module HTTPX::Plugins::Proxy::Socks5::Packet

def authenticate(parameters)
  parameters.authenticate
end

def connect(uri)
  packet = [VERSION, CONNECT, 0].pack("C*")
  begin
    ip = IPAddr.new(uri.host)
    ipcode = ip.ipv6? ? IPV6 : IPV4
    packet << [ipcode].pack("C") << ip.hton
  rescue IPAddr::InvalidAddressError
    packet << [DOMAIN, uri.host.bytesize, uri.host].pack("CCA*")
  end
  packet << [uri.port].pack("n")
  packet
end

def negotiate(parameters)
  methods = [NOAUTH]
  methods << PASSWD if parameters.can_authenticate?
  methods.unshift(methods.size)
  methods.unshift(VERSION)
  methods.pack("C*")
end