, "cookie signed by wrong key should be rejected")
+}
+
+func TestProtect_SchemeAuthRedirectsWithCookie(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	token, err := sessionkey.SignToken(kp.PrivateKey, "pin-user", "example.com", auth.MethodPIN, time.Hour)
+	require.NoError(t, err)
+
+	scheme := &stubScheme{
+		method: auth.MethodPIN,
+		authFn: func(r *http.Request) (string, string, error) {
+			if r.FormValue("pin") == "111111" {
+				return token, "", nil
+			}
+			return "", "pin", nil
+		},
+	}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	var backendCalled bool
+	backend := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		backendCalled = true
+		w.WriteHeader(http.StatusOK)
+	})
+	handler := mw.Protect(backend)
+
+	// Submit the PIN via form POST.
+	form := url.Values{"pin": {"111111"}}
+	req := httptest.NewRequest(http.MethodPost, "http://example.com/somepath", strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.False(t, backendCalled, "backend should not be called during auth, only a redirect should be returned")
+	assert.Equal(t, http.StatusSeeOther, rec.Code)
+	assert.Equal(t, "/somepath", rec.Header().Get("Location"), "redirect should point to the original request URI")
+
+	cookies := rec.Result().Cookies()
+	var sessionCookie *http.Cookie
+	for _, c := range cookies {
+		if c.Name == auth.SessionCookieName {
+			sessionCookie = c
+			break
+		}
+	}
+	require.NotNil(t, sessionCookie, "session cookie should be set after successful auth")
+	assert.True(t, sessionCookie.HttpOnly)
+	assert.True(t, sessionCookie.Secure)
+	assert.Equal(t, http.SameSiteLaxMode, sessionCookie.SameSite)
+}
+
+func TestProtect_FailedAuthDoesNotSetCookie(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{
+		method: auth.MethodPIN,
+		authFn: func(_ *http.Request) (string, string, error) {
+			return "", "pin", nil
+		},
+	}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	handler := mw.Protect(newPassthroughHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	for _, c := range rec.Result().Cookies() {
+		assert.NotEqual(t, auth.SessionCookieName, c.Name, "no session cookie should be set on failed auth")
+	}
+}
+
+func TestProtect_MultipleSchemes(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	token, err := sessionkey.SignToken(kp.PrivateKey, "password-user", "example.com", auth.MethodPassword, time.Hour)
+	require.NoError(t, err)
+
+	// First scheme (PIN) always fails, second scheme (password) succeeds.
+	pinScheme := &stubScheme{
+		method: auth.MethodPIN,
+		authFn: func(_ *http.Request) (string, string, error) {
+			return "", "pin", nil
+		},
+	}
+	passwordScheme := &stubScheme{
+		method: auth.MethodPassword,
+		authFn: func(r *http.Request) (string, string, error) {
+			if r.FormValue("password") == "secret" {
+				return token, "", nil
+			}
+			return "", "password", nil
+		},
+	}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{pinScheme, passwordScheme}, kp.PublicKey, time.Hour, "", ""))
+
+	var backendCalled bool
+	backend := http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		backendCalled = true
+		w.WriteHeader(http.StatusOK)
+	})
+	handler := mw.Protect(backend)
+
+	form := url.Values{"password": {"secret"}}
+	req := httptest.NewRequest(http.MethodPost, "http://example.com/", strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.False(t, backendCalled, "backend should not be called during auth")
+	assert.Equal(t, http.StatusSeeOther, rec.Code)
+}
+
+func TestProtect_InvalidTokenFromSchemeReturns400(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	// Return a garbage token that won't validate.
+	scheme := &stubScheme{
+		method: auth.MethodPIN,
+		authFn: func(_ *http.Request) (string, string, error) {
+			return "invalid-jwt-token", "", nil
+		},
+	}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	handler := mw.Protect(newPassthroughHandler())
+
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusBadRequest, rec.Code)
+}
+
+func TestAddDomain_RandomBytes32NotEd25519(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+
+	// 32 random bytes that happen to be valid base64 and correct size
+	// but are actually a valid ed25519 public key length-wise.
+	// This should succeed because ed25519 public keys are just 32 bytes.
+	randomBytes := make([]byte, ed25519.PublicKeySize)
+	_, err := rand.Read(randomBytes)
+	require.NoError(t, err)
+
+	key := base64.StdEncoding.EncodeToString(randomBytes)
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+
+	err = mw.AddDomain("example.com", []Scheme{scheme}, key, time.Hour, "", "")
+	require.NoError(t, err, "any 32-byte key should be accepted at registration time")
+}
+
+func TestAddDomain_InvalidKeyDoesNotCorruptExistingConfig(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{method: auth.MethodPIN, promptID: "pin"}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	// Attempt to overwrite with an invalid key.
+	err := mw.AddDomain("example.com", []Scheme{scheme}, "bad", time.Hour, "", "")
+	require.Error(t, err)
+
+	// The original valid config should still be intact.
+	mw.domainsMux.RLock()
+	config, exists := mw.domains["example.com"]
+	mw.domainsMux.RUnlock()
+
+	assert.True(t, exists, "original config should still exist")
+	assert.Len(t, config.Schemes, 1)
+	assert.Equal(t, time.Hour, config.SessionExpiration)
+}
+
+func TestProtect_FailedPinAuthCapturesAuthMethod(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	// Scheme that always fails authentication (returns empty token)
+	scheme := &stubScheme{
+		method: auth.MethodPIN,
+		authFn: func(_ *http.Request) (string, string, error) {
+			return "", "pin", nil
+		},
+	}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	capturedData := &proxy.CapturedData{}
+	handler := mw.Protect(newPassthroughHandler())
+
+	// Submit wrong PIN - should capture auth method
+	form := url.Values{"pin": {"wrong-pin"}}
+	req := httptest.NewRequest(http.MethodPost, "http://example.com/", strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req = req.WithContext(proxy.WithCapturedData(req.Context(), capturedData))
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusUnauthorized, rec.Code)
+	assert.Equal(t, "pin", capturedData.GetAuthMethod(), "Auth method should be captured for failed PIN auth")
+}
+
+func TestProtect_FailedPasswordAuthCapturesAuthMethod(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{
+		method: auth.MethodPassword,
+		authFn: func(_ *http.Request) (string, string, error) {
+			return "", "password", nil
+		},
+	}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	capturedData := &proxy.CapturedData{}
+	handler := mw.Protect(newPassthroughHandler())
+
+	// Submit wrong password - should capture auth method
+	form := url.Values{"password": {"wrong-password"}}
+	req := httptest.NewRequest(http.MethodPost, "http://example.com/", strings.NewReader(form.Encode()))
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	req = req.WithContext(proxy.WithCapturedData(req.Context(), capturedData))
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusUnauthorized, rec.Code)
+	assert.Equal(t, "password", capturedData.GetAuthMethod(), "Auth method should be captured for failed password auth")
+}
+
+func TestProtect_NoCredentialsDoesNotCaptureAuthMethod(t *testing.T) {
+	mw := NewMiddleware(log.StandardLogger(), nil)
+	kp := generateTestKeyPair(t)
+
+	scheme := &stubScheme{
+		method: auth.MethodPIN,
+		authFn: func(_ *http.Request) (string, string, error) {
+			return "", "pin", nil
+		},
+	}
+	require.NoError(t, mw.AddDomain("example.com", []Scheme{scheme}, kp.PublicKey, time.Hour, "", ""))
+
+	capturedData := &proxy.CapturedData{}
+	handler := mw.Protect(newPassthroughHandler())
+
+	// No credentials submitted - should not capture auth method
+	req := httptest.NewRequest(http.MethodGet, "http://example.com/", nil)
+	req = req.WithContext(proxy.WithCapturedData(req.Context(), capturedData))
+	rec := httptest.NewRecorder()
+	handler.ServeHTTP(rec, req)
+
+	assert.Equal(t, http.StatusUnauthorized, rec.Code)
+	assert.Empty(t, capturedData.GetAuthMethod(), "Auth method should not be captured when no credentials submitted")
+}
+
+func TestWasCredentialSubmitted(t *testing.T) {
+	tests := []struct {
+		name     string
+		method   auth.Method
+		formData url.Values
+		query    url.Values
+		expected bool
+	}{
+		{
+			name:     "PIN submitted",
+			method:   auth.MethodPIN,
+			formData: url.Values{"pin": {"123456"}},
+			expected: true,
+		},
+		{
+			name:     "PIN not submitted",
+			method:   auth.MethodPIN,
+			formData: url.Values{},
+			expected: false,
+		},
+		{
+			name:     "Password submitted",
+			method:   auth.MethodPassword,
+			formData: url.Values{"password": {"secret"}},
+			expected: true,
+		},
+		{
+			name:     "Password not submitted",
+			method:   auth.MethodPassword,
+			formData: url.Values{},
+			expected: false,
+		},
+		{
+			name:     "OIDC token in query",
+			method:   auth.MethodOIDC,
+			query:    url.Values{"session_token": {"abc123"}},
+			expected: true,
+		},
+		{
+			name:     "OIDC token not in query",
+			method:   auth.MethodOIDC,
+			query:    url.Values{},
+			expected: false,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			reqURL := "http://example.com/"
+			if len(tt.query) > 0 {
+				reqURL += "?" + tt.query.Encode()
+			}
+
+			var body *strings.Reader
+			if len(tt.formData) > 0 {
+				body = strings.NewReader(tt.formData.Encode())
+			} else {
+				body = strings.NewReader("")
+			}
+
+			req := httptest.NewRequest(http.MethodPost, reqURL, body)
+			req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+
+			result := wasCredentialSubmitted(req, tt.method)
+			assert.Equal(t, tt.expected, result)
+		})
+	}
+}