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mirror of https://github.com/cwinfo/matterbridge.git synced 2024-11-23 01:11:37 +00:00
matterbridge/matterclient/matterclient.go

917 lines
22 KiB
Go

package matterclient
import (
"crypto/md5"
"crypto/tls"
"encoding/json"
"errors"
"fmt"
"net/http"
"net/http/cookiejar"
"net/url"
"strings"
"sync"
"time"
log "github.com/sirupsen/logrus"
prefixed "github.com/x-cray/logrus-prefixed-formatter"
"github.com/gorilla/websocket"
"github.com/hashicorp/golang-lru"
"github.com/jpillora/backoff"
"github.com/mattermost/platform/model"
)
type Credentials struct {
Login string
Team string
Pass string
Server string
NoTLS bool
SkipTLSVerify bool
}
type Message struct {
Raw *model.WebSocketEvent
Post *model.Post
Team string
Channel string
Username string
Text string
Type string
UserID string
}
type Team struct {
Team *model.Team
Id string
Channels []*model.Channel
MoreChannels []*model.Channel
Users map[string]*model.User
}
type MMClient struct {
sync.RWMutex
*Credentials
Team *Team
OtherTeams []*Team
Client *model.Client4
User *model.User
Users map[string]*model.User
MessageChan chan *Message
log *log.Entry
WsClient *websocket.Conn
WsQuit bool
WsAway bool
WsConnected bool
WsSequence int64
WsPingChan chan *model.WebSocketResponse
ServerVersion string
OnWsConnect func()
lruCache *lru.Cache
}
func New(login, pass, team, server string) *MMClient {
cred := &Credentials{Login: login, Pass: pass, Team: team, Server: server}
mmclient := &MMClient{Credentials: cred, MessageChan: make(chan *Message, 100), Users: make(map[string]*model.User)}
log.SetFormatter(&prefixed.TextFormatter{PrefixPadding: 13, DisableColors: true})
mmclient.log = log.WithFields(log.Fields{"prefix": "matterclient"})
mmclient.lruCache, _ = lru.New(500)
return mmclient
}
func (m *MMClient) SetDebugLog() {
log.SetFormatter(&prefixed.TextFormatter{PrefixPadding: 13, DisableColors: true, FullTimestamp: false, ForceFormatting: true})
}
func (m *MMClient) SetLogLevel(level string) {
l, err := log.ParseLevel(level)
if err != nil {
log.SetLevel(log.InfoLevel)
return
}
log.SetLevel(l)
}
func (m *MMClient) Login() error {
// check if this is a first connect or a reconnection
firstConnection := true
if m.WsConnected {
firstConnection = false
}
m.WsConnected = false
if m.WsQuit {
return nil
}
b := &backoff.Backoff{
Min: time.Second,
Max: 5 * time.Minute,
Jitter: true,
}
uriScheme := "https://"
if m.NoTLS {
uriScheme = "http://"
}
// login to mattermost
m.Client = model.NewAPIv4Client(uriScheme + m.Credentials.Server)
m.Client.HttpClient.Transport = &http.Transport{TLSClientConfig: &tls.Config{InsecureSkipVerify: m.SkipTLSVerify}, Proxy: http.ProxyFromEnvironment}
m.Client.HttpClient.Timeout = time.Second * 10
for {
d := b.Duration()
// bogus call to get the serverversion
_, resp := m.Client.Logout()
if resp.Error != nil {
return fmt.Errorf("%#v", resp.Error.Error())
}
if firstConnection && !supportedVersion(resp.ServerVersion) {
return fmt.Errorf("unsupported mattermost version: %s", resp.ServerVersion)
}
m.ServerVersion = resp.ServerVersion
if m.ServerVersion == "" {
m.log.Debugf("Server not up yet, reconnecting in %s", d)
time.Sleep(d)
} else {
m.log.Infof("Found version %s", m.ServerVersion)
break
}
}
b.Reset()
var resp *model.Response
//var myinfo *model.Result
var appErr *model.AppError
var logmsg = "trying login"
for {
m.log.Debugf("%s %s %s %s", logmsg, m.Credentials.Team, m.Credentials.Login, m.Credentials.Server)
if strings.Contains(m.Credentials.Pass, model.SESSION_COOKIE_TOKEN) {
m.log.Debugf(logmsg + " with token")
token := strings.Split(m.Credentials.Pass, model.SESSION_COOKIE_TOKEN+"=")
if len(token) != 2 {
return errors.New("incorrect MMAUTHTOKEN. valid input is MMAUTHTOKEN=yourtoken")
}
m.Client.HttpClient.Jar = m.createCookieJar(token[1])
m.Client.AuthToken = token[1]
m.Client.AuthType = model.HEADER_BEARER
m.User, resp = m.Client.GetMe("")
if resp.Error != nil {
return resp.Error
}
if m.User == nil {
m.log.Errorf("LOGIN TOKEN: %s is invalid", m.Credentials.Pass)
return errors.New("invalid " + model.SESSION_COOKIE_TOKEN)
}
} else {
m.User, resp = m.Client.Login(m.Credentials.Login, m.Credentials.Pass)
}
appErr = resp.Error
if appErr != nil {
d := b.Duration()
m.log.Debug(appErr.DetailedError)
if firstConnection {
if appErr.Message == "" {
return errors.New(appErr.DetailedError)
}
return errors.New(appErr.Message)
}
m.log.Debugf("LOGIN: %s, reconnecting in %s", appErr, d)
time.Sleep(d)
logmsg = "retrying login"
continue
}
break
}
// reset timer
b.Reset()
err := m.initUser()
if err != nil {
return err
}
if m.Team == nil {
return errors.New("team not found")
}
m.wsConnect()
return nil
}
func (m *MMClient) wsConnect() {
b := &backoff.Backoff{
Min: time.Second,
Max: 5 * time.Minute,
Jitter: true,
}
m.WsConnected = false
wsScheme := "wss://"
if m.NoTLS {
wsScheme = "ws://"
}
// setup websocket connection
wsurl := wsScheme + m.Credentials.Server + model.API_URL_SUFFIX_V4 + "/websocket"
header := http.Header{}
header.Set(model.HEADER_AUTH, "BEARER "+m.Client.AuthToken)
m.log.Debugf("WsClient: making connection: %s", wsurl)
for {
wsDialer := &websocket.Dialer{Proxy: http.ProxyFromEnvironment, TLSClientConfig: &tls.Config{InsecureSkipVerify: m.SkipTLSVerify}}
var err error
m.WsClient, _, err = wsDialer.Dial(wsurl, header)
if err != nil {
d := b.Duration()
m.log.Debugf("WSS: %s, reconnecting in %s", err, d)
time.Sleep(d)
continue
}
break
}
m.log.Debug("WsClient: connected")
m.WsSequence = 1
m.WsPingChan = make(chan *model.WebSocketResponse)
// only start to parse WS messages when login is completely done
m.WsConnected = true
}
func (m *MMClient) Logout() error {
m.log.Debugf("logout as %s (team: %s) on %s", m.Credentials.Login, m.Credentials.Team, m.Credentials.Server)
m.WsQuit = true
m.WsClient.Close()
m.WsClient.UnderlyingConn().Close()
if strings.Contains(m.Credentials.Pass, model.SESSION_COOKIE_TOKEN) {
m.log.Debug("Not invalidating session in logout, credential is a token")
return nil
}
_, resp := m.Client.Logout()
if resp.Error != nil {
return resp.Error
}
return nil
}
func (m *MMClient) WsReceiver() {
for {
var rawMsg json.RawMessage
var err error
if m.WsQuit {
m.log.Debug("exiting WsReceiver")
return
}
if !m.WsConnected {
time.Sleep(time.Millisecond * 100)
continue
}
if _, rawMsg, err = m.WsClient.ReadMessage(); err != nil {
m.log.Error("error:", err)
// reconnect
m.wsConnect()
}
var event model.WebSocketEvent
if err := json.Unmarshal(rawMsg, &event); err == nil && event.IsValid() {
m.log.Debugf("WsReceiver event: %#v", event)
msg := &Message{Raw: &event, Team: m.Credentials.Team}
m.parseMessage(msg)
// check if we didn't empty the message
if msg.Text != "" {
m.MessageChan <- msg
continue
}
// if we have file attached but the message is empty, also send it
if msg.Post != nil {
if msg.Text != "" || len(msg.Post.FileIds) > 0 || msg.Post.Type == "slack_attachment" {
m.MessageChan <- msg
}
}
continue
}
var response model.WebSocketResponse
if err := json.Unmarshal(rawMsg, &response); err == nil && response.IsValid() {
m.log.Debugf("WsReceiver response: %#v", response)
m.parseResponse(response)
continue
}
}
}
func (m *MMClient) parseMessage(rmsg *Message) {
switch rmsg.Raw.Event {
case model.WEBSOCKET_EVENT_POSTED, model.WEBSOCKET_EVENT_POST_EDITED, model.WEBSOCKET_EVENT_POST_DELETED:
m.parseActionPost(rmsg)
/*
case model.ACTION_USER_REMOVED:
m.handleWsActionUserRemoved(&rmsg)
case model.ACTION_USER_ADDED:
m.handleWsActionUserAdded(&rmsg)
*/
}
}
func (m *MMClient) parseResponse(rmsg model.WebSocketResponse) {
if rmsg.Data != nil {
// ping reply
if rmsg.Data["text"].(string) == "pong" {
m.WsPingChan <- &rmsg
}
}
}
func (m *MMClient) parseActionPost(rmsg *Message) {
// add post to cache, if it already exists don't relay this again.
// this should fix reposts
if ok, _ := m.lruCache.ContainsOrAdd(digestString(rmsg.Raw.Data["post"].(string)), true); ok {
m.log.Debugf("message %#v in cache, not processing again", rmsg.Raw.Data["post"].(string))
rmsg.Text = ""
return
}
data := model.PostFromJson(strings.NewReader(rmsg.Raw.Data["post"].(string)))
// we don't have the user, refresh the userlist
if m.GetUser(data.UserId) == nil {
m.log.Infof("User %s is not known, ignoring message %s", data)
return
}
rmsg.Username = m.GetUserName(data.UserId)
rmsg.Channel = m.GetChannelName(data.ChannelId)
rmsg.UserID = data.UserId
rmsg.Type = data.Type
teamid, _ := rmsg.Raw.Data["team_id"].(string)
// edit messsages have no team_id for some reason
if teamid == "" {
// we can find the team_id from the channelid
teamid = m.GetChannelTeamId(data.ChannelId)
rmsg.Raw.Data["team_id"] = teamid
}
if teamid != "" {
rmsg.Team = m.GetTeamName(teamid)
}
// direct message
if rmsg.Raw.Data["channel_type"] == "D" {
rmsg.Channel = m.GetUser(data.UserId).Username
}
rmsg.Text = data.Message
rmsg.Post = data
}
func (m *MMClient) UpdateUsers() error {
mmusers, resp := m.Client.GetUsers(0, 50000, "")
if resp.Error != nil {
return errors.New(resp.Error.DetailedError)
}
m.Lock()
for _, user := range mmusers {
m.Users[user.Id] = user
}
m.Unlock()
return nil
}
func (m *MMClient) UpdateChannels() error {
mmchannels, resp := m.Client.GetChannelsForTeamForUser(m.Team.Id, m.User.Id, "")
if resp.Error != nil {
return errors.New(resp.Error.DetailedError)
}
m.Lock()
m.Team.Channels = mmchannels
m.Unlock()
mmchannels, resp = m.Client.GetPublicChannelsForTeam(m.Team.Id, 0, 5000, "")
if resp.Error != nil {
return errors.New(resp.Error.DetailedError)
}
m.Lock()
m.Team.MoreChannels = mmchannels
m.Unlock()
return nil
}
func (m *MMClient) GetChannelName(channelId string) string {
m.RLock()
defer m.RUnlock()
for _, t := range m.OtherTeams {
if t == nil {
continue
}
if t.Channels != nil {
for _, channel := range t.Channels {
if channel.Id == channelId {
return channel.Name
}
}
}
if t.MoreChannels != nil {
for _, channel := range t.MoreChannels {
if channel.Id == channelId {
return channel.Name
}
}
}
}
return ""
}
func (m *MMClient) GetChannelId(name string, teamId string) string {
m.RLock()
defer m.RUnlock()
if teamId == "" {
teamId = m.Team.Id
}
for _, t := range m.OtherTeams {
if t.Id == teamId {
for _, channel := range append(t.Channels, t.MoreChannels...) {
if channel.Name == name {
return channel.Id
}
}
}
}
return ""
}
func (m *MMClient) GetChannelTeamId(id string) string {
m.RLock()
defer m.RUnlock()
for _, t := range append(m.OtherTeams, m.Team) {
for _, channel := range append(t.Channels, t.MoreChannels...) {
if channel.Id == id {
return channel.TeamId
}
}
}
return ""
}
func (m *MMClient) GetChannelHeader(channelId string) string {
m.RLock()
defer m.RUnlock()
for _, t := range m.OtherTeams {
for _, channel := range append(t.Channels, t.MoreChannels...) {
if channel.Id == channelId {
return channel.Header
}
}
}
return ""
}
func (m *MMClient) PostMessage(channelId string, text string) (string, error) {
post := &model.Post{ChannelId: channelId, Message: text}
res, resp := m.Client.CreatePost(post)
if resp.Error != nil {
return "", resp.Error
}
return res.Id, nil
}
func (m *MMClient) PostMessageWithFiles(channelId string, text string, fileIds []string) (string, error) {
post := &model.Post{ChannelId: channelId, Message: text, FileIds: fileIds}
res, resp := m.Client.CreatePost(post)
if resp.Error != nil {
return "", resp.Error
}
return res.Id, nil
}
func (m *MMClient) EditMessage(postId string, text string) (string, error) {
post := &model.Post{Message: text}
res, resp := m.Client.UpdatePost(postId, post)
if resp.Error != nil {
return "", resp.Error
}
return res.Id, nil
}
func (m *MMClient) DeleteMessage(postId string) error {
_, resp := m.Client.DeletePost(postId)
if resp.Error != nil {
return resp.Error
}
return nil
}
func (m *MMClient) JoinChannel(channelId string) error {
m.RLock()
defer m.RUnlock()
for _, c := range m.Team.Channels {
if c.Id == channelId {
m.log.Debug("Not joining ", channelId, " already joined.")
return nil
}
}
m.log.Debug("Joining ", channelId)
_, resp := m.Client.AddChannelMember(channelId, m.User.Id)
if resp.Error != nil {
return resp.Error
}
return nil
}
func (m *MMClient) GetPostsSince(channelId string, time int64) *model.PostList {
res, resp := m.Client.GetPostsSince(channelId, time)
if resp.Error != nil {
return nil
}
return res
}
func (m *MMClient) SearchPosts(query string) *model.PostList {
res, resp := m.Client.SearchPosts(m.Team.Id, query, false)
if resp.Error != nil {
return nil
}
return res
}
func (m *MMClient) GetPosts(channelId string, limit int) *model.PostList {
res, resp := m.Client.GetPostsForChannel(channelId, 0, limit, "")
if resp.Error != nil {
return nil
}
return res
}
func (m *MMClient) GetPublicLink(filename string) string {
res, resp := m.Client.GetFileLink(filename)
if resp.Error != nil {
return ""
}
return res
}
func (m *MMClient) GetPublicLinks(filenames []string) []string {
var output []string
for _, f := range filenames {
res, resp := m.Client.GetFileLink(f)
if resp.Error != nil {
continue
}
output = append(output, res)
}
return output
}
func (m *MMClient) GetFileLinks(filenames []string) []string {
uriScheme := "https://"
if m.NoTLS {
uriScheme = "http://"
}
var output []string
for _, f := range filenames {
res, resp := m.Client.GetFileLink(f)
if resp.Error != nil {
// public links is probably disabled, create the link ourselves
output = append(output, uriScheme+m.Credentials.Server+model.API_URL_SUFFIX_V3+"/files/"+f+"/get")
continue
}
output = append(output, res)
}
return output
}
func (m *MMClient) UpdateChannelHeader(channelId string, header string) {
channel := &model.Channel{Id: channelId, Header: header}
m.log.Debugf("updating channelheader %#v, %#v", channelId, header)
_, resp := m.Client.UpdateChannel(channel)
if resp.Error != nil {
log.Error(resp.Error)
}
}
func (m *MMClient) UpdateLastViewed(channelId string) {
m.log.Debugf("posting lastview %#v", channelId)
view := &model.ChannelView{ChannelId: channelId}
_, resp := m.Client.ViewChannel(m.User.Id, view)
if resp.Error != nil {
m.log.Errorf("ChannelView update for %s failed: %s", channelId, resp.Error)
}
}
func (m *MMClient) UpdateUserNick(nick string) error {
user := m.User
user.Nickname = nick
_, resp := m.Client.UpdateUser(user)
if resp.Error != nil {
return resp.Error
}
return nil
}
func (m *MMClient) UsernamesInChannel(channelId string) []string {
res, resp := m.Client.GetChannelMembers(channelId, 0, 50000, "")
if resp.Error != nil {
m.log.Errorf("UsernamesInChannel(%s) failed: %s", channelId, resp.Error)
return []string{}
}
allusers := m.GetUsers()
result := []string{}
for _, member := range *res {
result = append(result, allusers[member.UserId].Nickname)
}
return result
}
func (m *MMClient) createCookieJar(token string) *cookiejar.Jar {
var cookies []*http.Cookie
jar, _ := cookiejar.New(nil)
firstCookie := &http.Cookie{
Name: "MMAUTHTOKEN",
Value: token,
Path: "/",
Domain: m.Credentials.Server,
}
cookies = append(cookies, firstCookie)
cookieURL, _ := url.Parse("https://" + m.Credentials.Server)
jar.SetCookies(cookieURL, cookies)
return jar
}
// SendDirectMessage sends a direct message to specified user
func (m *MMClient) SendDirectMessage(toUserId string, msg string) {
m.log.Debugf("SendDirectMessage to %s, msg %s", toUserId, msg)
// create DM channel (only happens on first message)
_, resp := m.Client.CreateDirectChannel(m.User.Id, toUserId)
if resp.Error != nil {
m.log.Debugf("SendDirectMessage to %#v failed: %s", toUserId, resp.Error)
return
}
channelName := model.GetDMNameFromIds(toUserId, m.User.Id)
// update our channels
m.UpdateChannels()
// build & send the message
msg = strings.Replace(msg, "\r", "", -1)
post := &model.Post{ChannelId: m.GetChannelId(channelName, ""), Message: msg}
m.Client.CreatePost(post)
}
// GetTeamName returns the name of the specified teamId
func (m *MMClient) GetTeamName(teamId string) string {
m.RLock()
defer m.RUnlock()
for _, t := range m.OtherTeams {
if t.Id == teamId {
return t.Team.Name
}
}
return ""
}
// GetChannels returns all channels we're members off
func (m *MMClient) GetChannels() []*model.Channel {
m.RLock()
defer m.RUnlock()
var channels []*model.Channel
// our primary team channels first
channels = append(channels, m.Team.Channels...)
for _, t := range m.OtherTeams {
if t.Id != m.Team.Id {
channels = append(channels, t.Channels...)
}
}
return channels
}
// GetMoreChannels returns existing channels where we're not a member off.
func (m *MMClient) GetMoreChannels() []*model.Channel {
m.RLock()
defer m.RUnlock()
var channels []*model.Channel
for _, t := range m.OtherTeams {
channels = append(channels, t.MoreChannels...)
}
return channels
}
// GetTeamFromChannel returns teamId belonging to channel (DM channels have no teamId).
func (m *MMClient) GetTeamFromChannel(channelId string) string {
m.RLock()
defer m.RUnlock()
var channels []*model.Channel
for _, t := range m.OtherTeams {
channels = append(channels, t.Channels...)
if t.MoreChannels != nil {
channels = append(channels, t.MoreChannels...)
}
for _, c := range channels {
if c.Id == channelId {
return t.Id
}
}
}
return ""
}
func (m *MMClient) GetLastViewedAt(channelId string) int64 {
m.RLock()
defer m.RUnlock()
res, resp := m.Client.GetChannelMember(channelId, m.User.Id, "")
if resp.Error != nil {
return model.GetMillis()
}
return res.LastViewedAt
}
func (m *MMClient) GetUsers() map[string]*model.User {
users := make(map[string]*model.User)
m.RLock()
defer m.RUnlock()
for k, v := range m.Users {
users[k] = v
}
return users
}
func (m *MMClient) GetUser(userId string) *model.User {
m.Lock()
defer m.Unlock()
_, ok := m.Users[userId]
if !ok {
res, resp := m.Client.GetUser(userId, "")
if resp.Error != nil {
return nil
}
m.Users[userId] = res
}
return m.Users[userId]
}
func (m *MMClient) GetUserName(userId string) string {
user := m.GetUser(userId)
if user != nil {
return user.Username
}
return ""
}
func (m *MMClient) GetStatus(userId string) string {
res, resp := m.Client.GetUserStatus(userId, "")
if resp.Error != nil {
return ""
}
if res.Status == model.STATUS_AWAY {
return "away"
}
if res.Status == model.STATUS_ONLINE {
return "online"
}
return "offline"
}
func (m *MMClient) GetStatuses() map[string]string {
var ids []string
statuses := make(map[string]string)
for id := range m.Users {
ids = append(ids, id)
}
res, resp := m.Client.GetUsersStatusesByIds(ids)
if resp.Error != nil {
return statuses
}
for _, status := range res {
statuses[status.UserId] = "offline"
if status.Status == model.STATUS_AWAY {
statuses[status.UserId] = "away"
}
if status.Status == model.STATUS_ONLINE {
statuses[status.UserId] = "online"
}
}
return statuses
}
func (m *MMClient) GetTeamId() string {
return m.Team.Id
}
func (m *MMClient) UploadFile(data []byte, channelId string, filename string) (string, error) {
f, resp := m.Client.UploadFile(data, channelId, filename)
if resp.Error != nil {
return "", resp.Error
}
return f.FileInfos[0].Id, nil
}
func (m *MMClient) StatusLoop() {
retries := 0
backoff := time.Second * 60
if m.OnWsConnect != nil {
m.OnWsConnect()
}
m.log.Debug("StatusLoop:", m.OnWsConnect)
for {
if m.WsQuit {
return
}
if m.WsConnected {
m.log.Debug("WS PING")
m.sendWSRequest("ping", nil)
select {
case <-m.WsPingChan:
m.log.Debug("WS PONG received")
backoff = time.Second * 60
case <-time.After(time.Second * 5):
if retries > 3 {
m.log.Debug("StatusLoop() timeout")
m.Logout()
m.WsQuit = false
err := m.Login()
if err != nil {
log.Errorf("Login failed: %#v", err)
break
}
if m.OnWsConnect != nil {
m.OnWsConnect()
}
go m.WsReceiver()
} else {
retries++
backoff = time.Second * 5
}
}
}
time.Sleep(backoff)
}
}
// initialize user and teams
func (m *MMClient) initUser() error {
m.Lock()
defer m.Unlock()
// we only load all team data on initial login.
// all other updates are for channels from our (primary) team only.
//m.log.Debug("initUser(): loading all team data")
teams, resp := m.Client.GetTeamsForUser(m.User.Id, "")
if resp.Error != nil {
return resp.Error
}
for _, team := range teams {
mmusers, resp := m.Client.GetUsersInTeam(team.Id, 0, 50000, "")
if resp.Error != nil {
return errors.New(resp.Error.DetailedError)
}
usermap := make(map[string]*model.User)
for _, user := range mmusers {
usermap[user.Id] = user
}
t := &Team{Team: team, Users: usermap, Id: team.Id}
mmchannels, resp := m.Client.GetChannelsForTeamForUser(team.Id, m.User.Id, "")
if resp.Error != nil {
return resp.Error
}
t.Channels = mmchannels
mmchannels, resp = m.Client.GetPublicChannelsForTeam(team.Id, 0, 5000, "")
if resp.Error != nil {
return resp.Error
}
t.MoreChannels = mmchannels
m.OtherTeams = append(m.OtherTeams, t)
if team.Name == m.Credentials.Team {
m.Team = t
m.log.Debugf("initUser(): found our team %s (id: %s)", team.Name, team.Id)
}
// add all users
for k, v := range t.Users {
m.Users[k] = v
}
}
return nil
}
func (m *MMClient) sendWSRequest(action string, data map[string]interface{}) error {
req := &model.WebSocketRequest{}
req.Seq = m.WsSequence
req.Action = action
req.Data = data
m.WsSequence++
m.log.Debugf("sendWsRequest %#v", req)
m.WsClient.WriteJSON(req)
return nil
}
func supportedVersion(version string) bool {
if strings.HasPrefix(version, "3.8.0") ||
strings.HasPrefix(version, "3.9.0") ||
strings.HasPrefix(version, "3.10.0") ||
strings.HasPrefix(version, "4.") {
return true
}
return false
}
func digestString(s string) string {
return fmt.Sprintf("%x", md5.Sum([]byte(s)))
}