Don't refer to key_update_requested responses as ACKs

It's a bit confusing when DTLS 1.3 also needs to ACK the KeyUpdate
message itself. I was going to call it a "reply", but it turned out that
none of the instances really needed to refer to this.

Bug: 42290594
Change-Id: I1cb674755920a0d7567b4c8eed46f12a0294faa5
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/73307
Reviewed-by: Nick Harper <nharper@chromium.org>
Commit-Queue: David Benjamin <davidben@google.com>

ssl/test/runner/conn.go

diff --git a/ssl/test/runner/conn.go b/ssl/test/runner/conn.go
index d516651..5af9fba 100644
--- a/ssl/test/runner/conn.go
+++ b/ssl/test/runner/conn.go
@@ -1711,9 +1711,9 @@
 	return errors.New("tls: unexpected post-handshake message")
 }
 
-// Reads a KeyUpdate acknowledgment from the peer. There may not be any
-// application data records before the message.
-func (c *Conn) ReadKeyUpdateACK() error {
+// Reads a KeyUpdate from the peer, with type key_update_not_requested. There
+// may not be any application data records before the message.
+func (c *Conn) ReadKeyUpdate() error {
 	c.in.Lock()
 	defer c.in.Unlock()
 

ssl/test/runner/runner.go

diff --git a/ssl/test/runner/runner.go b/ssl/test/runner/runner.go
index 59d381b..b7481c1 100644
--- a/ssl/test/runner/runner.go
+++ b/ssl/test/runner/runner.go
@@ -1158,10 +1158,10 @@
 			continue
 		}
 
-		// Process the KeyUpdate ACK. However many KeyUpdates the runner
+		// Process the KeyUpdate reply. However many KeyUpdates the runner
 		// sends, the shim should respond only once.
 		if test.sendKeyUpdates > 0 && test.keyUpdateRequest == keyUpdateRequested {
-			if err := tlsConn.ReadKeyUpdateACK(); err != nil {
+			if err := tlsConn.ReadKeyUpdate(); err != nil {
 				return err
 			}
 		}
@@ -3540,8 +3540,8 @@
 			expectedError:    ":DECODE_ERROR:",
 		},
 		{
-			// Test that KeyUpdates are acknowledged properly.
-			name: "KeyUpdate-RequestACK",
+			// Test that shim responds to KeyUpdate requests.
+			name: "KeyUpdate-Requested",
 			config: Config{
 				MaxVersion: VersionTLS13,
 				Bugs: ProtocolBugs{
@@ -3554,10 +3554,10 @@
 			keyUpdateRequest: keyUpdateRequested,
 		},
 		{
-			// Test that KeyUpdates are acknowledged properly if the
+			// Test that shim responds to KeyUpdate requests if
 			// peer's KeyUpdate is discovered while a write is
 			// pending.
-			name: "KeyUpdate-RequestACK-UnfinishedWrite",
+			name: "KeyUpdate-Requested-UnfinishedWrite",
 			config: Config{
 				MaxVersion: VersionTLS13,
 				Bugs: ProtocolBugs{