diff --git a/src/index.html b/src/index.html
index 2587398..bd41440 100644
--- a/src/index.html
+++ b/src/index.html
@@ -363,26 +363,39 @@ <h2>
                   </div>
 
                   <div data-collapse="state.internet.vpn03.generate">
-                    <div class="form-group">
+                    <div class="form-group has-feedback" data-ng-class="{
+                        'has-error': hasError('vpn03Cert'),
+                        'has-success': wizardForm.vpn03Cert.$valid
+                      }">
                       <label for="vpn03Cert" class="col-md-6 control-label" translate>
-                        .certificate.label</label>
+                        .certificate.label</label><span></span>
                       <div class="col-md-6">
-                        <span class="btn btn-primary btn-file">
-                          <span translate>.browse</span>
-                          <input type="file" data-ng-model="wizard.internet.vpn03.cert">
-                        </span>
+                        <input type="file" name="vpn03Cert"
+                          data-ng-model="wizard.internet.vpn03.cert"
+                          data-file-valid data-ng-required="!state.internet.vpn03.generate && wizard.internet.vpn03.enabled && wizard.internet.share">
+                        <div class="help-block" ng-show="hasError('vpn03Cert')">
+                          <div ng-show="wizardForm.vpn03Cert.$error.required" translate>
+                            .error.required
+                          </div>
+                        </div>
                       </div>
                     </div>
-
-                    <div class="form-group">
+                    <div class="form-group has-feedback" data-ng-class="{
+                        'has-error': hasError('vpn03Key'),
+                        'has-success': wizardForm.vpn03Key.$valid
+                      }">
                       <label for="vpn03Key" class="col-md-6 control-label" translate>
                         .key.label
                       </label>
                       <div class="col-md-6">
-                        <span class="btn btn-primary btn-file">
-                          <span translate>.browse</span>
-                          <input type="file" data-ng-model="wizard.internet.vpn03.key">
-                        </span>
+                        <input type="file" name="vpn03Key"
+                          data-ng-model="wizard.internet.vpn03.key"
+                          data-file-valid data-ng-required="!state.internet.vpn03.generate && wizard.internet.vpn03.enabled && wizard.internet.share">
+                        <div class="help-block" ng-show="hasError('vpn03Key')">
+                          <div ng-show="wizardForm.vpn03Key.$error.required" translate>
+                            .error.required
+                          </div>
+                        </div>
                       </div>
                     </div>
                   </div>
diff --git a/src/js/directives/fileRequired.js b/src/js/directives/fileRequired.js
new file mode 100644
index 0000000..0ba1efa
--- /dev/null
+++ b/src/js/directives/fileRequired.js
@@ -0,0 +1,31 @@
+//required validation for input type file is not supported yet
+//see: https://github.com/angular/angular.js/issues/1375
+//see: https://github.com/angular/angular.js/pull/8987
+
+'use strict';
+
+module.exports = function(app) {
+  app.directive('fileValid', function() {
+    return {
+      require: 'ngModel',
+      scope: {
+        required: '=ngRequired'
+      },
+      link: function(scope, element, attributes, ngModel) {
+        console.log(scope.required);
+        scope.$watch('required', function(newValue, oldValue) {
+          console.log('required changed');
+        });
+
+        //handle element change
+        element.bind('change',function() {
+          scope.$apply(function() {
+            ngModel.$setViewValue(element.val());
+            ngModel.$render();
+          });
+        });
+
+      }
+    };
+  });
+};
diff --git a/src/js/directives/index.js b/src/js/directives/index.js
index 9d91ff3..9e42bea 100644
--- a/src/js/directives/index.js
+++ b/src/js/directives/index.js
@@ -3,4 +3,5 @@
 module.exports = function(app) {
   require('./compareTo')(app);
   require('./ipv4Address')(app);
+  require('./fileRequired')(app);
 };
diff --git a/src/nls/locale-de.json b/src/nls/locale-de.json
index 9b6f696..1cdd7f0 100644
--- a/src/nls/locale-de.json
+++ b/src/nls/locale-de.json
@@ -66,7 +66,8 @@
       "label": "VPN03 Zertifikat und Schlüssel für diesen Router generieren. ",
       "certificate.label": "VPN Zertifikat",
       "key.label": "Schlüssel",
-      "browse": "Durchsuchen"
+      "browse": "Durchsuchen",
+      "error.required": "Diese Datei wird benötigt. Wenn du den Haken oben setzt, wird sie automatisch generiert"
     }
   },
   "ip": {
diff --git a/src/nls/locale-en.json b/src/nls/locale-en.json
index ebac392..233d8c1 100644
--- a/src/nls/locale-en.json
+++ b/src/nls/locale-en.json
@@ -66,7 +66,8 @@
       "label": "Generate new VPN03 certificate and key for this router",
       "certificate.label": "VPN certificate",
       "key.label": "VPN key",
-      "browse": "Browse"
+      "browse": "Browse",
+      "error.required": "The file is required. It is generated automatically if you select the checkbox above."
     }
   },
   "ip": {