Add tests for malformed HelloRequests.

Change-Id: Iff053022c7ffe5b01c0daf95726cc7d49c33cbd6
Reviewed-on: https://boringssl-review.googlesource.com/6640
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/ssl/test/runner/conn.go b/ssl/test/runner/conn.go
index 7178d20..cb60a92 100644
--- a/ssl/test/runner/conn.go
+++ b/ssl/test/runner/conn.go
@@ -1201,8 +1201,11 @@
 
 func (c *Conn) Renegotiate() error {
 	if !c.isClient {
-		helloReq := new(helloRequestMsg)
-		c.writeRecord(recordTypeHandshake, helloReq.marshal())
+		helloReq := new(helloRequestMsg).marshal()
+		if c.config.Bugs.BadHelloRequest != nil {
+			helloReq = c.config.Bugs.BadHelloRequest
+		}
+		c.writeRecord(recordTypeHandshake, helloReq)
 	}
 
 	c.handshakeComplete = false