status-go/services/shhext/api.go

790 lines
24 KiB
Go

package shhext
import (
"context"
"crypto/ecdsa"
"encoding/hex"
"errors"
"fmt"
"math/big"
"time"
"github.com/ethereum/go-ethereum/log"
"github.com/ethereum/go-ethereum/p2p/enode"
"github.com/ethereum/go-ethereum/rlp"
"github.com/status-im/status-go/db"
"github.com/status-im/status-go/mailserver"
"github.com/status-im/status-go/params"
"github.com/status-im/status-go/services/shhext/mailservers"
"github.com/status-im/status-go/whisper/v6"
gethbridge "github.com/status-im/status-go/eth-node/bridge/geth"
"github.com/status-im/status-go/eth-node/types"
enstypes "github.com/status-im/status-go/eth-node/types/ens"
"github.com/status-im/status-go/protocol"
"github.com/status-im/status-go/protocol/encryption/multidevice"
statustransp "github.com/status-im/status-go/protocol/transport/whisper"
)
const (
// defaultWorkTime is a work time reported in messages sent to MailServer nodes.
defaultWorkTime = 5
// defaultRequestTimeout is the default request timeout in seconds
defaultRequestTimeout = 10
// ensContractAddress is the address of the ENS resolver
ensContractAddress = "0x314159265dd8dbb310642f98f50c066173c1259b"
)
var (
// ErrInvalidMailServerPeer is returned when it fails to parse enode from params.
ErrInvalidMailServerPeer = errors.New("invalid mailServerPeer value")
// ErrInvalidSymKeyID is returned when it fails to get a symmetric key.
ErrInvalidSymKeyID = errors.New("invalid symKeyID value")
// ErrInvalidPublicKey is returned when public key can't be extracted
// from MailServer's nodeID.
ErrInvalidPublicKey = errors.New("can't extract public key")
// ErrPFSNotEnabled is returned when an endpoint PFS only is called but
// PFS is disabled
ErrPFSNotEnabled = errors.New("pfs not enabled")
)
// -----
// PAYLOADS
// -----
// MessagesRequest is a RequestMessages() request payload.
type MessagesRequest struct {
// MailServerPeer is MailServer's enode address.
MailServerPeer string `json:"mailServerPeer"`
// From is a lower bound of time range (optional).
// Default is 24 hours back from now.
From uint32 `json:"from"`
// To is a upper bound of time range (optional).
// Default is now.
To uint32 `json:"to"`
// Limit determines the number of messages sent by the mail server
// for the current paginated request
Limit uint32 `json:"limit"`
// Cursor is used as starting point for paginated requests
Cursor string `json:"cursor"`
// Topic is a regular Whisper topic.
// DEPRECATED
Topic types.TopicType `json:"topic"`
// Topics is a list of Whisper topics.
Topics []types.TopicType `json:"topics"`
// SymKeyID is an ID of a symmetric key to authenticate to MailServer.
// It's derived from MailServer password.
SymKeyID string `json:"symKeyID"`
// Timeout is the time to live of the request specified in seconds.
// Default is 10 seconds
Timeout time.Duration `json:"timeout"`
// Force ensures that requests will bypass enforced delay.
Force bool `json:"force"`
}
func (r *MessagesRequest) setDefaults(now time.Time) {
// set From and To defaults
if r.To == 0 {
r.To = uint32(now.UTC().Unix())
}
if r.From == 0 {
oneDay := uint32(86400) // -24 hours
if r.To < oneDay {
r.From = 0
} else {
r.From = r.To - oneDay
}
}
if r.Timeout == 0 {
r.Timeout = defaultRequestTimeout
}
}
// MessagesResponse is a response for shhext_requestMessages2 method.
type MessagesResponse struct {
// Cursor from the response can be used to retrieve more messages
// for the previous request.
Cursor string `json:"cursor"`
// Error indicates that something wrong happened when sending messages
// to the requester.
Error error `json:"error"`
}
// SyncMessagesRequest is a SyncMessages() request payload.
type SyncMessagesRequest struct {
// MailServerPeer is MailServer's enode address.
MailServerPeer string `json:"mailServerPeer"`
// From is a lower bound of time range (optional).
// Default is 24 hours back from now.
From uint32 `json:"from"`
// To is a upper bound of time range (optional).
// Default is now.
To uint32 `json:"to"`
// Limit determines the number of messages sent by the mail server
// for the current paginated request
Limit uint32 `json:"limit"`
// Cursor is used as starting point for paginated requests
Cursor string `json:"cursor"`
// FollowCursor if true loads messages until cursor is empty.
FollowCursor bool `json:"followCursor"`
// Topics is a list of Whisper topics.
// If empty, a full bloom filter will be used.
Topics []types.TopicType `json:"topics"`
}
// SyncMessagesResponse is a response from the mail server
// to which SyncMessagesRequest was sent.
type SyncMessagesResponse struct {
// Cursor from the response can be used to retrieve more messages
// for the previous request.
Cursor string `json:"cursor"`
// Error indicates that something wrong happened when sending messages
// to the requester.
Error string `json:"error"`
}
// InitiateHistoryRequestParams type for initiating history requests from a peer.
type InitiateHistoryRequestParams struct {
Peer string
SymKeyID string
Requests []TopicRequest
Force bool
Timeout time.Duration
}
// -----
// PUBLIC API
// -----
// PublicAPI extends whisper public API.
type PublicAPI struct {
service *Service
publicAPI types.PublicWhisperAPI
log log.Logger
}
// NewPublicAPI returns instance of the public API.
func NewPublicAPI(s *Service) *PublicAPI {
return &PublicAPI{
service: s,
publicAPI: s.w.PublicWhisperAPI(),
log: log.New("package", "status-go/services/sshext.PublicAPI"),
}
}
func (api *PublicAPI) getPeer(rawurl string) (*enode.Node, error) {
if len(rawurl) == 0 {
return mailservers.GetFirstConnected(api.service.server, api.service.peerStore)
}
return enode.ParseV4(rawurl)
}
// RetryConfig specifies configuration for retries with timeout and max amount of retries.
type RetryConfig struct {
BaseTimeout time.Duration
// StepTimeout defines duration increase per each retry.
StepTimeout time.Duration
MaxRetries int
}
// RequestMessagesSync repeats MessagesRequest using configuration in retry conf.
func (api *PublicAPI) RequestMessagesSync(conf RetryConfig, r MessagesRequest) (MessagesResponse, error) {
var resp MessagesResponse
shh := api.service.w
events := make(chan types.EnvelopeEvent, 10)
var (
requestID types.HexBytes
err error
retries int
)
for retries <= conf.MaxRetries {
sub := shh.SubscribeEnvelopeEvents(events)
r.Timeout = conf.BaseTimeout + conf.StepTimeout*time.Duration(retries)
timeout := r.Timeout
// FIXME this weird conversion is required because MessagesRequest expects seconds but defines time.Duration
r.Timeout = time.Duration(int(r.Timeout.Seconds()))
requestID, err = api.RequestMessages(context.Background(), r)
if err != nil {
sub.Unsubscribe()
return resp, err
}
mailServerResp, err := waitForExpiredOrCompleted(types.BytesToHash(requestID), events, timeout)
sub.Unsubscribe()
if err == nil {
resp.Cursor = hex.EncodeToString(mailServerResp.Cursor)
resp.Error = mailServerResp.Error
return resp, nil
}
retries++
api.log.Error("[RequestMessagesSync] failed", "err", err, "retries", retries)
}
return resp, fmt.Errorf("failed to request messages after %d retries", retries)
}
func waitForExpiredOrCompleted(requestID types.Hash, events chan types.EnvelopeEvent, timeout time.Duration) (*types.MailServerResponse, error) {
expired := fmt.Errorf("request %x expired", requestID)
after := time.NewTimer(timeout)
defer after.Stop()
for {
var ev types.EnvelopeEvent
select {
case ev = <-events:
case <-after.C:
return nil, expired
}
if ev.Hash != requestID {
continue
}
switch ev.Event {
case types.EventMailServerRequestCompleted:
data, ok := ev.Data.(*types.MailServerResponse)
if ok {
return data, nil
}
return nil, errors.New("invalid event data type")
case types.EventMailServerRequestExpired:
return nil, expired
}
}
}
// RequestMessages sends a request for historic messages to a MailServer.
func (api *PublicAPI) RequestMessages(_ context.Context, r MessagesRequest) (types.HexBytes, error) {
api.log.Info("RequestMessages", "request", r)
shh := api.service.w
now := api.service.w.GetCurrentTime()
r.setDefaults(now)
if r.From > r.To {
return nil, fmt.Errorf("Query range is invalid: from > to (%d > %d)", r.From, r.To)
}
mailServerNode, err := api.getPeer(r.MailServerPeer)
if err != nil {
return nil, fmt.Errorf("%v: %v", ErrInvalidMailServerPeer, err)
}
var (
symKey []byte
publicKey *ecdsa.PublicKey
)
if r.SymKeyID != "" {
symKey, err = shh.GetSymKey(r.SymKeyID)
if err != nil {
return nil, fmt.Errorf("%v: %v", ErrInvalidSymKeyID, err)
}
} else {
publicKey = mailServerNode.Pubkey()
}
payload, err := makeMessagesRequestPayload(r)
if err != nil {
return nil, err
}
envelope, err := makeEnvelop(
payload,
symKey,
publicKey,
api.service.nodeID,
shh.MinPow(),
now,
)
if err != nil {
return nil, err
}
hash := envelope.Hash()
if !r.Force {
err = api.service.requestsRegistry.Register(hash, r.Topics)
if err != nil {
return nil, err
}
}
if err := shh.RequestHistoricMessagesWithTimeout(mailServerNode.ID().Bytes(), envelope, r.Timeout*time.Second); err != nil {
if !r.Force {
api.service.requestsRegistry.Unregister(hash)
}
return nil, err
}
return hash[:], nil
}
// createSyncMailRequest creates SyncMailRequest. It uses a full bloom filter
// if no topics are given.
func createSyncMailRequest(r SyncMessagesRequest) (types.SyncMailRequest, error) {
var bloom []byte
if len(r.Topics) > 0 {
bloom = topicsToBloom(r.Topics...)
} else {
bloom = types.MakeFullNodeBloom()
}
cursor, err := hex.DecodeString(r.Cursor)
if err != nil {
return types.SyncMailRequest{}, err
}
return types.SyncMailRequest{
Lower: r.From,
Upper: r.To,
Bloom: bloom,
Limit: r.Limit,
Cursor: cursor,
}, nil
}
func createSyncMessagesResponse(r types.SyncEventResponse) SyncMessagesResponse {
return SyncMessagesResponse{
Cursor: hex.EncodeToString(r.Cursor),
Error: r.Error,
}
}
// SyncMessages sends a request to a given MailServerPeer to sync historic messages.
// MailServerPeers needs to be added as a trusted peer first.
func (api *PublicAPI) SyncMessages(ctx context.Context, r SyncMessagesRequest) (SyncMessagesResponse, error) {
log.Info("SyncMessages start", "request", r)
var response SyncMessagesResponse
mailServerEnode, err := enode.ParseV4(r.MailServerPeer)
if err != nil {
return response, fmt.Errorf("invalid MailServerPeer: %v", err)
}
mailServerID := mailServerEnode.ID().Bytes()
request, err := createSyncMailRequest(r)
if err != nil {
return response, fmt.Errorf("failed to create a sync mail request: %v", err)
}
for {
log.Info("Sending a request to sync messages", "request", request)
resp, err := api.service.syncMessages(ctx, mailServerID, request)
if err != nil {
return response, err
}
log.Info("Syncing messages response", "error", resp.Error, "cursor", fmt.Sprintf("%#x", resp.Cursor))
if resp.Error != "" || len(resp.Cursor) == 0 || !r.FollowCursor {
return createSyncMessagesResponse(resp), nil
}
request.Cursor = resp.Cursor
}
}
type Author struct {
PublicKey types.HexBytes `json:"publicKey"`
Alias string `json:"alias"`
Identicon string `json:"identicon"`
}
type Metadata struct {
DedupID []byte `json:"dedupId"`
EncryptionID types.HexBytes `json:"encryptionId"`
MessageID types.HexBytes `json:"messageId"`
Author Author `json:"author"`
}
// ConfirmMessagesProcessedByID is a method to confirm that messages was consumed by
// the client side.
// TODO: this is broken now as it requires dedup ID while a message hash should be used.
func (api *PublicAPI) ConfirmMessagesProcessedByID(messageConfirmations []*Metadata) error {
confirmationCount := len(messageConfirmations)
dedupIDs := make([][]byte, confirmationCount)
encryptionIDs := make([][]byte, confirmationCount)
for i, confirmation := range messageConfirmations {
dedupIDs[i] = confirmation.DedupID
encryptionIDs[i] = confirmation.EncryptionID
}
return api.service.ConfirmMessagesProcessed(encryptionIDs)
}
// Post is used to send one-to-one for those who did not enabled device-to-device sync,
// in other words don't use PFS-enabled messages. Otherwise, SendDirectMessage is used.
// It's important to call PublicAPI.afterSend() so that the client receives a signal
// with confirmation that the message left the device.
func (api *PublicAPI) Post(ctx context.Context, newMessage types.NewMessage) (types.HexBytes, error) {
return api.publicAPI.Post(ctx, newMessage)
}
// SendPublicMessage sends a public chat message to the underlying transport.
// Message's payload is a transit encoded message.
// It's important to call PublicAPI.afterSend() so that the client receives a signal
// with confirmation that the message left the device.
func (api *PublicAPI) SendPublicMessage(ctx context.Context, msg SendPublicMessageRPC) (types.HexBytes, error) {
chat := protocol.Chat{
Name: msg.Chat,
}
return api.service.messenger.SendRaw(ctx, chat, msg.Payload)
}
// SendDirectMessage sends a 1:1 chat message to the underlying transport
// Message's payload is a transit encoded message.
// It's important to call PublicAPI.afterSend() so that the client receives a signal
// with confirmation that the message left the device.
func (api *PublicAPI) SendDirectMessage(ctx context.Context, msg SendDirectMessageRPC) (types.HexBytes, error) {
chat := protocol.Chat{
ChatType: protocol.ChatTypeOneToOne,
ID: types.EncodeHex(msg.PubKey),
}
return api.service.messenger.SendRaw(ctx, chat, msg.Payload)
}
func (api *PublicAPI) Join(chat protocol.Chat) error {
return api.service.messenger.Join(chat)
}
func (api *PublicAPI) Leave(chat protocol.Chat) error {
return api.service.messenger.Leave(chat)
}
func (api *PublicAPI) LeaveGroupChat(ctx Context, chatID string) (*protocol.MessengerResponse, error) {
return api.service.messenger.LeaveGroupChat(ctx, chatID)
}
func (api *PublicAPI) CreateGroupChatWithMembers(ctx Context, name string, members []string) (*protocol.MessengerResponse, error) {
return api.service.messenger.CreateGroupChatWithMembers(ctx, name, members)
}
func (api *PublicAPI) AddMembersToGroupChat(ctx Context, chatID string, members []string) (*protocol.MessengerResponse, error) {
return api.service.messenger.AddMembersToGroupChat(ctx, chatID, members)
}
func (api *PublicAPI) RemoveMemberFromGroupChat(ctx Context, chatID string, member string) (*protocol.MessengerResponse, error) {
return api.service.messenger.RemoveMemberFromGroupChat(ctx, chatID, member)
}
func (api *PublicAPI) AddAdminsToGroupChat(ctx Context, chatID string, members []string) (*protocol.MessengerResponse, error) {
return api.service.messenger.AddAdminsToGroupChat(ctx, chatID, members)
}
func (api *PublicAPI) ConfirmJoiningGroup(ctx context.Context, chatID string) (*protocol.MessengerResponse, error) {
return api.service.messenger.ConfirmJoiningGroup(ctx, chatID)
}
func (api *PublicAPI) requestMessagesUsingPayload(request db.HistoryRequest, peer, symkeyID string, payload []byte, force bool, timeout time.Duration, topics []types.TopicType) (hash types.Hash, err error) {
shh := api.service.w
now := api.service.w.GetCurrentTime()
mailServerNode, err := api.getPeer(peer)
if err != nil {
return hash, fmt.Errorf("%v: %v", ErrInvalidMailServerPeer, err)
}
var (
symKey []byte
publicKey *ecdsa.PublicKey
)
if symkeyID != "" {
symKey, err = shh.GetSymKey(symkeyID)
if err != nil {
return hash, fmt.Errorf("%v: %v", ErrInvalidSymKeyID, err)
}
} else {
publicKey = mailServerNode.Pubkey()
}
envelope, err := makeEnvelop(
payload,
symKey,
publicKey,
api.service.nodeID,
shh.MinPow(),
now,
)
if err != nil {
return hash, err
}
hash = envelope.Hash()
err = request.Replace(hash)
if err != nil {
return hash, err
}
if !force {
err = api.service.requestsRegistry.Register(hash, topics)
if err != nil {
return hash, err
}
}
if err := shh.RequestHistoricMessagesWithTimeout(mailServerNode.ID().Bytes(), envelope, timeout); err != nil {
if !force {
api.service.requestsRegistry.Unregister(hash)
}
return hash, err
}
return hash, nil
}
// InitiateHistoryRequests is a stateful API for initiating history request for each topic.
// Caller of this method needs to define only two parameters per each TopicRequest:
// - Topic
// - Duration in nanoseconds. Will be used to determine starting time for history request.
// After that status-go will guarantee that request for this topic and date will be performed.
func (api *PublicAPI) InitiateHistoryRequests(parent context.Context, request InitiateHistoryRequestParams) (rst []types.HexBytes, err error) {
tx := api.service.storage.NewTx()
defer func() {
if err == nil {
err = tx.Commit()
}
}()
ctx := NewContextFromService(parent, api.service, tx)
requests, err := api.service.historyUpdates.CreateRequests(ctx, request.Requests)
if err != nil {
return nil, err
}
var (
payload []byte
hash types.Hash
)
for i := range requests {
req := requests[i]
options := CreateTopicOptionsFromRequest(req)
bloom := options.ToBloomFilterOption()
payload, err = bloom.ToMessagesRequestPayload()
if err != nil {
return rst, err
}
hash, err = api.requestMessagesUsingPayload(req, request.Peer, request.SymKeyID, payload, request.Force, request.Timeout, options.Topics())
if err != nil {
return rst, err
}
rst = append(rst, hash.Bytes())
}
return rst, err
}
// CompleteRequest client must mark request completed when all envelopes were processed.
func (api *PublicAPI) CompleteRequest(parent context.Context, hex string) (err error) {
tx := api.service.storage.NewTx()
ctx := NewContextFromService(parent, api.service, tx)
err = api.service.historyUpdates.UpdateFinishedRequest(ctx, types.HexToHash(hex))
if err == nil {
return tx.Commit()
}
return err
}
func (api *PublicAPI) LoadFilters(parent context.Context, chats []*statustransp.Filter) ([]*statustransp.Filter, error) {
return api.service.messenger.LoadFilters(chats)
}
func (api *PublicAPI) SaveChat(parent context.Context, chat *protocol.Chat) error {
api.log.Info("saving chat", "chat", chat)
return api.service.messenger.SaveChat(chat)
}
func (api *PublicAPI) Chats(parent context.Context) []*protocol.Chat {
return api.service.messenger.Chats()
}
func (api *PublicAPI) DeleteChat(parent context.Context, chatID string) error {
return api.service.messenger.DeleteChat(chatID)
}
func (api *PublicAPI) SaveContact(parent context.Context, contact *protocol.Contact) error {
return api.service.messenger.SaveContact(contact)
}
func (api *PublicAPI) BlockContact(parent context.Context, contact *protocol.Contact) ([]*protocol.Chat, error) {
api.log.Info("blocking contact", "contact", contact.ID)
return api.service.messenger.BlockContact(contact)
}
func (api *PublicAPI) Contacts(parent context.Context) []*protocol.Contact {
return api.service.messenger.Contacts()
}
func (api *PublicAPI) RemoveFilters(parent context.Context, chats []*statustransp.Filter) error {
return api.service.messenger.RemoveFilters(chats)
}
// EnableInstallation enables an installation for multi-device sync.
func (api *PublicAPI) EnableInstallation(installationID string) error {
return api.service.messenger.EnableInstallation(installationID)
}
// DisableInstallation disables an installation for multi-device sync.
func (api *PublicAPI) DisableInstallation(installationID string) error {
return api.service.messenger.DisableInstallation(installationID)
}
// GetOurInstallations returns all the installations available given an identity
func (api *PublicAPI) GetOurInstallations() ([]*multidevice.Installation, error) {
return api.service.messenger.Installations()
}
// SetInstallationMetadata sets the metadata for our own installation
func (api *PublicAPI) SetInstallationMetadata(installationID string, data *multidevice.InstallationMetadata) error {
return api.service.messenger.SetInstallationMetadata(installationID, data)
}
// VerifyENSNames takes a list of ensdetails and returns whether they match the public key specified
func (api *PublicAPI) VerifyENSNames(details []enstypes.ENSDetails) (map[string]enstypes.ENSResponse, error) {
return api.service.messenger.VerifyENSNames(params.MainnetEthereumNetworkURL, ensContractAddress, details)
}
type ApplicationMessagesResponse struct {
Messages []*protocol.Message `json:"messages"`
Cursor string `json:"cursor"`
}
func (api *PublicAPI) ChatMessages(chatID, cursor string, limit int) (*ApplicationMessagesResponse, error) {
messages, cursor, err := api.service.messenger.MessageByChatID(chatID, cursor, limit)
if err != nil {
return nil, err
}
return &ApplicationMessagesResponse{
Messages: messages,
Cursor: cursor,
}, nil
}
func (api *PublicAPI) DeleteMessage(id string) error {
return api.service.messenger.DeleteMessage(id)
}
func (api *PublicAPI) DeleteMessagesByChatID(id string) error {
return api.service.messenger.DeleteMessagesByChatID(id)
}
func (api *PublicAPI) MarkMessagesSeen(chatID string, ids []string) error {
return api.service.messenger.MarkMessagesSeen(chatID, ids)
}
func (api *PublicAPI) UpdateMessageOutgoingStatus(id, newOutgoingStatus string) error {
return api.service.messenger.UpdateMessageOutgoingStatus(id, newOutgoingStatus)
}
func (api *PublicAPI) SendChatMessage(ctx context.Context, message *protocol.Message) (*protocol.MessengerResponse, error) {
return api.service.messenger.SendChatMessage(ctx, message)
}
func (api *PublicAPI) ReSendChatMessage(ctx context.Context, messageID string) (*protocol.MessengerResponse, error) {
return api.service.messenger.ReSendChatMessage(ctx, messageID)
}
// -----
// HELPER
// -----
// makeEnvelop makes an envelop for a historic messages request.
// Symmetric key is used to authenticate to MailServer.
// PK is the current node ID.
func makeEnvelop(
payload []byte,
symKey []byte,
publicKey *ecdsa.PublicKey,
nodeID *ecdsa.PrivateKey,
pow float64,
now time.Time,
) (types.Envelope, error) {
params := whisper.MessageParams{
PoW: pow,
Payload: payload,
WorkTime: defaultWorkTime,
Src: nodeID,
}
// Either symKey or public key is required.
// This condition is verified in `message.Wrap()` method.
if len(symKey) > 0 {
params.KeySym = symKey
} else if publicKey != nil {
params.Dst = publicKey
}
message, err := whisper.NewSentMessage(&params)
if err != nil {
return nil, err
}
envelope, err := message.Wrap(&params, now)
if err != nil {
return nil, err
}
return gethbridge.NewGethEnvelopeWrapper(envelope), nil
}
// makeMessagesRequestPayload makes a specific payload for MailServer
// to request historic messages.
func makeMessagesRequestPayload(r MessagesRequest) ([]byte, error) {
cursor, err := hex.DecodeString(r.Cursor)
if err != nil {
return nil, fmt.Errorf("invalid cursor: %v", err)
}
if len(cursor) > 0 && len(cursor) != mailserver.CursorLength {
return nil, fmt.Errorf("invalid cursor size: expected %d but got %d", mailserver.CursorLength, len(cursor))
}
payload := mailserver.MessagesRequestPayload{
Lower: r.From,
Upper: r.To,
Bloom: createBloomFilter(r),
Limit: r.Limit,
Cursor: cursor,
// Client must tell the MailServer if it supports batch responses.
// This can be removed in the future.
Batch: true,
}
return rlp.EncodeToBytes(payload)
}
func createBloomFilter(r MessagesRequest) []byte {
if len(r.Topics) > 0 {
return topicsToBloom(r.Topics...)
}
return types.TopicToBloom(r.Topic)
}
func topicsToBloom(topics ...types.TopicType) []byte {
i := new(big.Int)
for _, topic := range topics {
bloom := types.TopicToBloom(topic)
i.Or(i, new(big.Int).SetBytes(bloom[:]))
}
combined := make([]byte, types.BloomFilterSize)
data := i.Bytes()
copy(combined[types.BloomFilterSize-len(data):], data[:])
return combined
}