1 files changed, 101 insertions, 0 deletions
diff --git a/test/functional/p2p_invalid_block.py b/test/functional/p2p_invalid_block.py
new file mode 100755
index 0000000000..e1f328ba77
--- /dev/null
+++ b/test/functional/p2p_invalid_block.py
@@ -0,0 +1,101 @@
+#!/usr/bin/env python3
+# Copyright (c) 2015-2017 The Bitcoin Core developers
+# Distributed under the MIT software license, see the accompanying
+# file COPYING or http://www.opensource.org/licenses/mit-license.php.
+"""Test node responses to invalid blocks.
+
+In this test we connect to one node over p2p, and test block requests:
+1) Valid blocks should be requested and become chain tip.
+2) Invalid block with duplicated transaction should be re-requested.
+3) Invalid block with bad coinbase value should be rejected and not
+re-requested.
+"""
+import copy
+
+from test_framework.blocktools import create_block, create_coinbase, create_transaction
+from test_framework.messages import COIN
+from test_framework.mininode import network_thread_start, P2PDataStore
+from test_framework.test_framework import BitcoinTestFramework
+from test_framework.util import assert_equal
+
+class InvalidBlockRequestTest(BitcoinTestFramework):
+    def set_test_params(self):
+        self.num_nodes = 1
+        self.setup_clean_chain = True
+        self.extra_args = [["-whitelist=127.0.0.1"]]
+
+    def run_test(self):
+        # Add p2p connection to node0
+        node = self.nodes[0]  # convenience reference to the node
+        node.add_p2p_connection(P2PDataStore())
+
+        network_thread_start()
+        node.p2p.wait_for_verack()
+
+        best_block = node.getblock(node.getbestblockhash())
+        tip = int(node.getbestblockhash(), 16)
+        height = best_block["height"] + 1
+        block_time = best_block["time"] + 1
+
+        self.log.info("Create a new block with an anyone-can-spend coinbase")
+
+        height = 1
+        block = create_block(tip, create_coinbase(height), block_time)
+        block.solve()
+        # Save the coinbase for later
+        block1 = block
+        tip = block.sha256
+        node.p2p.send_blocks_and_test([block1], node, True)
+
+        self.log.info("Mature the block.")
+        node.generate(100)
+
+        best_block = node.getblock(node.getbestblockhash())
+        tip = int(node.getbestblockhash(), 16)
+        height = best_block["height"] + 1
+        block_time = best_block["time"] + 1
+
+        # Use merkle-root malleability to generate an invalid block with
+        # same blockheader.
+        # Manufacture a block with 3 transactions (coinbase, spend of prior
+        # coinbase, spend of that spend).  Duplicate the 3rd transaction to
+        # leave merkle root and blockheader unchanged but invalidate the block.
+        self.log.info("Test merkle root malleability.")
+
+        block2 = create_block(tip, create_coinbase(height), block_time)
+        block_time += 1
+
+        # b'0x51' is OP_TRUE
+        tx1 = create_transaction(block1.vtx[0], 0, b'\x51', 50 * COIN)
+        tx2 = create_transaction(tx1, 0, b'\x51', 50 * COIN)
+
+        block2.vtx.extend([tx1, tx2])
+        block2.hashMerkleRoot = block2.calc_merkle_root()
+        block2.rehash()
+        block2.solve()
+        orig_hash = block2.sha256
+        block2_orig = copy.deepcopy(block2)
+
+        # Mutate block 2
+        block2.vtx.append(tx2)
+        assert_equal(block2.hashMerkleRoot, block2.calc_merkle_root())
+        assert_equal(orig_hash, block2.rehash())
+        assert(block2_orig.vtx != block2.vtx)
+
+        node.p2p.send_blocks_and_test([block2], node, False, False, 16, b'bad-txns-duplicate')
+
+        self.log.info("Test very broken block.")
+
+        block3 = create_block(tip, create_coinbase(height), block_time)
+        block_time += 1
+        block3.vtx[0].vout[0].nValue = 100 * COIN  # Too high!
+        block3.vtx[0].sha256 = None
+        block3.vtx[0].calc_sha256()
+        block3.hashMerkleRoot = block3.calc_merkle_root()
+        block3.rehash()
+        block3.solve()
+
+        node.p2p.send_blocks_and_test([block3], node, False, False, 16, b'bad-cb-amount')
+
+if __name__ == '__main__':
+    InvalidBlockRequestTest().main()