metasploit-framework/lib/rex/proto/kerberos/model/ticket.rb

151 lines
4.8 KiB
Ruby

# -*- coding: binary -*-
module Rex
module Proto
module Kerberos
module Model
# This class provides a representation of a Kerberos ticket that helps
# a client authenticate to a service.
class Ticket < Element
# @!attribute tkt_vno
# @return [Fixnum] The ticket version number
attr_accessor :tkt_vno
# @!attribute realm
# @return [String] The realm that issued the ticket
attr_accessor :realm
# @!attribute sname
# @return [Rex::Proto::Kerberos::Model::PrincipalName] The name part of the server's identity
attr_accessor :sname
# @!attribute enc_part
# @return [Rex::Proto::Kerberos::Model::EncryptedData] The encrypted part of the ticket
attr_accessor :enc_part
# Decodes the Rex::Proto::Kerberos::Model::KrbError from an input
#
# @param input [String, OpenSSL::ASN1::ASN1Data] the input to decode from
# @return [self] if decoding succeeds
# @raise [RuntimeError] if decoding doesn't succeed
def decode(input)
case input
when String
decode_string(input)
when OpenSSL::ASN1::ASN1Data
decode_asn1(input)
else
raise ::RuntimeError, 'Failed to decode Ticket, invalid input'
end
self
end
def encode
elems = []
elems << OpenSSL::ASN1::ASN1Data.new([encode_tkt_vno], 0, :CONTEXT_SPECIFIC)
elems << OpenSSL::ASN1::ASN1Data.new([encode_realm], 1, :CONTEXT_SPECIFIC)
elems << OpenSSL::ASN1::ASN1Data.new([encode_sname], 2, :CONTEXT_SPECIFIC)
elems << OpenSSL::ASN1::ASN1Data.new([encode_enc_part], 3, :CONTEXT_SPECIFIC)
seq = OpenSSL::ASN1::Sequence.new(elems)
seq_asn1 = OpenSSL::ASN1::ASN1Data.new([seq], TICKET, :APPLICATION)
seq_asn1.to_der
end
private
# Encodes the tkt_vno field
#
# @return [OpenSSL::ASN1::Integer]
def encode_tkt_vno
bn = OpenSSL::BN.new(tkt_vno)
int = OpenSSL::ASN1::Integer(bn)
int
end
# Encodes the realm field
#
# @return [OpenSSL::ASN1::GeneralString]
def encode_realm
OpenSSL::ASN1::GeneralString.new(realm)
end
# Encodes the sname field
#
# @return [String]
def encode_sname
sname.encode
end
# Encodes the enc_part field
#
# @return [String]
def encode_enc_part
enc_part.encode
end
# Decodes a Rex::Proto::Kerberos::Model::Ticket from an String
#
# @param input [String] the input to decode from
def decode_string(input)
asn1 = OpenSSL::ASN1.decode(input)
decode_asn1(asn1)
end
# Decodes a Rex::Proto::Kerberos::Model::Ticket
#
# @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
# @raise [RuntimeError] if decoding doesn't succeed
def decode_asn1(input)
input.value[0].value.each do |val|
case val.tag
when 0
self.tkt_vno = decode_tkt_vno(val)
when 1
self.realm = decode_realm(val)
when 2
self.sname = decode_sname(val)
when 3
self.enc_part = decode_enc_part(val)
else
raise ::RuntimeError, 'Failed to decode Ticket SEQUENCE'
end
end
end
# Decodes the tkt_vno from an OpenSSL::ASN1::ASN1Data
#
# @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
# @return [Fixnum]
def decode_tkt_vno(input)
input.value[0].value.to_i
end
#
# @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
# @return [String]
def decode_realm(input)
input.value[0].value
end
# Decodes the sname field
#
# @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
# @return [Rex::Proto::Kerberos::Model::PrincipalName]
def decode_sname(input)
Rex::Proto::Kerberos::Model::PrincipalName.decode(input.value[0])
end
# Decodes the enc_part from an OpenSSL::ASN1::ASN1Data
#
# @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
# @return [Rex::Proto::Kerberos::Model::EncryptedData]
def decode_enc_part(input)
Rex::Proto::Kerberos::Model::EncryptedData.decode(input.value[0])
end
end
end
end
end
end