async def process_sub_proto_handshake(self, cmd: Command,
msg: _DecodedMsgType) -> None:
if not isinstance(cmd, Status):
await self.disconnect(DisconnectReason.other)
raise HandshakeFailure(
"Expected a HLS Status msg, got {}, disconnecting".format(cmd))
msg = cast(Dict[str, Any], msg)
if msg['network_id'] != self.network_id:
await self.disconnect(DisconnectReason.useless_peer)
raise HandshakeFailure(
"{} network ({}) does not match ours ({}), disconnecting".
format(self, msg['network_id'], self.network_id))
chain_info = await self._local_chain_info
genesis_block_hash = chain_info.genesis_block_hash
if msg['genesis_block_hash'] != genesis_block_hash:
await self.disconnect(DisconnectReason.useless_peer)
raise HandshakeFailure(
"{} genesis ({}) does not match ours ({}), disconnecting".
format(self, encode_hex(msg['genesis_block_hash']),
encode_hex(genesis_block_hash)))
self.node_type = msg['node_type']
self.send_wallet_address_verification(self.local_salt, msg['salt'])
# After the sub_proto handshake, the peer will send back a signed message containing the wallet address
cmd, msg = await self.read_msg()
if isinstance(cmd, Disconnect):
# Peers sometimes send a disconnect msg before they send the sub-proto handshake.
raise HandshakeFailure(
"{} disconnected before completing wallet address verification: {}"
.format(self, msg['reason_name']))
await self.process_sub_proto_wallet_address_verification(cmd, msg)
async def process_sub_proto_handshake(self, cmd: Command,
msg: _DecodedMsgType) -> None:
if not isinstance(cmd, (Status, StatusV2)):
await self.disconnect(DisconnectReason.subprotocol_error)
raise HandshakeFailure(
"Expected a LES Status msg, got {}, disconnecting".format(cmd))
msg = cast(Dict[str, Any], msg)
if msg['networkId'] != self.network_id:
await self.disconnect(DisconnectReason.useless_peer)
raise HandshakeFailure(
"{} network ({}) does not match ours ({}), disconnecting".
format(self, msg['networkId'], self.network_id))
genesis = await self.genesis
if msg['genesisHash'] != genesis.hash:
await self.disconnect(DisconnectReason.useless_peer)
raise HandshakeFailure(
"{} genesis ({}) does not match ours ({}), disconnecting".
format(self, encode_hex(msg['genesisHash']), genesis.hex_hash))
# Eventually we might want to keep connections to peers where we are the only side serving
# data, but right now both our chain syncer and the Peer.boot() method expect the remote
# to reply to header requests, so if they don't we simply disconnect here.
if 'serveHeaders' not in msg:
await self.disconnect(DisconnectReason.useless_peer)
raise HandshakeFailure(
f"{self} doesn't serve headers, disconnecting")
self.head_td = msg['headTd']
self.head_hash = msg['headHash']
self.head_number = msg['headNum']
async def _handshake(
initiator: 'HandshakeInitiator',
reader: asyncio.StreamReader,
writer: asyncio.StreamWriter,
token: CancelToken,
) -> Tuple[bytes, bytes, sha3.keccak_256, sha3.keccak_256]:
"""See the handshake() function above.
This code was factored out into this helper so that we can create Peers with directly
connected readers/writers for our tests.
"""
initiator_nonce = keccak(os.urandom(HASH_LEN))
auth_msg = initiator.create_auth_message(initiator_nonce)
auth_init = initiator.encrypt_auth_message(auth_msg)
writer.write(auth_init)
auth_ack = await token.cancellable_wait(
reader.read(ENCRYPTED_AUTH_ACK_LEN), timeout=REPLY_TIMEOUT)
if reader.at_eof():
# This is what happens when Parity nodes have blacklisted us
# (https://github.com/ethereum/py-evm/issues/901).
raise HandshakeFailure("%s disconnected before sending auth ack",
repr(initiator.remote))
ephemeral_pubkey, responder_nonce = initiator.decode_auth_ack_message(
auth_ack)
aes_secret, mac_secret, egress_mac, ingress_mac = initiator.derive_secrets(
initiator_nonce, responder_nonce, ephemeral_pubkey, auth_init,
auth_ack)
return aes_secret, mac_secret, egress_mac, ingress_mac
async def process_p2p_handshake(self, cmd: protocol.Command,
msg: protocol.PayloadType) -> None:
msg = cast(Dict[str, Any], msg)
if not isinstance(cmd, Hello):
await self.disconnect(DisconnectReason.bad_protocol)
raise HandshakeFailure(
f"Expected a Hello msg, got {cmd}, disconnecting")
remote_capabilities = msg['capabilities']
try:
self.sub_proto = self.select_sub_protocol(remote_capabilities)
except NoMatchingPeerCapabilities:
await self.disconnect(DisconnectReason.useless_peer)
raise HandshakeFailure(
f"No matching capabilities between us ({self.capabilities}) and {self.remote} "
f"({remote_capabilities}), disconnecting")
self.logger.debug(
"Finished P2P handshake with %s, using sub-protocol %s",
self.remote, self.sub_proto)
async def process_sub_proto_wallet_address_verification(
self, cmd: Command, msg: _DecodedMsgType) -> None:
if not isinstance(cmd, WalletAddressVerification):
await self.disconnect(DisconnectReason.other)
raise HandshakeFailure(
"Expected a HLS WalletAddressVerification msg, got {}, disconnecting"
.format(cmd))
msg = cast(Dict[str, Any], msg)
# make sure the salt they replied with is the salt we sent:
if msg['peer_salt'] != self.local_salt:
raise HandshakeFailure(
"The peer replied with a signed message using the wrong salt")
salt = msg['local_salt'] + msg['peer_salt']
validate_transaction_signature(salt, msg['v'], msg['r'], msg['s'])
self.wallet_address = extract_wallet_verification_sender(
salt, msg['v'], msg['r'], msg['s'])
async def do_p2p_handshake(self) -> None:
"""Perform the handshake for the P2P base protocol.
Raises HandshakeFailure if the handshake is not successful.
"""
self.base_protocol.send_handshake()
try:
cmd, msg = await self.read_msg()
except rlp.DecodingError:
raise HandshakeFailure(
"Got invalid rlp_templates data during handshake")
except MalformedMessage as e:
raise HandshakeFailure(
"Got malformed message during handshake") from e
if isinstance(cmd, Disconnect):
msg = cast(Dict[str, Any], msg)
# Peers sometimes send a disconnect msg before they send the initial P2P handshake.
raise HandshakeFailure(
f"{self} disconnected before completing sub-proto handshake: {msg['reason_name']}"
)
await self.process_p2p_handshake(cmd, msg)
async def do_sub_proto_handshake(self) -> None:
"""Perform the handshake for the sub-protocol agreed with the remote peer.
Raises HandshakeFailure if the handshake is not successful.
"""
await self.send_sub_proto_handshake()
cmd, msg = await self.read_msg()
if isinstance(cmd, Ping):
# Parity sends a Ping before the sub-proto handshake, so respond to that and read the
# next one, which hopefully will be the actual handshake.
self.base_protocol.send_pong()
cmd, msg = await self.read_msg()
if isinstance(cmd, Disconnect):
msg = cast(Dict[str, Any], msg)
# Peers sometimes send a disconnect msg before they send the sub-proto handshake.
raise HandshakeFailure(
f"{self} disconnected before completing sub-proto handshake: {msg['reason_name']}"
)
await self.process_sub_proto_handshake(cmd, msg)
self.logger.debug("Finished %s handshake with %s", self.sub_proto,
self.remote)
