// Can only be called from the handling goroutine for conn.
func handleFollowUsername(conn *userConn, content []byte) {
var msg cliproto_up.FollowUsername
if err := proto.Unmarshal(content, &msg); err != nil {
conn.conn.Close()
return
}
// Start transaction.
store.StartTransaction()
defer store.EndTransaction()
sessionsLock.Lock()
defer sessionsLock.Unlock()
// Authentication check.
if conn.session == 0 {
conn.conn.Close()
return
}
// Lookup this user.
followId := store.NameLookup("user", "name username", *msg.Username)
if followId == 0 {
sendFollowUsernameFail(conn, *msg.Username, "No Such User")
return
}
// Check we're not already following this user.
// If we are, discard the message.
for _, existing := range conn.following {
if existing == followId {
return
}
}
// Start following this user.
followUser(conn, followId)
}
// Can only be called from the handling goroutine for conn.
func handleAuth(conn *userConn, content []byte) {
var msg cliproto_up.Authenticate
if err := proto.Unmarshal(content, &msg); err != nil {
conn.conn.Close()
return
}
// Try to get information, then release locks and hash the password.
// If the situation changes we may have to hash it again anyway,
// but scrypt hashing is extremely expensive and we want to try to
// do this without holding our locks in the vast majority of cases.
var tryPassGenerated bool
var trySaltGenerated bool
var tryPass, trySalt, tryKey string
if *msg.Password != "" {
tryPass = *msg.Password
store.StartTransaction()
userId := store.NameLookup("user", "name username",
*msg.Username)
if userId != 0 {
user := store.GetEntity(userId)
if user != nil {
trySalt = user.Value("auth salt")
}
}
store.EndTransaction()
if trySalt == "" {
trySaltGenerated = true
var err error
trySalt, tryKey, err = genRandomSalt(conn,
[]byte(tryPass))
if err != nil {
return
}
} else {
var err error
tryPass, err = genKey(conn, []byte(tryPass),
[]byte(trySalt))
if err != nil {
return
}
}
} else {
tryPassGenerated = true
trySaltGenerated = true
var err error
tryPass, trySalt, tryKey, err = genRandomPass(conn)
if err != nil {
return
}
}
// TODO: Validate username and password against constraints.
// We hold this through quite a lot of logic.
// Would be good to be locked less.
store.StartTransaction()
defer store.EndTransaction()
sessionsLock.Lock()
defer sessionsLock.Unlock()
waitingLock.Lock()
defer waitingLock.Unlock()
if conn.session != 0 || conn.waitingAuth != nil {
conn.conn.Close()
return
}
userId := store.NameLookup("user", "name username", *msg.Username)
if userId != 0 {
if *msg.Password == "" {
sendAuthFail(conn, "Invalid Password")
return
}
// The user already exists.
user := store.GetEntity(userId)
// Try to authenticate them to it.
var key string
// If their salt and password matches our attempt above,
// we can just take that key.
salt := user.Value("auth salt")
if trySalt == salt && tryPass == *msg.Password {
key = tryKey
} else {
saltBytes := []byte(user.Value("auth salt"))
passBytes := []byte(*msg.Password)
var err error
key, err = genKey(conn, passBytes, saltBytes)
if err != nil {
return
}
}
if user.Value("auth password") != string(key) {
sendAuthFail(conn, "Invalid Password")
return
}
// It's the real user.
if *msg.SessionId != 0 {
// They are attaching to an existing session.
// Check it exists and is attached to this user.
strSessionId := strconv.FormatUint(*msg.SessionId, 10)
if user.Value("attach "+strSessionId) == "" {
sendAuthFail(conn, "Invalid Session")
return
}
// The session does exist.
conn.session = *msg.SessionId
// If this node is already attached to
// the session, drop the other connection.
if sessions[conn.session] != nil {
sessions[conn.session].conn.Close()
} else {
// Create change attaching this node ID
// to the session.
id := config.Id()
idStr := strconv.FormatUint(uint64(id), 10)
chset := make([]store.Change, 1)
chset[0].TargetEntity = conn.session
chset[0].Key = "attach " + idStr
chset[0].Value = "true"
req := makeRequest(chset)
go chrequest.Request(req)
}
// Put us in the sessions map.
sessions[conn.session] = conn
// Tell the client they authenticated successfully.
sendAuthSuccess(conn, "")
} else {
// They are creating a new session.
req := makeNewSessionRequest(userId)
go chrequest.Request(req)
// Stuff details in waiting auth.
conn.waitingAuth = new(authData)
conn.waitingAuth.msg = msg
conn.waitingAuth.requestId = req.RequestId
waiting[conn.waitingAuth.requestId] = conn
}
} else {
// The user does not already exist.
// Check they weren't trying to attach to a session.
if *msg.SessionId != 0 {
sendAuthFail(conn, "User Does Not Exist")
return
}
// We're creating a new user.
newUser := *msg.Username
newPass := *msg.Password
if !strings.HasPrefix(newUser, "Guest-") {
// We're creating a new non-guest user.
// Make sure they have a password.
if newPass == "" {
sendAuthFail(conn, "No Password")
return
}
var salt string
var hash string
if tryPass == newPass && trySaltGenerated {
salt = trySalt
hash = tryKey
} else {
passBytes := []byte(newPass)
var err error
salt, hash, err = genRandomSalt(conn, passBytes)
if err != nil {
return
}
}
// Create the new user.
req := makeNewUserRequest(newUser, hash, salt, false)
go chrequest.Request(req)
// Stuff details in waiting auth.
conn.waitingAuth = new(authData)
conn.waitingAuth.msg = msg
conn.waitingAuth.requestId = req.RequestId
waiting[conn.waitingAuth.requestId] = conn
return
}
// We're creating a new guest user.
// Guests get automatic passwords, and can't set them.
if newPass != "" {
sendAuthFail(conn, "Cannot Set Password For Guest User")
return
}
var hash string
var salt string
if tryPassGenerated && trySaltGenerated {
newPass = tryPass
salt = trySalt
hash = tryKey
} else {
var err error
newPass, salt, hash, err = genRandomPass(conn)
if err != nil {
return
}
}
waitingLock.Lock()
// Create the new user.
req := makeNewUserRequest(newUser, hash, salt, true)
go chrequest.Request(req)
// Stuff details in waiting auth.
conn.waitingAuth = new(authData)
conn.waitingAuth.msg = msg
conn.waitingAuth.requestId = req.RequestId
waiting[conn.waitingAuth.requestId] = conn
waitingLock.Unlock()
return
}
}