Fix Monero address validation (#1652)

Add a CryptonoteAddressValidator and tests
The current implementation accepts valid standard addresses and
subaddresses on the basis of valid Base58 characters and length.
Verification of the address checksum is pending

assets/src/main/java/bisq/asset/CryptonoteAddressValidator.java

@@ -0,0 +1,55 @@
+/*
+ * This file is part of Bisq.
+ *
+ * Bisq is free software: you can redistribute it and/or modify it
+ * under the terms of the GNU Affero General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or (at
+ * your option) any later version.
+ *
+ * Bisq is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE. See the GNU Affero General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Affero General Public License
+ * along with Bisq. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package bisq.asset;
+
+/**
+ * {@link AddressValidator} for Base58-encoded Cryptonote addresses.
+ *
+ * @author Chris Beams
+ * @since 0.7.0
+ */
+public class CryptonoteAddressValidator implements AddressValidator {
+
+    private final String prefix;
+    private final String subAddressPrefix;
+    private final String validCharactersRegex = "^[1-9A-HJ-NP-Za-km-z]+$";
+
+    public CryptonoteAddressValidator(String prefix, String subAddressPrefix) {
+        this.prefix = prefix;
+        this.subAddressPrefix = subAddressPrefix;
+    }
+
+    @Override
+    public AddressValidationResult validate(String address) {
+        if (!address.matches(validCharactersRegex)) {
+            // Invalid characters
+            return AddressValidationResult.invalidStructure();
+        }
+
+        if (address.startsWith(prefix) && address.length() == 94 + prefix.length()) {
+            // Standard address
+            return AddressValidationResult.validAddress();
+        } else if (address.startsWith(subAddressPrefix) && address.length() == 94 + subAddressPrefix.length()) {
+            // Subaddress
+            return AddressValidationResult.validAddress();
+        } else {
+            // Integrated? Invalid? Doesn't matter
+            return AddressValidationResult.invalidStructure();
+        }
+    }
+}

assets/src/main/java/bisq/asset/coins/Monero.java

@@ -18,11 +18,11 @@
 package bisq.asset.coins;
 
 import bisq.asset.Coin;
-import bisq.asset.DefaultAddressValidator;
+import bisq.asset.CryptonoteAddressValidator;
 
 public class Monero extends Coin {
 
     public Monero() {
-        super("Monero", "XMR", new DefaultAddressValidator());
+        super("Monero", "XMR", new CryptonoteAddressValidator("4", "8"));
     }
 }

assets/src/test/java/bisq/asset/coins/MoneroTest.java

@@ -17,11 +17,28 @@
 
 package bisq.asset.coins;
 
-import bisq.asset.AbstractAssetWithDefaultValidatorTest;
+import bisq.asset.AbstractAssetTest;
+import org.junit.Test;
 
-public class MoneroTest extends AbstractAssetWithDefaultValidatorTest {
+public class MoneroTest extends AbstractAssetTest {
 
     public MoneroTest() {
         super(new Monero());
     }
+
+    @Test
+    public void testValidAddresses() {
+        assertValidAddress("4BJHitCigGy6giuYsJFP26KGkTKiQDJ6HJP1pan2ir2CCV8Twc2WWmo4fu1NVXt8XLGYAkjo5cJ3yH68Lfz9ZXEUJ9MeqPW");
+        assertValidAddress("46tM15KsogEW5MiVmBn7waPF8u8ZsB6aHjJk7BAv1wvMKfWhQ2h2so5BCJ9cRakfPt5BFo452oy3K8UK6L2u2v7aJ3Nf7P2");
+        assertValidAddress("86iQTnEqQ9mXJFvBvbY3KU5do5Jh2NCkpTcZsw3TMZ6oKNJhELvAreZFQ1p8EknRRTKPp2vg9fJvy47Q4ARVChjLMuUAFQJ");
+    }
+
+    @Test
+    public void testInvalidAddresses() {
+        assertInvalidAddress("");
+        assertInvalidAddress("4BJHitCigGy6giuYsJFP26KGkTKiQDJ6HJP1pan2ir2CCV8Twc2WWmo4fu1NVXt8XLGYAkjo5cJ3yH68Lfz9ZXEUJ9MeqP");
+        assertInvalidAddress("4BJHitCigGy6giuYsJFP26KGkTKiQDJ6HJP1pan2ir2CCV8Twc2WWmo4fu1NVXt8XLGYAkjo5cJ3yH68Lfz9ZXEUJ9MeqPWW");
+        assertInvalidAddress("86iQTnEqQ9mXJFvBvbY3KU5do5Jh2NCkpTcZsw3TMZ6oKNJhELvAreZFQ1p8EknRRTKPp2vg9fJvy47Q4ARVChjLMuUAFQ!");
+        assertInvalidAddress("76iQTnEqQ9mXJFvBvbY3KU5do5Jh2NCkpTcZsw3TMZ6oKNJhELvAreZFQ1p8EknRRTKPp2vg9fJvy47Q4ARVChjLMuUAFQJ");
+    }
 }