#!/usr/bin/env python3 # Copyright (c) 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 various fingerprinting protections. If an stale block more than a month old or its header are requested by a peer, the node should pretend that it does not have it to avoid fingerprinting. """ import threading import time from test_framework.blocktools import (create_block, create_coinbase) from test_framework.mininode import ( CInv, NetworkThread, NodeConn, NodeConnCB, msg_headers, msg_block, msg_getdata, msg_getheaders, wait_until, ) from test_framework.test_framework import BitcoinTestFramework from test_framework.util import ( assert_equal, p2p_port) class P2PFingerprintTest(BitcoinTestFramework): def __init__(self): BitcoinTestFramework.__init__(self) # TODO When this asserts, you have probably backported bitcoin#11121, so you'll have to remove this constructor assert(not callable(getattr(BitcoinTestFramework(), "set_test_params", None))) self.set_test_params() def set_test_params(self): self.setup_clean_chain = True self.num_nodes = 1 # Build a chain of blocks on top of given one def build_chain(self, nblocks, prev_hash, prev_height, prev_median_time): blocks = [] for _ in range(nblocks): coinbase = create_coinbase(prev_height + 1) block_time = prev_median_time + 1 block = create_block(int(prev_hash, 16), coinbase, block_time) block.solve() blocks.append(block) prev_hash = block.hash prev_height += 1 prev_median_time = block_time return blocks # Send a getdata request for a given block hash def send_block_request(self, block_hash, node): msg = msg_getdata() msg.inv.append(CInv(2, block_hash)) # 2 == "Block" node.send_message(msg) # Send a getheaders request for a given single block hash def send_header_request(self, block_hash, node): msg = msg_getheaders() msg.hashstop = block_hash node.send_message(msg) # Check whether last block received from node has a given hash def last_block_equals(self, expected_hash, node): block_msg = node.last_message.get("block") return block_msg and block_msg.block.rehash() == expected_hash # Check whether last block header received from node has a given hash def last_header_equals(self, expected_hash, node): headers_msg = node.last_message.get("headers") return (headers_msg and headers_msg.headers and headers_msg.headers[0].rehash() == expected_hash) # Checks that stale blocks timestamped more than a month ago are not served # by the node while recent stale blocks and old active chain blocks are. # This does not currently test that stale blocks timestamped within the # last month but that have over a month's worth of work are also withheld. def run_test(self): node0 = NodeConnCB() connections = [] connections.append(NodeConn('127.0.0.1', p2p_port(0), self.nodes[0], node0)) node0.add_connection(connections[0]) NetworkThread().start() node0.wait_for_verack() # Set node time to 60 days ago self.nodes[0].setmocktime(int(time.time()) - 60 * 24 * 60 * 60) # Generating a chain of 10 blocks block_hashes = self.nodes[0].generate(nblocks=10) # Create longer chain starting 2 blocks before current tip height = len(block_hashes) - 2 block_hash = block_hashes[height - 1] block_time = self.nodes[0].getblockheader(block_hash)["mediantime"] + 1 new_blocks = self.build_chain(5, block_hash, height, block_time) # Force reorg to a longer chain node0.send_message(msg_headers(new_blocks)) node0.wait_for_getdata() for block in new_blocks: node0.send_and_ping(msg_block(block)) # Check that reorg succeeded assert_equal(self.nodes[0].getblockcount(), 13) stale_hash = int(block_hashes[-1], 16) # Check that getdata request for stale block succeeds self.send_block_request(stale_hash, node0) test_function = lambda: self.last_block_equals(stale_hash, node0) wait_until(test_function, timeout=3) # Check that getheader request for stale block header succeeds self.send_header_request(stale_hash, node0) test_function = lambda: self.last_header_equals(stale_hash, node0) wait_until(test_function, timeout=3) # Longest chain is extended so stale is much older than chain tip self.nodes[0].setmocktime(0) tip = self.nodes[0].generate(nblocks=1)[0] assert_equal(self.nodes[0].getblockcount(), 14) # Send getdata & getheaders to refresh last received getheader message block_hash = int(tip, 16) self.send_block_request(block_hash, node0) self.send_header_request(block_hash, node0) node0.sync_with_ping() # Request for very old stale block should now fail self.send_block_request(stale_hash, node0) time.sleep(3) assert not self.last_block_equals(stale_hash, node0) # Request for very old stale block header should now fail self.send_header_request(stale_hash, node0) time.sleep(3) assert not self.last_header_equals(stale_hash, node0) # Verify we can fetch very old blocks and headers on the active chain block_hash = int(block_hashes[2], 16) self.send_block_request(block_hash, node0) self.send_header_request(block_hash, node0) node0.sync_with_ping() self.send_block_request(block_hash, node0) test_function = lambda: self.last_block_equals(block_hash, node0) wait_until(test_function, timeout=3) self.send_header_request(block_hash, node0) test_function = lambda: self.last_header_equals(block_hash, node0) wait_until(test_function, timeout=3) if __name__ == '__main__': P2PFingerprintTest().main()