def _test() -> None:
import argparse
import signal
from p2p import ecies
from p2p import kademlia
from p2p.constants import ROPSTEN_BOOTNODES
from p2p.discovery import DiscoveryProtocol
from evm.chains.ropsten import RopstenChain, ROPSTEN_GENESIS_HEADER
from evm.db.backends.level import LevelDB
from tests.p2p.integration_test_helpers import FakeAsyncChainDB, LocalGethPeerPool
logging.basicConfig(level=logging.INFO, format='%(levelname)s: %(message)s')
logging.getLogger('p2p.chain.ChainSyncer').setLevel(logging.DEBUG)
parser = argparse.ArgumentParser()
parser.add_argument('-db', type=str, required=True)
parser.add_argument('-local-geth', action="store_true")
args = parser.parse_args()
loop = asyncio.get_event_loop()
chaindb = FakeAsyncChainDB(LevelDB(args.db))
chaindb.persist_header(ROPSTEN_GENESIS_HEADER)
privkey = ecies.generate_privkey()
if args.local_geth:
peer_pool = LocalGethPeerPool(ETHPeer, chaindb, RopstenChain.network_id, privkey)
discovery = None
else:
listen_host = '0.0.0.0'
listen_port = 30303
addr = kademlia.Address(listen_host, listen_port, listen_port)
discovery = DiscoveryProtocol(privkey, addr, ROPSTEN_BOOTNODES)
loop.run_until_complete(discovery.create_endpoint())
print("Bootstrapping discovery service...")
loop.run_until_complete(discovery.bootstrap())
peer_pool = PeerPool(ETHPeer, chaindb, RopstenChain.network_id, privkey, discovery)
asyncio.ensure_future(peer_pool.run())
downloader = ChainSyncer(chaindb, peer_pool)
# On ROPSTEN the discovery table is usually full of bad peers so we can't require too many
# peers in order to sync.
downloader.min_peers_to_sync = 1
async def run():
# downloader.run() will run in a loop until the SIGINT/SIGTERM handler triggers its cancel
# token, at which point it returns and we stop the pool and downloader.
await downloader.run()
await peer_pool.stop()
await downloader.stop()
if discovery is not None:
discovery.stop()
# Give any pending discovery tasks some time to finish.
await asyncio.sleep(2)
for sig in [signal.SIGINT, signal.SIGTERM]:
loop.add_signal_handler(sig, downloader.cancel_token.trigger)
loop.run_until_complete(run())
loop.close()
class Server(BaseService):
"""Server listening for incoming connections"""
logger = logging.getLogger("p2p.server.Server")
_tcp_listener = None
_udp_listener = None
peer_pool: PeerPool = None
def __init__(
self,
privkey: datatypes.PrivateKey,
port: int,
chain: AsyncChain,
chaindb: AsyncChainDB,
headerdb: 'BaseAsyncHeaderDB',
base_db: BaseDB,
network_id: int,
max_peers: int = DEFAULT_MAX_PEERS,
peer_class: Type[BasePeer] = ETHPeer,
peer_pool_class: Type[PeerPool] = PreferredNodePeerPool,
bootstrap_nodes: Tuple[Node, ...] = None,
token: CancelToken = None,
) -> None:
super().__init__(token)
self.headerdb = headerdb
self.chaindb = chaindb
self.chain = chain
self.base_db = base_db
self.privkey = privkey
self.port = port
self.network_id = network_id
self.peer_class = peer_class
self.peer_pool_class = peer_pool_class
self.max_peers = max_peers
self.bootstrap_nodes = bootstrap_nodes
self.upnp_service = UPnPService(port, token=self.cancel_token)
if not bootstrap_nodes:
self.logger.warn("Running with no bootstrap nodes")
async def _start_tcp_listener(self) -> None:
# TODO: Support IPv6 addresses as well.
self._tcp_listener = await asyncio.start_server(
self.receive_handshake,
host='0.0.0.0',
port=self.port,
)
async def _close_tcp_listener(self) -> None:
self._tcp_listener.close()
await self._tcp_listener.wait_closed()
async def _start_udp_listener(self, discovery: DiscoveryProtocol) -> None:
loop = asyncio.get_event_loop()
# TODO: Support IPv6 addresses as well.
self._udp_transport, _ = await loop.create_datagram_endpoint(
lambda: discovery,
local_addr=('0.0.0.0', self.port),
family=socket.AF_INET)
async def _close_udp_listener(self) -> None:
cast(asyncio.DatagramTransport, self._udp_transport).abort()
async def _close(self) -> None:
await asyncio.gather(self._close_tcp_listener(),
self._close_udp_listener())
def _make_syncer(self, peer_pool: PeerPool) -> BaseService:
# This method exists only so that ShardSyncer can provide a different implementation.
return FullNodeSyncer(self.chain, self.chaindb, self.base_db,
peer_pool, self.cancel_token)
def _make_peer_pool(self, discovery: DiscoveryProtocol) -> PeerPool:
# This method exists only so that ShardSyncer can provide a different implementation.
return self.peer_pool_class(
self.peer_class,
self.headerdb,
self.network_id,
self.privkey,
discovery,
max_peers=self.max_peers,
)
async def _run(self) -> None:
self.logger.info("Running server...")
mapped_external_ip = await self.upnp_service.add_nat_portmap()
if mapped_external_ip is None:
external_ip = '0.0.0.0'
else:
external_ip = mapped_external_ip
await self._start_tcp_listener()
self.logger.info(
"enode://%s@%s:%s",
self.privkey.public_key.to_hex()[2:],
external_ip,
self.port,
)
self.logger.info('network: %s', self.network_id)
self.logger.info('peers: max_peers=%s', self.max_peers)
addr = Address(external_ip, self.port, self.port)
self.discovery = DiscoveryProtocol(
self.privkey, addr, bootstrap_nodes=self.bootstrap_nodes)
await self._start_udp_listener(self.discovery)
self.peer_pool = self._make_peer_pool(self.discovery)
asyncio.ensure_future(self.discovery.bootstrap())
asyncio.ensure_future(self.peer_pool.run())
asyncio.ensure_future(self.upnp_service.run())
self.syncer = self._make_syncer(self.peer_pool)
await self.syncer.run()
async def _cleanup(self) -> None:
self.logger.info("Closing server...")
await asyncio.gather(
self.peer_pool.cancel(),
self.discovery.stop(),
)
await self._close()
async def receive_handshake(self, reader: asyncio.StreamReader,
writer: asyncio.StreamWriter) -> None:
expected_exceptions = (
TimeoutError,
PeerConnectionLost,
HandshakeFailure,
asyncio.IncompleteReadError,
)
try:
await self._receive_handshake(reader, writer)
except expected_exceptions as e:
self.logger.debug("Could not complete handshake: %s", e)
except OperationCancelled:
pass
except Exception as e:
self.logger.exception("Unexpected error handling handshake")
async def _receive_handshake(self, reader: asyncio.StreamReader,
writer: asyncio.StreamWriter) -> None:
msg = await self.wait(reader.read(ENCRYPTED_AUTH_MSG_LEN),
timeout=REPLY_TIMEOUT)
ip, socket, *_ = writer.get_extra_info("peername")
remote_address = Address(ip, socket)
self.logger.debug("Receiving handshake from %s", remote_address)
got_eip8 = False
try:
ephem_pubkey, initiator_nonce, initiator_pubkey = decode_authentication(
msg, self.privkey)
except DecryptionError:
# Try to decode as EIP8
got_eip8 = True
msg_size = big_endian_to_int(msg[:2])
remaining_bytes = msg_size - ENCRYPTED_AUTH_MSG_LEN + 2
msg += await self.wait(reader.read(remaining_bytes),
timeout=REPLY_TIMEOUT)
try:
ephem_pubkey, initiator_nonce, initiator_pubkey = decode_authentication(
msg, self.privkey)
except DecryptionError as e:
self.logger.debug("Failed to decrypt handshake: %s", e)
return
initiator_remote = Node(initiator_pubkey, remote_address)
responder = HandshakeResponder(initiator_remote, self.privkey,
got_eip8, self.cancel_token)
responder_nonce = secrets.token_bytes(HASH_LEN)
auth_ack_msg = responder.create_auth_ack_message(responder_nonce)
auth_ack_ciphertext = responder.encrypt_auth_ack_message(auth_ack_msg)
# Use the `writer` to send the reply to the remote
writer.write(auth_ack_ciphertext)
await self.wait(writer.drain())
# Call `HandshakeResponder.derive_shared_secrets()` and use return values to create `Peer`
aes_secret, mac_secret, egress_mac, ingress_mac = responder.derive_secrets(
initiator_nonce=initiator_nonce,
responder_nonce=responder_nonce,
remote_ephemeral_pubkey=ephem_pubkey,
auth_init_ciphertext=msg,
auth_ack_ciphertext=auth_ack_ciphertext)
# Create and register peer in peer_pool
peer = self.peer_class(
remote=initiator_remote,
privkey=self.privkey,
reader=reader,
writer=writer,
aes_secret=aes_secret,
mac_secret=mac_secret,
egress_mac=egress_mac,
ingress_mac=ingress_mac,
headerdb=self.headerdb,
network_id=self.network_id,
inbound=True,
)
if self.peer_pool.is_full:
peer.disconnect(DisconnectReason.too_many_peers)
else:
# We use self.wait() here as a workaround for
# https://github.com/ethereum/py-evm/issues/670.
await self.wait(self.do_handshake(peer))
async def do_handshake(self, peer: BasePeer) -> None:
await peer.do_p2p_handshake(),
await peer.do_sub_proto_handshake()
self._start_peer(peer)
def _start_peer(self, peer: BasePeer) -> None:
# This method exists only so that we can monkey-patch it in tests.
self.peer_pool.start_peer(peer)
class Server(BaseService):
"""Server listening for incoming connections"""
logger = logging.getLogger("p2p.server.Server")
_tcp_listener = None
_udp_listener = None
_nat_portmap_lifetime = 30 * 60
def __init__(self,
privkey: datatypes.PrivateKey,
port: int,
chain: AsyncChain,
chaindb: AsyncChainDB,
headerdb: 'BaseAsyncHeaderDB',
base_db: BaseDB,
network_id: int,
max_peers: int = DEFAULT_MAX_PEERS,
peer_class: Type[BasePeer] = ETHPeer,
peer_pool_class: Type[PeerPool] = PreferredNodePeerPool,
bootstrap_nodes: Tuple[Node, ...] = None,
token: CancelToken = None,
) -> None:
super().__init__(token)
self.headerdb = headerdb
self.chaindb = chaindb
self.chain = chain
self.base_db = base_db
self.privkey = privkey
self.port = port
self.network_id = network_id
self.peer_class = peer_class
self.peer_pool_class = peer_pool_class
self.max_peers = max_peers
self.bootstrap_nodes = bootstrap_nodes
if not bootstrap_nodes:
self.logger.warn("Running with no bootstrap nodes")
async def refresh_nat_portmap(self) -> None:
"""Run an infinite loop refreshing our NAT port mapping.
On every iteration we configure the port mapping with a lifetime of 30 minutes and then
sleep for that long as well.
"""
while self.is_running:
try:
# We start with a sleep because our _run() method will setup the initial portmap.
await self.wait_first(asyncio.sleep(self._nat_portmap_lifetime))
await self.add_nat_portmap()
except OperationCancelled:
break
async def add_nat_portmap(self) -> None:
self.logger.info("Setting up NAT portmap...")
# This is experimental and it's OK if it fails, hence the bare except.
try:
upnp_dev = await self._discover_upnp_device()
if upnp_dev is None:
return
await self._add_nat_portmap(upnp_dev)
except upnpclient.soap.SOAPError as e:
if e.args == (718, 'ConflictInMappingEntry'):
# An entry already exists with the parameters we specified. Maybe the router
# didn't clean it up after it expired or it has been configured by other piece
# of software, either way we should not override it.
# https://tools.ietf.org/id/draft-ietf-pcp-upnp-igd-interworking-07.html#errors
self.logger.info("NAT port mapping already configured, not overriding it")
else:
self.logger.exception("Failed to setup NAT portmap")
except Exception:
self.logger.exception("Failed to setup NAT portmap")
def _find_internal_ip_on_device_network(self, upnp_dev: upnpclient.upnp.Device) -> str:
parsed_url = urlparse(upnp_dev.location)
# Get an ipaddress.IPv4Network instance for the upnp device's network.
upnp_dev_net = ipaddress.ip_network(parsed_url.hostname + '/24', strict=False)
for iface in netifaces.interfaces():
for family, addresses in netifaces.ifaddresses(iface).items():
# TODO: Support IPv6 addresses as well.
if family != netifaces.AF_INET:
continue
for item in addresses:
if ipaddress.ip_address(item['addr']) in upnp_dev_net:
return item['addr']
return None
async def _add_nat_portmap(self, upnp_dev: upnpclient.upnp.Device) -> None:
# Detect our internal IP address (or abort if we can't determine
# the internal IP address
internal_ip = self._find_internal_ip_on_device_network(upnp_dev)
if internal_ip is None:
self.logger.warn(
"Unable to detect internal IP address in order to setup NAT portmap"
)
return
external_ip = upnp_dev.WANIPConn1.GetExternalIPAddress()['NewExternalIPAddress']
for protocol, description in [('TCP', 'ethereum p2p'), ('UDP', 'ethereum discovery')]:
upnp_dev.WANIPConn1.AddPortMapping(
NewRemoteHost=external_ip,
NewExternalPort=self.port,
NewProtocol=protocol,
NewInternalPort=self.port,
NewInternalClient=internal_ip,
NewEnabled='1',
NewPortMappingDescription=description,
NewLeaseDuration=self._nat_portmap_lifetime,
)
self.logger.info("NAT port forwarding successfully setup")
async def _discover_upnp_device(self) -> upnpclient.upnp.Device:
loop = asyncio.get_event_loop()
# UPnP discovery can take a long time, so use a loooong timeout here.
discover_timeout = 10 * REPLY_TIMEOUT
# Use loop.run_in_executor() because upnpclient.discover() is blocking and may take a
# while to complete.
devices = await self.wait_first(
loop.run_in_executor(None, upnpclient.discover),
timeout=discover_timeout)
# If there are no UPNP devices we can exit early
if not devices:
self.logger.info("No UPNP-enabled devices found")
return None
# Now we loop over all of the devices until we find one that we can use.
for device in devices:
try:
device.WANIPConn1
except AttributeError:
continue
return device
return None
async def _start_tcp_listener(self) -> None:
# TODO: Support IPv6 addresses as well.
self._tcp_listener = await asyncio.start_server(
self.receive_handshake,
host='0.0.0.0',
port=self.port,
)
async def _close_tcp_listener(self) -> None:
self._tcp_listener.close()
await self._tcp_listener.wait_closed()
async def _start_udp_listener(self, discovery: DiscoveryProtocol) -> None:
loop = asyncio.get_event_loop()
# TODO: Support IPv6 addresses as well.
self._udp_transport, _ = await loop.create_datagram_endpoint(
lambda: discovery,
local_addr=('0.0.0.0', self.port),
family=socket.AF_INET)
async def _close_udp_listener(self) -> None:
cast(asyncio.DatagramTransport, self._udp_transport).abort()
async def _close(self) -> None:
await asyncio.gather(
self._close_tcp_listener(), self._close_udp_listener())
def _make_syncer(self, peer_pool: PeerPool) -> BaseService:
# This method exists only so that ShardSyncer can provide a different implementation.
return FullNodeSyncer(
self.chain, self.chaindb, self.base_db, peer_pool, self.cancel_token)
def _make_peer_pool(self, discovery: DiscoveryProtocol) -> PeerPool:
# This method exists only so that ShardSyncer can provide a different implementation.
return self.peer_pool_class(
self.peer_class,
self.headerdb,
self.network_id,
self.privkey,
discovery,
max_peers=self.max_peers,
)
async def _run(self) -> None:
self.logger.info("Running server...")
upnp_dev = await self._discover_upnp_device()
external_ip = '0.0.0.0'
if upnp_dev is not None:
external_ip = upnp_dev.WANIPConn1.GetExternalIPAddress()['NewExternalIPAddress']
await self._add_nat_portmap(upnp_dev)
await self._start_tcp_listener()
self.logger.info(
"enode://%s@%s:%s",
self.privkey.public_key.to_hex()[2:],
external_ip,
self.port,
)
self.logger.info('network: %s', self.network_id)
addr = Address(external_ip, self.port, self.port)
self.discovery = DiscoveryProtocol(self.privkey, addr, bootstrap_nodes=self.bootstrap_nodes)
await self._start_udp_listener(self.discovery)
self.peer_pool = self._make_peer_pool(self.discovery)
asyncio.ensure_future(self.refresh_nat_portmap())
asyncio.ensure_future(self.discovery.bootstrap())
asyncio.ensure_future(self.peer_pool.run())
self.syncer = self._make_syncer(self.peer_pool)
await self.syncer.run()
async def _cleanup(self) -> None:
self.logger.info("Closing server...")
await asyncio.gather(self.peer_pool.cancel(), self.discovery.stop())
await self._close()
async def receive_handshake(
self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter) -> None:
expected_exceptions = (
TimeoutError,
PeerConnectionLost,
HandshakeFailure,
asyncio.IncompleteReadError,
)
try:
await self._receive_handshake(reader, writer)
except expected_exceptions as e:
self.logger.debug("Could not complete handshake: %s", e)
except unclean_close_exceptions:
self.logger.exception("Unclean exit while receiving handshake")
except OperationCancelled:
pass
except Exception as e:
self.logger.exception("Unexpected error handling handshake")
async def _receive_handshake(
self, reader: asyncio.StreamReader, writer: asyncio.StreamWriter) -> None:
msg = await self.wait_first(
reader.read(ENCRYPTED_AUTH_MSG_LEN),
timeout=REPLY_TIMEOUT)
ip, socket, *_ = writer.get_extra_info("peername")
remote_address = Address(ip, socket)
self.logger.debug("Receiving handshake from %s", remote_address)
try:
ephem_pubkey, initiator_nonce, initiator_pubkey = decode_authentication(
msg, self.privkey)
except DecryptionError:
# Try to decode as EIP8
msg_size = big_endian_to_int(msg[:2])
remaining_bytes = msg_size - ENCRYPTED_AUTH_MSG_LEN + 2
msg += await self.wait_first(
reader.read(remaining_bytes),
timeout=REPLY_TIMEOUT)
try:
ephem_pubkey, initiator_nonce, initiator_pubkey = decode_authentication(
msg, self.privkey)
except DecryptionError as e:
self.logger.debug("Failed to decrypt handshake: %s", e)
return
# Create `HandshakeResponder(remote: kademlia.Node, privkey: datatypes.PrivateKey)` instance
initiator_remote = Node(initiator_pubkey, remote_address)
responder = HandshakeResponder(initiator_remote, self.privkey, self.cancel_token)
# Call `HandshakeResponder.create_auth_ack_message(nonce: bytes)` to create the reply
responder_nonce = secrets.token_bytes(HASH_LEN)
auth_ack_msg = responder.create_auth_ack_message(nonce=responder_nonce)
auth_ack_ciphertext = responder.encrypt_auth_ack_message(auth_ack_msg)
# Use the `writer` to send the reply to the remote
writer.write(auth_ack_ciphertext)
await writer.drain()
# Call `HandshakeResponder.derive_shared_secrets()` and use return values to create `Peer`
aes_secret, mac_secret, egress_mac, ingress_mac = responder.derive_secrets(
initiator_nonce=initiator_nonce,
responder_nonce=responder_nonce,
remote_ephemeral_pubkey=ephem_pubkey,
auth_init_ciphertext=msg,
auth_ack_ciphertext=auth_ack_ciphertext
)
# Create and register peer in peer_pool
peer = self.peer_class(
remote=initiator_remote,
privkey=self.privkey,
reader=reader,
writer=writer,
aes_secret=aes_secret,
mac_secret=mac_secret,
egress_mac=egress_mac,
ingress_mac=ingress_mac,
headerdb=self.headerdb,
network_id=self.network_id,
inbound=True,
)
await self.do_handshake(peer)
async def do_handshake(self, peer: BasePeer) -> None:
await peer.do_p2p_handshake(),
await peer.do_sub_proto_handshake()
self._start_peer(peer)
def _start_peer(self, peer: BasePeer) -> None:
# This method exists only so that we can monkey-patch it in tests.
self.peer_pool.start_peer(peer)
class Server(BaseService):
"""Server listening for incoming connections"""
logger = logging.getLogger("p2p.server.Server")
_server = None
def __init__(
self,
privkey: datatypes.PrivateKey,
address: Address,
chain: AsyncChain,
chaindb: AsyncChainDB,
headerdb: 'BaseAsyncHeaderDB',
db: BaseDB,
network_id: int,
min_peers: int = DEFAULT_MIN_PEERS,
peer_class: Type[BasePeer] = ETHPeer,
peer_pool_class: Type[PeerPool] = PeerPool,
bootstrap_nodes: List[str] = [],
) -> None:
super().__init__(CancelToken('Server'))
self.headerdb = headerdb
self.privkey = privkey
self.address = address
self.network_id = network_id
self.peer_class = peer_class
if not bootstrap_nodes:
if self.network_id == MAINNET_NETWORK_ID:
bootstrap_nodes = MAINNET_BOOTNODES
elif self.network_id == ROPSTEN_NETWORK_ID:
bootstrap_nodes = ROPSTEN_BOOTNODES
else:
self.logger.warn(
"No bootstrap nodes for network id: {}".format(network_id))
bootstrap_nodes = []
self.discovery = DiscoveryProtocol(self.privkey,
self.address,
bootstrap_nodes=bootstrap_nodes)
self.peer_pool = peer_pool_class(
peer_class,
self.headerdb,
self.network_id,
self.privkey,
self.discovery,
min_peers=min_peers,
)
self.syncer = FullNodeSyncer(chain, chaindb, db, self.peer_pool,
self.cancel_token)
async def refresh_nat_portmap(self) -> None:
"""Run an infinite loop refreshing our NAT port mapping.
On every iteration we configure the port mapping with a lifetime of 30 minutes and then
sleep for that long as well.
"""
lifetime = 30 * 60
while not self.is_finished:
self.logger.info("Setting up NAT portmap...")
# This is experimental and it's OK if it fails, hence the bare except.
try:
await self._add_nat_portmap(lifetime)
except Exception as e:
if (isinstance(e, upnpclient.soap.SOAPError)
and e.args == (718, 'ConflictInMappingEntry')):
# An entry already exists with the parameters we specified. Maybe the router
# didn't clean it up after it expired or it has been configured by other piece
# of software, either way we should not override it.
# https://tools.ietf.org/id/draft-ietf-pcp-upnp-igd-interworking-07.html#errors
self.logger.info(
"NAT port mapping already configured, not overriding it"
)
else:
self.logger.exception("Failed to setup NAT portmap")
try:
await wait_with_token(asyncio.sleep(lifetime),
token=self.cancel_token)
except OperationCancelled:
break
async def _add_nat_portmap(self, lifetime: int) -> None:
loop = asyncio.get_event_loop()
# Use loop.run_in_executor() because upnpclient.discover() is blocking and may take a
# while to complete. And we must use a ThreadPoolExecutor() because the response from
# upnpclient.discover() can't be pickled.
devices = await wait_with_token(loop.run_in_executor(
ThreadPoolExecutor(max_workers=1), upnpclient.discover),
token=self.cancel_token,
timeout=2 * REPLY_TIMEOUT)
if not devices:
self.logger.info("No UPNP-enabled devices found")
return
device = devices[0]
device.WANIPConn1.AddPortMapping(
NewRemoteHost=device.WANIPConn1.GetExternalIPAddress()
['NewExternalIPAddress'],
NewExternalPort=self.address.tcp_port,
NewProtocol='TCP',
NewInternalPort=self.address.tcp_port,
NewInternalClient=self.address.ip,
NewEnabled='1',
NewPortMappingDescription='Created by Py-EVM',
NewLeaseDuration=lifetime)
self.logger.info("NAT port forwarding successfully setup")
async def _start(self) -> None:
self._server = await asyncio.start_server(
self.receive_handshake,
host=self.address.ip,
port=self.address.tcp_port,
)
async def _close(self) -> None:
self._server.close()
await self._server.wait_closed()
async def _run(self) -> None:
self.logger.info("Running server...")
await self._start()
self.logger.info(
"enode://%s@%s:%s",
self.privkey.public_key.to_hex()[2:],
self.address.ip,
self.address.tcp_port,
)
await self.discovery.create_endpoint()
asyncio.ensure_future(self.refresh_nat_portmap())
asyncio.ensure_future(self.discovery.bootstrap())
asyncio.ensure_future(self.peer_pool.run())
await self.syncer.run()
async def _cleanup(self) -> None:
self.logger.info("Closing server...")
await self.peer_pool.cancel()
await self.discovery.stop()
await self._close()
async def receive_handshake(self, reader: asyncio.StreamReader,
writer: asyncio.StreamWriter) -> None:
expected_exceptions = (TimeoutError, PeerConnectionLost,
HandshakeFailure, asyncio.IncompleteReadError,
ConnectionResetError, BrokenPipeError)
try:
await self._receive_handshake(reader, writer)
except expected_exceptions as e:
self.logger.debug("Could not complete handshake", exc_info=True)
except OperationCancelled:
pass
except Exception as e:
self.logger.exception("Unexpected error handling handshake")
async def _receive_handshake(self, reader: asyncio.StreamReader,
writer: asyncio.StreamWriter) -> None:
msg = await wait_with_token(
reader.read(ENCRYPTED_AUTH_MSG_LEN),
token=self.cancel_token,
timeout=REPLY_TIMEOUT,
)
ip, socket, *_ = writer.get_extra_info("peername")
remote_address = Address(ip, socket)
self.logger.debug("Receiving handshake from %s", remote_address)
try:
ephem_pubkey, initiator_nonce, initiator_pubkey = decode_authentication(
msg, self.privkey)
except DecryptionError:
# Try to decode as EIP8
msg_size = big_endian_to_int(msg[:2])
remaining_bytes = msg_size - ENCRYPTED_AUTH_MSG_LEN + 2
msg += await wait_with_token(
reader.read(remaining_bytes),
token=self.cancel_token,
timeout=REPLY_TIMEOUT,
)
try:
ephem_pubkey, initiator_nonce, initiator_pubkey = decode_authentication(
msg, self.privkey)
except DecryptionError as e:
self.logger.debug("Failed to decrypt handshake", exc_info=True)
return
# Create `HandshakeResponder(remote: kademlia.Node, privkey: datatypes.PrivateKey)` instance
initiator_remote = Node(initiator_pubkey, remote_address)
responder = HandshakeResponder(initiator_remote, self.privkey,
self.cancel_token)
# Call `HandshakeResponder.create_auth_ack_message(nonce: bytes)` to create the reply
responder_nonce = secrets.token_bytes(HASH_LEN)
auth_ack_msg = responder.create_auth_ack_message(nonce=responder_nonce)
auth_ack_ciphertext = responder.encrypt_auth_ack_message(auth_ack_msg)
# Use the `writer` to send the reply to the remote
writer.write(auth_ack_ciphertext)
await writer.drain()
# Call `HandshakeResponder.derive_shared_secrets()` and use return values to create `Peer`
aes_secret, mac_secret, egress_mac, ingress_mac = responder.derive_secrets(
initiator_nonce=initiator_nonce,
responder_nonce=responder_nonce,
remote_ephemeral_pubkey=ephem_pubkey,
auth_init_ciphertext=msg,
auth_ack_ciphertext=auth_ack_ciphertext)
# Create and register peer in peer_pool
peer = self.peer_class(remote=initiator_remote,
privkey=self.privkey,
reader=reader,
writer=writer,
aes_secret=aes_secret,
mac_secret=mac_secret,
egress_mac=egress_mac,
ingress_mac=ingress_mac,
headerdb=self.headerdb,
network_id=self.network_id)
await self.do_handshake(peer)
async def do_handshake(self, peer: BasePeer) -> None:
await peer.do_p2p_handshake(),
await peer.do_sub_proto_handshake()
self.peer_pool.start_peer(peer)