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# -*- coding: binary -*-
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module Rex
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  module Proto
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    module Kerberos
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      module Model
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        # This class provides a representation of a Kerberos KDC-REP (response) data
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        # definition
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        class KdcResponse < Element
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          # @!attribute pvno
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          #   @return [Integer] The protocol version number
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          attr_accessor :pvno
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          # @!attribute msg_type
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          #   @return [Integer] The type of a protocol message
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          attr_accessor :msg_type
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          # @!attribute pa_data
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          #   @return [Array<Rex::Proto::Kerberos::Model::PreAuthDataEntry>,nil] An array of PreAuthDataEntry. nil if not present.
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          attr_accessor :pa_data
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          # @!attribute crealm
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          #   @return [String] The realm part of the client's principal identifier
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          attr_accessor :crealm
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          # @!attribute cname
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          #   @return [Rex::Proto::Kerberos::Model::PrincipalName] The name part of the client's principal identifier
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          attr_accessor :cname
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          # @!attribute ticket
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          #   @return [Rex::Proto::Kerberos::Model::Ticket] The issued ticket
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          attr_accessor :ticket
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          # @!attribute enc_part
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          #   @return [Rex::Proto::Kerberos::Model::EncryptedData] The encrypted part of the response
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          attr_accessor :enc_part
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          # Decodes the Rex::Proto::Kerberos::Model::KdcResponse from an input
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          #
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          # @param input [String, OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @return [self] if decoding succeeds
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          # @raise [Rex::Proto::Kerberos::Model::Error::KerberosDecodingError] if decoding doesn't succeed
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          def decode(input)
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            case input
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            when String
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              decode_string(input)
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            when OpenSSL::ASN1::ASN1Data
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              decode_asn1(input)
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            else
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              raise ::Rex::Proto::Kerberos::Model::Error::KerberosDecodingError, 'Failed to decode KdcResponse, invalid input'
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            end
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            self
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          end
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          # Rex::Proto::Kerberos::Model::KdcResponse encoding isn't supported
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          #
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          # @raise [NotImplementedError]
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          def encode
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            raise ::NotImplementedError, 'KdcResponse encoding not supported'
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          end
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          private
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          # Decodes a Rex::Proto::Kerberos::Model::KdcResponse from an String
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          #
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          # @param input [String] the input to decode from
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          def decode_string(input)
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            asn1 = OpenSSL::ASN1.decode(input)
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            decode_asn1(asn1)
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          end
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          # Decodes a Rex::Proto::Kerberos::Model::KdcResponse
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          #
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          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @raise [Rex::Proto::Kerberos::Model::Error::KerberosDecodingError] if decoding doesn't succeed
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          def decode_asn1(input)
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            input.value[0].value.each do |val|
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              case val.tag
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              when 0
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                self.pvno = decode_pvno(val)
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              when 1
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                self.msg_type = decode_msg_type(val)
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              when 2
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                self.pa_data = decode_pa_data(val)
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              when 3
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                self.crealm = decode_crealm(val)
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              when 4
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                self.cname = decode_cname(val)
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              when 5
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                self.ticket = decode_ticket(val)
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              when 6
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                self.enc_part = decode_enc_part(val)
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              else
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                raise ::Rex::Proto::Kerberos::Model::Error::KerberosDecodingError, "Failed to decode KDC-RESPONSE SEQUENCE (#{val.tag})"
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              end
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            end
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          end
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          # Decodes the pvno from an OpenSSL::ASN1::ASN1Data
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          #
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          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @return [Integer]
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          def decode_pvno(input)
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            input.value[0].value.to_i
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          end
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          # Decodes the msg_type from an OpenSSL::ASN1::ASN1Data
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          #
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          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @return [Integer]
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          def decode_msg_type(input)
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            input.value[0].value.to_i
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          end
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          # Decodes the pa_data field
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          #
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          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @return [Array<Rex::Proto::Kerberos::Model::PreAuthDataEntry>]
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          def decode_pa_data(input)
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            pre_auth = []
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            input.value[0].value.each do |pre_auth_data|
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              pre_auth << Rex::Proto::Kerberos::Model::PreAuthDataEntry.decode(pre_auth_data)
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            end
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            pre_auth
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          end
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          # Decodes the crealm field
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          #
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          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @return [String]
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          def decode_crealm(input)
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            input.value[0].value
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          end
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          # Decodes the cname field
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          #
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          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @return [Rex::Proto::Kerberos::Type::PrincipalName]
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          def decode_cname(input)
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            Rex::Proto::Kerberos::Model::PrincipalName.decode(input.value[0])
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          end
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          # Decodes the ticket field
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          #
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          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @return [Rex::Proto::Kerberos::Type::Ticket]
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          def decode_ticket(input)
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            Rex::Proto::Kerberos::Model::Ticket.decode(input.value[0])
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          end
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          # Decodes the enc_part
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          #
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          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
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          # @return [Rex::Proto::Kerberos::Model::EncryptedData]
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          def decode_enc_part(input)
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            Rex::Proto::Kerberos::Model::EncryptedData.decode(input.value[0])
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          end
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        end
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      end
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    end
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  end
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end
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