control "V-73045" do
  title "PostgreSQL must off-load audit data to a separate log management facility;
this must be continuous and in near real time for systems with a network connection
to the storage facility and weekly or more often for stand-alone systems."
  desc  "Information stored in one location is vulnerable to accidental or
incidental deletion or alteration.

Off-loading is a common process in information systems with limited audit storage
capacity.

PostgreSQL may write audit records to database tables, to files in the file system,
to other kinds of local repository, or directly to a centralized log management
system. Whatever the method used, it must be compatible with off-loading the records
to the centralized system."
  impact 0.5
  tag "severity": "medium"
  tag "gtitle": "SRG-APP-000515-DB-000318"
  tag "gid": "V-73045"
  tag "rid": "SV-87697r1_rule"
  tag "stig_id": "PGS9-00-011300"
  tag "cci": "CCI-001851"
  tag "nist": ["AU-4 (1)", "Rev_4"]
  tag "check": "First, as the database administrator (shown here as \"postgres\"),
ensure PostgreSQL uses syslog by running the following SQL:

$ sudo su - postgres
$ psql -c \"SHOW log_destination\"

If log_destination is not syslog, this is a finding.

Next, as the database administrator, check which log facility is configured by
running the following SQL:

$ psql -c \"SHOW syslog_facility\"

Check with the organization to see how syslog facilities are defined in their
organization.

If the wrong facility is configured, this is a finding.

If PostgreSQL does not have a continuous network connection to the centralized log
management system, and PostgreSQL audit records are not transferred to the
centralized log management system weekly or more often, this is a finding."

  tag "fix": "Note: The following instructions use the PGDATA environment variable.
See supplementary content APPENDIX-F for instructions on configuring PGDATA.

Configure PostgreSQL or deploy and configure software tools to transfer audit
records to a centralized log management system, continuously and in near-real time
where a continuous network connection to the log management system exists, or at
least weekly in the absence of such a connection.

To ensure that logging is enabled, review supplementary content APPENDIX-C for
instructions on enabling logging.

With logging enabled, as the database administrator (shown here as \"postgres\"),
configure the follow parameters in postgresql.conf (the example uses the default
values - tailor for environment):

Note: Consult the organization on how syslog facilities are defined in the syslog
daemon configuration.

$ sudo su - postgres
$ vi ${PGDATA?}/postgresql.conf
log_destination = 'syslog'
syslog_facility = 'LOCAL0'
syslog_ident = 'postgres'

Now, as the system administrator, reload the server with the new configuration:

# SYSTEMD SERVER ONLY
$ sudo systemctl reload postgresql-9.5

# INITD SERVER ONLY
$ sudo service postgresql-9.5 reload"

  only_if { false }

end