Apply GREASE to TLS 1.3 tickets.

Change-Id: I5d4fc0d3204744e93d71a36923469035c19a5b10
Reviewed-on: https://boringssl-review.googlesource.com/11560
CQ-Verified: CQ bot account: commit-bot@chromium.org <commit-bot@chromium.org>
Reviewed-by: Steven Valdez <svaldez@google.com>
Reviewed-by: David Benjamin <davidben@google.com>
Commit-Queue: David Benjamin <davidben@google.com>
diff --git a/ssl/test/runner/conn.go b/ssl/test/runner/conn.go
index 84e1eb8..7f395d5 100644
--- a/ssl/test/runner/conn.go
+++ b/ssl/test/runner/conn.go
@@ -1398,6 +1398,10 @@
 
 	if c.isClient {
 		if newSessionTicket, ok := msg.(*newSessionTicketMsg); ok {
+			if c.config.Bugs.ExpectGREASE && !newSessionTicket.hasGREASEExtension {
+				return errors.New("tls: no GREASE ticket extension found")
+			}
+
 			if c.config.ClientSessionCache == nil || newSessionTicket.ticketLifetime == 0 {
 				return nil
 			}