made field elements serialize to json

Author: ic0ns

src/main/java/de/rub/nds/protocol/crypto/ec/FieldElement.java

@@ -8,6 +8,7 @@
  */
 package de.rub.nds.protocol.crypto.ec;
 
+import com.fasterxml.jackson.annotation.JsonTypeInfo;
 import jakarta.xml.bind.annotation.XmlAccessType;
 import jakarta.xml.bind.annotation.XmlAccessorType;
 import java.io.Serializable;
@@ -22,6 +23,7 @@
  * All arithmetic operations are performed within the laws of the specified field.
  */
 @XmlAccessorType(XmlAccessType.FIELD)
+@JsonTypeInfo(use = JsonTypeInfo.Id.CLASS, include = JsonTypeInfo.As.PROPERTY, property = "@class")
 public abstract class FieldElement implements Serializable {
 
     /*
@@ -31,7 +33,13 @@ public abstract class FieldElement implements Serializable {
     private final BigInteger data;
     private final BigInteger modulus;
 
-    public FieldElement(BigInteger data, BigInteger modulus) {
+    /** Default constructor for JAXB. */
+    protected FieldElement() {
+        this.data = null;
+        this.modulus = null;
+    }
+
+    protected FieldElement(BigInteger data, BigInteger modulus) {
         this.data = data;
         this.modulus = modulus;
     }

src/main/java/de/rub/nds/protocol/crypto/ec/FieldElementF2m.java

@@ -35,6 +35,7 @@ public FieldElementF2m(BigInteger data, BigInteger modulus) {
         super(data, modulus);
     }
 
+    @SuppressWarnings("unused")
     private FieldElementF2m() {
         super(null, null);
     }

src/main/java/de/rub/nds/protocol/crypto/ec/FieldElementFp.java

@@ -18,6 +18,7 @@ public FieldElementFp(BigInteger data, BigInteger modulus) {
         super(data.mod(modulus), modulus);
     }
 
+    @SuppressWarnings("unused")
     private FieldElementFp() {
         super(null, null);
     }