wallet copying

src/main/java/com/sparrowwallet/drongo/ExtendedPublicKey.java

@@ -111,6 +111,11 @@ public class ExtendedPublicKey {
         return true;
     }
 
+    public ExtendedPublicKey copy() {
+        //DeterministicKey is effectively final
+        return new ExtendedPublicKey(pubKey, Arrays.copyOf(parentFingerprint, parentFingerprint.length), pubKeyChildNumber);
+    }
+
     @Override
     public boolean equals(Object o) {
         if (this == o) return true;

src/main/java/com/sparrowwallet/drongo/KeyDerivation.java

@@ -9,7 +9,7 @@ import java.util.List;
 public class KeyDerivation {
     private final String masterFingerprint;
     private final String derivationPath;
-    private final List<ChildNumber> derivation;
+    private final transient List<ChildNumber> derivation;
 
     public KeyDerivation(String masterFingerprint, String derivationPath) {
         this.masterFingerprint = masterFingerprint;
@@ -73,6 +73,10 @@ public class KeyDerivation {
         return true;
     }
 
+    public KeyDerivation copy() {
+        return new KeyDerivation(masterFingerprint, derivationPath);
+    }
+
     public String toString() {
         return masterFingerprint + (derivationPath != null ? derivationPath.replace("m", "") : "");
     }

src/main/java/com/sparrowwallet/drongo/crypto/DeterministicKey.java

@@ -6,13 +6,14 @@ import com.sparrowwallet.drongo.protocol.Base58;
 import com.sparrowwallet.drongo.protocol.Sha256Hash;
 
 import java.util.Arrays;
+import java.util.Collections;
 import java.util.List;
 
 public class DeterministicKey extends ECKey {
     private final DeterministicKey parent;
     private final List<ChildNumber> childNumberPath;
     private final int depth;
-    private byte[] parentFingerprint; // 0 if this key is root node of key hierarchy
+    private final byte[] parentFingerprint; // 0 if this key is root node of key hierarchy
 
     /** 32 bytes */
     private final byte[] chainCode;
@@ -80,7 +81,7 @@ public class DeterministicKey extends ECKey {
      * the first child of that node.
      */
     public List<ChildNumber> getPath() {
-        return childNumberPath;
+        return Collections.unmodifiableList(childNumberPath);
     }
 
     public DeterministicKey getParent() {

src/main/java/com/sparrowwallet/drongo/policy/Miniscript.java

@@ -35,4 +35,8 @@ public class Miniscript {
             throw new IllegalArgumentException("Could not find multisig threshold in " + this);
         }
     }
+
+    public Miniscript copy() {
+        return new Miniscript(script);
+    }
 }

src/main/java/com/sparrowwallet/drongo/policy/Policy.java

@@ -55,4 +55,8 @@ public class Policy {
 
         throw new PolicyException("No standard policy for " + policyType + " policy with script type " + scriptType);
     }
+
+    public Policy copy() {
+        return new Policy(name, miniscript.copy());
+    }
 }

src/main/java/com/sparrowwallet/drongo/wallet/Keystore.java

@@ -4,10 +4,16 @@ import com.sparrowwallet.drongo.ExtendedPublicKey;
 import com.sparrowwallet.drongo.KeyDerivation;
 
 public class Keystore {
+    public static final String DEFAULT_LABEL = "Keystore 1";
+
     private String label;
     private KeyDerivation keyDerivation;
     private ExtendedPublicKey extendedPublicKey;
 
+    public Keystore() {
+        this(DEFAULT_LABEL);
+    }
+
     public Keystore(String label) {
         this.label = label;
     }
@@ -39,4 +45,15 @@ public class Keystore {
     public void setExtendedPublicKey(ExtendedPublicKey extendedPublicKey) {
         this.extendedPublicKey = extendedPublicKey;
     }
+
+    public Keystore copy() {
+        Keystore copy = new Keystore(label);
+        if(keyDerivation != null) {
+            copy.setKeyDerivation(keyDerivation.copy());
+        }
+        if(extendedPublicKey != null) {
+            copy.setExtendedPublicKey(extendedPublicKey.copy());
+        }
+        return copy;
+    }
 }

src/main/java/com/sparrowwallet/drongo/wallet/Wallet.java

@@ -5,14 +5,27 @@ import com.sparrowwallet.drongo.policy.PolicyType;
 import com.sparrowwallet.drongo.protocol.ScriptType;
 
 import java.util.ArrayList;
+import java.util.Collections;
 import java.util.List;
 
 public class Wallet {
+
     private PolicyType policyType;
     private ScriptType scriptType;
     private Policy defaultPolicy;
     private List<Keystore> keystores = new ArrayList<>();
 
+    public Wallet() {
+
+    }
+
+    public Wallet(PolicyType policyType, ScriptType scriptType) {
+        this.policyType = policyType;
+        this.scriptType = scriptType;
+        this.keystores = Collections.singletonList(new Keystore());
+        this.defaultPolicy = Policy.getPolicy(policyType, scriptType, keystores, null);
+    }
+
     public PolicyType getPolicyType() {
         return policyType;
     }
@@ -44,4 +57,15 @@ public class Wallet {
     public void setKeystores(List<Keystore> keystores) {
         this.keystores = keystores;
     }
+
+    public Wallet copy() {
+        Wallet copy = new Wallet();
+        copy.setPolicyType(policyType);
+        copy.setScriptType(scriptType);
+        copy.setDefaultPolicy(defaultPolicy.copy());
+        for(Keystore keystore : keystores) {
+            copy.getKeystores().add(keystore.copy());
+        }
+        return copy;
+    }
 }

src/main/java/module-info.java

@@ -1,4 +1,4 @@
-module com.sparrowwallet.drongo {
+open module com.sparrowwallet.drongo {
     requires org.bouncycastle.provider;
     requires slf4j.api;
     exports com.sparrowwallet.drongo;