sync: merge changes from go 1.24.0

handshake_messages.go

@@ -98,6 +98,8 @@ type clientHelloMsg struct {
 	pskBinders              [][]byte
 	quicTransportParameters []byte
 	encryptedClientHello    []byte
+	// extensions are only populated on the server-side of a handshake
+	extensions []uint16
 
 	// [uTLS]
 	nextProtoNeg bool
@@ -477,6 +479,7 @@ func (m *clientHelloMsg) unmarshal(data []byte) bool {
 			return false
 		}
 		seenExts[extension] = true
+		m.extensions = append(m.extensions, extension)
 
 		switch extension {
 		case extensionServerName:
@@ -669,6 +672,10 @@ func (m *clientHelloMsg) unmarshal(data []byte) bool {
 				}
 				m.pskBinders = append(m.pskBinders, binder)
 			}
+		case extensionEncryptedClientHello:
+			if !extData.ReadBytes(&m.encryptedClientHello, len(extData)) {
+				return false
+			}
 		default:
 			// Ignore unknown extensions.
 			continue