* That may happen later by the connection pool thread.
   */
  fun cancel()

  /**
   * Carries an exchange. This is usually a connection, but it could also be a connect plan for
   * CONNECT tunnels. Note that CONNECT tunnels are significantly less capable than connections.
   */
  interface Carrier {
    val route: Route

    fun trackFailure(
      call: RealCall,
      e: IOException?,
    )

    // Make an SSL Tunnel on the first message pair of each SSL + proxy connection.
    val url = route.address.url
    val requestLine = "CONNECT ${url.toHostHeader(includeDefaultPort = true)} HTTP/1.1"
    while (true) {
      val source = this.source!!
      val sink = this.sink!!
      val tunnelCodec =
        Http1ExchangeCodec(
          // No client for CONNECT tunnels:
          client = null,

    replaceWith = ReplaceWith(expression = "socketAddress"),
    level = DeprecationLevel.ERROR,
  )
  fun socketAddress(): InetSocketAddress = socketAddress

  /**
   * Returns true if this route tunnels HTTPS or HTTP/2 through an HTTP proxy.
   * See [RFC 2817, Section 5.2][rfc_2817].
   *
   * [rfc_2817]: http://www.ietf.org/rfc/rfc2817.txt
   */
  fun requiresTunnel(): Boolean {

      connectionSpecIndex = -1,
      isTlsFallback = false,
    )
  }

  /**
   * Returns a request that creates a TLS tunnel via an HTTP proxy. Everything in the tunnel request
   * is sent unencrypted to the proxy server, so tunnels include only the minimum set of headers.
   * This avoids sending potentially sensitive data like HTTP cookies to the proxy unencrypted.
   *

  internal var hasFailure: Boolean = false
    private set

  internal val connection: RealConnection
    get() = codec.carrier as? RealConnection ?: error("no connection for CONNECT tunnels")

  internal val isCoalescedConnection: Boolean
    get() = finder.routePlanner.address.url.host != codec.carrier.route.address.url.host

  @Throws(IOException::class)
  fun writeRequestHeaders(request: Request) {

 * [newFixedLengthSource(0)][newFixedLengthSource] and may skip reading and closing that source.
 */
class Http1ExchangeCodec(
  /** The client that configures this stream. May be null for HTTPS proxy tunnels. */
  private val client: OkHttpClient?,
  override val carrier: ExchangeCodec.Carrier,
  private val source: BufferedSource,
  private val sink: BufferedSink,
) : ExchangeCodec {
  private var state = STATE_IDLE

This means Ztunnel will have multiple distinct certificates at a time, one for each unique identity (service account) running on its node.

When fetching certificates, ztunnel will authenticate to the CA with its own identity, but request the identity of another workload.
Critically, the CA must enforce that the ztunnel has permission to request that identity.

   * connections are requested concurrently OkHttp will pessimistically connect multiple times, then
   * close any unnecessary connections. This test confirms that behavior works as intended.
   *
   * This test uses proxy tunnels to get a hook while a connection is being established.
   */
  @ParameterizedTest
  @ArgumentsSource(ProtocolParamProvider::class)
  fun concurrentHttp2ConnectionsDeduplicated(
    protocol: Protocol,

fi

ZTUNNEL_REPO_SHA="${ZTUNNEL_REPO_SHA:-$(grep ZTUNNEL_REPO_SHA istio.deps  -A 4 | grep lastStableSHA | cut -f 4 -d '"')}"
ISTIO_ZTUNNEL_VERSION="${ISTIO_ZTUNNEL_VERSION:-${ZTUNNEL_REPO_SHA}}"
ISTIO_ZTUNNEL_RELEASE_URL="${ISTIO_ZTUNNEL_RELEASE_URL:-${ISTIO_ZTUNNEL_BASE_URL}/ztunnel-${ISTIO_ZTUNNEL_VERSION}-${TARGET_ARCH}}"
ISTIO_ZTUNNEL_LINUX_RELEASE_NAME="${ISTIO_ZTUNNEL_LINUX_RELEASE_NAME:-ztunnel-${ISTIO_ZTUNNEL_VERSION}}"

      Funnel<? super T> funnel, long expectedInsertions, double fpp) {
    return create(funnel, expectedInsertions, fpp, BloomFilterStrategies.MURMUR128_MITZ_64);
  }

  @VisibleForTesting
  static <T extends @Nullable Object> BloomFilter<T> create(
      Funnel<? super T> funnel, long expectedInsertions, double fpp, Strategy strategy) {
    checkNotNull(funnel);
    checkArgument(