fix Client-/ServerCertificateTypeExtension handling on server side (#908)

The ServerCertificateTypeExtension was encoded wrongly. This PR fixes this.

Author: chbtt

TLS-Core/src/main/java/de/rub/nds/tlsattacker/core/protocol/preparator/extension/ClientCertificateTypeExtensionPreparator.java

@@ -13,6 +13,7 @@
 import de.rub.nds.tlsattacker.core.protocol.message.extension.ClientCertificateTypeExtensionMessage;
 import de.rub.nds.tlsattacker.core.protocol.serializer.extension.ExtensionSerializer;
 import de.rub.nds.tlsattacker.core.workflow.chooser.Chooser;
+import de.rub.nds.tlsattacker.transport.ConnectionEndType;
 
 public class ClientCertificateTypeExtensionPreparator
     extends ExtensionPreparator<ClientCertificateTypeExtensionMessage> {
@@ -30,7 +31,12 @@ public void prepareExtensionContent() {
         msg.setCertificateTypes(
             CertificateType.toByteArray(chooser.getConfig().getClientCertificateTypeDesiredTypes()));
         msg.setCertificateTypesLength(msg.getCertificateTypes().getValue().length);
-        msg.setIsClientMessage(chooser.getConfig().isClientCertificateTypeExtensionMessageState());
+
+        if (chooser.getTalkingConnectionEnd() == ConnectionEndType.CLIENT) {
+            msg.setIsClientMessage(true);
+        } else {
+            msg.setIsClientMessage(false);
+        }
     }
 
 }

TLS-Core/src/main/java/de/rub/nds/tlsattacker/core/protocol/preparator/extension/ServerCertificateTypeExtensionPreparator.java

@@ -13,6 +13,7 @@
 import de.rub.nds.tlsattacker.core.protocol.message.extension.ServerCertificateTypeExtensionMessage;
 import de.rub.nds.tlsattacker.core.protocol.serializer.extension.ExtensionSerializer;
 import de.rub.nds.tlsattacker.core.workflow.chooser.Chooser;
+import de.rub.nds.tlsattacker.transport.ConnectionEndType;
 
 public class ServerCertificateTypeExtensionPreparator
     extends ExtensionPreparator<ServerCertificateTypeExtensionMessage> {
@@ -30,7 +31,12 @@ public void prepareExtensionContent() {
         msg.setCertificateTypes(
             CertificateType.toByteArray(chooser.getConfig().getServerCertificateTypeDesiredTypes()));
         msg.setCertificateTypesLength(msg.getCertificateTypes().getValue().length);
-        msg.setIsClientMessage(chooser.getConfig().isClientCertificateTypeExtensionMessageState());
+
+        if (chooser.getTalkingConnectionEnd() == ConnectionEndType.CLIENT) {
+            msg.setIsClientMessage(true);
+        } else {
+            msg.setIsClientMessage(false);
+        }
     }
 
 }

TLS-Core/src/main/java/de/rub/nds/tlsattacker/core/protocol/serializer/extension/ClientCertificateTypeExtensionSerializer.java

@@ -11,6 +11,7 @@
 
 import de.rub.nds.tlsattacker.core.constants.ExtensionByteLength;
 import de.rub.nds.tlsattacker.core.protocol.message.extension.ClientCertificateTypeExtensionMessage;
+import java.util.Objects;
 
 public class ClientCertificateTypeExtensionSerializer
     extends ExtensionSerializer<ClientCertificateTypeExtensionMessage> {
@@ -24,12 +25,11 @@ public ClientCertificateTypeExtensionSerializer(ClientCertificateTypeExtensionMe
 
     @Override
     public byte[] serializeExtensionContent() {
-        if (msg.getCertificateTypesLength() != null) {
+        if (Objects.equals(msg.getIsClientMessage().getValue(), Boolean.TRUE)) {
             appendInt(msg.getCertificateTypesLength().getValue(), ExtensionByteLength.CERTIFICATE_TYPE_TYPE_LENGTH);
         }
         appendBytes(msg.getCertificateTypes().getValue());
 
         return getAlreadySerialized();
     }
-
 }

TLS-Core/src/main/java/de/rub/nds/tlsattacker/core/protocol/serializer/extension/ServerCertificateTypeExtensionSerializer.java

@@ -11,6 +11,7 @@
 
 import de.rub.nds.tlsattacker.core.constants.ExtensionByteLength;
 import de.rub.nds.tlsattacker.core.protocol.message.extension.ServerCertificateTypeExtensionMessage;
+import java.util.Objects;
 
 public class ServerCertificateTypeExtensionSerializer
     extends ExtensionSerializer<ServerCertificateTypeExtensionMessage> {
@@ -24,12 +25,11 @@ public ServerCertificateTypeExtensionSerializer(ServerCertificateTypeExtensionMe
 
     @Override
     public byte[] serializeExtensionContent() {
-        if (msg.getCertificateTypesLength() != null) {
+        if (Objects.equals(msg.getIsClientMessage().getValue(), Boolean.TRUE)) {
             appendInt(msg.getCertificateTypesLength().getValue(), ExtensionByteLength.CERTIFICATE_TYPE_TYPE_LENGTH);
         }
         appendBytes(msg.getCertificateTypes().getValue());
 
         return getAlreadySerialized();
     }
-
 }