Add PreAuthEncTimeStamp#encode support

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

@@ -33,8 +33,16 @@ module Rex
               self
             end
 
+            # Encodes a Rex::Proto::Kerberos::Model::Field::PreAuthEncTimeStamp into an
+            # ASN.1 String
+            #
+            # @return [String]
             def encode
-              raise ::RuntimeError, 'EncryptedData encoding is not supported'
+              pa_time_stamp_asn1 = OpenSSL::ASN1::ASN1Data.new([encode_pa_time_stamp], 0, :CONTEXT_SPECIFIC)
+              pausec_asn1 = OpenSSL::ASN1::ASN1Data.new([encode_pausec], 1, :CONTEXT_SPECIFIC)
+              seq = OpenSSL::ASN1::Sequence.new([pa_time_stamp_asn1, pausec_asn1])
+
+              seq.to_der
             end
 
             # Decrypts a Rex::Proto::Kerberos::Model::Field::PreAuthEncTimeStamp
@@ -64,6 +72,23 @@ module Rex
 
             private
 
+            # Encodes the pa_time_stamp
+            #
+            # @return [OpenSSL::ASN1::GeneralizedTime]
+            def encode_pa_time_stamp
+              OpenSSL::ASN1::GeneralizedTime.new(pa_time_stamp)
+            end
+
+            # Encodes the pausec
+            #
+            # @return [OpenSSL::ASN1::Integer]
+            def encode_pausec
+              int_bn = OpenSSL::BN.new(pausec)
+              int = OpenSSL::ASN1::Integer(int_bn)
+
+              int
+            end
+
             # Decodes a Rex::Proto::Kerberos::Model::Field::PreAuthEncTimeStamp
             #
             # @param input [String] the input to decode from

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

@@ -148,4 +148,11 @@ describe Rex::Proto::Kerberos::Model::Field::PreAuthEncTimeStamp do
     end
   end
 
+  describe "#encode" do
+    it "encodes Rex::Proto::Kerberos::Model::Field::PreAuthEncTimeStamp correctly" do
+      pre_auth_enc_time_stamp.decode(time_stamp_raw)
+      expect(pre_auth_enc_time_stamp.encode).to eq(time_stamp_raw)
+    end
+  end
+
 end

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

@@ -50,7 +50,7 @@ describe Rex::Proto::Kerberos::Model::Field::PreAuthPacRequest do
   end
 
   describe "#encode" do
-    it "encodes Rex::Proto::Kerberos::Model::Type::EncryptedData correctly" do
+    it "encodes Rex::Proto::Kerberos::Model::Field::PreAuthPacRequest correctly" do
       pre_auth_pac_request.decode(pac_sample)
       expect(pre_auth_pac_request.encode).to eq(pac_sample)
     end