tordam

A library for peer discovery inside the Tor network
git clone https://git.parazyd.org/tordam
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peer_announce.go (3265B)


      1 // Copyright (c) 2017-2021 Ivan Jelincic <parazyd@dyne.org>
      2 //
      3 // This file is part of tordam
      4 //
      5 // This program is free software: you can redistribute it and/or modify
      6 // it under the terms of the GNU Affero General Public License as published by
      7 // the Free Software Foundation, either version 3 of the License, or
      8 // (at your option) any later version.
      9 //
     10 // This program is distributed in the hope that it will be useful,
     11 // but WITHOUT ANY WARRANTY; without even the implied warranty of
     12 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
     13 // GNU Affero General Public License for more details.
     14 //
     15 // You should have received a copy of the GNU Affero General Public License
     16 // along with this program. If not, see <https://www.gnu.org/licenses/>.
     17 
     18 package tordam
     19 
     20 import (
     21 	"context"
     22 	"crypto/ed25519"
     23 	"encoding/base64"
     24 	"fmt"
     25 	"strings"
     26 
     27 	"github.com/creachadair/jrpc2"
     28 	"github.com/creachadair/jrpc2/channel"
     29 	"golang.org/x/net/proxy"
     30 )
     31 
     32 // Announce is a function that announces to a certain onion address. Upon
     33 // success, it appends the peers received from the endpoint to the global
     34 // Peers map, which in turn also writes it to the peers db file.
     35 func Announce(onionaddr string) error {
     36 	rpcInfo(fmt.Sprintf("Announcing to %s", onionaddr))
     37 
     38 	if err := ValidateOnionInternal(onionaddr); err != nil {
     39 		return err
     40 	}
     41 
     42 	socks, err := proxy.SOCKS5("tcp", Cfg.TorAddr.String(), nil, proxy.Direct)
     43 	if err != nil {
     44 		return err
     45 	}
     46 
     47 	// conn, err := net.Dial(jrpc2.Network(Cfg.Listen), Cfg.Listen)
     48 	conn, err := socks.Dial("tcp", onionaddr)
     49 	if err != nil {
     50 		return err
     51 	}
     52 	defer conn.Close()
     53 
     54 	cli := jrpc2.NewClient(channel.RawJSON(conn, conn), nil)
     55 	defer cli.Close()
     56 	ctx := context.Background()
     57 
     58 	b64pk := base64.StdEncoding.EncodeToString(
     59 		SignKey.Public().(ed25519.PublicKey))
     60 
     61 	var resp [2]string
     62 	data := []string{Onion, b64pk, strings.Join(Cfg.Portmap, ",")}
     63 
     64 	if peer, ok := Peers[onionaddr]; ok {
     65 		// Here the implication is that it's not our first announce, so we
     66 		// should have received a revoke key to use for a subsequent announce.
     67 		data = append(data, peer.SelfRevoke)
     68 	}
     69 
     70 	if err := cli.CallResult(ctx, "ann.Init", data, &resp); err != nil {
     71 		return err
     72 	}
     73 	nonce := resp[0]
     74 
     75 	// TODO: Think about this >
     76 	var peer Peer
     77 	if _, ok := Peers[onionaddr]; ok {
     78 		peer = Peers[onionaddr]
     79 	}
     80 	peer.SelfRevoke = resp[1]
     81 	Peers[onionaddr] = peer
     82 
     83 	sig := base64.StdEncoding.EncodeToString(
     84 		ed25519.Sign(SignKey, []byte(nonce)))
     85 
     86 	var newPeers []string
     87 	if err := cli.CallResult(ctx, "ann.Validate",
     88 		[]string{Onion, sig}, &newPeers); err != nil {
     89 		return err
     90 	}
     91 
     92 	return AppendPeers(newPeers)
     93 }
     94 
     95 // AppendPeers appends given []string peers to the global Peers map. Usually
     96 // received by validating ourself to a peer and them replying with a list of
     97 // their valid peers. If a peer is not in format of "unlikelyname.onion:port",
     98 // they will not be appended.
     99 // As a placeholder, this function can return an error, but it has no reason
    100 // to do so right now.
    101 func AppendPeers(p []string) error {
    102 	for _, i := range p {
    103 		if _, ok := Peers[i]; ok {
    104 			continue
    105 		}
    106 		if err := ValidateOnionInternal(i); err != nil {
    107 			rpcWarn(fmt.Sprintf("received garbage peer (%v)", err))
    108 			continue
    109 		}
    110 		Peers[i] = Peer{}
    111 	}
    112 
    113 	return nil
    114 }