fix sni panic (#297)

vendor/github.com/ginuerzh/tls-dissector/handshake.go

@@ -98,6 +98,9 @@ func (h *ClientHelloHandshake) ReadFrom(r io.Reader) (n int64, err error) {
 
 	// extLen := int(binary.BigEndian.Uint16(b[pos : pos+2]))
 	pos += 2
+	if pos >= len(b) {
+		return
+	}
 
 	br := bytes.NewReader(b[pos:])
 	for br.Len() > 0 {

vendor/vendor.json

@@ -105,10 +105,10 @@
 			"revisionTime": "2017-09-11T08:28:29Z"
 		},
 		{
-			"checksumSHA1": "ZefD404me5Nm13S6NTsfJ57UApI=",
+			"checksumSHA1": "oAor5oKUyfFTHUT7ICWfe/aZTrY=",
 			"path": "github.com/ginuerzh/tls-dissector",
-			"revision": "ede94e83b36efefb6d06e5a29d28e2211b8bd6a9",
-			"revisionTime": "2017-10-29T12:10:54Z"
+			"revision": "7037c35ed6947fe9d9c33785fca4ac96eef8e62b",
+			"revisionTime": "2018-11-03T04:46:17Z"
 		},
 		{
 			"checksumSHA1": "fBx0fqiyrl26gkGo14J9pJ8zB2Y=",