// Copyright 2016 The go-ethereum Authors
// This file is part of the go-ethereum library.
//
// The go-ethereum library is free software: you can redistribute it and/or modify
// it under the terms of the GNU Lesser General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// The go-ethereum library 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 Lesser General Public License for more details.
//
// You should have received a copy of the GNU Lesser General Public License
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
package whisperv5
import (
"context"
"crypto/ecdsa"
"errors"
"fmt"
"sync"
"time"
"github.com/ethereum/go-ethereum/common"
"github.com/ethereum/go-ethereum/common/hexutil"
"github.com/ethereum/go-ethereum/crypto"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p/discover"
"github.com/ethereum/go-ethereum/rpc"
)
const (
filterTimeout = 300 // filters are considered timeout out after filterTimeout seconds
)
var (
ErrSymAsym = errors.New("specify either a symmetric or an asymmetric key")
ErrInvalidSymmetricKey = errors.New("invalid symmetric key")
ErrInvalidPublicKey = errors.New("invalid public key")
ErrInvalidSigningPubKey = errors.New("invalid signing public key")
ErrTooLowPoW = errors.New("message rejected, PoW too low")
ErrNoTopics = errors.New("missing topic(s)")
)
// PublicWhisperAPI provides the whisper RPC service that can be
// use publicly without security implications.
type PublicWhisperAPI struct {
w *Whisper
mu sync.Mutex
lastUsed map[string]time.Time // keeps track when a filter was polled for the last time.
}
// NewPublicWhisperAPI create a new RPC whisper service.
func NewPublicWhisperAPI(w *Whisper) *PublicWhisperAPI {
api := &PublicWhisperAPI{
w: w,
lastUsed: make(map[string]time.Time),
}
go api.run()
return api
}
// run the api event loop.
// this loop deletes filter that have not been used within filterTimeout
func (api *PublicWhisperAPI) run() {
timeout := time.NewTicker(2 * time.Minute)
for {
<-timeout.C
api.mu.Lock()
for id, lastUsed := range api.lastUsed {
if time.Since(lastUsed).Seconds() >= filterTimeout {
delete(api.lastUsed, id)
if err := api.w.Unsubscribe(id); err != nil {
log.Error("could not unsubscribe whisper filter", "error", err)
}
log.Debug("delete whisper filter (timeout)", "id", id)
}
}
api.mu.Unlock()
}
}
// Version returns the Whisper sub-protocol version.
func (api *PublicWhisperAPI) Version(ctx context.Context) string {
return ProtocolVersionStr
}
// Info contains diagnostic information.
type Info struct {
Memory int `json:"memory"` // Memory size of the floating messages in bytes.
Messages int `json:"messages"` // Number of floating messages.
MinPow float64 `json:"minPow"` // Minimal accepted PoW
MaxMessageSize uint32 `json:"maxMessageSize"` // Maximum accepted message size
}
// Info returns diagnostic information about the whisper node.
func (api *PublicWhisperAPI) Info(ctx context.Context) Info {
stats := api.w.Stats()
return Info{
Memory: stats.memoryUsed,
Messages: len(api.w.messageQueue) + len(api.w.p2pMsgQueue),
MinPow: api.w.MinPow(),
MaxMessageSize: api.w.MaxMessageSize(),
}
}
// SetMaxMessageSize sets the maximum message size that is accepted.
// Upper limit is defined in whisperv5.MaxMessageSize.
func (api *PublicWhisperAPI) SetMaxMessageSize(ctx context.Context, size uint32) (bool, error) {
return true, api.w.SetMaxMessageSize(size)
}
// SetMinPow sets the minimum PoW for a message before it is accepted.
func (api *PublicWhisperAPI) SetMinPoW(ctx context.Context, pow float64) (bool, error) {
return true, api.w.SetMinimumPoW(pow)
}
// MarkTrustedPeer marks a peer trusted. , which will allow it to send historic (expired) messages.
// Note: This function is not adding new nodes, the node needs to exists as a peer.
func (api *PublicWhisperAPI) MarkTrustedPeer(ctx context.Context, enode string) (bool, error) {
n, err := discover.ParseNode(enode)
if err != nil {
return false, err
}
return true, api.w.AllowP2PMessagesFromPeer(n.ID[:])
}
// NewKeyPair generates a new public and private key pair for message decryption and encryption.
// It returns an ID that can be used to refer to the keypair.
func (api *PublicWhisperAPI) NewKeyPair(ctx context.Context) (string, error) {
return api.w.NewKeyPair()
}
// AddPrivateKey imports the given private key.
func (api *PublicWhisperAPI) AddPrivateKey(ctx context.Context, privateKey hexutil.Bytes) (string, error) {
key, err := crypto.ToECDSA(privateKey)
if err != nil {
return "", err
}
return api.w.AddKeyPair(key)
}
// DeleteKeyPair removes the key with the given key if it exists.
func (api *PublicWhisperAPI) DeleteKeyPair(ctx context.Context, key string) (bool, error) {
if ok := api.w.DeleteKeyPair(key); ok {
return true, nil
}
return false, fmt.Errorf("key pair %s not found", key)
}
// HasKeyPair returns an indication if the node has a key pair that is associated with the given id.
func (api *PublicWhisperAPI) HasKeyPair(ctx context.Context, id string) bool {
return api.w.HasKeyPair(id)
}
// GetPublicKey returns the public key associated with the given key. The key is the hex
// encoded representation of a key in the form specified in section 4.3.6 of ANSI X9.62.
func (api *PublicWhisperAPI) GetPublicKey(ctx context.Context, id string) (hexutil.Bytes, error) {
key, err := api.w.GetPrivateKey(id)
if err != nil {
return hexutil.Bytes{}, err
}
return crypto.FromECDSAPub(&key.PublicKey), nil
}
// GetPublicKey returns the private key associated with the given key. The key is the hex
// encoded representation of a key in the form specified in section 4.3.6 of ANSI X9.62.
func (api *PublicWhisperAPI) GetPrivateKey(ctx context.Context, id string) (hexutil.Bytes, error) {
key, err := api.w.GetPrivateKey(id)
if err != nil {
return hexutil.Bytes{}, err
}
return crypto.FromECDSA(key), nil
}
// NewSymKey generate a random symmetric key.
// It returns an ID that can be used to refer to the key.
// Can be used encrypting and decrypting messages where the key is known to both parties.
func (api *PublicWhisperAPI) NewSymKey(ctx context.Context) (string, error) {
return api.w.GenerateSymKey()
}
// AddSymKey import a symmetric key.
// It returns an ID that can be used to refer to the key.
// Can be used encrypting and decrypting messages where the key is known to both parties.
func (api *PublicWhisperAPI) AddSymKey(ctx context.Context, key hexutil.Bytes) (string, error) {
return api.w.AddSymKeyDirect([]byte(key))
}
// GenerateSymKeyFromPassword derive a key from the given password, stores it, and returns its ID.
func (api *PublicWhisperAPI) GenerateSymKeyFromPassword(ctx context.Context, passwd string) (string, error) {
return api.w.AddSymKeyFromPassword(passwd)
}
// HasSymKey returns an indication if the node has a symmetric key associated with the given key.
func (api *PublicWhisperAPI) HasSymKey(ctx context.Context, id string) bool {
return api.w.HasSymKey(id)
}
// GetSymKey returns the symmetric key associated with the given id.
func (api *PublicWhisperAPI) GetSymKey(ctx context.Context, id string) (hexutil.Bytes, error) {
return api.w.GetSymKey(id)
}
// DeleteSymKey deletes the symmetric key that is associated with the given id.
func (api *PublicWhisperAPI) DeleteSymKey(ctx context.Context, id string) bool {
return api.w.DeleteSymKey(id)
}
//go:generate gencodec -type NewMessage -field-override newMessageOverride -out gen_newmessage_json.go
// NewMessage represents a new whisper message that is posted through the RPC.
type NewMessage struct {
SymKeyID string `json:"symKeyID"`
PublicKey []byte `json:"pubKey"`
Sig string `json:"sig"`
TTL uint32 `json:"ttl"`
Topic TopicType `json:"topic"`
Payload []byte `json:"payload"`
Padding []byte `json:"padding"`
PowTime uint32 `json:"powTime"`
PowTarget float64 `json:"powTarget"`
TargetPeer string `json:"targetPeer"`
}
type newMessageOverride struct {
PublicKey hexutil.Bytes
Payload hexutil.Bytes
Padding hexutil.Bytes
}
// Post a message on the Whisper network.
func (api *PublicWhisperAPI) Post(ctx context.Context, req NewMessage) (bool, error) {
var (
symKeyGiven = len(req.SymKeyID) > 0
pubKeyGiven = len(req.PublicKey) > 0
err error
)
// user must specify either a symmetric or an asymmetric key
if (symKeyGiven && pubKeyGiven) || (!symKeyGiven && !pubKeyGiven) {
return false, ErrSymAsym
}
params := &MessageParams{
TTL: req.TTL,
Payload: req.Payload,
Padding: req.Padding,
WorkTime: req.PowTime,
PoW: req.PowTarget,
Topic: req.Topic,
}
// Set key that is used to sign the message
if len(req.Sig) > 0 {
if params.Src, err = api.w.GetPrivateKey(req.Sig); err != nil {
return false, err
}
}
// Set symmetric key that is used to encrypt the message
if symKeyGiven {
if params.Topic == (TopicType{}) { // topics are mandatory with symmetric encryption
return false, ErrNoTopics
}
if params.KeySym, err = api.w.GetSymKey(req.SymKeyID); err != nil {
return false, err
}
if !validateSymmetricKey(params.KeySym) {
return false, ErrInvalidSymmetricKey
}
}
// Set asymmetric key that is used to encrypt the message
if pubKeyGiven {
params.Dst = crypto.ToECDSAPub(req.PublicKey)
if !ValidatePublicKey(params.Dst) {
return false, ErrInvalidPublicKey
}
}
// encrypt and sent message
whisperMsg, err := NewSentMessage(params)
if err != nil {
return false, err
}
env, err := whisperMsg.Wrap(params)
if err != nil {
return false, err
}
// send to specific node (skip PoW check)
if len(req.TargetPeer) > 0 {
n, err := discover.ParseNode(req.TargetPeer)
if err != nil {
return false, fmt.Errorf("failed to parse target peer: %s", err)
}
return true, api.w.SendP2PMessage(n.ID[:], env)
}
// ensure that the message PoW meets the node's minimum accepted PoW
if req.PowTarget < api.w.MinPow() {
return false, ErrTooLowPoW
}
return true, api.w.Send(env)
}
//go:generate gencodec -type Criteria -field-override criteriaOverride -out gen_criteria_json.go
// Criteria holds various filter options for inbound messages.
type Criteria struct {
SymKeyID string `json:"symKeyID"`
PrivateKeyID string `json:"privateKeyID"`
Sig []byte `json:"sig"`
MinPow float64 `json:"minPow"`
Topics []TopicType `json:"topics"`
AllowP2P bool `json:"allowP2P"`
}
type criteriaOverride struct {
Sig hexutil.Bytes
}
// Messages set up a subscription that fires events when messages arrive that match
// the given set of criteria.
func (api *PublicWhisperAPI) Messages(ctx context.Context, crit Criteria) (*rpc.Subscription, error) {
var (
symKeyGiven = len(crit.SymKeyID) > 0
pubKeyGiven = len(crit.PrivateKeyID) > 0
err error
)
// ensure that the RPC connection supports subscriptions
notifier, supported := rpc.NotifierFromContext(ctx)
if !supported {
return nil, rpc.ErrNotificationsUnsupported
}
// user must specify either a symmetric or an asymmetric key
if (symKeyGiven && pubKeyGiven) || (!symKeyGiven && !pubKeyGiven) {
return nil, ErrSymAsym
}
filter := Filter{
PoW: crit.MinPow,
Messages: make(map[common.Hash]*ReceivedMessage),
AllowP2P: crit.AllowP2P,
}
if len(crit.Sig) > 0 {
filter.Src = crypto.ToECDSAPub(crit.Sig)
if !ValidatePublicKey(filter.Src) {
return nil, ErrInvalidSigningPubKey
}
}
for i, bt := range crit.Topics {
if len(bt) == 0 || len(bt) > 4 {
return nil, fmt.Errorf("subscribe: topic %d has wrong size: %d", i, len(bt))
}
filter.Topics = append(filter.Topics, bt[:])
}
// listen for message that are encrypted with the given symmetric key
if symKeyGiven {
if len(filter.Topics) == 0 {
return nil, ErrNoTopics
}
key, err := api.w.GetSymKey(crit.SymKeyID)
if err != nil {
return nil, err
}
if !validateSymmetricKey(key) {
return nil, ErrInvalidSymmetricKey
}
filter.KeySym = key
filter.SymKeyHash = crypto.Keccak256Hash(filter.KeySym)
}
// listen for messages that are encrypted with the given public key
if pubKeyGiven {
filter.KeyAsym, err = api.w.GetPrivateKey(crit.PrivateKeyID)
if err != nil || filter.KeyAsym == nil {
return nil, ErrInvalidPublicKey
}
}
id, err := api.w.Subscribe(&filter)
if err != nil {
return nil, err
}
// create subscription and start waiting for message events
rpcSub := notifier.CreateSubscription()
go func() {
// for now poll internally, refactor whisper internal for channel support
ticker := time.NewTicker(250 * time.Millisecond)
defer ticker.Stop()
for {
select {
case <-ticker.C:
if filter := api.w.GetFilter(id); filter != nil {
for _, rpcMessage := range toMessage(filter.Retrieve()) {
if err := notifier.Notify(rpcSub.ID, rpcMessage); err != nil {
log.Error("Failed to send notification", "err", err)
}
}
}
case <-rpcSub.Err():
api.w.Unsubscribe(id)
return
case <-notifier.Closed():
api.w.Unsubscribe(id)
return
}
}
}()
return rpcSub, nil
}
//go:generate gencodec -type Message -field-override messageOverride -out gen_message_json.go
// Message is the RPC representation of a whisper message.
type Message struct {
Sig []byte `json:"sig,omitempty"`
TTL uint32 `json:"ttl"`
Timestamp uint32 `json:"timestamp"`
Topic TopicType `json:"topic"`
Payload []byte `json:"payload"`
Padding []byte `json:"padding"`
PoW float64 `json:"pow"`
Hash []byte `json:"hash"`
Dst []byte `json:"recipientPublicKey,omitempty"`
}
type messageOverride struct {
Sig hexutil.Bytes
Payload hexutil.Bytes
Padding hexutil.Bytes
Hash hexutil.Bytes
Dst hexutil.Bytes
}
// ToWhisperMessage converts an internal message into an API version.
func ToWhisperMessage(message *ReceivedMessage) *Message {
msg := Message{
Payload: message.Payload,
Padding: message.Padding,
Timestamp: message.Sent,
TTL: message.TTL,
PoW: message.PoW,
Hash: message.EnvelopeHash.Bytes(),
Topic: message.Topic,
}
if message.Dst != nil {
b := crypto.FromECDSAPub(message.Dst)
if b != nil {
msg.Dst = b
}
}
if isMessageSigned(message.Raw[0]) {
b := crypto.FromECDSAPub(message.SigToPubKey())
if b != nil {
msg.Sig = b
}
}
return &msg
}
// toMessage converts a set of messages to its RPC representation.
func toMessage(messages []*ReceivedMessage) []*Message {
msgs := make([]*Message, len(messages))
for i, msg := range messages {
msgs[i] = ToWhisperMessage(msg)
}
return msgs
}
// GetFilterMessages returns the messages that match the filter criteria and
// are received between the last poll and now.
func (api *PublicWhisperAPI) GetFilterMessages(id string) ([]*Message, error) {
api.mu.Lock()
f := api.w.GetFilter(id)
if f == nil {
api.mu.Unlock()
return nil, fmt.Errorf("filter not found")
}
api.lastUsed[id] = time.Now()
api.mu.Unlock()
receivedMessages := f.Retrieve()
messages := make([]*Message, 0, len(receivedMessages))
for _, msg := range receivedMessages {
messages = append(messages, ToWhisperMessage(msg))
}
return messages, nil
}
// DeleteMessageFilter deletes a filter.
func (api *PublicWhisperAPI) DeleteMessageFilter(id string) (bool, error) {
api.mu.Lock()
defer api.mu.Unlock()
delete(api.lastUsed, id)
return true, api.w.Unsubscribe(id)
}
// NewMessageFilter creates a new filter that can be used to poll for
// (new) messages that satisfy the given criteria.
func (api *PublicWhisperAPI) NewMessageFilter(req Criteria) (string, error) {
var (
src *ecdsa.PublicKey
keySym []byte
keyAsym *ecdsa.PrivateKey
topics [][]byte
symKeyGiven = len(req.SymKeyID) > 0
asymKeyGiven = len(req.PrivateKeyID) > 0
err error
)
// user must specify either a symmetric or an asymmetric key
if (symKeyGiven && asymKeyGiven) || (!symKeyGiven && !asymKeyGiven) {
return "", ErrSymAsym
}
if len(req.Sig) > 0 {
src = crypto.ToECDSAPub(req.Sig)
if !ValidatePublicKey(src) {
return "", ErrInvalidSigningPubKey
}
}
if symKeyGiven {
if keySym, err = api.w.GetSymKey(req.SymKeyID); err != nil {
return "", err
}
if !validateSymmetricKey(keySym) {
return "", ErrInvalidSymmetricKey
}
}
if asymKeyGiven {
if keyAsym, err = api.w.GetPrivateKey(req.PrivateKeyID); err != nil {
return "", err
}
}
if len(req.Topics) > 0 {
topics = make([][]byte, 1)
for _, topic := range req.Topics {
topics = append(topics, topic[:])
}
}
f := &Filter{
Src: src,
KeySym: keySym,
KeyAsym: keyAsym,
PoW: req.MinPow,
AllowP2P: req.AllowP2P,
Topics: topics,
Messages: make(map[common.Hash]*ReceivedMessage),
}
id, err := api.w.Subscribe(f)
if err != nil {
return "", err
}
api.mu.Lock()
api.lastUsed[id] = time.Now()
api.mu.Unlock()
return id, nil
}
