throws GeneralSecurityException, IOException {
    KeyStore keystore = KeyStore.getInstance(KeyStore.getDefaultType());
    try (InputStream in = new FileInputStream(keystoreFile)) {
      keystore.load(in, password.toCharArray());
    }
    KeyManagerFactory keyManagerFactory =
        KeyManagerFactory.getInstance(KeyManagerFactory.getDefaultAlgorithm());
    keyManagerFactory.init(keystore, password.toCharArray());

  @Throws(SignatureException::class)
  fun checkSignature(issuer: PublicKey): Boolean {
    val signedData = CertificateAdapters.tbsCertificate.toDer(tbsCertificate)

    return Signature.getInstance(tbsCertificate.signatureAlgorithmName).run {
      initVerify(issuer)
      update(signedData.toByteArray())
      verify(signatureValue.byteString.toByteArray())
    }
  }

 */
open class Platform {
  /** Prefix used on custom headers. */
  fun getPrefix() = "OkHttp"

  open fun newSSLContext(): SSLContext = SSLContext.getInstance("TLS")

  open fun platformTrustManager(): X509TrustManager {
    val factory =
      TrustManagerFactory.getInstance(
        TrustManagerFactory.getDefaultAlgorithm(),
      )
    factory.init(null as KeyStore?)
    val trustManagers = factory.trustManagers!!

      "CN=cash.app,OU=cash",
    )
  }

  /** Confirm golden values of encoded PEMs.  */
  @Test
  fun pems() {
    val keyFactory = KeyFactory.getInstance("RSA")
    val publicKeyBytes =
      (
        "MIGfMA0GCSqGSIb3DQEBAQUAA4GNADCBiQKBgQCApFHhtrLan28q+oMolZuaTfWBA0V5aM" +

    val sslContext2 = get().newSSLContext()
    sslContext2.init(null, null, null)
    val sslSocketFactory2 = sslContext2.socketFactory
    val trustManagerFactory =
      TrustManagerFactory.getInstance(
        TrustManagerFactory.getDefaultAlgorithm(),
      )
    trustManagerFactory.init(null as KeyStore?)
    val trustManager = trustManagerFactory.trustManagers[0] as X509TrustManager
    client =

  private val provider: Provider = BouncyCastleJsseProvider()

  override fun newSSLContext(): SSLContext = SSLContext.getInstance("TLS", provider)

  override fun platformTrustManager(): X509TrustManager {
    val factory =
      TrustManagerFactory.getInstance(
        "PKIX",
        BouncyCastleJsseProvider.PROVIDER_NAME,
      )
    factory.init(null as KeyStore?)

      )

    val keyManagerFactory = KeyManagerFactory.getInstance("NewSunX509")
    keyManagerFactory.init(KeyStoreBuilderParameters(builderList))
    val keyManager = keyManagerFactory.keyManagers[0] as X509ExtendedKeyManager

    val trustManager = Platform.get().platformTrustManager()

    val sslContext = SSLContext.getInstance("TLS")
    sslContext.init(arrayOf(keyManager), arrayOf(trustManager), SecureRandom())

          issuerUniqueID = null,
          subjectUniqueID = null,
          extensions = extensions(),
        )

      // Signature.
      val signature =
        Signature.getInstance(tbsCertificate.signatureAlgorithmName).run {
          initSign(issuerKeyPair.private)
          update(CertificateAdapters.tbsCertificate.toDer(tbsCertificate).toByteArray())
          sign().toByteString()
        }

  // defaulted versions for TLS based on what is requested.
  override fun newSSLContext(): SSLContext = SSLContext.getInstance("TLSv1.3", provider)

  override fun platformTrustManager(): X509TrustManager {
    val factory =
      TrustManagerFactory.getInstance(
        TrustManagerFactory.getDefaultAlgorithm(),
        provider,
      )
    factory.init(null as KeyStore?)

   * certificates.
   */
  private SSLSocketFactory defaultSslSocketFactory(X509TrustManager trustManager)
      throws NoSuchAlgorithmException, KeyManagementException {
    SSLContext sslContext = SSLContext.getInstance("TLS");
    sslContext.init(null, new TrustManager[] { trustManager }, null);

    return sslContext.getSocketFactory();
  }

  /** Returns a trust manager that trusts the VM's default certificate authorities. */