Gokhan Atil's Technology Blog

Oracle Enterprise Manager Cloud Control: Write Powerful Scripts With EMCLI

Last week, I attended the Oracle Open World and gave a presentation about writing scripts with EMCLI. If you’re unfamiliar with EMCLI, it’s the command line interface for Oracle Enterprise Manager Cloud Control. Here’s my presentation:

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How To Recover The Weblogic Administrator Password Of The Enterprise Manager?

As you know, Weblogic is a part of the Enterprise Manager Cloud Control environment, and it’s automatically installed and configured by the EM installer. The Enterprise Manager asks you to enter a username and password for Weblogic administration. This information is stored in secure files; you usually do not need them unless you use the Weblogic console. So it’s easy to forget this username and password, and that’s what happened to me. Fortunately, there’s a way to recover them without resetting a new user/password. Here are the steps:

First, we need to know the DOMAIN_HOME directory. My OMS is located in “/u02/Middleware/oms”. You can find yours if you read “/etc/oragchomelist”. If the full path of OMS is “/u02/Middleware/oms”, the middleware home is “/u02/Middleware/”. Under my middleware home, I need to go GCDomains folder:

oracle@db-cloud /$ cd /u02/Middleware
oracle@db-cloud Middleware$ cd gc_inst/user_projects/domains/GCDomain

Then we get the encrypted information from boot.properties file:

oracle@db-cloud GCDomain$ cat servers/EMGC_ADMINSERVER/security/boot.properties

# Generated by Configuration Wizard on Wed Jun 04 10:22:47 EEST 2014
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How To Retrieve Passwords From The Named Credentials in EM12c?

The username, password, and role name of the named credentials are stored in the em_nc_cred_columns table. When we examine it, we can see that there’s one-to-many relation with em_nc_creds using the target_guid column, and the sensitive information is stored in the cred_attr_value column. That column is encrypted using the em_crypto package. The encryption algorithm uses a secret key which is stored in the “Admin Credentials Wallet” and a salt (random data for additional security). The wallet file is located in:


And the salt data can be found in the cred_salt column of the em_nc_cred_columns table. Here’s what it looks like:


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BBED Block Browser Editor For Oracle 11g

BBED (Block Browser Editor) is a tool for Oracle internal use, and it helps you to read and manipulate data at the Oracle Database block level. No need to say that it’s very powerful and extremely dangerous because you can corrupt data/header blocks. There’s an unofficial but very comprehensive manual for BBED. It’s written by Graham Thornton. You can download it as PDF: http://orafaq.com/papers/dissassembling_the_data_block.pdf

The object code of BBED is shipped for earlier releases of Oracle. All you need is to compile it. On Oracle 11g, the required files are not shipped. So you need to copy the following files from an Oracle 10g home to Oracle 11g home:

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