From 249cb74cebe384c749fa0b7a0383f14c422a7e00 Mon Sep 17 00:00:00 2001
From: hariprasad-SAP <111269823+hariprasad-SAP@users.noreply.github.com>
Date: Mon, 15 Aug 2022 14:07:39 +0530
Subject: [PATCH 1/2] Update ExternalMechanism.java to be RFC compliant

The SASL External mechanism is configured in this class (ExternalMechanism.java) of Apache qpid-jms.

We can notice that the initial response is configured in Line 28. It is always set to EMPTY (empty byte array defined here) and cannot be configured to a custom string that we can use as identity string. Hence this library is NOT RFC compliant

If we have to pass the authorization identity string to the server then we must configure the initial response of that client.
---
 .../java/org/apache/qpid/jms/sasl/ExternalMechanism.java    | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/qpid-jms-client/src/main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java b/qpid-jms-client/src/main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java
index 13d8fc0f2..e5b0bd146 100644
--- a/qpid-jms-client/src/main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java
+++ b/qpid-jms-client/src/main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java
@@ -25,7 +25,11 @@ public class ExternalMechanism extends AbstractMechanism {
 
     @Override
     public byte[] getInitialResponse() {
-        return EMPTY;
+        String username = getUsername();
+        if(username == null || username.isEmpty()){
+            return EMPTY;
+          }
+        return username.getBytes(StandardCharsets.UTF_8);
     }
 
     @Override

From 8032c29f4a98a9212331e228652fb2b7e54d1882 Mon Sep 17 00:00:00 2001
From: hariprasad-SAP <111269823+hariprasad-SAP@users.noreply.github.com>
Date: Mon, 15 Aug 2022 14:16:12 +0530
Subject: [PATCH 2/2] Added the import statement for StandardCharsets

---
 .../main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java    | 1 +
 1 file changed, 1 insertion(+)

diff --git a/qpid-jms-client/src/main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java b/qpid-jms-client/src/main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java
index e5b0bd146..8abc0bb1c 100644
--- a/qpid-jms-client/src/main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java
+++ b/qpid-jms-client/src/main/java/org/apache/qpid/jms/sasl/ExternalMechanism.java
@@ -16,6 +16,7 @@
  */
 package org.apache.qpid.jms.sasl;
 
+import java.nio.charset.StandardCharsets;
 import java.security.Principal;
 
 /**