metasploit-framework/lib/rex/proto/steam/message.rb

126 lines
3.1 KiB
Ruby

# -*- coding: binary -*-
module Rex
module Proto
##
#
# Steam protocol support, taken from https://developer.valvesoftware.com/wiki/Server_queries
#
##
module Steam
# The Steam header ussed when the message is fragmented.
FRAGMENTED_HEADER = 0xFFFFFFFE
# The Steam header ussed when the message is not fragmented.
UNFRAGMENTED_HEADER = 0xFFFFFFFF
# Decodes a Steam response message.
#
# @param message [String] the message to decode
# @return [Array] the message type and body
def decode_message(message)
# minimum size is header (4) + type (1)
return if message.length < 5
header, type = message.unpack('NC')
# TODO: handle fragmented responses
return if header != UNFRAGMENTED_HEADER
[type, message[5, message.length]]
end
# Encodes a Steam message.
#
# @param type [String, Fixnum] the message type
# @param body [String] the message body
# @return [String] the encoded Steam message
def encode_message(type, body)
if type.is_a? Fixnum
type_num = type
elsif type.is_a? String
type_num = type.ord
else
fail ArgumentError, 'type must be a String or Fixnum'
end
[UNFRAGMENTED_HEADER, type_num ].pack('NC') + body
end
# Builds an A2S_INFO message
#
# @return [String] the A2S_INFO message
def a2s_info
encode_message('T', "Source Engine Query\x00")
end
# Decodes an A2S_INFO response message
#
# @parameter response [String] the A2S_INFO resposne to decode
# @return [Hash] the fields extracted from the response
def a2s_info_decode(response)
# abort if it is impossibly short
return nil if response.length < 19
message_type, body = decode_message(response)
# abort if it isn't a valid Steam response
return nil if message_type != 0x49 # 'I'
info = {}
info[:version], info[:name], info[:map], info[:folder], info[:game_name],
info[:game_id], players, players_max, info[:bots],
type, env, vis, vac, info[:game_version], _edf = body.unpack("CZ*Z*Z*Z*SCCCCCCCZ*C")
# translate type
case type
when 100 # d
server_type = 'Dedicated'
when 108 # l
server_type = 'Non-dedicated'
when 112 # p
server_type = 'SourceTV relay (proxy)'
else
server_type = "Unknown (#{type})"
end
info[:type] = server_type
# translate environment
case env
when 108 # l
server_env = 'Linux'
when 119 # w
server_env = 'Windows'
when 109 # m
when 111 # o
server_env = 'Mac'
else
server_env = "Unknown (#{env})"
end
info[:environment] = server_env
# translate visibility
case vis
when 0
server_vis = 'public'
when 1
server_vis = 'private'
else
server_vis = "Unknown (#{vis})"
end
info[:visibility] = server_vis
# translate VAC
case vac
when 0
server_vac = 'unsecured'
when 1
server_vac = 'secured'
else
server_vac = "Unknown (#{vac})"
end
info[:VAC] = server_vac
# format players/max
info[:players] = "#{players}/#{players_max}"
# TODO: parse EDF
info
end
end
end
end