"TLS-ECH-Client-Reject-NoClientCertificate-TLS12": "We won't attempt to negotiate 1.2 if ECH is enabled",
        "TLS-ECH-Client-Reject-TLS12": "We won't attempt to negotiate 1.2 if ECH is enabled",
        "TLS-ECH-Client-TLS12-RejectRetryConfigs": "We won't attempt to negotiate 1.2 if ECH is enabled",
        "TLS-ECH-Client-Rejected-OverrideName-TLS12": "We won't attempt to negotiate 1.2 if ECH is enabled",

		supportedVersions:            supportedVersions,
	}

	// The version at the beginning of the ClientHello was capped at TLS 1.2
	// for compatibility reasons. The supported_versions extension is used
	// to negotiate versions now. See RFC 8446, Section 4.2.1.
	if hello.vers > VersionTLS12 {
		hello.vers = VersionTLS12
	}

	if c.handshakes > 0 {
		hello.secureRenegotiation = c.clientFinished[:]
	}

	for i := range conn.channels {
		rwc[i] = conn.channels[i]
	}
	return conn.selectedProtocol, rwc, nil
}

func (conn *Conn) initialize(ws *websocket.Conn) {
	negotiated := ws.Config().Protocol
	conn.selectedProtocol = negotiated[0]
	p := conn.protocols[conn.selectedProtocol]
	if p.Binary {
		conn.codec = rawCodec
	} else {
		conn.codec = base64Codec
	}
	conn.ws = ws

	"Service Unavailable":             http.StatusServiceUnavailable,
	"Gateway Timeout":                 http.StatusGatewayTimeout,
	"HTTP Version Not Supported":      http.StatusHTTPVersionNotSupported,
	"Variant Also Negotiates":         http.StatusVariantAlsoNegotiates,
	"Insufficient Storage":            http.StatusInsufficientStorage,
	"Loop Detected":                   http.StatusLoopDetected,

    memory if web socket compression is negotiated but not used.


## Version 4.5.0-RC1

_2020-03-17_

**This release candidate turns on web socket compression.**

The [spec][rfc_7692] includes a sophisticated mechanism for client and server to negotiate
compression features. We strive to offer great performance in our default configuration and so we're

			log.Fatalf("conn error: %s", err)
		}

		cs := tlsConn.ConnectionState()
		if cs.HandshakeComplete {
			if *expectALPN != "" && cs.NegotiatedProtocol != *expectALPN {
				log.Fatalf("unexpected protocol negotiated: want %q, got %q", *expectALPN, cs.NegotiatedProtocol)
			}

			if *expectECHAccepted && !cs.ECHAccepted {
				log.Fatal("expected ECH to be accepted, but connection state shows it was not")

		mfs, err := gatherers.Gather()
		if err != nil {
			if len(mfs) == 0 {
				writeErrorResponseJSON(r.Context(), w, toAdminAPIErr(r.Context(), err), r.URL)
				return
			}
		}

		contentType := expfmt.Negotiate(r.Header)
		w.Header().Set("Content-Type", string(contentType))

		enc := expfmt.NewEncoder(w, contentType)
		for _, mf := range mfs {
			if err := enc.Encode(mf); err != nil {

	// previous session with a session ticket or similar mechanism.
	DidResume bool

	// CipherSuite is the cipher suite negotiated for the connection (e.g.
	// TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256, TLS_AES_128_GCM_SHA256).
	CipherSuite uint16

	// NegotiatedProtocol is the application protocol negotiated with ALPN.
	NegotiatedProtocol string

	// NegotiatedProtocolIsMutual used to indicate a mutual NPN negotiation.
	//

	}
}

// Test that QUICConn.ConnectionState can be used during the handshake,
// and that it reports the application protocol as soon as it has been
// negotiated.
func TestQUICConnectionState(t *testing.T) {
	config := testConfig.Clone()
	config.MinVersion = VersionTLS13
	config.NextProtos = []string{"h3"}
	cli := newTestQUICClient(t, config)

// accept and expose cipher suite IDs instead of this type.
type CipherSuite struct {
	ID   uint16
	Name string

	// Supported versions is the list of TLS protocol versions that can
	// negotiate this cipher suite.
	SupportedVersions []uint16

	// Insecure is true if the cipher suite has known security issues
	// due to its primitives, design, or implementation.
	Insecure bool
}

var (