tordam

rpc_announce.go (5400B)

---

 // Copyright (c) 2017-2021 Ivan Jelincic <parazyd@dyne.org>
 //
 // This file is part of tordam
 //
 // This program is free software: you can redistribute it and/or modify
 // it under the terms of the GNU Affero General Public License as published by
 // the Free Software Foundation, either version 3 of the License, or
 // (at your option) any later version.
 //
 // This program is distributed in the hope that it will be useful,
 // but WITHOUT ANY WARRANTY; without even the implied warranty of
 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
 // GNU Affero General Public License for more details.
 //
 // You should have received a copy of the GNU Affero General Public License
 // along with this program. If not, see <https://www.gnu.org/licenses/>.
 
 package tordam
 
 import (
 	"context"
 	"crypto/ed25519"
 	"encoding/base64"
 	"errors"
 	"fmt"
 	"strings"
 	"time"
 )
 
 // Ann is the struct for the JSON-RPC announce endpoint.
 type Ann struct{}
 
 // Init takes three parameters:
 // - onion: onionaddress:port where the peer and tordam can be reached
 // - pubkey: ed25519 public signing key in base64
 // - portmap: List of ports available for communication
 // - (optional) revoke: Revocation key for updating peer info
 //  {
 //   "jsonrpc":"2.0",
 //   "id": 1,
 //   "method": "ann.Init",
 //   "params": ["unlikelynameforan.onion:49371", "214=", "69:420,323:2354"]
 //  }
 // Returns:
 // - nonce: A random nonce which is to be signed by the client
 // - revoke: A key which can be used to revoke key and portmap and reannounce the peer
 //  {
 //   "jsonrpc":"2.0",
 //   "id":1,
 //   "result": ["somenonce", "somerevokekey"]
 //  }
 // On any kind of failure returns an error and the reason.
 func (Ann) Init(ctx context.Context, vals []string) ([]string, error) {
 	if len(vals) != 3 && len(vals) != 4 {
 		return nil, errors.New("invalid parameters")
 	}
 
 	onion := vals[0]
 	pubkey := vals[1]
 	portmap := strings.Split(vals[2], ",")
 
 	if err := ValidateOnionInternal(onion); err != nil {
 		rpcWarn(err.Error())
 		return nil, err
 	}
 
 	rpcInfo(fmt.Sprintf("got request for %s", onion))
 
 	var peer Peer
 	reallySeen := false
 	peer, ok := Peers[onion]
 	if ok {
 		// We have seen this peer
 		if peer.Pubkey != nil || peer.PeerRevoke != "" {
 			reallySeen = true
 		}
 	}
 
 	if reallySeen {
 		// Peer announced to us before
 		if len(vals) != 4 {
 			rpcWarn("no revocation key provided")
 			return nil, errors.New("no revocation key provided")
 		}
 		revoke := vals[3]
 		if strings.Compare(revoke, peer.PeerRevoke) != 0 {
 			rpcWarn("revocation key doesn't match")
 			return nil, errors.New("revocation key doesn't match")
 		}
 	}
 
 	pk, err := base64.StdEncoding.DecodeString(pubkey)
 	if err != nil {
 		rpcWarn("got invalid base64 public key")
 		return nil, errors.New("invalid base64 public key")
 	} else if len(pk) != 32 {
 		rpcWarn("got invalid pubkey (len != 32)")
 		return nil, errors.New("invalid public key")
 	}
 
 	if err := ValidatePortmap(portmap); err != nil {
 		rpcWarn(err.Error())
 		return nil, err
 	}
 
 	nonce, err := RandomGarbage(32)
 	if err != nil {
 		rpcInternalErr(err.Error())
 		return nil, errors.New("internal error")
 	}
 
 	newrevoke, err := RandomGarbage(128)
 	if err != nil {
 		rpcInternalErr(err.Error())
 		return nil, errors.New("internal error")
 	}
 
 	peer.Pubkey = pk
 	peer.Portmap = portmap
 	peer.Nonce = nonce
 	peer.PeerRevoke = newrevoke
 	peer.LastSeen = time.Now().Unix()
 	peer.Trusted = 0
 	Peers[onion] = peer
 
 	return []string{nonce, newrevoke}, nil
 }
 
 // Validate takes two parameters:
 // - onion: onionaddress:port where the peer and tordam can be reached
 // - signature: base64 signature of the previously obtained nonce
 //  {
 //   "jsonrpc":"2.0",
 //   "id":2,
 //   "method": "ann.Announce",
 //   "params": ["unlikelynameforan.onion:49371", "deadbeef=="]
 //  }
 // Returns:
 // - peers: A list of known validated peers (max. 50)
 //  {
 //   "jsonrpc":"2.0",
 //   "id":2,
 //   "result": ["unlikelynameforan.onion:69", "yetanother.onion:420"]
 //  }
 // On any kind of failure returns an error and the reason.
 func (Ann) Validate(ctx context.Context, vals []string) ([]string, error) {
 	if len(vals) != 2 {
 		return nil, errors.New("invalid parameters")
 	}
 
 	onion := vals[0]
 	signature := vals[1]
 
 	if err := ValidateOnionInternal(onion); err != nil {
 		rpcWarn(err.Error())
 		return nil, err
 	}
 
 	rpcInfo(fmt.Sprintf("got request for %s", onion))
 
 	peer, ok := Peers[onion]
 	if !ok {
 		rpcWarn(fmt.Sprintf("%s not in peer map", onion))
 		return nil, errors.New("this onion was not seen before")
 	}
 
 	if peer.Pubkey == nil || peer.Nonce == "" {
 		rpcWarn(fmt.Sprintf("%s tried to validate before init", onion))
 		return nil, errors.New("tried to validate before init")
 	}
 
 	sig, err := base64.StdEncoding.DecodeString(signature)
 	if err != nil {
 		rpcWarn("invalid base64 signature string")
 		return nil, errors.New("invalid base64 signature string")
 	}
 
 	if !ed25519.Verify(peer.Pubkey, []byte(peer.Nonce), sig) {
 		rpcWarn("signature verification failed")
 		// delete(Peers, onion)
 		return nil, errors.New("signature verification failed")
 	}
 
 	rpcInfo(fmt.Sprintf("validation success for %s", onion))
 
 	var ret []string
 	for addr, data := range Peers {
 		if data.Trusted > 0 {
 			ret = append(ret, addr)
 		}
 	}
 
 	peer.Nonce = ""
 	peer.Trusted = 1
 	peer.LastSeen = time.Now().Unix()
 	Peers[onion] = peer
 
 	rpcInfo(fmt.Sprintf("sending back list of peers to %s", onion))
 	return ret, nil
 }