yggdrasil-go/src/yggdrasil/wire.go
2018-06-02 22:19:42 +01:00

572 lines
14 KiB
Go

package yggdrasil
// Wire formatting tools
// These are all ugly and probably not very secure
// TODO clean up unused/commented code, and add better comments to whatever is left
// Packet types, as an Encode_uint64 at the start of each packet
// TODO? make things still work after reordering (after things stabilize more?)
// Type safety would also be nice, `type wire_type uint64`, rewrite as needed?
const (
wire_Traffic = iota // data being routed somewhere, handle for crypto
wire_ProtocolTraffic // protocol traffic, pub keys for crypto
wire_LinkProtocolTraffic // link proto traffic, pub keys for crypto
wire_SwitchAnnounce // inside protocol traffic header
wire_SwitchHopRequest // inside protocol traffic header
wire_SwitchHop // inside protocol traffic header
wire_SessionPing // inside protocol traffic header
wire_SessionPong // inside protocol traffic header
wire_DHTLookupRequest // inside protocol traffic header
wire_DHTLookupResponse // inside protocol traffic header
wire_SearchRequest // inside protocol traffic header
wire_SearchResponse // inside protocol traffic header
)
// Encode uint64 using a variable length scheme
// Similar to binary.Uvarint, but big-endian
func wire_encode_uint64(elem uint64) []byte {
return wire_put_uint64(elem, nil)
}
// Occasionally useful for appending to an existing slice (if there's room)
func wire_put_uint64(elem uint64, out []byte) []byte {
bs := make([]byte, 0, 10)
bs = append(bs, byte(elem&0x7f))
for e := elem >> 7; e > 0; e >>= 7 {
bs = append(bs, byte(e|0x80))
}
// Now reverse bytes, because we set them in the wrong order
// TODO just put them in the right place the first time...
last := len(bs) - 1
for idx := 0; idx < len(bs)/2; idx++ {
bs[idx], bs[last-idx] = bs[last-idx], bs[idx]
}
return append(out, bs...)
}
func wire_uint64_len(elem uint64) int {
l := 1
for e := elem >> 7; e > 0; e >>= 7 {
l++
}
return l
}
// Decode uint64 from a []byte slice
// Returns the decoded uint64 and the number of bytes used
func wire_decode_uint64(bs []byte) (uint64, int) {
length := 0
elem := uint64(0)
for _, b := range bs {
elem <<= 7
elem |= uint64(b & 0x7f)
length++
if b&0x80 == 0 {
break
}
}
return elem, length
}
func wire_intToUint(i int64) uint64 {
var u uint64
if i < 0 {
u = uint64(-i) << 1
u |= 0x01 // sign bit
} else {
u = uint64(i) << 1
}
return u
}
func wire_intFromUint(u uint64) int64 {
var i int64
i = int64(u >> 1)
if u&0x01 != 0 {
i *= -1
}
return i
}
////////////////////////////////////////////////////////////////////////////////
// Takes coords, returns coords prefixed with encoded coord length
func wire_encode_coords(coords []byte) []byte {
coordLen := wire_encode_uint64(uint64(len(coords)))
bs := make([]byte, 0, len(coordLen)+len(coords))
bs = append(bs, coordLen...)
bs = append(bs, coords...)
return bs
}
func wire_put_coords(coords []byte, bs []byte) []byte {
bs = wire_put_uint64(uint64(len(coords)), bs)
bs = append(bs, coords...)
return bs
}
// Takes a packet that begins with coords (starting with coord length)
// Returns a slice of coords and the number of bytes read
func wire_decode_coords(packet []byte) ([]byte, int) {
coordLen, coordBegin := wire_decode_uint64(packet)
coordEnd := coordBegin + int(coordLen)
if coordBegin == 0 || coordEnd > len(packet) {
return nil, 0
}
return packet[coordBegin:coordEnd], coordEnd
}
////////////////////////////////////////////////////////////////////////////////
// Announces that we can send parts of a Message with a particular seq
type msgAnnounce struct {
Root sigPubKey
Tstamp int64
Seq uint64
Len uint64
//Deg uint64
Rseq uint64
}
func (m *msgAnnounce) encode() []byte {
bs := wire_encode_uint64(wire_SwitchAnnounce)
bs = append(bs, m.Root[:]...)
bs = append(bs, wire_encode_uint64(wire_intToUint(m.Tstamp))...)
bs = append(bs, wire_encode_uint64(m.Seq)...)
bs = append(bs, wire_encode_uint64(m.Len)...)
bs = append(bs, wire_encode_uint64(m.Rseq)...)
return bs
}
func (m *msgAnnounce) decode(bs []byte) bool {
var pType uint64
var tstamp uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_SwitchAnnounce:
return false
case !wire_chop_slice(m.Root[:], &bs):
return false
case !wire_chop_uint64(&tstamp, &bs):
return false
case !wire_chop_uint64(&m.Seq, &bs):
return false
case !wire_chop_uint64(&m.Len, &bs):
return false
case !wire_chop_uint64(&m.Rseq, &bs):
return false
}
m.Tstamp = wire_intFromUint(tstamp)
return true
}
type msgHopReq struct {
Root sigPubKey
Tstamp int64
Seq uint64
Hop uint64
}
func (m *msgHopReq) encode() []byte {
bs := wire_encode_uint64(wire_SwitchHopRequest)
bs = append(bs, m.Root[:]...)
bs = append(bs, wire_encode_uint64(wire_intToUint(m.Tstamp))...)
bs = append(bs, wire_encode_uint64(m.Seq)...)
bs = append(bs, wire_encode_uint64(m.Hop)...)
return bs
}
func (m *msgHopReq) decode(bs []byte) bool {
var pType uint64
var tstamp uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_SwitchHopRequest:
return false
case !wire_chop_slice(m.Root[:], &bs):
return false
case !wire_chop_uint64(&tstamp, &bs):
return false
case !wire_chop_uint64(&m.Seq, &bs):
return false
case !wire_chop_uint64(&m.Hop, &bs):
return false
}
m.Tstamp = wire_intFromUint(tstamp)
return true
}
type msgHop struct {
Root sigPubKey
Tstamp int64
Seq uint64
Hop uint64
Port switchPort
Next sigPubKey
Sig sigBytes
}
func (m *msgHop) encode() []byte {
bs := wire_encode_uint64(wire_SwitchHop)
bs = append(bs, m.Root[:]...)
bs = append(bs, wire_encode_uint64(wire_intToUint(m.Tstamp))...)
bs = append(bs, wire_encode_uint64(m.Seq)...)
bs = append(bs, wire_encode_uint64(m.Hop)...)
bs = append(bs, wire_encode_uint64(uint64(m.Port))...)
bs = append(bs, m.Next[:]...)
bs = append(bs, m.Sig[:]...)
return bs
}
func (m *msgHop) decode(bs []byte) bool {
var pType uint64
var tstamp uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_SwitchHop:
return false
case !wire_chop_slice(m.Root[:], &bs):
return false
case !wire_chop_uint64(&tstamp, &bs):
return false
case !wire_chop_uint64(&m.Seq, &bs):
return false
case !wire_chop_uint64(&m.Hop, &bs):
return false
case !wire_chop_uint64((*uint64)(&m.Port), &bs):
return false
case !wire_chop_slice(m.Next[:], &bs):
return false
case !wire_chop_slice(m.Sig[:], &bs):
return false
}
m.Tstamp = wire_intFromUint(tstamp)
return true
}
// Format used to check signatures only, so no need to also support decoding
func wire_encode_locator(loc *switchLocator) []byte {
coords := wire_encode_coords(loc.getCoords())
var bs []byte
bs = append(bs, loc.root[:]...)
bs = append(bs, wire_encode_uint64(wire_intToUint(loc.tstamp))...)
bs = append(bs, coords...)
return bs
}
func wire_chop_slice(toSlice []byte, fromSlice *[]byte) bool {
if len(*fromSlice) < len(toSlice) {
return false
}
copy(toSlice, *fromSlice)
*fromSlice = (*fromSlice)[len(toSlice):]
return true
}
func wire_chop_coords(toCoords *[]byte, fromSlice *[]byte) bool {
coords, coordLen := wire_decode_coords(*fromSlice)
if coordLen == 0 {
return false
}
*toCoords = append((*toCoords)[:0], coords...)
*fromSlice = (*fromSlice)[coordLen:]
return true
}
func wire_chop_uint64(toUInt64 *uint64, fromSlice *[]byte) bool {
dec, decLen := wire_decode_uint64(*fromSlice)
if decLen == 0 {
return false
}
*toUInt64 = dec
*fromSlice = (*fromSlice)[decLen:]
return true
}
////////////////////////////////////////////////////////////////////////////////
// Wire traffic packets
type wire_trafficPacket struct {
TTL uint64
Coords []byte
Handle handle
Nonce boxNonce
Payload []byte
}
// This is basically MarshalBinary, but decode doesn't allow that...
func (p *wire_trafficPacket) encode() []byte {
bs := util_getBytes()
bs = wire_put_uint64(wire_Traffic, bs)
bs = wire_put_uint64(p.TTL, bs)
bs = wire_put_coords(p.Coords, bs)
bs = append(bs, p.Handle[:]...)
bs = append(bs, p.Nonce[:]...)
bs = append(bs, p.Payload...)
return bs
}
// Not just UnmarshalBinary becuase the original slice isn't always copied from
func (p *wire_trafficPacket) decode(bs []byte) bool {
var pType uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_Traffic:
return false
case !wire_chop_uint64(&p.TTL, &bs):
return false
case !wire_chop_coords(&p.Coords, &bs):
return false
case !wire_chop_slice(p.Handle[:], &bs):
return false
case !wire_chop_slice(p.Nonce[:], &bs):
return false
}
p.Payload = append(util_getBytes(), bs...)
return true
}
type wire_protoTrafficPacket struct {
TTL uint64
Coords []byte
ToKey boxPubKey
FromKey boxPubKey
Nonce boxNonce
Payload []byte
}
func (p *wire_protoTrafficPacket) encode() []byte {
coords := wire_encode_coords(p.Coords)
bs := wire_encode_uint64(wire_ProtocolTraffic)
bs = append(bs, wire_encode_uint64(p.TTL)...)
bs = append(bs, coords...)
bs = append(bs, p.ToKey[:]...)
bs = append(bs, p.FromKey[:]...)
bs = append(bs, p.Nonce[:]...)
bs = append(bs, p.Payload...)
return bs
}
func (p *wire_protoTrafficPacket) decode(bs []byte) bool {
var pType uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_ProtocolTraffic:
return false
case !wire_chop_uint64(&p.TTL, &bs):
return false
case !wire_chop_coords(&p.Coords, &bs):
return false
case !wire_chop_slice(p.ToKey[:], &bs):
return false
case !wire_chop_slice(p.FromKey[:], &bs):
return false
case !wire_chop_slice(p.Nonce[:], &bs):
return false
}
p.Payload = bs
return true
}
type wire_linkProtoTrafficPacket struct {
Nonce boxNonce
Payload []byte
}
func (p *wire_linkProtoTrafficPacket) encode() []byte {
bs := wire_encode_uint64(wire_LinkProtocolTraffic)
bs = append(bs, p.Nonce[:]...)
bs = append(bs, p.Payload...)
return bs
}
func (p *wire_linkProtoTrafficPacket) decode(bs []byte) bool {
var pType uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_LinkProtocolTraffic:
return false
case !wire_chop_slice(p.Nonce[:], &bs):
return false
}
p.Payload = bs
return true
}
////////////////////////////////////////////////////////////////////////////////
func (p *sessionPing) encode() []byte {
var pTypeVal uint64
if p.IsPong {
pTypeVal = wire_SessionPong
} else {
pTypeVal = wire_SessionPing
}
bs := wire_encode_uint64(pTypeVal)
//p.sendPermPub used in top level (crypto), so skipped here
bs = append(bs, p.Handle[:]...)
bs = append(bs, p.SendSesPub[:]...)
bs = append(bs, wire_encode_uint64(wire_intToUint(p.Tstamp))...)
coords := wire_encode_coords(p.Coords)
bs = append(bs, coords...)
bs = append(bs, wire_encode_uint64(uint64(p.MTU))...)
return bs
}
func (p *sessionPing) decode(bs []byte) bool {
var pType uint64
var tstamp uint64
var mtu uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_SessionPing && pType != wire_SessionPong:
return false
//p.sendPermPub used in top level (crypto), so skipped here
case !wire_chop_slice(p.Handle[:], &bs):
return false
case !wire_chop_slice(p.SendSesPub[:], &bs):
return false
case !wire_chop_uint64(&tstamp, &bs):
return false
case !wire_chop_coords(&p.Coords, &bs):
return false
case !wire_chop_uint64(&mtu, &bs):
mtu = 1280
}
p.Tstamp = wire_intFromUint(tstamp)
if pType == wire_SessionPong {
p.IsPong = true
}
p.MTU = uint16(mtu)
return true
}
////////////////////////////////////////////////////////////////////////////////
func (r *dhtReq) encode() []byte {
coords := wire_encode_coords(r.Coords)
bs := wire_encode_uint64(wire_DHTLookupRequest)
bs = append(bs, coords...)
bs = append(bs, r.Dest[:]...)
return bs
}
func (r *dhtReq) decode(bs []byte) bool {
var pType uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_DHTLookupRequest:
return false
case !wire_chop_coords(&r.Coords, &bs):
return false
case !wire_chop_slice(r.Dest[:], &bs):
return false
default:
return true
}
}
func (r *dhtRes) encode() []byte {
coords := wire_encode_coords(r.Coords)
bs := wire_encode_uint64(wire_DHTLookupResponse)
bs = append(bs, coords...)
bs = append(bs, r.Dest[:]...)
for _, info := range r.Infos {
coords = wire_encode_coords(info.coords)
bs = append(bs, info.key[:]...)
bs = append(bs, coords...)
}
return bs
}
func (r *dhtRes) decode(bs []byte) bool {
var pType uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_DHTLookupResponse:
return false
case !wire_chop_coords(&r.Coords, &bs):
return false
case !wire_chop_slice(r.Dest[:], &bs):
return false
}
for len(bs) > 0 {
info := dhtInfo{}
switch {
case !wire_chop_slice(info.key[:], &bs):
return false
case !wire_chop_coords(&info.coords, &bs):
return false
}
r.Infos = append(r.Infos, &info)
}
return true
}
////////////////////////////////////////////////////////////////////////////////
func (r *searchReq) encode() []byte {
coords := wire_encode_coords(r.coords)
bs := wire_encode_uint64(wire_SearchRequest)
bs = append(bs, r.key[:]...)
bs = append(bs, coords...)
bs = append(bs, r.dest[:]...)
return bs
}
func (r *searchReq) decode(bs []byte) bool {
var pType uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_SearchRequest:
return false
case !wire_chop_slice(r.key[:], &bs):
return false
case !wire_chop_coords(&r.coords, &bs):
return false
case !wire_chop_slice(r.dest[:], &bs):
return false
default:
return true
}
}
func (r *searchRes) encode() []byte {
coords := wire_encode_coords(r.coords)
bs := wire_encode_uint64(wire_SearchResponse)
bs = append(bs, r.key[:]...)
bs = append(bs, coords...)
bs = append(bs, r.dest[:]...)
return bs
}
func (r *searchRes) decode(bs []byte) bool {
var pType uint64
switch {
case !wire_chop_uint64(&pType, &bs):
return false
case pType != wire_SearchResponse:
return false
case !wire_chop_slice(r.key[:], &bs):
return false
case !wire_chop_coords(&r.coords, &bs):
return false
case !wire_chop_slice(r.dest[:], &bs):
return false
default:
return true
}
}