5 files changed, 11 insertions, 4 deletions
diff --git a/Core/Authentication/Provider/AuthenticationProviderInterface.php b/Core/Authentication/Provider/AuthenticationProviderInterface.php
index adad258..eaf9e07 100644
--- a/Core/Authentication/Provider/AuthenticationProviderInterface.php
+++ b/Core/Authentication/Provider/AuthenticationProviderInterface.php
@@ -25,6 +25,13 @@ use Symfony\Component\Security\Core\Authentication\AuthenticationManagerInterfac
 interface AuthenticationProviderInterface extends AuthenticationManagerInterface
 {
     /**
+     * Use this constant for not provided username
+     *
+     * @var string
+     */
+    const USERNAME_NONE_PROVIDED = 'NONE_PROVIDED';
+
+    /**
      * Checks whether this provider supports the given token.
      *
      * @param TokenInterface $token A TokenInterface instance
diff --git a/Core/Authentication/Provider/LdapBindAuthenticationProvider.php b/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
index adc42ef..7283ab9 100644
--- a/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
+++ b/Core/Authentication/Provider/LdapBindAuthenticationProvider.php
@@ -58,7 +58,7 @@ class LdapBindAuthenticationProvider extends UserAuthenticationProvider
      */
     protected function retrieveUser($username, UsernamePasswordToken $token)
     {
-        if ('NONE_PROVIDED' === $username) {
+        if (AuthenticationProviderInterface::USERNAME_NONE_PROVIDED === $username) {
             throw new UsernameNotFoundException('Username can not be null');
         }
 
diff --git a/Core/Authentication/Provider/UserAuthenticationProvider.php b/Core/Authentication/Provider/UserAuthenticationProvider.php
index 2674088..9dc4751 100644
--- a/Core/Authentication/Provider/UserAuthenticationProvider.php
+++ b/Core/Authentication/Provider/UserAuthenticationProvider.php
@@ -63,7 +63,7 @@ abstract class UserAuthenticationProvider implements AuthenticationProviderInter
 
         $username = $token->getUsername();
         if ('' === $username || null === $username) {
-            $username = 'NONE_PROVIDED';
+            $username = AuthenticationProviderInterface::USERNAME_NONE_PROVIDED;
         }
 
         try {
diff --git a/Core/README.md b/Core/README.md
index 3c6a117..a423666 100644
--- a/Core/README.md
+++ b/Core/README.md
@@ -11,7 +11,7 @@ Resources
 
 Documentation:
 
-https://symfony.com/doc/3.0/book/security.html
+https://symfony.com/doc/3.1/book/security.html
 
 Tests
 -----
diff --git a/Core/composer.json b/Core/composer.json
index eb20c5d..f6391e0 100644
--- a/Core/composer.json
+++ b/Core/composer.json
@@ -44,7 +44,7 @@
     "minimum-stability": "dev",
     "extra": {
         "branch-alias": {
-            "dev-master": "3.0-dev"
+            "dev-master": "3.1-dev"
         }
     }
 }