diff --git a/kyuubi-server/src/main/scala/yaooqinn/kyuubi/auth/KyuubiAuthFactory.scala b/kyuubi-server/src/main/scala/yaooqinn/kyuubi/auth/KyuubiAuthFactory.scala
index bf7519573..4e942078f 100644
--- a/kyuubi-server/src/main/scala/yaooqinn/kyuubi/auth/KyuubiAuthFactory.scala
+++ b/kyuubi-server/src/main/scala/yaooqinn/kyuubi/auth/KyuubiAuthFactory.scala
@@ -65,7 +65,7 @@ class KyuubiAuthFactory(conf: SparkConf) extends Logging {
           throw new TTransportException("Failed to start token manager", e)
       }
       Some(server)
-    case AuthType.NONE | AuthType.NOSASL => None
+    case AuthType.NONE | AuthType.NOSASL | AuthType.LDAP => None
     case other => throw new ServiceException("Unsupported authentication method: " + other)
   }
 
diff --git a/kyuubi-server/src/main/scala/yaooqinn/kyuubi/auth/PlainSaslServer.scala b/kyuubi-server/src/main/scala/yaooqinn/kyuubi/auth/PlainSaslServer.scala
index afb4d1163..917c20b8e 100644
--- a/kyuubi-server/src/main/scala/yaooqinn/kyuubi/auth/PlainSaslServer.scala
+++ b/kyuubi-server/src/main/scala/yaooqinn/kyuubi/auth/PlainSaslServer.scala
@@ -72,7 +72,7 @@ class PlainSaslServer(handler: CallbackHandler, authMethod: AuthMethods) extends
         case 0 =>
           tokenList.addLast(messageToken.toString)
           messageToken.setLength(0)
-        case b: Byte => messageToken.append(b)
+        case b: Byte => messageToken.append(b.toChar)
       }
       tokenList.addLast(messageToken.toString)
       // validate response