Transaction: make verify() a static helper method

core/src/main/java/org/bitcoinj/core/Block.java

@@ -684,8 +684,8 @@ public class Block extends Message {
         checkTransactions(height, flags);
         checkMerkleRoot();
         checkSigOps();
-        for (Transaction transaction : transactions)
+        for (Transaction tx : transactions)
-            transaction.verify();
+            Transaction.verify(params, tx);
         }
 
     /**

core/src/main/java/org/bitcoinj/core/Peer.java

@@ -713,7 +713,7 @@ public class Peer extends PeerSocketHandler {
 
     protected void processTransaction(final Transaction tx) throws VerificationException {
         // Check a few basic syntax issues to ensure the received TX isn't nonsense.
-        tx.verify();
+        tx.verify(params, tx);
         lock.lock();
         try {
             if (log.isDebugEnabled())

core/src/main/java/org/bitcoinj/core/Transaction.java

@@ -1727,59 +1727,6 @@ public class Transaction extends Message {
                         .orElse(null);
     }
 
-    /**
-     * <p>Checks the transaction contents for sanity, in ways that can be done in a standalone manner.
-     * Does <b>not</b> perform all checks on a transaction such as whether the inputs are already spent.
-     * Specifically this method verifies:</p>
-     *
-     * <ul>
-     *     <li>That there is at least one input and output.</li>
-     *     <li>That the serialized size is not larger than the max block size.</li>
-     *     <li>That no outputs have negative value.</li>
-     *     <li>That the outputs do not sum to larger than the max allowed quantity of coin in the system.</li>
-     *     <li>If the tx is a coinbase tx, the coinbase scriptSig size is within range. Otherwise that there are no
-     *     coinbase inputs in the tx.</li>
-     * </ul>
-     *
-     * @throws VerificationException
-     */
-    public void verify() throws VerificationException {
-        if (inputs.size() == 0 || outputs.size() == 0)
-            throw new VerificationException.EmptyInputsOrOutputs();
-        if (this.getMessageSize() > Block.MAX_BLOCK_SIZE)
-            throw new VerificationException.LargerThanMaxBlockSize();
-
-        HashSet<TransactionOutPoint> outpoints = new HashSet<>();
-        for (TransactionInput input : inputs) {
-            if (outpoints.contains(input.getOutpoint()))
-                throw new VerificationException.DuplicatedOutPoint();
-            outpoints.add(input.getOutpoint());
-        }
-
-        Coin valueOut = Coin.ZERO;
-        for (TransactionOutput output : outputs) {
-            Coin value = output.getValue();
-            if (value.signum() < 0)
-                throw new VerificationException.NegativeValueOutput();
-            try {
-                valueOut = valueOut.add(value);
-            } catch (ArithmeticException e) {
-                throw new VerificationException.ExcessiveValue();
-            }
-            if (params.network().exceedsMaxMoney(valueOut))
-                throw new VerificationException.ExcessiveValue();
-        }
-
-        if (isCoinBase()) {
-            if (inputs.get(0).getScriptBytes().length < 2 || inputs.get(0).getScriptBytes().length > 100)
-                throw new VerificationException.CoinbaseScriptSizeOutOfRange();
-        } else {
-            for (TransactionInput input : inputs)
-                if (input.isCoinBase())
-                    throw new VerificationException.UnexpectedCoinbaseInput();
-        }
-    }
-
     /**
      * <p>A transaction is time-locked if at least one of its inputs is non-final and it has a lock time. A transaction can
      * also have a relative lock time which this method doesn't tell. Use {@link #hasRelativeLockTime()} to find out.</p>
@@ -1899,4 +1846,59 @@ public class Transaction extends Message {
     public void setMemo(String memo) {
         this.memo = memo;
     }
+
+    /**
+     * <p>Checks the transaction contents for sanity, in ways that can be done in a standalone manner.
+     * Does <b>not</b> perform all checks on a transaction such as whether the inputs are already spent.
+     * Specifically this method verifies:</p>
+     *
+     * <ul>
+     *     <li>That there is at least one input and output.</li>
+     *     <li>That the serialized size is not larger than the max block size.</li>
+     *     <li>That no outputs have negative value.</li>
+     *     <li>That the outputs do not sum to larger than the max allowed quantity of coin in the system.</li>
+     *     <li>If the tx is a coinbase tx, the coinbase scriptSig size is within range. Otherwise that there are no
+     *     coinbase inputs in the tx.</li>
+     * </ul>
+     *
+     * @param params parameters for the verification rules
+     * @param tx     transaction to verify
+     * @throws VerificationException if at least one of the rules is violated
+     */
+    public static void verify(NetworkParameters params, Transaction tx) throws VerificationException {
+        if (tx.inputs.size() == 0 || tx.outputs.size() == 0)
+            throw new VerificationException.EmptyInputsOrOutputs();
+        if (tx.getMessageSize() > Block.MAX_BLOCK_SIZE)
+            throw new VerificationException.LargerThanMaxBlockSize();
+
+        HashSet<TransactionOutPoint> outpoints = new HashSet<>();
+        for (TransactionInput input : tx.inputs) {
+            if (outpoints.contains(input.getOutpoint()))
+                throw new VerificationException.DuplicatedOutPoint();
+            outpoints.add(input.getOutpoint());
+        }
+
+        Coin valueOut = Coin.ZERO;
+        for (TransactionOutput output : tx.outputs) {
+            Coin value = output.getValue();
+            if (value.signum() < 0)
+                throw new VerificationException.NegativeValueOutput();
+            try {
+                valueOut = valueOut.add(value);
+            } catch (ArithmeticException e) {
+                throw new VerificationException.ExcessiveValue();
+            }
+            if (params.network().exceedsMaxMoney(valueOut))
+                throw new VerificationException.ExcessiveValue();
+        }
+
+        if (tx.isCoinBase()) {
+            if (tx.inputs.get(0).getScriptBytes().length < 2 || tx.inputs.get(0).getScriptBytes().length > 100)
+                throw new VerificationException.CoinbaseScriptSizeOutOfRange();
+        } else {
+            for (TransactionInput input : tx.inputs)
+                if (input.isCoinBase())
+                    throw new VerificationException.UnexpectedCoinbaseInput();
+        }
+    }
 }

core/src/main/java/org/bitcoinj/protocols/payments/PaymentProtocol.java

@@ -345,7 +345,6 @@ public class PaymentProtocol {
             @Nullable List<Protos.Output> refundOutputs, @Nullable String memo, @Nullable byte[] merchantData) {
         Protos.Payment.Builder builder = Protos.Payment.newBuilder();
         for (Transaction transaction : transactions) {
-            transaction.verify();
             builder.addTransactions(ByteString.copyFrom(transaction.bitcoinSerialize()));
         }
         if (refundOutputs != null) {

core/src/main/java/org/bitcoinj/wallet/Wallet.java

@@ -2002,7 +2002,7 @@ public class Wallet extends BaseTaggableObject
         // spend against one of our other pending transactions.
         lock.lock();
         try {
-            tx.verify();
+            Transaction.verify(params, tx);
             // Ignore it if we already know about this transaction. Receiving a pending transaction never moves it
             // between pools.
             EnumSet<Pool> containingPools = getContainingPools(tx);
@@ -2782,7 +2782,7 @@ public class Wallet extends BaseTaggableObject
      * @throws VerificationException If transaction fails to verify
      */
     public boolean maybeCommitTx(Transaction tx) throws VerificationException {
-        tx.verify();
+        Transaction.verify(params, tx);
         lock.lock();
         try {
             if (pending.containsKey(tx.getTxId()))

core/src/test/java/org/bitcoinj/core/TransactionTest.java

@@ -87,21 +87,21 @@ public class TransactionTest {
     public void emptyOutputs() {
         Transaction tx = FakeTxBuilder.createFakeTx(TESTNET);
         tx.clearOutputs();
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test(expected = VerificationException.EmptyInputsOrOutputs.class)
     public void emptyInputs() {
         Transaction tx = FakeTxBuilder.createFakeTx(TESTNET);
         tx.clearInputs();
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test(expected = VerificationException.LargerThanMaxBlockSize.class)
     public void tooHuge() {
         Transaction tx = FakeTxBuilder.createFakeTx(TESTNET);
         tx.getInput(0).setScriptBytes(new byte[Block.MAX_BLOCK_SIZE]);
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test(expected = VerificationException.DuplicatedOutPoint.class)
@@ -110,14 +110,14 @@ public class TransactionTest {
         TransactionInput input = tx.getInput(0);
         input.setScriptBytes(new byte[1]);
         tx.addInput(input);
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test(expected = VerificationException.NegativeValueOutput.class)
     public void negativeOutput() {
         Transaction tx = FakeTxBuilder.createFakeTx(TESTNET);
         tx.getOutput(0).setValue(Coin.NEGATIVE_SATOSHI);
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test(expected = VerificationException.ExcessiveValue.class)
@@ -126,14 +126,14 @@ public class TransactionTest {
         Coin half = BitcoinNetwork.MAX_MONEY.divide(2).add(Coin.SATOSHI);
         tx.getOutput(0).setValue(half);
         tx.addOutput(half, ADDRESS);
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test(expected = VerificationException.UnexpectedCoinbaseInput.class)
     public void coinbaseInputInNonCoinbaseTX() {
         Transaction tx = FakeTxBuilder.createFakeTx(TESTNET);
         tx.addInput(Sha256Hash.ZERO_HASH, 0xFFFFFFFFL, new ScriptBuilder().data(new byte[10]).build());
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test(expected = VerificationException.CoinbaseScriptSizeOutOfRange.class)
@@ -141,7 +141,7 @@ public class TransactionTest {
         Transaction tx = FakeTxBuilder.createFakeTx(TESTNET);
         tx.clearInputs();
         tx.addInput(Sha256Hash.ZERO_HASH, 0xFFFFFFFFL, new ScriptBuilder().build());
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test(expected = VerificationException.CoinbaseScriptSizeOutOfRange.class)
@@ -150,7 +150,7 @@ public class TransactionTest {
         tx.clearInputs();
         TransactionInput input = tx.addInput(Sha256Hash.ZERO_HASH, 0xFFFFFFFFL, new ScriptBuilder().data(new byte[99]).build());
         assertEquals(101, input.getScriptBytes().length);
-        tx.verify();
+        Transaction.verify(TESTNET, tx);
     }
 
     @Test

core/src/test/java/org/bitcoinj/script/ScriptTest.java

@@ -392,7 +392,7 @@ public class ScriptTest {
             try {
                 Map<TransactionOutPoint, Script> scriptPubKeys = parseScriptPubKeys(test.get(0));
                 transaction = TESTNET.getDefaultSerializer().makeTransaction(ByteBuffer.wrap(ByteUtils.parseHex(test.get(1).asText().toLowerCase())));
-                transaction.verify();
+                Transaction.verify(TESTNET, transaction);
                 Set<VerifyFlag> verifyFlags = parseVerifyFlags(test.get(2).asText());
 
                 for (int i = 0; i < transaction.getInputs().size(); i++) {
@@ -433,7 +433,7 @@ public class ScriptTest {
 
             boolean valid = true;
             try {
-                transaction.verify();
+                Transaction.verify(TESTNET, transaction);
             } catch (VerificationException e) {
                 valid = false;
             }