feat(crypto): shielded transaction API security enhancement

common/src/main/java/org/tron/common/parameter/CommonParameter.java

@@ -335,7 +335,7 @@ public class CommonParameter {
 
   @Getter
   @Setter
-  public boolean allowShieldedTransactionApi; // clearParam: true
+  public boolean allowShieldedTransactionApi; // clearParam: false
   @Getter
   @Setter
   public long blockNumForEnergyLimit;

framework/src/main/java/org/tron/core/config/args/Args.java

@@ -726,7 +726,7 @@ public static void applyConfigParams(
       logger.warn("Configuring [node.fullNodeAllowShieldedTransaction] will be deprecated. "
           + "Please use [node.allowShieldedTransactionApi] instead.");
     } else {
-      PARAMETER.allowShieldedTransactionApi = true;
+      PARAMETER.allowShieldedTransactionApi = false;
     }
 
     PARAMETER.zenTokenId = config.hasPath(ConfigKey.NODE_ZEN_TOKENID)

framework/src/main/java/org/tron/core/zen/ShieldedTRC20ParametersBuilder.java

@@ -14,6 +14,7 @@
 import org.tron.api.GrpcAPI;
 import org.tron.api.GrpcAPI.BytesMessage;
 import org.tron.api.GrpcAPI.ShieldedTRC20Parameters;
+import org.tron.common.math.StrictMathWrapper;
 import org.tron.common.utils.ByteArray;
 import org.tron.common.utils.ByteUtil;
 import org.tron.common.utils.Sha256Hash;
@@ -547,8 +548,8 @@ public void addSpend(
       byte[] anchor,
       byte[] path,
       long position) throws ZksnarkException {
+    valueBalance = StrictMathWrapper.addExact(valueBalance, note.getValue());
     spends.add(new SpendDescriptionInfo(expsk, note, anchor, path, position));
-    valueBalance += note.getValue();
   }
 
   public void addSpend(
@@ -558,8 +559,8 @@ public void addSpend(
       byte[] anchor,
       byte[] path,
       long position) {
+    valueBalance = StrictMathWrapper.addExact(valueBalance, note.getValue());
     spends.add(new SpendDescriptionInfo(expsk, note, alpha, anchor, path, position));
-    valueBalance += note.getValue();
   }
 
   public void addSpend(
@@ -570,23 +571,23 @@ public void addSpend(
       byte[] anchor,
       byte[] path,
       long position) {
+    valueBalance = StrictMathWrapper.addExact(valueBalance, note.getValue());
     spends.add(new SpendDescriptionInfo(ak, nsk, note, alpha, anchor, path, position));
-    valueBalance += note.getValue();
   }
 
   public void addOutput(byte[] ovk, PaymentAddress to, long value, byte[] memo)
       throws ZksnarkException {
     Note note = new Note(to, value);
     note.setMemo(memo);
+    valueBalance = StrictMathWrapper.subtractExact(valueBalance, value);
     receives.add(new ReceiveDescriptionInfo(ovk, note));
-    valueBalance -= value;
   }
 
   public void addOutput(byte[] ovk, DiversifierT d, byte[] pkD, long value, byte[] r, byte[] memo) {
     Note note = new Note(d, pkD, value, r);
     note.setMemo(memo);
+    valueBalance = StrictMathWrapper.subtractExact(valueBalance, value);
     receives.add(new ReceiveDescriptionInfo(ovk, note));
-    valueBalance -= value;
   }
 
   public static class SpendDescriptionInfo {

framework/src/main/java/org/tron/core/zen/ZenTransactionBuilder.java

@@ -10,6 +10,7 @@
 import lombok.Setter;
 import lombok.extern.slf4j.Slf4j;
 import org.apache.commons.lang3.ArrayUtils;
+import org.tron.common.math.StrictMathWrapper;
 import org.tron.common.utils.ByteArray;
 import org.tron.common.zksnark.IncrementalMerkleVoucherContainer;
 import org.tron.common.zksnark.JLibrustzcash;
@@ -66,17 +67,17 @@ public ZenTransactionBuilder() {
   }
 
   public void addSpend(SpendDescriptionInfo spendDescriptionInfo) {
+    valueBalance = StrictMathWrapper.addExact(valueBalance, spendDescriptionInfo.note.getValue());
     spends.add(spendDescriptionInfo);
-    valueBalance += spendDescriptionInfo.note.getValue();
   }
 
   public void addSpend(
       ExpandedSpendingKey expsk,
       Note note,
       byte[] anchor,
       IncrementalMerkleVoucherContainer voucher) throws ZksnarkException {
+    valueBalance = StrictMathWrapper.addExact(valueBalance, note.getValue());
     spends.add(new SpendDescriptionInfo(expsk, note, anchor, voucher));
-    valueBalance += note.getValue();
   }
 
   public void addSpend(
@@ -85,8 +86,8 @@ public void addSpend(
       byte[] alpha,
       byte[] anchor,
       IncrementalMerkleVoucherContainer voucher) {
+    valueBalance = StrictMathWrapper.addExact(valueBalance, note.getValue());
     spends.add(new SpendDescriptionInfo(expsk, note, alpha, anchor, voucher));
-    valueBalance += note.getValue();
   }
 
   public void addSpend(
@@ -97,23 +98,23 @@ public void addSpend(
       byte[] alpha,
       byte[] anchor,
       IncrementalMerkleVoucherContainer voucher) {
+    valueBalance = StrictMathWrapper.addExact(valueBalance, note.getValue());
     spends.add(new SpendDescriptionInfo(ak, nsk, ovk, note, alpha, anchor, voucher));
-    valueBalance += note.getValue();
   }
 
   public void addOutput(byte[] ovk, PaymentAddress to, long value, byte[] memo)
       throws ZksnarkException {
     Note note = new Note(to, value);
     note.setMemo(memo);
+    valueBalance = StrictMathWrapper.subtractExact(valueBalance, value);
     receives.add(new ReceiveDescriptionInfo(ovk, note));
-    valueBalance -= value;
   }
 
   public void addOutput(byte[] ovk, DiversifierT d, byte[] pkD, long value, byte[] r, byte[] memo) {
     Note note = new Note(d, pkD, value, r);
     note.setMemo(memo);
+    valueBalance = StrictMathWrapper.subtractExact(valueBalance, value);
     receives.add(new ReceiveDescriptionInfo(ovk, note));
-    valueBalance -= value;
   }
 
   public void setTransparentInput(byte[] address, long value) {

framework/src/main/resources/config.conf

@@ -178,7 +178,13 @@ node {
 
   minParticipationRate = 15
 
-  # allowShieldedTransactionApi = true
+  # WARNING: Some shielded transaction APIs require sending private keys as parameters.
+  # Calling these APIs on untrusted or remote nodes may leak your private keys.
+  # It is recommended to invoke them locally for development and testing.
+  # To opt in, set: allowShieldedTransactionApi = true
+  # Migration: the legacy key node.fullNodeAllowShieldedTransaction is still supported
+  # but deprecated; please migrate to node.allowShieldedTransactionApi.
+  # allowShieldedTransactionApi = false
 
   # openPrintLog = true
 

framework/src/test/java/org/tron/core/ShieldedTRC20BuilderTest.java

@@ -9,6 +9,7 @@
 import org.apache.commons.lang3.ArrayUtils;
 import org.apache.commons.lang3.tuple.Pair;
 import org.bouncycastle.util.encoders.Hex;
+import org.junit.AfterClass;
 import org.junit.Assert;
 import org.junit.BeforeClass;
 import org.junit.Ignore;
@@ -73,9 +74,18 @@ public class ShieldedTRC20BuilderTest extends BaseTest {
   VerifyTransferProof transferContract = new VerifyTransferProof();
   VerifyBurnProof burnContract = new VerifyBurnProof();
 
+  private static boolean origShieldedApi;
+
   @BeforeClass
   public static void initZksnarkParams() {
     ZksnarkInitService.librustzcashInitZksnarkParams();
+    origShieldedApi = Args.getInstance().allowShieldedTransactionApi;
+    Args.getInstance().allowShieldedTransactionApi = true;
+  }
+
+  @AfterClass
+  public static void restoreShieldedApi() {
+    Args.getInstance().allowShieldedTransactionApi = origShieldedApi;
   }
 
   @Ignore

framework/src/test/java/org/tron/core/actuator/ShieldedTransferActuatorTest.java

@@ -1157,6 +1157,9 @@ public void publicAddressToShieldNoteValueFailure() {
       actuator.validate();
       actuator.execute(ret);
       Assert.assertTrue(false);
+    } catch (ArithmeticException e) {
+      // StrictMathWrapper.subtractExact throws ArithmeticException on overflow
+      Assert.assertTrue(true);
     } catch (ContractValidateException e) {
       Assert.assertTrue(e instanceof ContractValidateException);
       Assert.assertEquals("librustzcashSaplingFinalCheck error", e.getMessage());
@@ -1346,5 +1349,58 @@ public void shieldAddressToPublic() {
       Assert.assertTrue(false);
     }
   }
+
+  /**
+   * Test that shielded transfer transaction validation works even when
+   * allowShieldedTransactionApi is disabled. This verifies that the API flag
+   * only gates wallet/helper APIs, not the core transaction validation logic.
+   */
+  @Test
+  public void shieldedTransferValidationWorksWhenApiDisabled() {
+    boolean orig = Args.getInstance().isAllowShieldedTransactionApi();
+    // Disable the shielded API (this should NOT affect transaction validation)
+    Args.getInstance().setAllowShieldedTransactionApi(false);
+
+    dbManager.getDynamicPropertiesStore().saveAllowShieldedTransaction(1);
+    dbManager.getDynamicPropertiesStore().saveTotalShieldedPoolValue(AMOUNT);
+
+    try {
+      ZenTransactionBuilder builder = new ZenTransactionBuilder(wallet);
+      SpendingKey sk = SpendingKey.random();
+      ExpandedSpendingKey expsk = sk.expandedSpendingKey();
+      PaymentAddress address = sk.defaultAddress();
+      Note note = new Note(address, AMOUNT);
+      IncrementalMerkleVoucherContainer voucher = createSimpleMerkleVoucherContainer(note.cm());
+      byte[] anchor = voucher.root().getContent().toByteArray();
+      dbManager.getMerkleContainer()
+          .putMerkleTreeIntoStore(anchor, voucher.getVoucherCapsule().getTree());
+      builder.addSpend(expsk, note, anchor, voucher);
+
+      addZeroValueOutputNote(builder);
+
+      long fee = dbManager.getDynamicPropertiesStore().getShieldedTransactionCreateAccountFee();
+      String addressNotExist =
+          Wallet.getAddressPreFixString() + "8ba2aaae540c642e44e3bed5522c63bbc21f0000";
+
+      builder.setTransparentOutput(ByteArray.fromHexString(addressNotExist), AMOUNT - fee);
+
+      TransactionCapsule transactionCap = builder.build();
+      Contract contract =
+          transactionCap.getInstance().toBuilder().getRawDataBuilder().getContract(0);
+      ShieldedTransferActuator actuator = new ShieldedTransferActuator();
+      actuator.setChainBaseManager(dbManager.getChainBaseManager()).setContract(contract)
+          .setTx(transactionCap);
+
+      // Validation should succeed even when API is disabled
+      actuator.validate();
+    } catch (ContractValidateException e) {
+      Assert.fail("Shielded transfer validation should not throw ContractValidateException: "
+          + e.getMessage());
+    } catch (Exception e) {
+      Assert.fail("Shielded transfer should not throw Exception: " + e.getMessage());
+    } finally {
+      Args.getInstance().setAllowShieldedTransactionApi(orig);
+    }
+  }
 }
 

framework/src/test/java/org/tron/core/config/args/ArgsTest.java

@@ -360,5 +360,14 @@ public void testConfigStorageDefaults() {
 
     Args.clearParam();
   }
+
+  @Test
+  public void testAllowShieldedTransactionApiDefault() {
+    Args.setParam(new String[]{}, TestConstants.TEST_CONF);
+    Assert.assertFalse(Args.getInstance().isAllowShieldedTransactionApi());
+    Args.getInstance().setAllowShieldedTransactionApi(true);
+    Assert.assertTrue(Args.getInstance().isAllowShieldedTransactionApi());
+    Args.getInstance().setAllowShieldedTransactionApi(false);
+  }
 }
 

framework/src/test/java/org/tron/core/services/RpcApiServicesTest.java

@@ -150,6 +150,7 @@ public class RpcApiServicesTest {
   public static void init() throws IOException {
     Args.setParam(new String[] {"-d", temporaryFolder.newFolder().toString()},
         TestConstants.TEST_CONF);
+    getInstance().allowShieldedTransactionApi = true;
     Assert.assertEquals(5, getInstance().getRpcMaxRstStream());
     Assert.assertEquals(10, getInstance().getRpcSecondsPerWindow());
     String OWNER_ADDRESS = Wallet.getAddressPreFixString()

framework/src/test/java/org/tron/core/services/http/CreateSpendAuthSigServletTest.java

@@ -8,7 +8,9 @@
 import java.io.UnsupportedEncodingException;
 import javax.annotation.Resource;
 import org.apache.http.client.methods.HttpPost;
+import org.junit.AfterClass;
 import org.junit.Assert;
+import org.junit.BeforeClass;
 import org.junit.Test;
 import org.springframework.mock.web.MockHttpServletRequest;
 import org.springframework.mock.web.MockHttpServletResponse;
@@ -18,6 +20,8 @@
 
 public class CreateSpendAuthSigServletTest extends BaseTest {
 
+  private static boolean origShieldedApi;
+
   static {
     Args.setParam(
             new String[]{
@@ -26,6 +30,17 @@ public class CreateSpendAuthSigServletTest extends BaseTest {
     );
   }
 
+  @BeforeClass
+  public static void enableShieldedApi() {
+    origShieldedApi = Args.getInstance().allowShieldedTransactionApi;
+    Args.getInstance().allowShieldedTransactionApi = true;
+  }
+
+  @AfterClass
+  public static void restoreShieldedApi() {
+    Args.getInstance().allowShieldedTransactionApi = origShieldedApi;
+  }
+
   @Resource
   private CreateSpendAuthSigServlet createSpendAuthSigServlet;
 

framework/src/test/java/org/tron/core/zksnark/MerkleContainerTest.java

@@ -3,7 +3,9 @@
 import com.google.protobuf.Any;
 import com.google.protobuf.ByteString;
 import javax.annotation.Resource;
+import org.junit.AfterClass;
 import org.junit.Assert;
+import org.junit.BeforeClass;
 import org.junit.Test;
 import org.tron.common.BaseTest;
 import org.tron.common.TestConstants;
@@ -38,10 +40,23 @@ public class MerkleContainerTest extends BaseTest {
   //  private static MerkleContainer merkleContainer;
 
 
+  private static boolean origShieldedApi;
+
   static {
     Args.setParam(new String[]{"-d", dbPath()}, TestConstants.TEST_CONF);
   }
 
+  @BeforeClass
+  public static void enableShieldedApi() {
+    origShieldedApi = Args.getInstance().allowShieldedTransactionApi;
+    Args.getInstance().allowShieldedTransactionApi = true;
+  }
+
+  @AfterClass
+  public static void restoreShieldedApi() {
+    Args.getInstance().allowShieldedTransactionApi = origShieldedApi;
+  }
+
   /*@Before
   public void init() {
     merkleContainer = MerkleContainer