From: Sergey Matveev <stargrave@stargrave.org>
Date: Sun, 10 Aug 2014 14:56:08 +0000 (+0400)
Subject: Fix nounces incrementing
X-Git-Tag: 1.0~6
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=71a068c0ed889a0e2ef41edc0a9e94cf78763005;p=govpn.git

Fix nounces incrementing

That bug leads to reusing the same nonce.

Signed-off-by: Sergey Matveev <stargrave@stargrave.org>
---

diff --git a/govpn.go b/govpn.go
index 412deb7..885f520 100644
--- a/govpn.go
+++ b/govpn.go
@@ -33,10 +33,6 @@ import (
 )
 
 const (
-	// NonceIncrServer is nonce increment value for server message
-	NonceIncrServer = 1
-	// NonceIncrClient is nonce increment value for client message
-	NonceIncrClient = 2
 	NonceSize       = 8
 	AliveTimeout    = time.Second * 90
 	// S20BS is Salsa20's internal blocksize in bytes
@@ -108,13 +104,11 @@ func main() {
 	var remote *net.UDPAddr
 
 	serverMode := false
-	nonceIncr := uint64(NonceIncrClient)
 	bindTo := "0.0.0.0:0"
 
 	if len(*bindAddr) > 1 {
 		bindTo = *bindAddr
 		serverMode = true
-		nonceIncr = uint64(NonceIncrServer)
 	}
 
 	bind, err := net.ResolveUDPAddr("udp", bindTo)
@@ -224,7 +218,7 @@ func main() {
 			if !peer.IsAlive() {
 				continue
 			}
-			peer.nonceOur = peer.nonceOur + nonceIncr
+			peer.nonceOur = peer.nonceOur + 2
 			pktData := ethPkt.Data()
 			binary.PutUvarint(nonce, peer.nonceOur)
 			copy(buf[S20BS:], pktData)
diff --git a/handshake.go b/handshake.go
index 331e4e6..a3403ea 100644
--- a/handshake.go
+++ b/handshake.go
@@ -251,7 +251,7 @@ func (h *Handshake) Client(conn *net.UDPConn, key *[32]byte, data []byte) *Peer
 		}
 
 		// Switch peer
-		peer := Peer{addr: h.addr, nonceOur: 0, nonceRecv: 0}
+		peer := Peer{addr: h.addr, nonceOur: 1, nonceRecv: 0}
 		peer.SetAlive()
 		peer.key = KeyFromSecrets(h.sServer[:], h.sClient[:])
 		fmt.Print("[OK]")