# # Ethereum P2P # (c) Copyright 2018 # Status Research & Development GmbH # # Licensed under either of # Apache License, version 2.0, (LICENSE-APACHEv2) # MIT license (LICENSE-MIT) # from strutils import nil import times, algorithm, logging import asyncdispatch2, eth_keys, ranges, stint, nimcrypto, rlp, chronicles import kademlia, enode export Node const MAINNET_BOOTNODES* = [ "enode://a979fb575495b8d6db44f750317d0f4622bf4c2aa3365d6af7c284339968eef29b69ad0dce72a4d8db5ebb4968de0e3bec910127f134779fbcb0cb6d3331163c@52.16.188.185:30303", # noqa: E501 "enode://aa36fdf33dd030378a0168efe6ed7d5cc587fafa3cdd375854fe735a2e11ea3650ba29644e2db48368c46e1f60e716300ba49396cd63778bf8a818c09bded46f@13.93.211.84:30303", # noqa: E501 "enode://78de8a0916848093c73790ead81d1928bec737d565119932b98c6b100d944b7a95e94f847f689fc723399d2e31129d182f7ef3863f2b4c820abbf3ab2722344d@191.235.84.50:30303", # noqa: E501 "enode://158f8aab45f6d19c6cbf4a089c2670541a8da11978a2f90dbf6a502a4a3bab80d288afdbeb7ec0ef6d92de563767f3b1ea9e8e334ca711e9f8e2df5a0385e8e6@13.75.154.138:30303", # noqa: E501 "enode://1118980bf48b0a3640bdba04e0fe78b1add18e1cd99bf22d53daac1fd9972ad650df52176e7c7d89d1114cfef2bc23a2959aa54998a46afcf7d91809f0855082@52.74.57.123:30303", # noqa: E501 ] ROPSTEN_BOOTNODES* = [ "enode://30b7ab30a01c124a6cceca36863ece12c4f5fa68e3ba9b0b51407ccc002eeed3b3102d20a88f1c1d3c3154e2449317b8ef95090e77b312d5cc39354f86d5d606@52.176.7.10:30303", # noqa: E501 "enode://865a63255b3bb68023b6bffd5095118fcc13e79dcf014fe4e47e065c350c7cc72af2e53eff895f11ba1bbb6a2b33271c1116ee870f266618eadfc2e78aa7349c@52.176.100.77:30303", # noqa: E501 "enode://6332792c4a00e3e4ee0926ed89e0d27ef985424d97b6a45bf0f23e51f0dcb5e66b875777506458aea7af6f9e4ffb69f43f3778ee73c81ed9d34c51c4b16b0b0f@52.232.243.152:30303", # noqa: E501 "enode://94c15d1b9e2fe7ce56e458b9a3b672ef11894ddedd0c6f247e0f1d3487f52b66208fb4aeb8179fce6e3a749ea93ed147c37976d67af557508d199d9594c35f09@192.81.208.223:30303", # noqa: E501 ] LOCAL_BOOTNODES = [ "enode://6456719e7267e061161c88720287a77b80718d2a3a4ff5daeba614d029dc77601b75e32190aed1c9b0b9ccb6fac3bcf000f48e54079fa79e339c25d8e9724226@127.0.0.1:30301" ] # UDP packet constants. MAC_SIZE = 256 div 8 # 32 SIG_SIZE = 520 div 8 # 65 HEAD_SIZE = MAC_SIZE + SIG_SIZE # 97 EXPIRATION = 60 # let messages expire after N secondes PROTO_VERSION = 4 type DiscoveryProtocol* = ref object privKey: PrivateKey address: Address bootstrapNodes*: seq[Node] thisNode*: Node kademlia: KademliaProtocol[DiscoveryProtocol] transp: DatagramTransport CommandId = enum cmdPing = 1 cmdPong = 2 cmdFindNode = 3 cmdNeighbours = 4 const MaxDgramSize = 1280 proc append*(w: var RlpWriter, a: IpAddress) = case a.family of IpAddressFamily.IPv6: w.append(a.address_v6.toMemRange) of IpAddressFamily.IPv4: w.append(a.address_v4.toMemRange) proc append(w: var RlpWriter, p: Port) {.inline.} = w.append(p.int) proc append(w: var RlpWriter, pk: PublicKey) {.inline.} = w.append(pk.getRaw()) proc append(w: var RlpWriter, h: MDigest[256]) {.inline.} = w.append(h.data) proc pack(cmdId: CommandId, payload: BytesRange, pk: PrivateKey): Bytes = ## Create and sign a UDP message to be sent to a remote node. ## ## See https://github.com/ethereum/devp2p/blob/master/rlpx.md#node-discovery for information on ## how UDP packets are structured. # TODO: There is a lot of unneeded allocations here let encodedData = @[cmdId.byte] & payload.toSeq() let signature = @(pk.signMessage(encodedData).getRaw()) let msgHash = keccak256.digest(signature & encodedData) result = @(msgHash.data) & signature & encodedData proc validateMsgHash(msg: Bytes, msgHash: var MDigest[256]): bool = msgHash.data[0 .. ^1] = msg.toOpenArray(0, msgHash.data.high) result = msgHash == keccak256.digest(msg.toOpenArray(MAC_SIZE, msg.high)) proc recoverMsgPublicKey(msg: Bytes, pk: var PublicKey): bool = recoverSignatureKey(msg.toOpenArray(MAC_SIZE, MAC_SIZE + 65), keccak256.digest(msg.toOpenArray(HEAD_SIZE, msg.high)).data, pk) == EthKeysStatus.Success proc unpack(msg: Bytes): tuple[cmdId: CommandId, payload: Bytes] = result = (cmdId: msg[HEAD_SIZE].CommandId, payload: msg[HEAD_SIZE + 1 .. ^1]) proc expiration(): uint32 = result = uint32(epochTime() + EXPIRATION) # Wire protocol proc send(d: DiscoveryProtocol, n: Node, data: seq[byte]) = let ta = initTAddress(n.node.address.ip, n.node.address.udpPort) let f = d.transp.sendTo(ta, data) f.callback = proc(data: pointer) {.gcsafe.} = if f.failed: debug "Discovery send failed", msg = f.readError.msg proc sendPing*(d: DiscoveryProtocol, n: Node): seq[byte] = let payload = rlp.encode((PROTO_VERSION, d.address, n.node.address, expiration())).toRange let msg = pack(cmdPing, payload, d.privKey) result = msg[0 ..< MAC_SIZE] trace ">>> ping ", n d.send(n, msg) proc sendPong*(d: DiscoveryProtocol, n: Node, token: MDigest[256]) = let payload = rlp.encode((n.node.address, token, expiration())).toRange let msg = pack(cmdPong, payload, d.privKey) trace ">>> pong ", n d.send(n, msg) proc sendFindNode*(d: DiscoveryProtocol, n: Node, targetNodeId: NodeId) = var data: array[64, byte] data[32 .. ^1] = targetNodeId.toByteArrayBE() let payload = rlp.encode((data, expiration())).toRange let msg = pack(cmdFindNode, payload, d.privKey) trace ">>> find_node to ", n#, ": ", msg.toHex() d.send(n, msg) proc sendNeighbours*(d: DiscoveryProtocol, node: Node, neighbours: seq[Node]) = const MAX_NEIGHBOURS_PER_PACKET = 12 # TODO: Implement a smarter way to compute it type Neighbour = tuple[ip: IpAddress, udpPort, tcpPort: Port, pk: PublicKey] var nodes = newSeqOfCap[Neighbour](MAX_NEIGHBOURS_PER_PACKET) shallow(nodes) template flush() = block: let payload = rlp.encode((nodes, expiration())).toRange let msg = pack(cmdNeighbours, payload, d.privkey) trace "Neighbours to", node, nodes d.send(node, msg) nodes.setLen(0) for i, n in neighbours: nodes.add((n.node.address.ip, n.node.address.udpPort, n.node.address.tcpPort, n.node.pubkey)) if nodes.len == MAX_NEIGHBOURS_PER_PACKET: flush() if nodes.len != 0: flush() proc newDiscoveryProtocol*(privKey: PrivateKey, address: Address, bootstrapNodes: openarray[ENode] ): DiscoveryProtocol = result.new() result.privKey = privKey result.address = address result.bootstrapNodes = newSeqOfCap[Node](bootstrapNodes.len) for n in bootstrapNodes: result.bootstrapNodes.add(newNode(n)) result.thisNode = newNode(privKey.getPublicKey(), address) result.kademlia = newKademliaProtocol(result.thisNode, result) {.explain.} proc recvPing(d: DiscoveryProtocol, node: Node, msgHash: MDigest[256]) {.inline.} = d.kademlia.recvPing(node, msgHash) proc recvPong(d: DiscoveryProtocol, node: Node, payload: Bytes) {.inline.} = let rlp = rlpFromBytes(payload.toRange) let tok = rlp.listElem(1).toBytes().toSeq() d.kademlia.recvPong(node, tok) proc recvNeighbours(d: DiscoveryProtocol, node: Node, payload: Bytes) {.inline.} = let rlp = rlpFromBytes(payload.toRange) let neighboursList = rlp.listElem(0) let sz = neighboursList.listLen() var neighbours = newSeqOfCap[Node](16) for i in 0 ..< sz: let n = neighboursList.listElem(i) let ipBlob = n.listElem(0).toBytes var ip: IpAddress case ipBlob.len of 4: ip = IpAddress(family: IpAddressFamily.IPv4) copyMem(addr ip.address_v4[0], baseAddr ipBlob, 4) of 16: ip = IpAddress(family: IpAddressFamily.IPv6) copyMem(addr ip.address_v6[0], baseAddr ipBlob, 16) else: error "Wrong ip address length!" continue let udpPort = n.listElem(1).toInt(uint16).Port let tcpPort = n.listElem(2).toInt(uint16).Port var pk: PublicKey if recoverPublicKey(n.listElem(3).toBytes.toOpenArray(), pk) != EthKeysStatus.Success: warn "Could not parse public key" continue neighbours.add(newNode(pk, Address(ip: ip, udpPort: udpPort, tcpPort: tcpPort))) d.kademlia.recvNeighbours(node, neighbours) proc recvFindNode(d: DiscoveryProtocol, node: Node, payload: Bytes) {.inline.} = let rlp = rlpFromBytes(payload.toRange) trace "<<< find_node from ", node let rng = rlp.listElem(0).toBytes let nodeId = readUIntBE[256](rng[32 .. ^1].toOpenArray()) d.kademlia.recvFindNode(node, nodeId) proc expirationValid(rlpEncodedPayload: seq[byte]): bool {.inline.} = let rlp = rlpFromBytes(rlpEncodedPayload.toRange) let expiration = rlp.listElem(rlp.listLen - 1).toInt(uint32) result = epochTime() <= expiration.float proc receive(d: DiscoveryProtocol, a: Address, msg: Bytes) = var msgHash: MDigest[256] if validateMsgHash(msg, msgHash): var remotePubkey: PublicKey if recoverMsgPublicKey(msg, remotePubkey): let (cmdId, payload) = unpack(msg) # echo "received cmd: ", cmdId, ", from: ", a # echo "pubkey: ", remotePubkey.raw_key.toHex() if expirationValid(payload): let node = newNode(remotePubkey, a) case cmdId of cmdPing: d.recvPing(node, msgHash) of cmdPong: d.recvPong(node, payload) of cmdNeighbours: d.recvNeighbours(node, payload) of cmdFindNode: d.recvFindNode(node, payload) else: debug "Unknown command", cmdId else: trace "Received msg already expired", cmdId, a else: error "Wrong public key from ", a else: error "Wrong msg mac from ", a proc processClient(transp: DatagramTransport, raddr: TransportAddress): Future[void] {.async, gcsafe.} = var proto = getUserData[DiscoveryProtocol](transp) var buf: seq[byte] try: # TODO: Maybe here better to use `peekMessage()` to avoid allocation, # but `Bytes` object is just a simple seq[byte], and `ByteRange` object # do not support custom length. var buf = transp.getMessage() let a = Address(ip: raddr.address, udpPort: raddr.port, tcpPort: raddr.port) proto.receive(a, buf) except: debug "receive failed", exception = getCurrentExceptionMsg() proc open*(d: DiscoveryProtocol) = let ta = initTAddress(d.address.ip, d.address.udpPort) d.transp = newDatagramTransport(processClient, udata = d, local = ta) proc lookupRandom*(d: DiscoveryProtocol): Future[seq[Node]] {.inline.} = d.kademlia.lookupRandom() proc run(d: DiscoveryProtocol) {.async.} = while true: discard await d.lookupRandom() await sleepAsync(3000) trace "Discovered nodes", nodes = d.kademlia.nodesDiscovered proc bootstrap*(d: DiscoveryProtocol) {.async.} = await d.kademlia.bootstrap(d.bootstrapNodes) discard d.run() proc resolve*(d: DiscoveryProtocol, n: NodeId): Future[Node] = d.kademlia.resolve(n) proc randomNodes*(d: DiscoveryProtocol, count: int): seq[Node] {.inline.} = d.kademlia.randomNodes(count) when isMainModule: import logging, byteutils addHandler(newConsoleLogger()) block: let m = hexToSeqByte"79664bff52ee17327b4a2d8f97d8fb32c9244d719e5038eb4f6b64da19ca6d271d659c3ad9ad7861a928ca85f8d8debfbe6b7ade26ad778f2ae2ba712567fcbd55bc09eb3e74a893d6b180370b266f6aaf3fe58a0ad95f7435bf3ddf1db940d20102f2cb842edbd4d182944382765da0ab56fb9e64a85a597e6bb27c656b4f1afb7e06b0fd4e41ccde6dba69a3c4a150845aaa4de2" var msgHash: MDigest[256] doAssert(validateMsgHash(m, msgHash)) var remotePubkey: PublicKey doAssert(recoverMsgPublicKey(m, remotePubkey)) let (cmdId, payload) = unpack(m) assert(payload == hexToSeqByte"f2cb842edbd4d182944382765da0ab56fb9e64a85a597e6bb27c656b4f1afb7e06b0fd4e41ccde6dba69a3c4a150845aaa4de2") assert(cmdId == cmdPong) assert(remotePubkey == initPublicKey("78de8a0916848093c73790ead81d1928bec737d565119932b98c6b100d944b7a95e94f847f689fc723399d2e31129d182f7ef3863f2b4c820abbf3ab2722344d")) let privKey = initPrivateKey("a2b50376a79b1a8c8a3296485572bdfbf54708bb46d3c25d73d2723aaaf6a617") # echo privKey # block: # var b = @[1.byte, 2, 3] # let m = pack(cmdPing, b.initBytesRange, privKey) # let (remotePubkey, cmdId, payload) = unpack(m) # assert(remotePubkey.raw_key.toHex == privKey.public_key.raw_key.toHex) var bootnodes = newSeq[ENode]() for item in LOCAL_BOOTNODES: bootnodes.add(initENode(item)) let listenPort = Port(30310) var address = Address(udpPort: listenPort, tcpPort: listenPort) address.ip.family = IpAddressFamily.IPv4 let discovery = newDiscoveryProtocol(privkey, address, bootnodes) echo discovery.thisNode.node.pubkey echo "this_node.id: ", discovery.thisNode.id.toHex() discovery.open() proc test() {.async.} = await discovery.bootstrap() waitFor test()