lib/rex/proto/kerberos/model/pre_auth_pac_options.rb
module Rex
module Proto
module Kerberos
module Model
# This class is a representation of a PA-PAC-OPTIONS, which specifies
# explicitly requested options in the PAC as defined in
# https://learn.microsoft.com/fr-fr/openspecs/windows_protocols/ms-kile/99721a01-c859-48d1-8310-ec1bab9b2838
# and
# https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-sfu/aeecfd82-a5e4-474c-92ab-8df9022cf955
class PreAuthPacOptions < Element
# @!attribute flags
# @return [Integer] The PA-PAC-OPTIONS flags
attr_accessor :flags
# Decodes the Rex::Proto::Kerberos::Model::PreAuthPacOptions from an input
#
# @param input [String, OpenSSL::ASN1::ASN1Data] the input to decode from
# @return [self] if decoding succeeds
# @raise [Rex::Proto::Kerberos::Model::Error::KerberosDecodingError] if decoding doesn't succeed
def decode(input)
case input
when String
decode_string(input)
when OpenSSL::ASN1::ASN1Data
decode_asn1(input)
else
raise ::Rex::Proto::Kerberos::Model::Error::KerberosDecodingError, 'Failed to decode PreAuthPacOptions, invalid input'
end
self
end
# Encodes the Rex::Proto::Kerberos::Model::PreAuthPacOptions into an ASN.1 String
#
# @return [String]
def encode
elems = []
elems << OpenSSL::ASN1::ASN1Data.new([encode_flags], 0, :CONTEXT_SPECIFIC)
seq = OpenSSL::ASN1::Sequence.new(elems)
seq.to_der
end
# Encodes the flags
#
# @return [OpenSSL::ASN1::BitString]
def encode_flags
OpenSSL::ASN1::BitString.new([flags.to_i].pack('N'))
end
# Decodes a Rex::Proto::Kerberos::Model::PreAuthPacOptions from an String
#
# @param input [String] the input to decode from
# @raise [Rex::Proto::Kerberos::Model::Error::KerberosDecodingError] if decoding doesn't succeed
def decode_string(input)
asn1 = OpenSSL::ASN1.decode(input)
decode_asn1(asn1)
rescue OpenSSL::ASN1::ASN1Error
raise Rex::Proto::Kerberos::Model::Error::KerberosDecodingError
end
# Decodes a Rex::Proto::Kerberos::Model::PreAuthPacOptions from an
# OpenSSL::ASN1::Sequence
#
# @param input [OpenSSL::ASN1::Sequence] the input to decode from
# @raise [Rex::Proto::Kerberos::Model::Error::KerberosDecodingError] if decoding doesn't succeed
def decode_asn1(input)
seq_values = input.value
seq_values.each do |val|
case val.tag
when 0
self.options = decode_flags(val)
else
raise ::Rex::Proto::Kerberos::Model::Error::KerberosDecodingError, 'Failed to decode PreAuthPacOptions SEQUENCE'
end
end
end
# Decodes the flags field
#
# @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
# @return [Integer]
def decode_flags(input)
input.value[0].value.unpack('N')[0]
end
end
end
end
end
end