Test that bad Finished messages are rejected.

That's a pretty obvious thing to test. I'm not sure how we forgot that one.

Change-Id: I7e1a7df6c6abbdd587e0f7723117f50d09faa5c4
Reviewed-on: https://boringssl-review.googlesource.com/4211
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/runner/common.go b/ssl/test/runner/common.go
index 11bec4e..73aeb82 100644
--- a/ssl/test/runner/common.go
+++ b/ssl/test/runner/common.go
@@ -683,6 +683,9 @@
 	// SendWarningAlerts, if non-zero, causes every record to be prefaced by
 	// a warning alert.
 	SendWarningAlerts alert
+
+	// BadFinished, if true, causes the Finished hash to be broken.
+	BadFinished bool
 }
 
 func (c *Config) serverInit() {