nim-libp2p/libp2p/transports/tortransport.nim

284 lines
9.7 KiB
Nim
Raw Normal View History

2022-11-04 18:20:23 +00:00
# Nim-LibP2P
2023-01-20 14:47:40 +00:00
# Copyright (c) 2023 Status Research & Development GmbH
2022-11-04 18:20:23 +00:00
# Licensed under either of
# * Apache License, version 2.0, ([LICENSE-APACHE](LICENSE-APACHE))
# * MIT license ([LICENSE-MIT](LICENSE-MIT))
# at your option.
# This file may not be copied, modified, or distributed except according to
# those terms.
## Tor transport implementation
2023-06-07 11:12:49 +00:00
{.push raises: [].}
2022-11-04 18:20:23 +00:00
import std/strformat
import chronos, chronicles, strutils
import stew/[byteutils, endians2, results, objects]
import ../multicodec
import transport,
tcptransport,
../switch,
../builders,
../stream/[lpstream, connection, chronosstream],
../multiaddress,
../upgrademngrs/upgrade
const
IPTcp = mapAnd(IP, mapEq("tcp"))
IPv4Tcp = mapAnd(IP4, mapEq("tcp"))
IPv6Tcp = mapAnd(IP6, mapEq("tcp"))
DnsTcp = mapAnd(DNSANY, mapEq("tcp"))
Socks5ProtocolVersion = byte(5)
NMethods = byte(1)
type
TorTransport* = ref object of Transport
transportAddress: TransportAddress
tcpTransport: TcpTransport
Socks5AuthMethod* {.pure.} = enum
NoAuth = 0
GSSAPI = 1
UsernamePassword = 2
NoAcceptableMethod = 0xff
Socks5RequestCommand* {.pure.} = enum
Connect = 1, Bind = 2, UdpAssoc = 3
Socks5AddressType* {.pure.} = enum
IPv4 = 1, FQDN = 3, IPv6 = 4
Socks5ReplyType* {.pure.} = enum
Succeeded = (0, "Succeeded"), ServerFailure = (1, "Server Failure"),
ConnectionNotAllowed = (2, "Connection Not Allowed"), NetworkUnreachable = (3, "Network Unreachable"),
HostUnreachable = (4, "Host Unreachable"), ConnectionRefused = (5, "Connection Refused"),
TtlExpired = (6, "Ttl Expired"), CommandNotSupported = (7, "Command Not Supported"),
AddressTypeNotSupported = (8, "Address Type Not Supported")
TransportStartError* = object of transport.TransportError
Socks5Error* = object of CatchableError
Socks5AuthFailedError* = object of Socks5Error
Socks5VersionError* = object of Socks5Error
Socks5ServerReplyError* = object of Socks5Error
proc new*(
T: typedesc[TorTransport],
transportAddress: TransportAddress,
flags: set[ServerFlags] = {},
upgrade: Upgrade): T {.public.} =
## Creates a Tor transport
T(
transportAddress: transportAddress,
upgrader: upgrade,
tcpTransport: TcpTransport.new(flags, upgrade))
proc handlesDial(address: MultiAddress): bool {.gcsafe.} =
return Onion3.match(address) or TCP.match(address) or DNSANY.match(address)
proc handlesStart(address: MultiAddress): bool {.gcsafe.} =
return TcpOnion3.match(address)
proc connectToTorServer(
transportAddress: TransportAddress): Future[StreamTransport] {.async, gcsafe.} =
let transp = await connect(transportAddress)
try:
discard await transp.write(@[Socks5ProtocolVersion, NMethods, Socks5AuthMethod.NoAuth.byte])
let
serverReply = await transp.read(2)
socks5ProtocolVersion = serverReply[0]
serverSelectedMethod = serverReply[1]
if socks5ProtocolVersion != Socks5ProtocolVersion:
raise newException(Socks5VersionError, "Unsupported socks version")
if serverSelectedMethod != Socks5AuthMethod.NoAuth.byte:
raise newException(Socks5AuthFailedError, "Unsupported auth method")
return transp
except CatchableError as err:
await transp.closeWait()
raise err
proc readServerReply(transp: StreamTransport) {.async, gcsafe.} =
## The specification for this code is defined on
## [link text](https://www.rfc-editor.org/rfc/rfc1928#section-5)
## and [link text](https://www.rfc-editor.org/rfc/rfc1928#section-6).
let
portNumOctets = 2
ipV4NumOctets = 4
ipV6NumOctets = 16
firstFourOctets = await transp.read(4)
socks5ProtocolVersion = firstFourOctets[0]
serverReply = firstFourOctets[1]
if socks5ProtocolVersion != Socks5ProtocolVersion:
raise newException(Socks5VersionError, "Unsupported socks version")
if serverReply != Socks5ReplyType.Succeeded.byte:
var socks5ReplyType: Socks5ReplyType
if socks5ReplyType.checkedEnumAssign(serverReply):
raise newException(Socks5ServerReplyError, fmt"Server reply error: {socks5ReplyType}")
else:
raise newException(LPError, fmt"Unexpected server reply: {serverReply}")
let atyp = firstFourOctets[3]
case atyp:
of Socks5AddressType.IPv4.byte:
discard await transp.read(ipV4NumOctets + portNumOctets)
of Socks5AddressType.FQDN.byte:
let fqdnNumOctets = await transp.read(1)
discard await transp.read(int(uint8.fromBytes(fqdnNumOctets)) + portNumOctets)
of Socks5AddressType.IPv6.byte:
discard await transp.read(ipV6NumOctets + portNumOctets)
else:
raise newException(LPError, "Address not supported")
2023-06-07 11:12:49 +00:00
proc parseOnion3(address: MultiAddress): (byte, seq[byte], seq[byte]) {.raises: [LPError, ValueError].} =
2022-11-04 18:20:23 +00:00
var addressArray = ($address).split('/')
if addressArray.len < 2: raise newException(LPError, fmt"Onion address not supported {address}")
addressArray = addressArray[2].split(':')
if addressArray.len == 0: raise newException(LPError, fmt"Onion address not supported {address}")
let
addressStr = addressArray[0] & ".onion"
dstAddr = @(uint8(addressStr.len).toBytes()) & addressStr.toBytes()
dstPort = address.data.buffer[37..38]
return (Socks5AddressType.FQDN.byte, dstAddr, dstPort)
proc parseIpTcp(address: MultiAddress):
(byte, seq[byte], seq[byte])
{.raises: [LPError, ValueError].} =
2022-11-04 18:20:23 +00:00
let (codec, atyp) =
if IPv4Tcp.match(address):
(multiCodec("ip4"), Socks5AddressType.IPv4.byte)
elif IPv6Tcp.match(address):
(multiCodec("ip6"), Socks5AddressType.IPv6.byte)
else:
raise newException(LPError, fmt"IP address not supported {address}")
let
dstAddr = address[codec].tryGet().protoArgument().tryGet()
dstPort = address[multiCodec("tcp")].tryGet().protoArgument().tryGet()
2022-11-04 18:20:23 +00:00
(atyp, dstAddr, dstPort)
proc parseDnsTcp(address: MultiAddress):
(byte, seq[byte], seq[byte])
{.raises: [LPError, ValueError].} =
2022-11-04 18:20:23 +00:00
let
dnsAddress = address[multiCodec("dns")].tryGet().protoArgument().tryGet()
2022-11-04 18:20:23 +00:00
dstAddr = @(uint8(dnsAddress.len).toBytes()) & dnsAddress
dstPort = address[multiCodec("tcp")].tryGet().protoArgument().tryGet()
2022-11-04 18:20:23 +00:00
(Socks5AddressType.FQDN.byte, dstAddr, dstPort)
proc dialPeer(
transp: StreamTransport, address: MultiAddress) {.async, gcsafe.} =
let (atyp, dstAddr, dstPort) =
if Onion3.match(address):
parseOnion3(address)
elif IPTcp.match(address):
parseIpTcp(address)
elif DnsTcp.match(address):
parseDnsTcp(address)
else:
raise newException(LPError, fmt"Address not supported: {address}")
let reserved = byte(0)
let request = @[
Socks5ProtocolVersion,
Socks5RequestCommand.Connect.byte,
reserved,
atyp] & dstAddr & dstPort
discard await transp.write(request)
await readServerReply(transp)
method dial*(
self: TorTransport,
hostname: string,
address: MultiAddress,
peerId: Opt[PeerId] = Opt.none(PeerId)): Future[Connection] {.async, gcsafe.} =
2022-11-04 18:20:23 +00:00
## dial a peer
##
if not handlesDial(address):
raise newException(LPError, fmt"Address not supported: {address}")
trace "Dialing remote peer", address = $address
let transp = await connectToTorServer(self.transportAddress)
try:
await dialPeer(transp, address)
return await self.tcpTransport.connHandler(transp, Opt.none(MultiAddress), Direction.Out)
except CatchableError as err:
await transp.closeWait()
raise err
method start*(
self: TorTransport,
addrs: seq[MultiAddress]) {.async.} =
## listen on the transport
##
var listenAddrs: seq[MultiAddress]
var onion3Addrs: seq[MultiAddress]
for i, ma in addrs:
if not handlesStart(ma):
warn "Invalid address detected, skipping!", address = ma
continue
let listenAddress = ma[0..1].tryGet()
2022-11-04 18:20:23 +00:00
listenAddrs.add(listenAddress)
let onion3 = ma[multiCodec("onion3")].tryGet()
2022-11-04 18:20:23 +00:00
onion3Addrs.add(onion3)
if len(listenAddrs) != 0 and len(onion3Addrs) != 0:
await procCall Transport(self).start(onion3Addrs)
await self.tcpTransport.start(listenAddrs)
else:
raise newException(TransportStartError, "Tor Transport couldn't start, no supported addr was provided.")
method accept*(self: TorTransport): Future[Connection] {.async, gcsafe.} =
## accept a new Tor connection
##
let conn = await self.tcpTransport.accept()
conn.observedAddr = Opt.none(MultiAddress)
return conn
method stop*(self: TorTransport) {.async, gcsafe.} =
## stop the transport
##
await procCall Transport(self).stop() # call base
await self.tcpTransport.stop()
method handles*(t: TorTransport, address: MultiAddress): bool {.gcsafe.} =
if procCall Transport(t).handles(address):
return handlesDial(address) or handlesStart(address)
type
TorSwitch* = ref object of Switch
proc new*(
T: typedesc[TorSwitch],
torServer: TransportAddress,
rng: ref HmacDrbgContext,
addresses: seq[MultiAddress] = @[],
flags: set[ServerFlags] = {}): TorSwitch
2023-06-07 11:12:49 +00:00
{.raises: [LPError], public.} =
2022-11-04 18:20:23 +00:00
var builder = SwitchBuilder.new()
.withRng(rng)
.withTransport(proc(upgr: Upgrade): Transport = TorTransport.new(torServer, flags, upgr))
if addresses.len != 0:
builder = builder.withAddresses(addresses)
let switch = builder.withMplex()
.withNoise()
.build()
let torSwitch = T(
peerInfo: switch.peerInfo,
ms: switch.ms,
transports: switch.transports,
connManager: switch.connManager,
peerStore: switch.peerStore,
2023-03-08 11:30:19 +00:00
dialer: Dialer.new(switch.peerInfo.peerId, switch.connManager, switch.peerStore, switch.transports, nil),
2022-11-04 18:20:23 +00:00
nameResolver: nil)
torSwitch.connManager.peerStore = switch.peerStore
return torSwitch
method addTransport*(s: TorSwitch, t: Transport) =
doAssert(false, "not implemented!")
method getTorTransport*(s: TorSwitch): Transport {.base.} =
return s.transports[0]