V-72931

control "V-72931" do
  title "PostgreSQL must generate audit records when unsuccessful attempts to
  delete categorized information (e.g., classification levels/security levels)
  occur."
  desc  "Changes in categorized information must be tracked. Without an audit
  trail, unauthorized access to protected data could go undetected.
  To aid in diagnosis, it is necessary to keep track of failed attempts in
  addition to the successful ones.
  For detailed information on categorizing information, refer to FIPS Publication
  199, Standards for Security Categorization of Federal Information and
  Information Systems, and FIPS Publication 200, Minimum Security Requirements
  for Federal Information and Information Systems."
  impact 0.5
  tag "severity": "medium"
  tag "gtitle": "SRG-APP-000502-DB-000349"
  tag "gid": "V-72931"
  tag "rid": "SV-87583r1_rule"
  tag "stig_id": "PGS9-00-005000"
  tag "cci": "CCI-000172"
  tag "nist": ["AU-12 c", "Rev_4"]
  tag "check": "First, as the database administrator, verify pgaudit is enabled
  by running the following SQL:
  $ sudo su - postgres
  $ psql -c \"SHOW shared_preload_libraries\"
  If the output does not contain \"pgaudit\", this is a finding.
  Next, verify that role, read, write, and ddl auditing are enabled:
  $ psql -c \"SHOW pgaudit.log\"
  If the output does not contain role, read, write, and ddl, 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.
  All errors and denials are logged if logging is enabled. To ensure that
  logging is enabled, review supplementary content APPENDIX-C for instructions
  on enabling logging.
  Using pgaudit PostgreSQL can be configured to audit these requests. See
  supplementary content APPENDIX-B for documentation on installing pgaudit.
  With pgaudit installed the following configurations can be made:
  $ sudo su - postgres
  $ vi ${PGDATA?}/postgresql.conf
  Add the following parameters (or edit existing parameters):
  pgaudit.log='ddl, role, read, write'
  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"

  sql = postgres_session(PG_DBA, PG_DBA_PASSWORD, PG_HOST)

  describe sql.query('SHOW shared_preload_libraries;', [PG_DB]) do
    its('output') { should include 'pgaudit' }
  end

  pgaudit_types = %w(ddl read role write)

  pgaudit_types.each do |type|
    describe sql.query('SHOW pgaudit.log;', [PG_DB]) do
      its('output') { should include type }
    end
  end
end