Add the definitions for KERB-SUPERSEDED-BY-USER

Author: zeroSteiner

lib/rex/proto/kerberos/model.rb

@@ -51,7 +51,9 @@ module NameType
           NT_UID = 5
         end
 
-        # From padata - https://www.iana.org/assignments/kerberos-parameters/kerberos-parameters.xhtml
+        # See:
+        # * https://www.iana.org/assignments/kerberos-parameters/kerberos-parameters.xhtml#pre-authentication
+        # * https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-kile/ae60c948-fda8-45c2-b1d1-a71b484dd1f7
 
         module PreAuthType
           PA_TGS_REQ = 1
@@ -65,6 +67,7 @@ module PreAuthType
           PA_FOR_USER = 129
           PA_SUPPORTED_ETYPES = 165
           PA_PAC_OPTIONS = 167
+          KERB_SUPERSEDED_BY_USER = 170
         end
 
         module AuthorizationDataType

lib/rex/proto/kerberos/model/kerb_superseded_by_user.rb

@@ -0,0 +1,81 @@
+# -*- coding: binary -*-
+
+module Rex
+  module Proto
+    module Kerberos
+      module Model
+        # This class provides a representation of a Kerberos KERB-SUPERSEDED-BY-USER
+        # message as defined in [MS-KILE 2.2.13](https://learn.microsoft.com/en-us/openspecs/windows_protocols/ms-kile/79170b21-ad15-4a1b-99c4-84b3992d9e70).
+        class KerbSupersededByUser < Element
+
+          attr_accessor :principal_name
+
+          attr_accessor :realm
+
+          def ==(other)
+            realm == other.realm && principal_name == other.principal_name
+          end
+
+          def decode(input)
+            case input
+            when String
+              decode_string(input)
+            when OpenSSL::ASN1::Sequence
+              decode_asn1(input)
+            else
+              raise ::Rex::Proto::Kerberos::Model::Error::KerberosDecodingError, 'Failed to decode KerbSupersededByUser, invalid input'
+            end
+
+            self
+          end
+
+          def encode
+            principal_name_asn1 = OpenSSL::ASN1::ASN1Data.new([encode_principal_name], 1, :CONTEXT_SPECIFIC)
+            realm_asn1 = OpenSSL::ASN1::ASN1Data.new([encode_realm], 2, :CONTEXT_SPECIFIC)
+            seq = OpenSSL::ASN1::Sequence.new([principal_name_asn1, realm_asn1])
+
+            seq.to_der
+          end
+
+          private
+
+          def decode_string(input)
+            asn1 = OpenSSL::ASN1.decode(input)
+
+            decode_asn1(asn1)
+          end
+
+          # Decodes a Rex::Proto::Kerberos::Model::KerbSupersededByUser from an
+          # OpenSSL::ASN1::Sequence
+          #
+          # @param input [OpenSSL::ASN1::Sequence] the input to decode from
+          def decode_asn1(input)
+            seq_values = input.value
+            self.principal_name = decode_principal_name(seq_values[0])
+            self.realm = decode_realm(seq_values[1])
+          end
+
+         def decode_principal_name(input)
+           PrincipalName.decode(input.value[0])
+          end
+
+          # Decodes the realm from an OpenSSL::ASN1::ASN1Data
+          #
+          # @param input [OpenSSL::ASN1::ASN1Data] the input to decode from
+          # @return [Array<String>]
+          def decode_realm(input)
+            input.value[0].value
+          end
+
+          def encode_principal_name
+            self.principal_name.encode
+          end
+
+          def encode_realm
+            OpenSSL::ASN1::OctetString.new(self.realm)
+          end
+        end
+      end
+    end
+  end
+end

lib/rex/proto/kerberos/model/pre_auth_data_entry.rb

@@ -76,6 +76,9 @@ def decoded_value
             when Rex::Proto::Kerberos::Model::PreAuthType::PA_FOR_USER
               decoded = OpenSSL::ASN1.decode(self.value)
               PreAuthForUser.decode(decoded)
+            when Rex::Proto::Kerberos::Model::PreAuthType::KERB_SUPERSEDED_BY_USER
+              decoded = OpenSSL::ASN1.decode(self.value)
+              KerbSupersededByUser.decode(decoded)
             else
               # Unknown type - just ignore for now
             end