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# -*- coding: binary -*-
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# This class provides a representation for Kerberos pre authenticated
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# data
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#   https://datatracker.ietf.org/doc/html/rfc4120#section-5.2.5
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#   HostAddress     ::= SEQUENCE  {
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#           addr-type       [0] Int32,
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#           address         [1] OCTET STRING
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#    }
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class Rex::Proto::Kerberos::Model::HostAddress < Rex::Proto::Kerberos::Model::Element
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  # @!attribute type
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  #   @return [Rex::Proto::Kerberos::Model::AddressType,Integer] The address addr-type
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  attr_accessor :type
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  # @!attribute address
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  #   @return [String] The address value
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  attr_accessor :address
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  # Decodes a Rex::Proto::Kerberos::Model::HostAddress
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  #
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  # @param input [String, OpenSSL::ASN1::Sequence] 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::Sequence
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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 HostAddress, invalid input'
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    end
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    self
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  end
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  # Encodes a Rex::Proto::Kerberos::Model::HostAddress into an ASN.1 String
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  #
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  # @return [String]
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  def encode
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    to_asn1.to_der
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  end
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  # Encodes a Rex::Proto::Kerberos::Model::HostAddress into ASN.1
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  #
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  # @return [OpenSSL::ASN1::ASN1Data] The HostAddress ASN1Data
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  def to_asn1
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    type_asn1 = OpenSSL::ASN1::ASN1Data.new([encode_type], 0, :CONTEXT_SPECIFIC)
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    address_asn1 = OpenSSL::ASN1::ASN1Data.new([encode_address], 1, :CONTEXT_SPECIFIC)
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    seq = OpenSSL::ASN1::Sequence.new([type_asn1, address_asn1])
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    seq
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  end
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  private
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  # Encodes the type
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  #
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  # @return [OpenSSL::ASN1::Integer]
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  def encode_type
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    int_bn = OpenSSL::BN.new(type.to_s)
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    int = OpenSSL::ASN1::Integer.new(int_bn)
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    int
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  end
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  # Encodes the address
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  #
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  # @return [OpenSSL::ASN1::OctetString]
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  def encode_address
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    OpenSSL::ASN1::OctetString.new(address)
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  end
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  # Decodes a Rex::Proto::Kerberos::Model::HostAddress
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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::HostAddress from an
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  # OpenSSL::ASN1::Sequence
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  #
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  # @param input [OpenSSL::ASN1::Sequence] the input to decode from
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  def decode_asn1(input)
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    seq_values = input.value
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    self.type  = decode_asn1_type(seq_values[0])
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    self.address = decode_asn1_address(seq_values[1])
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  end
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  # Decodes the 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_asn1_type(input)
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    input.value[0].value.to_i
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  end
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  # Decodes the address 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_asn1_address(input)
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    input.value[0].value
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  end
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end
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