Server subsystem failed. Reason: weblogic.security.SecurityInitializationException: Authentication for user denied during weblogic admin start

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Applies to:
Weblogic: 10.3.6 and later
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Problem Summary:
Unable to start weblogic admin server becuae of weblogic.security.SecurityInitializationException: Authentication for user denied

Error:
####<Feb 25, 2014 11:20:33 PM IST> <Critical> <WebLogicServer> <localhost.com> <AdminServer> <Main Thread> <<WLS Kernel>> <> <> <1393392033466> <BEA-000386> <Server subsystem failed. Reason: weblogic.security.SecurityInitializationException: Authentication for user  denied
weblogic.security.SecurityInitializationException: Authentication for user  denied
        at weblogic.security.service.CommonSecurityServiceManagerDelegateImpl.doBootAuthorization(CommonSecurityServiceManagerDelegateImpl.java:965)
        at weblogic.security.service.CommonSecurityServiceManagerDelegateImpl.initialize(CommonSecurityServiceManagerDelegateImpl.java:1050)
.....................
Caused By: javax.security.auth.login.FailedLoginException: [Security:090304]Authentication Failed: User  javax.security.auth.login.LoginException: [Security:090301]Password Not Supplied
        at weblogic.security.providers.authentication.LDAPAtnLoginModuleImpl.login(LDAPAtnLoginModuleImpl.java:261)
        at com.bea.common.security.internal.service.LoginModuleWrapper$1.run(LoginModuleWrapper.java:110)

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Root Cause:
boot.properties file is missing from the location $Domain_home/servers/AdminServer/security or password has been changed.

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Resolution:
1. Copy boot.properties file from the back up if any or create test boot.properties file under $Domain_home/servers/AdminServer/security folder
2. Configure weblogic username and password in boot.properties.
    Put below 2 lines in boot.properties file,
    username=<adminuser>
    password=<password>
3. During start up WLS read credentials from this file and encrypt it.