Class: Rex::Proto::Kademlia::BootstrapResponse

Inherits:
Message
  • Object
show all
Defined in:
lib/rex/proto/kademlia/bootstrap_response.rb

Overview

A Kademlia bootstrap response message

Constant Summary collapse

BOOTSTRAP_PEER_SIZE =

The minimum size of a peer in a KADEMLIA2_BOOTSTRAP_RES message: peer ID (16-bytes), IP (4 bytes), UDP port (2 bytes), TCP port (2 bytes) and version (1 byte)

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Constants inherited from Message

Message::COMPRESSED_PACKET, Message::STANDARD_PACKET

Instance Attribute Summary collapse

Attributes inherited from Message

#body, #type

Class Method Summary collapse

Instance Method Summary collapse

Methods inherited from Message

#==, #to_str

Constructor Details

#initialize(peer_id, tcp_port, version, peers) ⇒ BootstrapResponse

Constructs a new bootstrap response



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# File 'lib/rex/proto/kademlia/bootstrap_response.rb', line 29

def initialize(peer_id, tcp_port, version, peers)
  @peer_id = peer_id
  @tcp_port = tcp_port
  @version = version
  @peers = peers
end

Instance Attribute Details

#peer_id ⇒ String (readonly) 



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# File 'lib/rex/proto/kademlia/bootstrap_response.rb', line 15

def peer_id
  @peer_id
end

#peers ⇒ Array<Hash<String, Object>> (readonly) 



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# File 'lib/rex/proto/kademlia/bootstrap_response.rb', line 21

def peers
  @peers
end

#tcp_port ⇒ Integer (readonly) 



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# File 'lib/rex/proto/kademlia/bootstrap_response.rb', line 17

def tcp_port
  @tcp_port
end

#version ⇒ Integer (readonly) 



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# File 'lib/rex/proto/kademlia/bootstrap_response.rb', line 19

def version
  @version
end

Class Method Details

.from_data(data) ⇒ BootstrapResponse

Builds a bootstrap response from given data



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# File 'lib/rex/proto/kademlia/bootstrap_response.rb', line 45

def self.from_data(data)
  message = Message.from_data(data)
  # abort if this isn't a valid response
  return unless message
  return unless message.type == BOOTSTRAP_RESPONSE
  return unless message.body.size >= 23
  bootstrap_peer_id = Rex::Proto::Kademlia.decode_peer_id(message.body.slice!(0, 16))
  bootstrap_tcp_port, bootstrap_version, num_peers = message.body.slice!(0, 5).unpack('vCv')
  # protocol says there are no peers and the body confirms this, so just return with no peers
  if num_peers == 0 && message.body.to_s.empty?
    peers = []
  else
    peers_data = message.body
    # peers data is too long/short, abort
    return if peers_data.size % BOOTSTRAP_PEER_SIZE != 0
    peers = []
    until peers_data.to_s.empty?
      peer_data = peers_data.slice!(0, BOOTSTRAP_PEER_SIZE)
      peer_id = Rex::Proto::Kademlia.decode_peer_id(peer_data.slice!(0, 16))
      ip, udp_port, tcp_port, version = peer_data.unpack('VvvC')
      peers << {
        id: peer_id,
        ip: Rex::Socket.addr_itoa(ip),
        tcp_port: tcp_port,
        udp_port: udp_port,
        version: version
      }
    end
  end
  BootstrapResponse.new(bootstrap_peer_id, bootstrap_tcp_port, bootstrap_version, peers)
end