# encoding: utf-8
# copyright: 2015, Vulcano Security GmbH
# author: Dominik Richter
# author: Christoph Hartmann
# license: All rights reserved

class Lines
  attr_reader :output

  def initialize(raw, desc)
    @output = raw
    @desc = desc
  end

  def lines
    output.split("\n")
  end

  def to_s
    @desc
  end
end

class PostgresSession < Inspec.resource(1)
  name 'postgres_session'
  desc 'Use the postgres_session InSpec audit resource to test SQL commands run against a PostgreSQL database.'
  example "
    sql = postgres_session('username', 'password')

    describe sql.query('SELECT * FROM pg_shadow WHERE passwd IS NULL;') do
      its('output') { should eq('') }
    end
  "

  def initialize(user, pass)
    @user = user || 'postgres'
    @pass = pass
  end

  def query(query, db = [])
    dbs = db.map { |x| "-d #{x}" }.join(' ')
    # TODO: simple escape, must be handled by a library
    # that does this securely
    escaped_query = query.gsub(/\\/, '\\\\').gsub(/"/, '\\"').gsub(/\$/, '\\$')
    # run the query
    cmd = inspec.command("PGPASSWORD='#{@pass}' psql -U #{@user} #{dbs} -h localhost -c \"#{escaped_query}\"")
    out = cmd.stdout + "\n" + cmd.stderr
    if cmd.exit_status != 0 or
       out =~ /could not connect to .*/ or
       out.downcase =~ /^error/
      # skip this test if the server can't run the query
      skip_resource "Can't read run query #{query.inspect} on postgres_session: #{out}"
    else
      # remove the whole header (i.e. up to the first ^-----+------+------$)
      # remove the tail
      lines = cmd.stdout
                 .sub(/(.*\n)+([-]+[+])*[-]+\n/, '')
                 .sub(/\n[^\n]*\n\n$/, '')
      Lines.new(lines.strip, "PostgreSQL query: #{query}")
    end
  end
end