From 5787d7775f66f6c9edbdd09bfdb5baa96ed9b330 Mon Sep 17 00:00:00 2001
From: Evgenii Stratonikov <evgeniy@nspcc.ru>
Date: Fri, 3 Jul 2020 17:52:44 +0300
Subject: [PATCH] transaction: fail creating tx if there is additional data
 present

---
 pkg/core/transaction/transaction.go      |  4 ++++
 pkg/core/transaction/transaction_test.go | 20 ++++++++++++++++++++
 2 files changed, 24 insertions(+)

diff --git a/pkg/core/transaction/transaction.go b/pkg/core/transaction/transaction.go
index 657300fe9..c4e0fe539 100644
--- a/pkg/core/transaction/transaction.go
+++ b/pkg/core/transaction/transaction.go
@@ -275,6 +275,10 @@ func NewTransactionFromBytes(network netmode.Magic, b []byte) (*Transaction, err
 	if r.Err != nil {
 		return nil, r.Err
 	}
+	_ = r.ReadB()
+	if r.Err == nil {
+		return nil, errors.New("additional data after the transaction")
+	}
 	tx.feePerByte = tx.NetworkFee / int64(len(b))
 	return tx, nil
 }
diff --git a/pkg/core/transaction/transaction_test.go b/pkg/core/transaction/transaction_test.go
index 37cd3771b..fe2d38a55 100644
--- a/pkg/core/transaction/transaction_test.go
+++ b/pkg/core/transaction/transaction_test.go
@@ -71,6 +71,26 @@ func TestNew(t *testing.T) {
 	testserdes.EncodeDecodeBinary(t, tx, &Transaction{Network: netmode.UnitTestNet})
 }
 
+func TestNewTransactionFromBytes(t *testing.T) {
+	script := []byte{0x51}
+	tx := New(netmode.UnitTestNet, script, 1)
+	tx.NetworkFee = 123
+	data, err := testserdes.EncodeBinary(tx)
+	require.NoError(t, err)
+
+	// set cached fields
+	tx.Hash()
+	tx.FeePerByte()
+
+	tx1, err := NewTransactionFromBytes(netmode.UnitTestNet, data)
+	require.NoError(t, err)
+	require.Equal(t, tx, tx1)
+
+	data = append(data, 42)
+	_, err = NewTransactionFromBytes(netmode.UnitTestNet, data)
+	require.Error(t, err)
+}
+
 func TestEncodingTXWithNoScript(t *testing.T) {
 	_, err := testserdes.EncodeBinary(new(Transaction))
 	require.Error(t, err)