From: Filippo Valsorda <filippo@golang.org>
Date: Sat, 8 May 2021 05:07:30 +0000 (-0400)
Subject: crypto/tls: use cryptobyte.NewFixedBuilder
X-Git-Tag: go1.18beta1~1080
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=cc5e3de593afca73cf1b4d732ddceffb2837b390;p=gostls13.git

crypto/tls: use cryptobyte.NewFixedBuilder

Change-Id: Ia2a9465680e766336dae34f5d2b3cb412185bf1f
Reviewed-on: https://go-review.googlesource.com/c/go/+/318131
Trust: Filippo Valsorda <filippo@golang.org>
Run-TryBot: Filippo Valsorda <filippo@golang.org>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Roland Shoemaker <roland@golang.org>
---

diff --git a/src/crypto/tls/handshake_messages.go b/src/crypto/tls/handshake_messages.go
index b5f81e4436..17cf85910f 100644
--- a/src/crypto/tls/handshake_messages.go
+++ b/src/crypto/tls/handshake_messages.go
@@ -329,8 +329,7 @@ func (m *clientHelloMsg) updateBinders(pskBinders [][]byte) {
 	m.pskBinders = pskBinders
 	if m.raw != nil {
 		lenWithoutBinders := len(m.marshalWithoutBinders())
-		// TODO(filippo): replace with NewFixedBuilder once CL 148882 is imported.
-		b := cryptobyte.NewBuilder(m.raw[:lenWithoutBinders])
+		b := cryptobyte.NewFixedBuilder(m.raw[:lenWithoutBinders])
 		b.AddUint16LengthPrefixed(func(b *cryptobyte.Builder) {
 			for _, binder := range m.pskBinders {
 				b.AddUint8LengthPrefixed(func(b *cryptobyte.Builder) {
@@ -338,7 +337,7 @@ func (m *clientHelloMsg) updateBinders(pskBinders [][]byte) {
 				})
 			}
 		})
-		if len(b.BytesOrPanic()) != len(m.raw) {
+		if out, err := b.Bytes(); err != nil || len(out) != len(m.raw) {
 			panic("tls: internal error: failed to update binders")
 		}
 	}