x/crypto/ssh: also log data packets when debugHandshake is set

Change-Id: Ibb26269608e506e8a676c276f847d77fe7014ceb
Reviewed-on: https://go-review.googlesource.com/22514
Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
Run-TryBot: Han-Wen Nienhuys <hanwen@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>

ssh/handshake.go

@@ -161,8 +161,12 @@ func (t *handshakeTransport) readOnePacket() ([]byte, error) {
 
 	t.readSinceKex += uint64(len(p))
 	if debugHandshake {
-		msg, err := decode(p)
-		log.Printf("%s got %T %v (%v)", t.id(), msg, msg, err)
+		if p[0] == msgChannelData || p[0] == msgChannelExtendedData {
+			log.Printf("%s got data (packet %d bytes)", t.id(), len(p))
+		} else {
+			msg, err := decode(p)
+			log.Printf("%s got %T %v (%v)", t.id(), msg, msg, err)
+		}
 	}
 	if p[0] != msgKexInit {
 		return p, nil