1078 lines
33 KiB
Go
1078 lines
33 KiB
Go
// Copyright 2018 The go-ethereum Authors
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// This file is part of the go-ethereum library.
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//
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// The go-ethereum library is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Lesser General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// The go-ethereum library is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Lesser General Public License for more details.
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//
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// You should have received a copy of the GNU Lesser General Public License
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// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
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package pss
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import (
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"bytes"
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"context"
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"crypto/ecdsa"
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"crypto/rand"
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"errors"
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"fmt"
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"hash"
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"sync"
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"time"
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"github.com/ethereum/go-ethereum/common"
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"github.com/ethereum/go-ethereum/crypto"
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"github.com/ethereum/go-ethereum/metrics"
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"github.com/ethereum/go-ethereum/p2p"
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"github.com/ethereum/go-ethereum/p2p/enode"
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"github.com/ethereum/go-ethereum/p2p/protocols"
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"github.com/ethereum/go-ethereum/rpc"
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"github.com/ethereum/go-ethereum/swarm/log"
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"github.com/ethereum/go-ethereum/swarm/network"
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"github.com/ethereum/go-ethereum/swarm/pot"
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"github.com/ethereum/go-ethereum/swarm/storage"
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whisper "github.com/ethereum/go-ethereum/whisper/whisperv5"
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"golang.org/x/crypto/sha3"
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)
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const (
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defaultPaddingByteSize = 16
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DefaultMsgTTL = time.Second * 120
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defaultDigestCacheTTL = time.Second * 10
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defaultSymKeyCacheCapacity = 512
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digestLength = 32 // byte length of digest used for pss cache (currently same as swarm chunk hash)
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defaultWhisperWorkTime = 3
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defaultWhisperPoW = 0.0000000001
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defaultMaxMsgSize = 1024 * 1024
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defaultCleanInterval = time.Second * 60 * 10
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defaultOutboxCapacity = 100000
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pssProtocolName = "pss"
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pssVersion = 2
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hasherCount = 8
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)
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var (
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addressLength = len(pot.Address{})
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)
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// cache is used for preventing backwards routing
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// will also be instrumental in flood guard mechanism
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// and mailbox implementation
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type pssCacheEntry struct {
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expiresAt time.Time
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}
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// abstraction to enable access to p2p.protocols.Peer.Send
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type senderPeer interface {
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Info() *p2p.PeerInfo
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ID() enode.ID
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Address() []byte
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Send(context.Context, interface{}) error
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}
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// per-key peer related information
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// member `protected` prevents garbage collection of the instance
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type pssPeer struct {
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lastSeen time.Time
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address PssAddress
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protected bool
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}
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// Pss configuration parameters
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type PssParams struct {
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MsgTTL time.Duration
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CacheTTL time.Duration
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privateKey *ecdsa.PrivateKey
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SymKeyCacheCapacity int
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AllowRaw bool // If true, enables sending and receiving messages without builtin pss encryption
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}
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// Sane defaults for Pss
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func NewPssParams() *PssParams {
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return &PssParams{
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MsgTTL: DefaultMsgTTL,
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CacheTTL: defaultDigestCacheTTL,
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SymKeyCacheCapacity: defaultSymKeyCacheCapacity,
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}
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}
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func (params *PssParams) WithPrivateKey(privatekey *ecdsa.PrivateKey) *PssParams {
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params.privateKey = privatekey
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return params
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}
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// Toplevel pss object, takes care of message sending, receiving, decryption and encryption, message handler dispatchers and message forwarding.
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//
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// Implements node.Service
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type Pss struct {
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*network.Kademlia // we can get the Kademlia address from this
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privateKey *ecdsa.PrivateKey // pss can have it's own independent key
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w *whisper.Whisper // key and encryption backend
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auxAPIs []rpc.API // builtins (handshake, test) can add APIs
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// sending and forwarding
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fwdPool map[string]*protocols.Peer // keep track of all peers sitting on the pssmsg routing layer
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fwdPoolMu sync.RWMutex
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fwdCache map[pssDigest]pssCacheEntry // checksum of unique fields from pssmsg mapped to expiry, cache to determine whether to drop msg
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fwdCacheMu sync.RWMutex
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cacheTTL time.Duration // how long to keep messages in fwdCache (not implemented)
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msgTTL time.Duration
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paddingByteSize int
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capstring string
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outbox chan *PssMsg
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// keys and peers
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pubKeyPool map[string]map[Topic]*pssPeer // mapping of hex public keys to peer address by topic.
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pubKeyPoolMu sync.RWMutex
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symKeyPool map[string]map[Topic]*pssPeer // mapping of symkeyids to peer address by topic.
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symKeyPoolMu sync.RWMutex
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symKeyDecryptCache []*string // fast lookup of symkeys recently used for decryption; last used is on top of stack
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symKeyDecryptCacheCursor int // modular cursor pointing to last used, wraps on symKeyDecryptCache array
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symKeyDecryptCacheCapacity int // max amount of symkeys to keep.
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// message handling
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handlers map[Topic]map[*handler]bool // topic and version based pss payload handlers. See pss.Handle()
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handlersMu sync.RWMutex
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hashPool sync.Pool
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topicHandlerCaps map[Topic]*handlerCaps // caches capabilities of each topic's handlers (see handlerCap* consts in types.go)
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// process
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quitC chan struct{}
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}
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func (p *Pss) String() string {
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return fmt.Sprintf("pss: addr %x, pubkey %v", p.BaseAddr(), common.ToHex(crypto.FromECDSAPub(&p.privateKey.PublicKey)))
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}
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// Creates a new Pss instance.
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//
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// In addition to params, it takes a swarm network Kademlia
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// and a FileStore storage for message cache storage.
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func NewPss(k *network.Kademlia, params *PssParams) (*Pss, error) {
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if params.privateKey == nil {
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return nil, errors.New("missing private key for pss")
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}
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cap := p2p.Cap{
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Name: pssProtocolName,
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Version: pssVersion,
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}
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ps := &Pss{
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Kademlia: k,
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privateKey: params.privateKey,
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w: whisper.New(&whisper.DefaultConfig),
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quitC: make(chan struct{}),
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fwdPool: make(map[string]*protocols.Peer),
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fwdCache: make(map[pssDigest]pssCacheEntry),
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cacheTTL: params.CacheTTL,
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msgTTL: params.MsgTTL,
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paddingByteSize: defaultPaddingByteSize,
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capstring: cap.String(),
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outbox: make(chan *PssMsg, defaultOutboxCapacity),
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pubKeyPool: make(map[string]map[Topic]*pssPeer),
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symKeyPool: make(map[string]map[Topic]*pssPeer),
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symKeyDecryptCache: make([]*string, params.SymKeyCacheCapacity),
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symKeyDecryptCacheCapacity: params.SymKeyCacheCapacity,
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handlers: make(map[Topic]map[*handler]bool),
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topicHandlerCaps: make(map[Topic]*handlerCaps),
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hashPool: sync.Pool{
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New: func() interface{} {
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return sha3.NewLegacyKeccak256()
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},
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},
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}
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for i := 0; i < hasherCount; i++ {
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hashfunc := storage.MakeHashFunc(storage.DefaultHash)()
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ps.hashPool.Put(hashfunc)
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}
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return ps, nil
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}
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/////////////////////////////////////////////////////////////////////
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// SECTION: node.Service interface
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/////////////////////////////////////////////////////////////////////
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func (p *Pss) Start(srv *p2p.Server) error {
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go func() {
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ticker := time.NewTicker(defaultCleanInterval)
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cacheTicker := time.NewTicker(p.cacheTTL)
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defer ticker.Stop()
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defer cacheTicker.Stop()
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for {
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select {
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case <-cacheTicker.C:
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p.cleanFwdCache()
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case <-ticker.C:
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p.cleanKeys()
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case <-p.quitC:
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return
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}
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}
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}()
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go func() {
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for {
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select {
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case msg := <-p.outbox:
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err := p.forward(msg)
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if err != nil {
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log.Error(err.Error())
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metrics.GetOrRegisterCounter("pss.forward.err", nil).Inc(1)
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}
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case <-p.quitC:
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return
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}
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}
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}()
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log.Info("Started Pss")
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log.Info("Loaded EC keys", "pubkey", common.ToHex(crypto.FromECDSAPub(p.PublicKey())), "secp256", common.ToHex(crypto.CompressPubkey(p.PublicKey())))
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return nil
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}
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func (p *Pss) Stop() error {
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log.Info("Pss shutting down")
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close(p.quitC)
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return nil
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}
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var pssSpec = &protocols.Spec{
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Name: pssProtocolName,
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Version: pssVersion,
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MaxMsgSize: defaultMaxMsgSize,
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Messages: []interface{}{
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PssMsg{},
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},
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}
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func (p *Pss) Protocols() []p2p.Protocol {
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return []p2p.Protocol{
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{
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Name: pssSpec.Name,
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Version: pssSpec.Version,
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Length: pssSpec.Length(),
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Run: p.Run,
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},
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}
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}
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func (p *Pss) Run(peer *p2p.Peer, rw p2p.MsgReadWriter) error {
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pp := protocols.NewPeer(peer, rw, pssSpec)
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p.fwdPoolMu.Lock()
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p.fwdPool[peer.Info().ID] = pp
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p.fwdPoolMu.Unlock()
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return pp.Run(p.handlePssMsg)
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}
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func (p *Pss) APIs() []rpc.API {
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apis := []rpc.API{
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{
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Namespace: "pss",
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Version: "1.0",
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Service: NewAPI(p),
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Public: true,
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},
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}
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apis = append(apis, p.auxAPIs...)
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return apis
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}
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// add API methods to the pss API
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// must be run before node is started
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func (p *Pss) addAPI(api rpc.API) {
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p.auxAPIs = append(p.auxAPIs, api)
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}
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// Returns the swarm Kademlia address of the pss node
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func (p *Pss) BaseAddr() []byte {
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return p.Kademlia.BaseAddr()
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}
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// Returns the pss node's public key
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func (p *Pss) PublicKey() *ecdsa.PublicKey {
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return &p.privateKey.PublicKey
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}
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/////////////////////////////////////////////////////////////////////
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// SECTION: Message handling
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/////////////////////////////////////////////////////////////////////
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// Links a handler function to a Topic
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//
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// All incoming messages with an envelope Topic matching the
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// topic specified will be passed to the given Handler function.
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//
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// There may be an arbitrary number of handler functions per topic.
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//
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// Returns a deregister function which needs to be called to
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// deregister the handler,
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func (p *Pss) Register(topic *Topic, hndlr *handler) func() {
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p.handlersMu.Lock()
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defer p.handlersMu.Unlock()
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handlers := p.handlers[*topic]
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if handlers == nil {
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handlers = make(map[*handler]bool)
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p.handlers[*topic] = handlers
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log.Debug("registered handler", "caps", hndlr.caps)
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}
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if hndlr.caps == nil {
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hndlr.caps = &handlerCaps{}
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}
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handlers[hndlr] = true
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if _, ok := p.topicHandlerCaps[*topic]; !ok {
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p.topicHandlerCaps[*topic] = &handlerCaps{}
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}
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if hndlr.caps.raw {
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p.topicHandlerCaps[*topic].raw = true
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}
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if hndlr.caps.prox {
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p.topicHandlerCaps[*topic].prox = true
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}
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return func() { p.deregister(topic, hndlr) }
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}
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func (p *Pss) deregister(topic *Topic, hndlr *handler) {
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p.handlersMu.Lock()
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defer p.handlersMu.Unlock()
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handlers := p.handlers[*topic]
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if len(handlers) > 1 {
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delete(p.handlers, *topic)
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// topic caps might have changed now that a handler is gone
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caps := &handlerCaps{}
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for h := range handlers {
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if h.caps.raw {
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caps.raw = true
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}
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if h.caps.prox {
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caps.prox = true
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}
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}
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p.topicHandlerCaps[*topic] = caps
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return
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}
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delete(handlers, hndlr)
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}
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// get all registered handlers for respective topics
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func (p *Pss) getHandlers(topic Topic) map[*handler]bool {
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p.handlersMu.RLock()
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defer p.handlersMu.RUnlock()
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return p.handlers[topic]
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}
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// Filters incoming messages for processing or forwarding.
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// Check if address partially matches
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// If yes, it CAN be for us, and we process it
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// Only passes error to pss protocol handler if payload is not valid pssmsg
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func (p *Pss) handlePssMsg(ctx context.Context, msg interface{}) error {
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metrics.GetOrRegisterCounter("pss.handlepssmsg", nil).Inc(1)
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pssmsg, ok := msg.(*PssMsg)
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if !ok {
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return fmt.Errorf("invalid message type. Expected *PssMsg, got %T ", msg)
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}
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log.Trace("handler", "self", label(p.Kademlia.BaseAddr()), "topic", label(pssmsg.Payload.Topic[:]))
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if int64(pssmsg.Expire) < time.Now().Unix() {
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metrics.GetOrRegisterCounter("pss.expire", nil).Inc(1)
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log.Warn("pss filtered expired message", "from", common.ToHex(p.Kademlia.BaseAddr()), "to", common.ToHex(pssmsg.To))
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return nil
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}
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if p.checkFwdCache(pssmsg) {
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log.Trace("pss relay block-cache match (process)", "from", common.ToHex(p.Kademlia.BaseAddr()), "to", (common.ToHex(pssmsg.To)))
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return nil
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}
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p.addFwdCache(pssmsg)
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psstopic := Topic(pssmsg.Payload.Topic)
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// raw is simplest handler contingency to check, so check that first
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var isRaw bool
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if pssmsg.isRaw() {
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if _, ok := p.topicHandlerCaps[psstopic]; ok {
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if !p.topicHandlerCaps[psstopic].raw {
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log.Debug("No handler for raw message", "topic", psstopic)
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return nil
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}
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}
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isRaw = true
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}
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// check if we can be recipient:
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// - no prox handler on message and partial address matches
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// - prox handler on message and we are in prox regardless of partial address match
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// store this result so we don't calculate again on every handler
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var isProx bool
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if _, ok := p.topicHandlerCaps[psstopic]; ok {
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isProx = p.topicHandlerCaps[psstopic].prox
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}
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isRecipient := p.isSelfPossibleRecipient(pssmsg, isProx)
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if !isRecipient {
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log.Trace("pss was for someone else :'( ... forwarding", "pss", common.ToHex(p.BaseAddr()), "prox", isProx)
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return p.enqueue(pssmsg)
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}
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log.Trace("pss for us, yay! ... let's process!", "pss", common.ToHex(p.BaseAddr()), "prox", isProx, "raw", isRaw, "topic", label(pssmsg.Payload.Topic[:]))
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if err := p.process(pssmsg, isRaw, isProx); err != nil {
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qerr := p.enqueue(pssmsg)
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if qerr != nil {
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return fmt.Errorf("process fail: processerr %v, queueerr: %v", err, qerr)
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}
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}
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return nil
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}
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// Entry point to processing a message for which the current node can be the intended recipient.
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// Attempts symmetric and asymmetric decryption with stored keys.
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// Dispatches message to all handlers matching the message topic
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func (p *Pss) process(pssmsg *PssMsg, raw bool, prox bool) error {
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metrics.GetOrRegisterCounter("pss.process", nil).Inc(1)
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var err error
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var recvmsg *whisper.ReceivedMessage
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var payload []byte
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var from PssAddress
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var asymmetric bool
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var keyid string
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var keyFunc func(envelope *whisper.Envelope) (*whisper.ReceivedMessage, string, PssAddress, error)
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envelope := pssmsg.Payload
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psstopic := Topic(envelope.Topic)
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if raw {
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payload = pssmsg.Payload.Data
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} else {
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if pssmsg.isSym() {
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keyFunc = p.processSym
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} else {
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asymmetric = true
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keyFunc = p.processAsym
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}
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recvmsg, keyid, from, err = keyFunc(envelope)
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if err != nil {
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return errors.New("Decryption failed")
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}
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payload = recvmsg.Payload
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}
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if len(pssmsg.To) < addressLength {
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if err := p.enqueue(pssmsg); err != nil {
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return err
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}
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}
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p.executeHandlers(psstopic, payload, from, raw, prox, asymmetric, keyid)
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return nil
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}
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func (p *Pss) executeHandlers(topic Topic, payload []byte, from PssAddress, raw bool, prox bool, asymmetric bool, keyid string) {
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handlers := p.getHandlers(topic)
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peer := p2p.NewPeer(enode.ID{}, fmt.Sprintf("%x", from), []p2p.Cap{})
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for h := range handlers {
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if !h.caps.raw && raw {
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log.Warn("norawhandler")
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continue
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}
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if !h.caps.prox && prox {
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log.Warn("noproxhandler")
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continue
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}
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err := (h.f)(payload, peer, asymmetric, keyid)
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if err != nil {
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log.Warn("Pss handler failed", "err", err)
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}
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}
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}
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// will return false if using partial address
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func (p *Pss) isSelfRecipient(msg *PssMsg) bool {
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return bytes.Equal(msg.To, p.Kademlia.BaseAddr())
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}
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// test match of leftmost bytes in given message to node's Kademlia address
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func (p *Pss) isSelfPossibleRecipient(msg *PssMsg, prox bool) bool {
|
|
local := p.Kademlia.BaseAddr()
|
|
|
|
// if a partial address matches we are possible recipient regardless of prox
|
|
// if not and prox is not set, we are surely not
|
|
if bytes.Equal(msg.To, local[:len(msg.To)]) {
|
|
|
|
return true
|
|
} else if !prox {
|
|
return false
|
|
}
|
|
|
|
depth := p.Kademlia.NeighbourhoodDepth()
|
|
po, _ := network.Pof(p.Kademlia.BaseAddr(), msg.To, 0)
|
|
log.Trace("selfpossible", "po", po, "depth", depth)
|
|
|
|
return depth <= po
|
|
}
|
|
|
|
/////////////////////////////////////////////////////////////////////
|
|
// SECTION: Encryption
|
|
/////////////////////////////////////////////////////////////////////
|
|
|
|
// Links a peer ECDSA public key to a topic
|
|
//
|
|
// This is required for asymmetric message exchange
|
|
// on the given topic
|
|
//
|
|
// The value in `address` will be used as a routing hint for the
|
|
// public key / topic association
|
|
func (p *Pss) SetPeerPublicKey(pubkey *ecdsa.PublicKey, topic Topic, address PssAddress) error {
|
|
if err := validateAddress(address); err != nil {
|
|
return err
|
|
}
|
|
pubkeybytes := crypto.FromECDSAPub(pubkey)
|
|
if len(pubkeybytes) == 0 {
|
|
return fmt.Errorf("invalid public key: %v", pubkey)
|
|
}
|
|
pubkeyid := common.ToHex(pubkeybytes)
|
|
psp := &pssPeer{
|
|
address: address,
|
|
}
|
|
p.pubKeyPoolMu.Lock()
|
|
if _, ok := p.pubKeyPool[pubkeyid]; !ok {
|
|
p.pubKeyPool[pubkeyid] = make(map[Topic]*pssPeer)
|
|
}
|
|
p.pubKeyPool[pubkeyid][topic] = psp
|
|
p.pubKeyPoolMu.Unlock()
|
|
log.Trace("added pubkey", "pubkeyid", pubkeyid, "topic", topic, "address", address)
|
|
return nil
|
|
}
|
|
|
|
// Automatically generate a new symkey for a topic and address hint
|
|
func (p *Pss) GenerateSymmetricKey(topic Topic, address PssAddress, addToCache bool) (string, error) {
|
|
keyid, err := p.w.GenerateSymKey()
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
p.addSymmetricKeyToPool(keyid, topic, address, addToCache, false)
|
|
return keyid, nil
|
|
}
|
|
|
|
// Links a peer symmetric key (arbitrary byte sequence) to a topic
|
|
//
|
|
// This is required for symmetrically encrypted message exchange
|
|
// on the given topic
|
|
//
|
|
// The key is stored in the whisper backend.
|
|
//
|
|
// If addtocache is set to true, the key will be added to the cache of keys
|
|
// used to attempt symmetric decryption of incoming messages.
|
|
//
|
|
// Returns a string id that can be used to retrieve the key bytes
|
|
// from the whisper backend (see pss.GetSymmetricKey())
|
|
func (p *Pss) SetSymmetricKey(key []byte, topic Topic, address PssAddress, addtocache bool) (string, error) {
|
|
if err := validateAddress(address); err != nil {
|
|
return "", err
|
|
}
|
|
return p.setSymmetricKey(key, topic, address, addtocache, true)
|
|
}
|
|
|
|
func (p *Pss) setSymmetricKey(key []byte, topic Topic, address PssAddress, addtocache bool, protected bool) (string, error) {
|
|
keyid, err := p.w.AddSymKeyDirect(key)
|
|
if err != nil {
|
|
return "", err
|
|
}
|
|
p.addSymmetricKeyToPool(keyid, topic, address, addtocache, protected)
|
|
return keyid, nil
|
|
}
|
|
|
|
// adds a symmetric key to the pss key pool, and optionally adds the key
|
|
// to the collection of keys used to attempt symmetric decryption of
|
|
// incoming messages
|
|
func (p *Pss) addSymmetricKeyToPool(keyid string, topic Topic, address PssAddress, addtocache bool, protected bool) {
|
|
psp := &pssPeer{
|
|
address: address,
|
|
protected: protected,
|
|
}
|
|
p.symKeyPoolMu.Lock()
|
|
if _, ok := p.symKeyPool[keyid]; !ok {
|
|
p.symKeyPool[keyid] = make(map[Topic]*pssPeer)
|
|
}
|
|
p.symKeyPool[keyid][topic] = psp
|
|
p.symKeyPoolMu.Unlock()
|
|
if addtocache {
|
|
p.symKeyDecryptCacheCursor++
|
|
p.symKeyDecryptCache[p.symKeyDecryptCacheCursor%cap(p.symKeyDecryptCache)] = &keyid
|
|
}
|
|
key, _ := p.GetSymmetricKey(keyid)
|
|
log.Trace("added symkey", "symkeyid", keyid, "symkey", common.ToHex(key), "topic", topic, "address", address, "cache", addtocache)
|
|
}
|
|
|
|
// Returns a symmetric key byte seqyence stored in the whisper backend
|
|
// by its unique id
|
|
//
|
|
// Passes on the error value from the whisper backend
|
|
func (p *Pss) GetSymmetricKey(symkeyid string) ([]byte, error) {
|
|
symkey, err := p.w.GetSymKey(symkeyid)
|
|
if err != nil {
|
|
return nil, err
|
|
}
|
|
return symkey, nil
|
|
}
|
|
|
|
// Returns all recorded topic and address combination for a specific public key
|
|
func (p *Pss) GetPublickeyPeers(keyid string) (topic []Topic, address []PssAddress, err error) {
|
|
p.pubKeyPoolMu.RLock()
|
|
defer p.pubKeyPoolMu.RUnlock()
|
|
for t, peer := range p.pubKeyPool[keyid] {
|
|
topic = append(topic, t)
|
|
address = append(address, peer.address)
|
|
}
|
|
|
|
return topic, address, nil
|
|
}
|
|
|
|
func (p *Pss) getPeerAddress(keyid string, topic Topic) (PssAddress, error) {
|
|
p.pubKeyPoolMu.RLock()
|
|
defer p.pubKeyPoolMu.RUnlock()
|
|
if peers, ok := p.pubKeyPool[keyid]; ok {
|
|
if t, ok := peers[topic]; ok {
|
|
return t.address, nil
|
|
}
|
|
}
|
|
return nil, fmt.Errorf("peer with pubkey %s, topic %x not found", keyid, topic)
|
|
}
|
|
|
|
// Attempt to decrypt, validate and unpack a
|
|
// symmetrically encrypted message
|
|
// If successful, returns the unpacked whisper ReceivedMessage struct
|
|
// encapsulating the decrypted message, and the whisper backend id
|
|
// of the symmetric key used to decrypt the message.
|
|
// It fails if decryption of the message fails or if the message is corrupted
|
|
func (p *Pss) processSym(envelope *whisper.Envelope) (*whisper.ReceivedMessage, string, PssAddress, error) {
|
|
metrics.GetOrRegisterCounter("pss.process.sym", nil).Inc(1)
|
|
|
|
for i := p.symKeyDecryptCacheCursor; i > p.symKeyDecryptCacheCursor-cap(p.symKeyDecryptCache) && i > 0; i-- {
|
|
symkeyid := p.symKeyDecryptCache[i%cap(p.symKeyDecryptCache)]
|
|
symkey, err := p.w.GetSymKey(*symkeyid)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
recvmsg, err := envelope.OpenSymmetric(symkey)
|
|
if err != nil {
|
|
continue
|
|
}
|
|
if !recvmsg.Validate() {
|
|
return nil, "", nil, fmt.Errorf("symmetrically encrypted message has invalid signature or is corrupt")
|
|
}
|
|
p.symKeyPoolMu.Lock()
|
|
from := p.symKeyPool[*symkeyid][Topic(envelope.Topic)].address
|
|
p.symKeyPoolMu.Unlock()
|
|
p.symKeyDecryptCacheCursor++
|
|
p.symKeyDecryptCache[p.symKeyDecryptCacheCursor%cap(p.symKeyDecryptCache)] = symkeyid
|
|
return recvmsg, *symkeyid, from, nil
|
|
}
|
|
return nil, "", nil, fmt.Errorf("could not decrypt message")
|
|
}
|
|
|
|
// Attempt to decrypt, validate and unpack an
|
|
// asymmetrically encrypted message
|
|
// If successful, returns the unpacked whisper ReceivedMessage struct
|
|
// encapsulating the decrypted message, and the byte representation of
|
|
// the public key used to decrypt the message.
|
|
// It fails if decryption of message fails, or if the message is corrupted
|
|
func (p *Pss) processAsym(envelope *whisper.Envelope) (*whisper.ReceivedMessage, string, PssAddress, error) {
|
|
metrics.GetOrRegisterCounter("pss.process.asym", nil).Inc(1)
|
|
|
|
recvmsg, err := envelope.OpenAsymmetric(p.privateKey)
|
|
if err != nil {
|
|
return nil, "", nil, fmt.Errorf("could not decrypt message: %s", err)
|
|
}
|
|
// check signature (if signed), strip padding
|
|
if !recvmsg.Validate() {
|
|
return nil, "", nil, fmt.Errorf("invalid message")
|
|
}
|
|
pubkeyid := common.ToHex(crypto.FromECDSAPub(recvmsg.Src))
|
|
var from PssAddress
|
|
p.pubKeyPoolMu.Lock()
|
|
if p.pubKeyPool[pubkeyid][Topic(envelope.Topic)] != nil {
|
|
from = p.pubKeyPool[pubkeyid][Topic(envelope.Topic)].address
|
|
}
|
|
p.pubKeyPoolMu.Unlock()
|
|
return recvmsg, pubkeyid, from, nil
|
|
}
|
|
|
|
// Symkey garbage collection
|
|
// a key is removed if:
|
|
// - it is not marked as protected
|
|
// - it is not in the incoming decryption cache
|
|
func (p *Pss) cleanKeys() (count int) {
|
|
for keyid, peertopics := range p.symKeyPool {
|
|
var expiredtopics []Topic
|
|
for topic, psp := range peertopics {
|
|
if psp.protected {
|
|
continue
|
|
}
|
|
|
|
var match bool
|
|
for i := p.symKeyDecryptCacheCursor; i > p.symKeyDecryptCacheCursor-cap(p.symKeyDecryptCache) && i > 0; i-- {
|
|
cacheid := p.symKeyDecryptCache[i%cap(p.symKeyDecryptCache)]
|
|
if *cacheid == keyid {
|
|
match = true
|
|
}
|
|
}
|
|
if !match {
|
|
expiredtopics = append(expiredtopics, topic)
|
|
}
|
|
}
|
|
for _, topic := range expiredtopics {
|
|
p.symKeyPoolMu.Lock()
|
|
delete(p.symKeyPool[keyid], topic)
|
|
log.Trace("symkey cleanup deletion", "symkeyid", keyid, "topic", topic, "val", p.symKeyPool[keyid])
|
|
p.symKeyPoolMu.Unlock()
|
|
count++
|
|
}
|
|
}
|
|
return
|
|
}
|
|
|
|
/////////////////////////////////////////////////////////////////////
|
|
// SECTION: Message sending
|
|
/////////////////////////////////////////////////////////////////////
|
|
|
|
func (p *Pss) enqueue(msg *PssMsg) error {
|
|
select {
|
|
case p.outbox <- msg:
|
|
return nil
|
|
default:
|
|
}
|
|
|
|
metrics.GetOrRegisterCounter("pss.enqueue.outbox.full", nil).Inc(1)
|
|
return errors.New("outbox full")
|
|
}
|
|
|
|
// Send a raw message (any encryption is responsibility of calling client)
|
|
//
|
|
// Will fail if raw messages are disallowed
|
|
func (p *Pss) SendRaw(address PssAddress, topic Topic, msg []byte) error {
|
|
if err := validateAddress(address); err != nil {
|
|
return err
|
|
}
|
|
pssMsgParams := &msgParams{
|
|
raw: true,
|
|
}
|
|
payload := &whisper.Envelope{
|
|
Data: msg,
|
|
Topic: whisper.TopicType(topic),
|
|
}
|
|
pssMsg := newPssMsg(pssMsgParams)
|
|
pssMsg.To = address
|
|
pssMsg.Expire = uint32(time.Now().Add(p.msgTTL).Unix())
|
|
pssMsg.Payload = payload
|
|
p.addFwdCache(pssMsg)
|
|
err := p.enqueue(pssMsg)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
// if we have a proxhandler on this topic
|
|
// also deliver message to ourselves
|
|
if _, ok := p.topicHandlerCaps[topic]; ok {
|
|
if p.isSelfPossibleRecipient(pssMsg, true) && p.topicHandlerCaps[topic].prox {
|
|
return p.process(pssMsg, true, true)
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// Send a message using symmetric encryption
|
|
//
|
|
// Fails if the key id does not match any of the stored symmetric keys
|
|
func (p *Pss) SendSym(symkeyid string, topic Topic, msg []byte) error {
|
|
symkey, err := p.GetSymmetricKey(symkeyid)
|
|
if err != nil {
|
|
return fmt.Errorf("missing valid send symkey %s: %v", symkeyid, err)
|
|
}
|
|
p.symKeyPoolMu.Lock()
|
|
psp, ok := p.symKeyPool[symkeyid][topic]
|
|
p.symKeyPoolMu.Unlock()
|
|
if !ok {
|
|
return fmt.Errorf("invalid topic '%s' for symkey '%s'", topic.String(), symkeyid)
|
|
}
|
|
return p.send(psp.address, topic, msg, false, symkey)
|
|
}
|
|
|
|
// Send a message using asymmetric encryption
|
|
//
|
|
// Fails if the key id does not match any in of the stored public keys
|
|
func (p *Pss) SendAsym(pubkeyid string, topic Topic, msg []byte) error {
|
|
if _, err := crypto.UnmarshalPubkey(common.FromHex(pubkeyid)); err != nil {
|
|
return fmt.Errorf("Cannot unmarshal pubkey: %x", pubkeyid)
|
|
}
|
|
p.pubKeyPoolMu.Lock()
|
|
psp, ok := p.pubKeyPool[pubkeyid][topic]
|
|
p.pubKeyPoolMu.Unlock()
|
|
if !ok {
|
|
return fmt.Errorf("invalid topic '%s' for pubkey '%s'", topic.String(), pubkeyid)
|
|
}
|
|
return p.send(psp.address, topic, msg, true, common.FromHex(pubkeyid))
|
|
}
|
|
|
|
// Send is payload agnostic, and will accept any byte slice as payload
|
|
// It generates an whisper envelope for the specified recipient and topic,
|
|
// and wraps the message payload in it.
|
|
// TODO: Implement proper message padding
|
|
func (p *Pss) send(to []byte, topic Topic, msg []byte, asymmetric bool, key []byte) error {
|
|
metrics.GetOrRegisterCounter("pss.send", nil).Inc(1)
|
|
|
|
if key == nil || bytes.Equal(key, []byte{}) {
|
|
return fmt.Errorf("Zero length key passed to pss send")
|
|
}
|
|
padding := make([]byte, p.paddingByteSize)
|
|
c, err := rand.Read(padding)
|
|
if err != nil {
|
|
return err
|
|
} else if c < p.paddingByteSize {
|
|
return fmt.Errorf("invalid padding length: %d", c)
|
|
}
|
|
wparams := &whisper.MessageParams{
|
|
TTL: defaultWhisperTTL,
|
|
Src: p.privateKey,
|
|
Topic: whisper.TopicType(topic),
|
|
WorkTime: defaultWhisperWorkTime,
|
|
PoW: defaultWhisperPoW,
|
|
Payload: msg,
|
|
Padding: padding,
|
|
}
|
|
if asymmetric {
|
|
pk, err := crypto.UnmarshalPubkey(key)
|
|
if err != nil {
|
|
return fmt.Errorf("Cannot unmarshal pubkey: %x", key)
|
|
}
|
|
wparams.Dst = pk
|
|
} else {
|
|
wparams.KeySym = key
|
|
}
|
|
// set up outgoing message container, which does encryption and envelope wrapping
|
|
woutmsg, err := whisper.NewSentMessage(wparams)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to generate whisper message encapsulation: %v", err)
|
|
}
|
|
// performs encryption.
|
|
// Does NOT perform / performs negligible PoW due to very low difficulty setting
|
|
// after this the message is ready for sending
|
|
envelope, err := woutmsg.Wrap(wparams)
|
|
if err != nil {
|
|
return fmt.Errorf("failed to perform whisper encryption: %v", err)
|
|
}
|
|
log.Trace("pssmsg whisper done", "env", envelope, "wparams payload", common.ToHex(wparams.Payload), "to", common.ToHex(to), "asym", asymmetric, "key", common.ToHex(key))
|
|
|
|
// prepare for devp2p transport
|
|
pssMsgParams := &msgParams{
|
|
sym: !asymmetric,
|
|
}
|
|
pssMsg := newPssMsg(pssMsgParams)
|
|
pssMsg.To = to
|
|
pssMsg.Expire = uint32(time.Now().Add(p.msgTTL).Unix())
|
|
pssMsg.Payload = envelope
|
|
err = p.enqueue(pssMsg)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
if _, ok := p.topicHandlerCaps[topic]; ok {
|
|
if p.isSelfPossibleRecipient(pssMsg, true) && p.topicHandlerCaps[topic].prox {
|
|
return p.process(pssMsg, true, true)
|
|
}
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// sendFunc is a helper function that tries to send a message and returns true on success.
|
|
// It is set here for usage in production, and optionally overridden in tests.
|
|
var sendFunc func(p *Pss, sp *network.Peer, msg *PssMsg) bool = sendMsg
|
|
|
|
// tries to send a message, returns true if successful
|
|
func sendMsg(p *Pss, sp *network.Peer, msg *PssMsg) bool {
|
|
var isPssEnabled bool
|
|
info := sp.Info()
|
|
for _, capability := range info.Caps {
|
|
if capability == p.capstring {
|
|
isPssEnabled = true
|
|
break
|
|
}
|
|
}
|
|
if !isPssEnabled {
|
|
log.Error("peer doesn't have matching pss capabilities, skipping", "peer", info.Name, "caps", info.Caps)
|
|
return false
|
|
}
|
|
|
|
// get the protocol peer from the forwarding peer cache
|
|
p.fwdPoolMu.RLock()
|
|
pp := p.fwdPool[sp.Info().ID]
|
|
p.fwdPoolMu.RUnlock()
|
|
|
|
err := pp.Send(context.TODO(), msg)
|
|
if err != nil {
|
|
metrics.GetOrRegisterCounter("pss.pp.send.error", nil).Inc(1)
|
|
log.Error(err.Error())
|
|
}
|
|
|
|
return err == nil
|
|
}
|
|
|
|
// Forwards a pss message to the peer(s) based on recipient address according to the algorithm
|
|
// described below. The recipient address can be of any length, and the byte slice will be matched
|
|
// to the MSB slice of the peer address of the equivalent length.
|
|
//
|
|
// If the recipient address (or partial address) is within the neighbourhood depth of the forwarding
|
|
// node, then it will be forwarded to all the nearest neighbours of the forwarding node. In case of
|
|
// partial address, it should be forwarded to all the peers matching the partial address, if there
|
|
// are any; otherwise only to one peer, closest to the recipient address. In any case, if the message
|
|
// forwarding fails, the node should try to forward it to the next best peer, until the message is
|
|
// successfully forwarded to at least one peer.
|
|
func (p *Pss) forward(msg *PssMsg) error {
|
|
metrics.GetOrRegisterCounter("pss.forward", nil).Inc(1)
|
|
sent := 0 // number of successful sends
|
|
to := make([]byte, addressLength)
|
|
copy(to[:len(msg.To)], msg.To)
|
|
neighbourhoodDepth := p.Kademlia.NeighbourhoodDepth()
|
|
|
|
// luminosity is the opposite of darkness. the more bytes are removed from the address, the higher is darkness,
|
|
// but the luminosity is less. here luminosity equals the number of bits given in the destination address.
|
|
luminosityRadius := len(msg.To) * 8
|
|
|
|
// proximity order function matching up to neighbourhoodDepth bits (po <= neighbourhoodDepth)
|
|
pof := pot.DefaultPof(neighbourhoodDepth)
|
|
|
|
// soft threshold for msg broadcast
|
|
broadcastThreshold, _ := pof(to, p.BaseAddr(), 0)
|
|
if broadcastThreshold > luminosityRadius {
|
|
broadcastThreshold = luminosityRadius
|
|
}
|
|
|
|
var onlySendOnce bool // indicates if the message should only be sent to one peer with closest address
|
|
|
|
// if measured from the recipient address as opposed to the base address (see Kademlia.EachConn
|
|
// call below), then peers that fall in the same proximity bin as recipient address will appear
|
|
// [at least] one bit closer, but only if these additional bits are given in the recipient address.
|
|
if broadcastThreshold < luminosityRadius && broadcastThreshold < neighbourhoodDepth {
|
|
broadcastThreshold++
|
|
onlySendOnce = true
|
|
}
|
|
|
|
p.Kademlia.EachConn(to, addressLength*8, func(sp *network.Peer, po int) bool {
|
|
if po < broadcastThreshold && sent > 0 {
|
|
return false // stop iterating
|
|
}
|
|
if sendFunc(p, sp, msg) {
|
|
sent++
|
|
if onlySendOnce {
|
|
return false
|
|
}
|
|
if po == addressLength*8 {
|
|
// stop iterating if successfully sent to the exact recipient (perfect match of full address)
|
|
return false
|
|
}
|
|
}
|
|
return true
|
|
})
|
|
|
|
// if we failed to send to anyone, re-insert message in the send-queue
|
|
if sent == 0 {
|
|
log.Debug("unable to forward to any peers")
|
|
if err := p.enqueue(msg); err != nil {
|
|
metrics.GetOrRegisterCounter("pss.forward.enqueue.error", nil).Inc(1)
|
|
log.Error(err.Error())
|
|
return err
|
|
}
|
|
}
|
|
|
|
// cache the message
|
|
p.addFwdCache(msg)
|
|
return nil
|
|
}
|
|
|
|
/////////////////////////////////////////////////////////////////////
|
|
// SECTION: Caching
|
|
/////////////////////////////////////////////////////////////////////
|
|
|
|
// cleanFwdCache is used to periodically remove expired entries from the forward cache
|
|
func (p *Pss) cleanFwdCache() {
|
|
metrics.GetOrRegisterCounter("pss.cleanfwdcache", nil).Inc(1)
|
|
p.fwdCacheMu.Lock()
|
|
defer p.fwdCacheMu.Unlock()
|
|
for k, v := range p.fwdCache {
|
|
if v.expiresAt.Before(time.Now()) {
|
|
delete(p.fwdCache, k)
|
|
}
|
|
}
|
|
}
|
|
|
|
func label(b []byte) string {
|
|
return fmt.Sprintf("%04x", b[:2])
|
|
}
|
|
|
|
// add a message to the cache
|
|
func (p *Pss) addFwdCache(msg *PssMsg) error {
|
|
metrics.GetOrRegisterCounter("pss.addfwdcache", nil).Inc(1)
|
|
|
|
var entry pssCacheEntry
|
|
var ok bool
|
|
|
|
p.fwdCacheMu.Lock()
|
|
defer p.fwdCacheMu.Unlock()
|
|
|
|
digest := p.digest(msg)
|
|
if entry, ok = p.fwdCache[digest]; !ok {
|
|
entry = pssCacheEntry{}
|
|
}
|
|
entry.expiresAt = time.Now().Add(p.cacheTTL)
|
|
p.fwdCache[digest] = entry
|
|
return nil
|
|
}
|
|
|
|
// check if message is in the cache
|
|
func (p *Pss) checkFwdCache(msg *PssMsg) bool {
|
|
p.fwdCacheMu.Lock()
|
|
defer p.fwdCacheMu.Unlock()
|
|
|
|
digest := p.digest(msg)
|
|
entry, ok := p.fwdCache[digest]
|
|
if ok {
|
|
if entry.expiresAt.After(time.Now()) {
|
|
log.Trace("unexpired cache", "digest", fmt.Sprintf("%x", digest))
|
|
metrics.GetOrRegisterCounter("pss.checkfwdcache.unexpired", nil).Inc(1)
|
|
return true
|
|
}
|
|
metrics.GetOrRegisterCounter("pss.checkfwdcache.expired", nil).Inc(1)
|
|
}
|
|
return false
|
|
}
|
|
|
|
// Digest of message
|
|
func (p *Pss) digest(msg *PssMsg) pssDigest {
|
|
return p.digestBytes(msg.serialize())
|
|
}
|
|
|
|
func (p *Pss) digestBytes(msg []byte) pssDigest {
|
|
hasher := p.hashPool.Get().(hash.Hash)
|
|
defer p.hashPool.Put(hasher)
|
|
hasher.Reset()
|
|
hasher.Write(msg)
|
|
digest := pssDigest{}
|
|
key := hasher.Sum(nil)
|
|
copy(digest[:], key[:digestLength])
|
|
return digest
|
|
}
|
|
|
|
func validateAddress(addr PssAddress) error {
|
|
if len(addr) > addressLength {
|
|
return errors.New("address too long")
|
|
}
|
|
return nil
|
|
}
|