fixing username mismatch issue
diff --git a/airavata-api/airavata-api-server/src/main/java/org/apache/airavata/api/server/security/DefaultAiravataSecurityManager.java b/airavata-api/airavata-api-server/src/main/java/org/apache/airavata/api/server/security/DefaultAiravataSecurityManager.java
index 8657e13..90039f4 100644
--- a/airavata-api/airavata-api-server/src/main/java/org/apache/airavata/api/server/security/DefaultAiravataSecurityManager.java
+++ b/airavata-api/airavata-api-server/src/main/java/org/apache/airavata/api/server/security/DefaultAiravataSecurityManager.java
@@ -179,8 +179,11 @@
                         if(authorizedUserName.contains("@")){
                             authorizedUserName = authorizedUserName.split("@")[0];
                         }
+                        if(subject.contains("@")){
+                            subject = subject.split("@")[0];
+                        }
                         //cannot impersonate users
-                        if(!authorizedUserName.equals(subject))
+                        if(!authorizedUserName.toLowerCase().equals(subject.toLowerCase()))
                             return false;
 
                         long expiryTimestamp = validationResponse.getExpiryTime();