Class: PacketGen::Header::IKE::SA

Inherits:

Payload

• Object
• Types::Fields
• Base
• Payload
• PacketGen::Header::IKE::SA

Defined in:

lib/packetgen/header/ike/sa.rb

Overview

This class handles Security Assocation payloads, as defined in RFC 7296 §3.3.

A SA payload contains a generic payload header (see Payload) and a set of SAProposal (#proposals field, which is a SAProposals object):

                     1                   2                   3
 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1 2 3 4 5 6 7 8 9 0 1
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
| Next Payload  |C|  RESERVED   |         Payload Length        |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+
|                                                               |
~                          <Proposals>                          ~
|                                                               |
+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+-+

Create a SA payload

# Create a IKE packet with a SA payload
pkt = PacketGen.gen('IP').add('UDP').add('IKE').add('IKE::SA')
# add a proposal. Protocol name is taken from SAProposal::PROTO_* constants
pkt.ike_sa.proposals << { num: 1, protocol: 'ESP' }
# add a transform to this proposal.
# type name is taken from Transform::TYPE_* constants.
# ID is taken from Transform::<TYPE>_* constants.
pkt.ike_sa.proposals.first.transforms << { type: 'ENCR', id: 'AES_CTR' }
# and finally, add an attribute to this transform (here, KEY_SIZE = 128 bits)
pkt.ike_sa.proposals[0].transforms[0].attributes << { type: 0x800e, value: 128 }
pkt.calc_length

Author:

• Sylvain Daubert

Since:

• 2.0.0

Constant Summary

PAYLOAD_TYPE =

Payload type number

Since:

• 2.0.0

33

Instance Attribute Summary

• #proposals ⇒ SAProposals

  Set of SA proposals.

Attributes inherited from Payload

#content, #critical, #flags, #hreserved, #length, #next

Attributes inherited from Base

#packet

Instance Method Summary

• #calc_length ⇒ Integer

  Compute length and set Payload#length field.

• #read(str) ⇒ self

  Populate object from a string.

Methods inherited from Payload

#base_read, #initialize

Methods inherited from Base

#added_to_packet, bind, bind_header, calculate_and_set_length, #header_id, inherited, #initialize, #ip_header, known_headers, #ll_header, #method_name, #parse?, #protocol_name, protocol_name

Methods inherited from Types::Fields

#[], #[]=, #bits_on, #body=, define_bit_fields_on, define_field, define_field_after, define_field_before, delete_field, #fields, fields, #force_binary, inherited, #initialize, #inspect, #is_optional?, #is_present?, #offset_of, #optional?, #optional_fields, #present?, remove_bit_fields_on, remove_field, #sz, #to_h, #to_s, update_field

Constructor Details

This class inherits a constructor from PacketGen::Header::IKE::Payload

Instance Attribute Details

#proposals ⇒ SAProposals

Set of SA proposals

Returns:

• (SAProposals)

# File 'lib/packetgen/header/ike/sa.rb', line 536

define_field_before :body, :proposals, SAProposals

Instance Method Details

#calc_length ⇒ Integer

Compute length and set Payload#length field

Returns:

• (Integer) —

  new length

Since:

• 2.0.0

# File 'lib/packetgen/header/ike/sa.rb', line 552

def calc_length
  proposals.each(&:calc_length)
  super
end

#read(str) ⇒ self

Populate object from a string

Parameters:

• str (String)

Returns:

• (self)

Since:

• 2.0.0

# File 'lib/packetgen/header/ike/sa.rb', line 541

def read(str)
  super
  hlen = self.class.new.sz
  plen = length - hlen
  proposals.read str[hlen, plen]
  body.read str[hlen + plen..-1]
  self
end