Creating DB vault & Test the connection:

Using CLI commands

Standalone:

/core-service=vault:add(vault-options=[("KEYSTORE_URL" => "PATH_TO_KEYSTORE"), ("KEYSTORE_PASSWORD" => "MASKED_PASSWORD"), ("KEYSTORE_ALIAS" => "ALIAS"), ("SALT" => "SALT"),("ITERATION_COUNT" => "ITERATION_COUNT"), ("ENC_FILE_DIR" => "ENC_FILE_DIR")])

The following is an example of the command with hypothetical values:
/core-service=vault:add(vault-options=[("KEYSTORE_URL" => "/home/user/vault/vault.keystore"), ("KEYSTORE_PASSWORD" => "MASK-3y28rCZlcKR"), ("KEYSTORE_ALIAS" => "vault"), ("SALT" => "12438567"),("ITERATION_COUNT" => "50"), ("ENC_FILE_DIR" => "/home/user/vault/")])

https://access.redhat.com/documentation/en-us/jboss_enterprise_application_platform/6.1/html/security_guide/generate_a_ssl_encryption_key_and_certificate