// Handles both un-configured and none selected.
        null, "" -> null
        else -> protocol
      }
    } else {
      super.getSelectedProtocol(sslSocket)
    }

  companion object {
    val isSupported: Boolean =
      try {
        // Trigger an early exception over a fatal error, prefer a RuntimeException over Error.
        Class.forName("org.openjsse.net.ssl.OpenJSSE", false, javaClass.classLoader)

        true

    AndroidCertificateChainCleaner.buildIfSupported(trustManager) ?: super.buildCertificateChainCleaner(trustManager)

  companion object {
    val isSupported: Boolean = isAndroid && Build.VERSION.SDK_INT >= 29

    fun buildIfSupported(): Platform? = if (isSupported) Android10Platform() else null
  }

@SuppressLint("NewApi")
@SuppressSignatureCheck
class Android10SocketAdapter : SocketAdapter {
  override fun matchesSocket(sslSocket: SSLSocket): Boolean = SSLSockets.isSupportedSocket(sslSocket)

  override fun isSupported(): Boolean = Companion.isSupported()

  @SuppressLint("NewApi")
  override fun getSelectedProtocol(sslSocket: SSLSocket): String? {
    return try {

 */
class BouncyCastleSocketAdapter : SocketAdapter {
  override fun matchesSocket(sslSocket: SSLSocket): Boolean = sslSocket is BCSSLSocket

  override fun isSupported(): Boolean = BouncyCastlePlatform.isSupported

  override fun getSelectedProtocol(sslSocket: SSLSocket): String? {
    val s = sslSocket as BCSSLSocket

    return when (val protocol = s.applicationProtocol) {
      null, "" -> null

 * directly.
 */
class ConscryptSocketAdapter : SocketAdapter {
  override fun matchesSocket(sslSocket: SSLSocket): Boolean = Conscrypt.isConscrypt(sslSocket)

  override fun isSupported(): Boolean = ConscryptPlatform.isSupported

  override fun getSelectedProtocol(sslSocket: SSLSocket): String? =
    when {
      matchesSocket(sslSocket) -> Conscrypt.getApplicationProtocol(sslSocket)

  private val setAlpnProtocols =
    sslSocketClass.getMethod("setAlpnProtocols", ByteArray::class.java)

  override fun isSupported(): Boolean = AndroidPlatform.isSupported

  override fun matchesSocket(sslSocket: SSLSocket): Boolean = sslSocketClass.isInstance(sslSocket)

  override fun configureTlsExtensions(
    sslSocket: SSLSocket,
    hostname: String?,

        // Handles both un-configured and none selected.
        null, "" -> null
        else -> protocol
      }
    } else {
      super.getSelectedProtocol(sslSocket)
    }

  companion object {
    val isSupported: Boolean =
      try {
        // Trigger an early exception over a fatal error, prefer a RuntimeException over Error.
        Class.forName("org.bouncycastle.jsse.provider.BouncyCastleJsseProvider", false, javaClass.classLoader)

      // Delay and Defer any initialisation of Conscrypt and BouncyCastle
      DeferredSocketAdapter(ConscryptSocketAdapter.factory),
      DeferredSocketAdapter(BouncyCastleSocketAdapter.factory),
    ).filter { it.isSupported() }

  @Throws(IOException::class)
  override fun connectSocket(
    socket: Socket,
    address: InetSocketAddress,
    connectTimeout: Int,
  ) {
    try {
      socket.connect(address, connectTimeout)

        this.gssContext.requestCredDeleg(true);
    }


    /**
     * 
     * {@inheritDoc}
     *
     * @see jcifs.smb.SSPContext#isSupported(org.bouncycastle.asn1.ASN1ObjectIdentifier)
     */
    @Override
    public boolean isSupported ( ASN1ObjectIdentifier mechanism ) {
        return KRB5_MECH_OID.equals(mechanism) || KRB5_MS_MECH_OID.equals(mechanism);
    }


    /**

            // only use token if the optimistic mechanism is supported
            if ( this.mechContext.isSupported(prefMech) ) {
                inputToken = tinit.getMechanismToken();
            }
            else {
                ASN1ObjectIdentifier found = null;
                for ( ASN1ObjectIdentifier mech : rm ) {
                    if ( this.mechContext.isSupported(mech) ) {
                        found = mech;