go-ricochet/ricochet.go

383 lines
12 KiB
Go

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