# $Id$

# Copyright (C) 2007--2008  American Registry for Internet Numbers ("ARIN")
#
# Permission to use, copy, modify, and distribute this software for any
# purpose with or without fee is hereby granted, provided that the above
# copyright notice and this permission notice appear in all copies.
#
# THE SOFTWARE IS PROVIDED "AS IS" AND ARIN DISCLAIMS ALL WARRANTIES WITH
# REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
# AND FITNESS.  IN NO EVENT SHALL ARIN BE LIABLE FOR ANY SPECIAL, DIRECT,
# INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
# LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE
# OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
# PERFORMANCE OF THIS SOFTWARE.

""" ROA (Route Origin Authorization).

At the moment this is just the ASN.1 encoder.

This corresponds to draft-ietf-sidr-roa-format, which is a work in
progress, so this may need updating later.
"""

from POW._der import *

# draft-ietf-sidr-roa-format-02 2.1.3.2 specifies:
#
#      RouteOriginAttestation ::= SEQUENCE { 
#         version [0] INTEGER DEFAULT 0, 
#         asID  ASID, 
#         exactMatch BOOLEAN,
#         ipAddrBlocks ROAIPAddrBlocks } 
#     
#      ASID ::= INTEGER 
#       
#      ROAIPAddrBlocks ::= SEQUENCE of ROAIPAddressFamily 
#       
#      ROAIPAddressFamily ::= SEQUENCE { 
#         addressFamily OCTET STRING (SIZE (2..3)), 
#         addresses SEQUENCE OF IPAddress } 
#    
#      IPAddress ::= BIT STRING 
#
# ... but we now implement the new format that will supposedly appear
# in the upcoming draft-ietf-sidr-roa-format-03:
#
#      RouteOriginAttestation ::= SEQUENCE {
#         version [0] INTEGER DEFAULT 0,
#         asID  ASID,
#         ipAddrBlocks SEQUENCE OF ROAIPAddressFamily }
#
#      ASID ::= INTEGER
#
#      ROAIPAddressFamily ::= SEQUENCE {
#         addressFamily OCTET STRING (SIZE (2..3)),
#         addresses SEQUENCE OF ROAIPAddress }
#
#      ROAIPAddress ::= {
#         address IPAddress,
#         maxLength INTEGER OPTIONAL }
#    
#      IPAddress ::= BIT STRING 

class ROAIPAddress(Sequence):
  def __init__(self, optional=0, default=''):
    self.address = BitString()
    self.maxLength = Integer(1)
    contents = [ self.address, self.maxLength ]
    Sequence.__init__(self, contents, optional, default)

class ROAIPAddresses(SequenceOf):
  def __init__(self, optional=0, default=''):
    SequenceOf.__init__(self, ROAIPAddress, optional, default)

class ROAIPAddressFamily(Sequence):
  def __init__(self, optional=0, default=''):
    self.addressFamily = OctetString()
    self.addresses = ROAIPAddresses()
    contents = [ self.addressFamily, self.addresses ]
    Sequence.__init__(self, contents, optional, default)

class ROAIPAddressFamilies(SequenceOf):
  def __init__(self, optional=0, default=''):
    SequenceOf.__init__(self,  ROAIPAddressFamily, optional, default)
 
class RouteOriginAttestation(Sequence):
  def __init__(self, optional=0, default=''):
    self.version = Integer()
    self.explicitVersion = Explicit(CLASS_CONTEXT, FORM_CONSTRUCTED, 0, self.version, 0, 'oAMCAQA=')
    self.asID = Integer()
    self.ipAddrBlocks = ROAIPAddressFamilies()
    contents = [ self.explicitVersion, self.asID, self.ipAddrBlocks ]
    Sequence.__init__(self, contents, optional, default)