Add support for PreAuthPacRequest#encode

lib/rex/proto/kerberos/model/field/pre_auth_pac_request.rb

@@ -31,12 +31,26 @@ module Rex
               self
             end
 
+            # Encodes a Rex::Proto::Kerberos::Model::Field::PreAuthPacRequest into an
+            # ASN.1 String
+            #
+            # @return [String]
             def encode
-              raise ::RuntimeError, 'PreAuthPacRequest encoding unsupported'
+              value_asn1 = OpenSSL::ASN1::ASN1Data.new([encode_value], 0, :CONTEXT_SPECIFIC)
+              seq = OpenSSL::ASN1::Sequence.new([value_asn1])
+
+              seq.to_der
             end
 
             private
 
+            # Encodes value attribute
+            #
+            # @return [OpenSSL::ASN1::Boolean]
+            def encode_value
+              OpenSSL::ASN1::Boolean.new(value)
+            end
+
             # Decodes a Rex::Proto::Kerberos::Model::Field::PreAuthPacRequest
             #
             # @param input [String] the input to decode from

lib/rex/proto/kerberos/model/type/encrypted_data.rb

@@ -36,7 +36,7 @@ module Rex
               self
             end
 
-            # Encodes a Rex::Proto::Kerberos::Model::Type::EncryptedData into an String
+            # Encodes a Rex::Proto::Kerberos::Model::Type::EncryptedData into an ASN.1 String
             #
             # @return [String]
             # @raise [RuntimeError] if encoding doesn't succeed

lib/rex/proto/kerberos/model/type/principal_name.rb

@@ -34,7 +34,8 @@ module Rex
               self
             end
 
-            # Encodes a Rex::Proto::Kerberos::Model::Type::PrincipalName into an String
+            # Encodes a Rex::Proto::Kerberos::Model::Type::PrincipalName into an
+            # ASN.1 String
             #
             # @return [String]
             def encode

spec/lib/rex/proto/kerberos/model/field/pre_auth_pac_request_spec.rb

@@ -49,4 +49,10 @@ describe Rex::Proto::Kerberos::Model::Field::PreAuthPacRequest do
     end
   end
 
+  describe "#encode" do
+    it "encodes Rex::Proto::Kerberos::Model::Type::EncryptedData correctly" do
+      pre_auth_pac_request.decode(pac_sample)
+      expect(pre_auth_pac_request.encode).to eq(pac_sample)
+    end
+  end
 end