"crypto/rand"
"crypto/subtle"
"encoding/binary"
+ "io"
"log"
"time"
type Handshake struct {
addr string
- conn RemoteConn
+ conn io.Writer
LastPing time.Time
Conf *PeerConf
dsaPubH *[ed25519.PublicKeySize]byte
}
// Create new handshake state.
-func HandshakeNew(addr string, conn RemoteConn, conf *PeerConf) *Handshake {
+func NewHandshake(addr string, conn io.Writer, conf *PeerConf) *Handshake {
state := Handshake{
addr: addr,
conn: conn,
// Start handshake's procedure from the client. It is the entry point
// for starting the handshake procedure. // First handshake packet
// will be sent immediately.
-func HandshakeStart(addr string, conn RemoteConn, conf *PeerConf) *Handshake {
- state := HandshakeNew(addr, conn, conf)
+func HandshakeStart(addr string, conn io.Writer, conf *PeerConf) *Handshake {
+ state := NewHandshake(addr, conn, conf)
var dhPubRepr *[32]byte
state.dhPriv, dhPubRepr = dhKeypairGen()
if err := randRead(state.rNonce[:]); err != nil {
log.Fatalln("Error reading random for nonce:", err)
}
- enc := make([]byte, 32)
- salsa20.XORKeyStream(enc, dhPubRepr[:], state.rNonce[:], state.dsaPubH)
+ var enc []byte
+ if conf.Noise {
+ enc = make([]byte, MTU-xtea.BlockSize-RSize)
+ } else {
+ enc = make([]byte, 32)
+ }
+ copy(enc, dhPubRepr[:])
+ salsa20.XORKeyStream(enc, enc, state.rNonce[:], state.dsaPubH)
data := append(state.rNonce[:], enc...)
data = append(data, idTag(state.Conf.Id, state.rNonce[:])...)
state.conn.Write(data)
// authenticated Peer is ready, then return nil.
func (h *Handshake) Server(data []byte) *Peer {
// R + ENC(H(DSAPub), R, El(CDHPub)) + IDtag
- if len(data) == 48 && h.rNonce == nil {
+ if h.rNonce == nil && len(data) >= 48 {
// Generate DH keypair
var dhPubRepr *[32]byte
h.dhPriv, dhPubRepr = dhKeypairGen()
if err := randRead(h.sServer[:]); err != nil {
log.Fatalln("Error reading random for S:", err)
}
- encRs := make([]byte, RSize+SSize)
- salsa20.XORKeyStream(encRs, append(h.rServer[:], h.sServer[:]...), h.rNonce[:], h.key)
+ var encRs []byte
+ if h.Conf.Noise {
+ encRs = make([]byte, MTU-len(encPub)-xtea.BlockSize)
+ } else {
+ encRs = make([]byte, RSize+SSize)
+ }
+ copy(encRs, append(h.rServer[:], h.sServer[:]...))
+ salsa20.XORKeyStream(encRs, encRs, h.rNonce[:], h.key)
// Send that to client
h.conn.Write(append(encPub, append(encRs, idTag(h.Conf.Id, encPub)...)...))
h.LastPing = time.Now()
} else
// ENC(K, R+1, RS + RC + SC + Sign(DSAPriv, K)) + IDtag
- if len(data) == 120 && h.rClient == nil {
+ if h.rClient == nil && len(data) >= 120 {
// Decrypted Rs compare rServer
dec := make([]byte, RSize+RSize+SSize+ed25519.SignatureSize)
salsa20.XORKeyStream(
}
// Send final answer to client
- enc := make([]byte, RSize)
- salsa20.XORKeyStream(enc, dec[RSize:RSize+RSize], h.rNonceNext(2), h.key)
+ var enc []byte
+ if h.Conf.Noise {
+ enc = make([]byte, MTU-xtea.BlockSize)
+ } else {
+ enc = make([]byte, RSize)
+ }
+ copy(enc, dec[RSize:RSize+RSize])
+ salsa20.XORKeyStream(enc, enc, h.rNonceNext(2), h.key)
h.conn.Write(append(enc, idTag(h.Conf.Id, enc)...))
// Switch peer
// will be created and used as a transport. If no mutually
// authenticated Peer is ready, then return nil.
func (h *Handshake) Client(data []byte) *Peer {
- switch len(data) {
- case 80: // ENC(H(DSAPub), R+1, El(SDHPub)) + ENC(K, R, RS + SS) + IDtag
- if h.key != nil {
- log.Println("Invalid handshake stage from", h.addr)
- return nil
- }
-
+ // ENC(H(DSAPub), R+1, El(SDHPub)) + ENC(K, R, RS + SS) + IDtag
+ if h.rServer == nil && h.key == nil && len(data) >= 80 {
// Decrypt remote public key and compute shared key
sDHRepr := new([32]byte)
salsa20.XORKeyStream(sDHRepr[:], data[:32], h.rNonceNext(1), h.dsaPubH)
}
sign := ed25519.Sign(h.Conf.DSAPriv, h.key[:])
- enc := make([]byte, RSize+RSize+SSize+ed25519.SignatureSize)
- salsa20.XORKeyStream(enc,
+ var enc []byte
+ if h.Conf.Noise {
+ enc = make([]byte, MTU-xtea.BlockSize)
+ } else {
+ enc = make([]byte, RSize+RSize+SSize+ed25519.SignatureSize)
+ }
+ copy(enc,
append(h.rServer[:],
append(h.rClient[:],
- append(h.sClient[:], sign[:]...)...)...), h.rNonceNext(1), h.key)
+ append(h.sClient[:], sign[:]...)...)...))
+ salsa20.XORKeyStream(enc, enc, h.rNonceNext(1), h.key)
// Send that to server
h.conn.Write(append(enc, idTag(h.Conf.Id, enc)...))
h.LastPing = time.Now()
- case 16: // ENC(K, R+2, RC) + IDtag
- if h.key == nil {
- log.Println("Invalid handshake stage from", h.addr)
- return nil
- }
-
+ } else
+ // ENC(K, R+2, RC) + IDtag
+ if h.key != nil && len(data) >= 16 {
// Decrypt rClient
dec := make([]byte, RSize)
salsa20.XORKeyStream(dec, data[:RSize], h.rNonceNext(2), h.key)
)
h.LastPing = time.Now()
return peer
- default:
- log.Println("Invalid handshake message from", h.addr)
+ } else {
+ log.Println("Invalid handshake stage from", h.addr)
}
return nil
}