plugeth/whisper/mailserver/mailserver.go
2017-02-13 13:15:20 +01:00

191 lines
4.9 KiB
Go

// Copyright 2016 The go-ethereum Authors
// This file is part of go-ethereum.
//
// go-ethereum is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// go-ethereum 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 General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with go-ethereum. If not, see <http://www.gnu.org/licenses/>.
package mailserver
import (
"bytes"
"encoding/binary"
"github.com/ethereum/go-ethereum/cmd/utils"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/rlp"
whisper "github.com/ethereum/go-ethereum/whisper/whisperv5"
"github.com/syndtr/goleveldb/leveldb"
"github.com/syndtr/goleveldb/leveldb/util"
)
const MailServerKeyName = "958e04ab302fb36ad2616a352cbac79d"
type WMailServer struct {
db *leveldb.DB
w *whisper.Whisper
pow float64
key []byte
}
type DBKey struct {
timestamp uint32
hash common.Hash
raw []byte
}
func NewDbKey(t uint32, h common.Hash) *DBKey {
const sz = common.HashLength + 4
var k DBKey
k.timestamp = t
k.hash = h
k.raw = make([]byte, sz)
binary.BigEndian.PutUint32(k.raw, k.timestamp)
copy(k.raw[4:], k.hash[:])
return &k
}
func (s *WMailServer) Init(shh *whisper.Whisper, path string, password string, pow float64) {
var err error
if len(path) == 0 {
utils.Fatalf("DB file is not specified")
}
if len(password) == 0 {
utils.Fatalf("Password is not specified for MailServer")
}
s.db, err = leveldb.OpenFile(path, nil)
if err != nil {
utils.Fatalf("Failed to open DB file: %s", err)
}
s.w = shh
s.pow = pow
err = s.w.AddSymKey(MailServerKeyName, []byte(password))
if err != nil {
utils.Fatalf("Failed to create symmetric key for MailServer: %s", err)
}
s.key = s.w.GetSymKey(MailServerKeyName)
}
func (s *WMailServer) Close() {
if s.db != nil {
s.db.Close()
}
}
func (s *WMailServer) Archive(env *whisper.Envelope) {
key := NewDbKey(env.Expiry-env.TTL, env.Hash())
rawEnvelope, err := rlp.EncodeToBytes(env)
if err != nil {
glog.V(logger.Error).Infof("rlp.EncodeToBytes failed: %s", err)
} else {
err = s.db.Put(key.raw, rawEnvelope, nil)
if err != nil {
glog.V(logger.Error).Infof("Writing to DB failed: %s", err)
}
}
}
func (s *WMailServer) DeliverMail(peer *whisper.Peer, request *whisper.Envelope) {
if peer == nil {
glog.V(logger.Error).Info("Whisper peer is nil")
return
}
ok, lower, upper, topic := s.validateRequest(peer.ID(), request)
if ok {
s.processRequest(peer, lower, upper, topic)
}
}
func (s *WMailServer) processRequest(peer *whisper.Peer, lower, upper uint32, topic whisper.TopicType) []*whisper.Envelope {
ret := make([]*whisper.Envelope, 0)
var err error
var zero common.Hash
var empty whisper.TopicType
kl := NewDbKey(lower, zero)
ku := NewDbKey(upper, zero)
i := s.db.NewIterator(&util.Range{Start: kl.raw, Limit: ku.raw}, nil)
defer i.Release()
for i.Next() {
var envelope whisper.Envelope
err = rlp.DecodeBytes(i.Value(), &envelope)
if err != nil {
glog.V(logger.Error).Infof("RLP decoding failed: %s", err)
}
if topic == empty || envelope.Topic == topic {
if peer == nil {
// used for test purposes
ret = append(ret, &envelope)
} else {
err = s.w.SendP2PDirect(peer, &envelope)
if err != nil {
glog.V(logger.Error).Infof("Failed to send direct message to peer: %s", err)
return nil
}
}
}
}
err = i.Error()
if err != nil {
glog.V(logger.Error).Infof("Level DB iterator error: %s", err)
}
return ret
}
func (s *WMailServer) validateRequest(peerID []byte, request *whisper.Envelope) (bool, uint32, uint32, whisper.TopicType) {
var topic whisper.TopicType
if s.pow > 0.0 && request.PoW() < s.pow {
return false, 0, 0, topic
}
f := whisper.Filter{KeySym: s.key}
decrypted := request.Open(&f)
if decrypted == nil {
glog.V(logger.Warn).Infof("Failed to decrypt p2p request")
return false, 0, 0, topic
}
if len(decrypted.Payload) < 8 {
glog.V(logger.Warn).Infof("Undersized p2p request")
return false, 0, 0, topic
}
src := crypto.FromECDSAPub(decrypted.Src)
if len(src)-len(peerID) == 1 {
src = src[1:]
}
if !bytes.Equal(peerID, src) {
glog.V(logger.Warn).Infof("Wrong signature of p2p request")
return false, 0, 0, topic
}
lower := binary.BigEndian.Uint32(decrypted.Payload[:4])
upper := binary.BigEndian.Uint32(decrypted.Payload[4:8])
if len(decrypted.Payload) >= 8+whisper.TopicLength {
topic = whisper.BytesToTopic(decrypted.Payload[8:])
}
return true, lower, upper, topic
}