383 lines
12 KiB
Go
383 lines
12 KiB
Go
package goricochet
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import (
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"errors"
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"github.com/golang/protobuf/proto"
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"github.com/s-rah/go-ricochet/auth"
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"github.com/s-rah/go-ricochet/chat"
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"github.com/s-rah/go-ricochet/contact"
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"github.com/s-rah/go-ricochet/control"
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"github.com/s-rah/go-ricochet/utils"
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"log"
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"net"
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"strconv"
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)
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// Ricochet is a protocol to conducting anonymous IM.
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type Ricochet struct {
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newconns chan *OpenConnection
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networkResolver utils.NetworkResolver
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rni utils.RicochetNetworkInterface
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}
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// Init sets up the Ricochet object.
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func (r *Ricochet) Init() {
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r.newconns = make(chan *OpenConnection)
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r.networkResolver = utils.NetworkResolver{}
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r.rni = new(utils.RicochetNetwork)
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}
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// Connect sets up a client ricochet connection to host e.g. qn6uo4cmsrfv4kzq.onion. If this
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// function finished successfully then the connection can be assumed to
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// be open and authenticated.
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// To specify a local port using the format "127.0.0.1:[port]|ricochet-id".
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func (r *Ricochet) Connect(host string) (*OpenConnection, error) {
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var err error
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conn, host, err := r.networkResolver.Resolve(host)
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if err != nil {
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return nil, err
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}
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return r.ConnectOpen(conn, host)
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}
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func (r *Ricochet) ConnectOpen(conn net.Conn, host string) (*OpenConnection, error) {
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oc, err := r.negotiateVersion(conn, true)
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if err != nil {
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return nil, err
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}
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oc.OtherHostname = host
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r.newconns <- oc
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return oc, nil
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}
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// Server launches a new server listening on port
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func (r *Ricochet) Server(service RicochetService, port int) {
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ln, err := net.Listen("tcp", "127.0.0.1:"+strconv.Itoa(port))
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if err != nil {
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log.Printf("Cannot Listen on Port %v", port)
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return
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}
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r.ServeListener(service, ln)
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}
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func (r *Ricochet) ServeListener(service RicochetService, ln net.Listener) {
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go r.ProcessMessages(service)
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service.OnReady()
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for {
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// accept connection on port
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conn, err := ln.Accept()
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if err != nil {
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return
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}
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go r.processNewConnection(conn, service)
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}
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}
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// processNewConnection sets up a new connection
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func (r *Ricochet) processNewConnection(conn net.Conn, service RicochetService) {
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oc, err := r.negotiateVersion(conn, false)
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if err == nil {
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r.newconns <- oc
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service.OnConnect(oc)
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}
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}
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// ProcessMessages is intended to be a background thread listening for all messages
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// a client will send. The given RicochetService will be used to respond to messages.
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// Prerequisites:
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// * Must have previously issued a successful Connect()
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func (r *Ricochet) ProcessMessages(service RicochetService) {
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for {
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oc := <-r.newconns
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go r.processConnection(oc, service)
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}
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}
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// ProcessConnection starts a blocking process loop which continually waits for
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// new messages to arrive from the connection and uses the given RicochetService
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// to process them.
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func (r *Ricochet) processConnection(oc *OpenConnection, service RicochetService) {
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service.OnConnect(oc)
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defer service.OnDisconnect(oc)
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for {
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if oc.Closed {
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return
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}
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packets, err := r.rni.RecvRicochetPackets(oc.conn)
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if err != nil {
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return
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}
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for _, packet := range packets {
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if len(packet.Data) == 0 {
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service.OnChannelClosed(oc, packet.Channel)
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continue
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}
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if packet.Channel == 0 {
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res := new(Protocol_Data_Control.Packet)
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err := proto.Unmarshal(packet.Data[:], res)
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if err != nil {
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service.OnGenericError(oc, packet.Channel)
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continue
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}
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if res.GetOpenChannel() != nil {
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opm := res.GetOpenChannel()
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if oc.GetChannelType(opm.GetChannelIdentifier()) != "none" {
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// Channel is already in use.
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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continue
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}
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// If I am a Client, the server can only open even numbered channels
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if oc.Client && opm.GetChannelIdentifier()%2 != 0 {
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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continue
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}
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// If I am a Server, the client can only open odd numbered channels
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if !oc.Client && opm.GetChannelIdentifier()%2 != 1 {
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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continue
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}
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switch opm.GetChannelType() {
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case "im.ricochet.auth.hidden-service":
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if oc.Client {
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// Servers are authed by default and can't auth with hidden-service
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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} else if oc.IsAuthed {
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// Can't auth if already authed
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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} else if oc.HasChannel("im.ricochet.auth.hidden-service") {
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// Can't open more than 1 auth channel
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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} else {
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clientCookie, err := proto.GetExtension(opm, Protocol_Data_AuthHiddenService.E_ClientCookie)
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if err == nil {
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clientCookieB := [16]byte{}
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copy(clientCookieB[:], clientCookie.([]byte)[:])
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service.OnAuthenticationRequest(oc, opm.GetChannelIdentifier(), clientCookieB)
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} else {
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// Must include Client Cookie
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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}
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}
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case "im.ricochet.chat":
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if !oc.IsAuthed {
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// Can't open chat channel if not authorized
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service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
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} else if !service.IsKnownContact(oc.OtherHostname) {
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// Can't open chat channel if not a known contact
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service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
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} else {
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service.OnOpenChannelRequest(oc, opm.GetChannelIdentifier(), "im.ricochet.chat")
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}
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case "im.ricochet.contact.request":
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if oc.Client {
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// Servers are not allowed to send contact requests
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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} else if !oc.IsAuthed {
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// Can't open a contact channel if not authed
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service.OnUnauthorizedError(oc, opm.GetChannelIdentifier())
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} else if oc.HasChannel("im.ricochet.contact.request") {
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// Only 1 contact channel is allowed to be open at a time
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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} else {
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contactRequestI, err := proto.GetExtension(opm, Protocol_Data_ContactRequest.E_ContactRequest)
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if err == nil {
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contactRequest, check := contactRequestI.(*Protocol_Data_ContactRequest.ContactRequest)
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if check {
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service.OnContactRequest(oc, opm.GetChannelIdentifier(), contactRequest.GetNickname(), contactRequest.GetMessageText())
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break
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}
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}
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service.OnBadUsageError(oc, opm.GetChannelIdentifier())
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}
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default:
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service.OnUnknownTypeError(oc, opm.GetChannelIdentifier())
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}
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} else if res.GetChannelResult() != nil {
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crm := res.GetChannelResult()
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if crm.GetOpened() {
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switch oc.GetChannelType(crm.GetChannelIdentifier()) {
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case "im.ricochet.auth.hidden-service":
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serverCookie, err := proto.GetExtension(crm, Protocol_Data_AuthHiddenService.E_ServerCookie)
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if err == nil {
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serverCookieB := [16]byte{}
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copy(serverCookieB[:], serverCookie.([]byte)[:])
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service.OnAuthenticationChallenge(oc, crm.GetChannelIdentifier(), serverCookieB)
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} else {
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service.OnBadUsageError(oc, crm.GetChannelIdentifier())
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}
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case "im.ricochet.chat":
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service.OnOpenChannelRequestSuccess(oc, crm.GetChannelIdentifier())
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case "im.ricochet.contact.request":
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responseI, err := proto.GetExtension(res.GetChannelResult(), Protocol_Data_ContactRequest.E_Response)
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if err == nil {
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response, check := responseI.(*Protocol_Data_ContactRequest.Response)
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if check {
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service.OnContactRequestAck(oc, crm.GetChannelIdentifier(), response.GetStatus().String())
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break
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}
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}
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service.OnBadUsageError(oc, crm.GetChannelIdentifier())
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default:
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service.OnBadUsageError(oc, crm.GetChannelIdentifier())
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}
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} else {
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if oc.GetChannelType(crm.GetChannelIdentifier()) != "none" {
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service.OnFailedChannelOpen(oc, crm.GetChannelIdentifier(), crm.GetCommonError().String())
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} else {
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oc.CloseChannel(crm.GetChannelIdentifier())
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}
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}
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} else {
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// Unknown Message
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oc.CloseChannel(packet.Channel)
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}
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} else if oc.GetChannelType(packet.Channel) == "im.ricochet.auth.hidden-service" {
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res := new(Protocol_Data_AuthHiddenService.Packet)
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err := proto.Unmarshal(packet.Data[:], res)
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if err != nil {
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oc.CloseChannel(packet.Channel)
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continue
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}
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if res.GetProof() != nil && !oc.Client { // Only Clients Send Proofs
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service.OnAuthenticationProof(oc, packet.Channel, res.GetProof().GetPublicKey(), res.GetProof().GetSignature(), service.IsKnownContact(oc.OtherHostname))
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} else if res.GetResult() != nil && oc.Client { // Only Servers Send Results
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service.OnAuthenticationResult(oc, packet.Channel, res.GetResult().GetAccepted(), res.GetResult().GetIsKnownContact())
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} else {
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// If neither of the above are satisfied we just close the connection
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oc.Close()
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}
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} else if oc.GetChannelType(packet.Channel) == "im.ricochet.chat" {
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// NOTE: These auth checks should be redundant, however they
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// are included here for defense-in-depth if for some reason
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// a previously authed connection becomes untrusted / not known and
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// the state is not cleaned up.
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if !oc.IsAuthed {
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// Can't send chat messages if not authorized
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service.OnUnauthorizedError(oc, packet.Channel)
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} else if !service.IsKnownContact(oc.OtherHostname) {
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// Can't send chat message if not a known contact
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service.OnUnauthorizedError(oc, packet.Channel)
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} else {
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res := new(Protocol_Data_Chat.Packet)
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err := proto.Unmarshal(packet.Data[:], res)
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if err != nil {
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oc.CloseChannel(packet.Channel)
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continue
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}
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if res.GetChatMessage() != nil {
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service.OnChatMessage(oc, packet.Channel, int32(res.GetChatMessage().GetMessageId()), res.GetChatMessage().GetMessageText())
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} else if res.GetChatAcknowledge() != nil {
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service.OnChatMessageAck(oc, packet.Channel, int32(res.GetChatMessage().GetMessageId()))
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} else {
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// If neither of the above are satisfied we just close the connection
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oc.Close()
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}
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}
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} else if oc.GetChannelType(packet.Channel) == "im.ricochet.contact.request" {
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// NOTE: These auth checks should be redundant, however they
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// are included here for defense-in-depth if for some reason
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// a previously authed connection becomes untrusted / not known and
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// the state is not cleaned up.
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if !oc.Client {
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// Clients are not allowed to send contact request responses
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service.OnBadUsageError(oc, packet.Channel)
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} else if !oc.IsAuthed {
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// Can't send a contact request if not authed
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service.OnBadUsageError(oc, packet.Channel)
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} else {
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res := new(Protocol_Data_ContactRequest.Response)
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err := proto.Unmarshal(packet.Data[:], res)
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log.Printf("%v", res)
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if err != nil {
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oc.CloseChannel(packet.Channel)
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continue
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}
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service.OnContactRequestAck(oc, packet.Channel, res.GetStatus().String())
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}
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} else if oc.GetChannelType(packet.Channel) == "none" {
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// Invalid Channel Assignment
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oc.CloseChannel(packet.Channel)
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} else {
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oc.Close()
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}
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}
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}
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}
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// negotiateVersion Perform version negotiation with the connected host.
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func (r *Ricochet) negotiateVersion(conn net.Conn, outbound bool) (*OpenConnection, error) {
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version := make([]byte, 4)
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version[0] = 0x49
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version[1] = 0x4D
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version[2] = 0x01
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version[3] = 0x01
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// If this was initiated by us then we need to initiate the version info.
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if outbound {
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// Send Version String
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conn.Write(version)
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res, err := r.rni.Recv(conn)
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if len(res) != 1 || err != nil {
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return nil, errors.New("Failed Version Negotiating")
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}
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if res[0] != 1 {
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return nil, errors.New("Failed Version Negotiating - Invalid Version ")
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}
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} else {
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// Do Version Negotiation
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buf := make([]byte, 10)
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n, err := conn.Read(buf)
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if err != nil && n >= 4 {
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return nil, err
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}
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if buf[0] == version[0] && buf[1] == version[1] {
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foundVersion := false
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if buf[2] >= 1 {
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for i := 3; i < n; i++ {
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if buf[i] == 0x01 {
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conn.Write([]byte{0x01})
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foundVersion = true
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}
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}
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}
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if !foundVersion {
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return nil, errors.New("Failed Version Negotiating - No Available Version")
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}
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} else {
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return nil, errors.New("Failed Version Negotiating - Invalid Version Header")
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}
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}
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oc := new(OpenConnection)
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oc.Init(outbound, conn)
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return oc, nil
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}
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