feat(auth): allow JWT IP changes by configuration (#1236)

* feat(auth): allow JWT IP changes by configuration

* fix(auth): make JWT IP change setting concurrency-safe

* test(auth): move JWT IP change setting tests out of MCP test file

cmd/dashboard/controller/jwt.go

@@ -152,7 +152,7 @@ func identityHandler() func(c *gin.Context) any {
 			return nil
 		}
 		currentIP := c.GetString(model.CtxKeyRealIPStr)
-		if sess.IP != currentIP {
+		if !singleton.Conf.JWTIPChangeAllowed() && sess.IP != currentIP {
 			c.Set(model.CtxKeyIsIPMismatch, true)
 			return nil
 		}

cmd/dashboard/controller/jwt_session_test.go

@@ -193,6 +193,61 @@ func TestIdentityHandlerFlagsIPMismatch(t *testing.T) {
 	assert.True(t, verify.GetBool(model.CtxKeyIsIPMismatch))
 }
 
+func TestIdentityHandlerAllowsIPMismatchWhenConfigured(t *testing.T) {
+	cleanup := setupJWTSessionTest(t)
+	defer cleanup()
+	singleton.Conf.SetJWTIPChangeAllowed(true)
+
+	ctx := newCtxForUser(0, "1.2.3.4", "ua")
+	user := model.User{Common: model.Common{ID: 100}, TokenVersion: 7}
+	claims, err := issueJWTSession(ctx, &user, 1)
+	require.NoError(t, err)
+
+	verify := newCtxForUser(0, "9.9.9.9", "ua")
+	verify.Set("JWT_PAYLOAD", jwt.MapClaims{
+		jwtClaimUserID: claims[jwtClaimUserID],
+		jwtClaimKeyID:  claims[jwtClaimKeyID],
+	})
+
+	identity := identityHandler()(verify)
+	require.NotNil(t, identity, "IP mismatch must be accepted when allow_jwt_ip_change is enabled")
+	assert.False(t, verify.GetBool(model.CtxKeyIsIPMismatch))
+}
+
+func TestIdentityHandlerConcurrentIPChangeSetting(t *testing.T) {
+	cleanup := setupJWTSessionTest(t)
+	defer cleanup()
+
+	ctx := newCtxForUser(0, "1.2.3.4", "ua")
+	user := model.User{Common: model.Common{ID: 100}, TokenVersion: 7}
+	claims, err := issueJWTSession(ctx, &user, 1)
+	require.NoError(t, err)
+
+	stop, done := make(chan struct{}), make(chan struct{})
+	go func() {
+		defer close(done)
+		for {
+			select {
+			case <-stop:
+				return
+			default:
+				singleton.Conf.SetJWTIPChangeAllowed(true)
+				singleton.Conf.SetJWTIPChangeAllowed(false)
+			}
+		}
+	}()
+	defer func() {
+		close(stop)
+		<-done
+	}()
+
+	for i := 0; i < 100; i++ {
+		verify := newCtxForUser(0, "1.2.3.4", "ua")
+		verify.Set("JWT_PAYLOAD", jwt.MapClaims(claims))
+		require.NotNil(t, identityHandler()(verify), "matching IP must pass during setting updates")
+	}
+}
+
 func TestIdentityHandlerRejectsUnknownKeyID(t *testing.T) {
 	cleanup := setupJWTSessionTest(t)
 	defer cleanup()

cmd/dashboard/controller/setting.go

@@ -97,6 +97,9 @@ func updateConfig(c *gin.Context) (any, error) {
 
 	singleton.Conf.EnableIPChangeNotification = sf.EnableIPChangeNotification
 	singleton.Conf.EnablePlainIPInNotification = sf.EnablePlainIPInNotification
+	if sf.AllowJWTIPChange != nil {
+		singleton.Conf.SetJWTIPChangeAllowed(*sf.AllowJWTIPChange)
+	}
 	singleton.Conf.Cover = sf.Cover
 	singleton.Conf.InstallHost = sf.InstallHost
 	singleton.Conf.DashboardHost = sf.DashboardHost
@@ -160,6 +163,12 @@ func fireMCPKillSwitch() {
 // the current config to avoid accidentally tripping the kill switch on
 // partial PATCH calls that omit enable_mcp.
 func resolveSettingEnableMCP(formValue *bool, current bool) bool {
+	return resolveOptionalBool(formValue, current)
+}
+
+// resolveOptionalBool preserves a setting for partial PATCH requests when its
+// boolean field is absent, while still allowing an explicit false value.
+func resolveOptionalBool(formValue *bool, current bool) bool {
 	if formValue == nil {
 		return current
 	}

cmd/dashboard/controller/setting_jwt_ip_change_test.go

@@ -0,0 +1,26 @@
+package controller
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/nezhahq/nezha/model"
+)
+
+func TestSettingForm_AllowJWTIPChangePreservesAbsentAndDecodesExplicitValues(t *testing.T) {
+	var omitted model.SettingForm
+	require.NoError(t, json.Unmarshal([]byte(`{"site_name":"X"}`), &omitted))
+	require.Nil(t, omitted.AllowJWTIPChange)
+
+	var enabled model.SettingForm
+	require.NoError(t, json.Unmarshal([]byte(`{"allow_jwt_ip_change":true}`), &enabled))
+	require.NotNil(t, enabled.AllowJWTIPChange)
+	require.True(t, *enabled.AllowJWTIPChange)
+
+	var disabled model.SettingForm
+	require.NoError(t, json.Unmarshal([]byte(`{"allow_jwt_ip_change":false}`), &disabled))
+	require.NotNil(t, disabled.AllowJWTIPChange)
+	require.False(t, *disabled.AllowJWTIPChange)
+}