Unable to login - PLAIN: user not authorized

Hello Team,

I am trying to setup openfire (v 4.3.2), I have installed and configured all necessary params and I can login & chat through the users I created using openfire admin console.
I have a custom plugin to validate the users, I have added that plugin to lib and have changed the necessary params to point openfire to validate through my class. Openfire picks up my class while validating but always ends with following error log

javax.security.sasl.SaslException: PLAIN authentication failed for: 407898

at org.jivesoftware.openfire.sasl.SaslServerPlainImpl.evaluateResponse(SaslServerPlainImpl.java:144) ~[xmppserver-4.3.2.jar:4.3.2]

at org.jivesoftware.openfire.net.SASLAuthentication.handle(SASLAuthentication.java:329) [xmppserver-4.3.2.jar:4.3.2]

at org.jivesoftware.openfire.net.StanzaHandler.process(StanzaHandler.java:185) [xmppserver-4.3.2.jar:4.3.2]

at org.jivesoftware.openfire.nio.ConnectionHandler.messageReceived(ConnectionHandler.java:177) [xmppserver-4.3.2.jar:4.3.2]

at org.apache.mina.core.filterchain.DefaultIoFilterChain$TailFilter.messageReceived(DefaultIoFilterChain.java:690) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:417) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:47) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:765) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.IoFilterAdapter.messageReceived(IoFilterAdapter.java:109) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:417) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:47) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:765) [mina-core-2.0.7.jar:?]

at org.apache.mina.filter.codec.ProtocolCodecFilter$ProtocolDecoderOutputImpl.flush(ProtocolCodecFilter.java:407) [mina-core-2.0.7.jar:?]

at org.apache.mina.filter.codec.ProtocolCodecFilter.messageReceived(ProtocolCodecFilter.java:236) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain.callNextMessageReceived(DefaultIoFilterChain.java:417) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain.access$1200(DefaultIoFilterChain.java:47) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.DefaultIoFilterChain$EntryImpl$1.messageReceived(DefaultIoFilterChain.java:765) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.filterchain.IoFilterEvent.fire(IoFilterEvent.java:74) [mina-core-2.0.7.jar:?]

at org.apache.mina.core.session.IoEvent.run(IoEvent.java:63) [mina-core-2.0.7.jar:?]

at org.apache.mina.filter.executor.OrderedThreadPoolExecutor$Worker.runTask(OrderedThreadPoolExecutor.java:769) [mina-core-2.0.7.jar:?]

at org.apache.mina.filter.executor.OrderedThreadPoolExecutor$Worker.runTasks(OrderedThreadPoolExecutor.java:761) [mina-core-2.0.7.jar:?]

at org.apache.mina.filter.executor.OrderedThreadPoolExecutor$Worker.run(OrderedThreadPoolExecutor.java:703) [mina-core-2.0.7.jar:?]

at java.lang.Thread.run(Thread.java:748) [?:1.8.0_201]

Caused by: javax.security.sasl.SaslException: PLAIN: user not authorized: 407898

at org.jivesoftware.openfire.sasl.SaslServerPlainImpl.evaluateResponse(SaslServerPlainImpl.java:133) ~[xmppserver-4.3.2.jar:4.3.2]

... 22 more

FYI: I do not wish to use company certificates for now as this is going to be test environment.
My plugin makes a REST call to validate the user. I have tested it through the CURL command and it works perfectly without.

Can someone please help me with the issue?

Thanks in advance