.heldCertificate(serverCertificate, intermediateCertificate.certificate())
    .build();
```

The client only needs to know the trusted root certificate. It checks the server's certificate by
validating the signatures within the chain.

```java
HandshakeCertificates clientCertificates = new HandshakeCertificates.Builder()
    .addTrustedCertificate(rootCertificate.certificate())
    .build();

    // Add a bad intermediate CA and have that issue a rogue certificate for localhost. Prepare
    // an SSL context for an attacking webserver. It includes both these rogue certificates plus the
    // trusted good certificate above. The attack is that by including the good certificate in the
    // chain, we may trick the certificate pinner into accepting the rouge certificate.
    val compromisedIntermediateCa =
      HeldCertificate

    val certificate: X509Certificate = heldCertificate.certificate
    val certificatePinner: CertificatePinner = CertificatePinner.Builder().build()
    val certificates: List<Certificate> = listOf()
    certificatePinner.check("", listOf(certificate))
    certificatePinner.check("", arrayOf<Certificate>(certificate, certificate).toList())
    val pin: String = CertificatePinner.pin(certificate)

      val keyManager =
        newKeyManager(
          null,
          serverCert,
          serverIntermediateCa.certificate,
        )
      val trustManager =
        newTrustManager(
          null,
          Arrays.asList(serverRootCa.certificate, clientRootCa.certificate),
          emptyList(),
        )
      val sslContext = SSLContext.getInstance("TLS")
      sslContext.init(

        try (InputStream in = new FileInputStream(filename)) {
            Certificate certificate = CertificateFactory.getInstance("X.509").generateCertificate(in);

            KeyStore keyStore = KeyStore.getInstance(KeyStore.getDefaultType());
            keyStore.load(null, null);
            keyStore.setCertificateEntry("server", certificate);

  /** Can still coalesce when pinning is used if pins match.  */
  @Test
  fun coalescesWhenCertificatePinsMatch() {
    val pinner =
      CertificatePinner
        .Builder()
        .add("san.com", pin(certificate.certificate))
        .build()
    client = client.newBuilder().certificatePinner(pinner).build()
    server.enqueue(MockResponse())
    server.enqueue(MockResponse())

                    final SSLHostConfigCertificate certificate =
                            new SSLHostConfigCertificate(sslHostConfig, SSLHostConfigCertificate.Type.UNDEFINED);
                    doSetupServerConfig(logger, props, "certificateKeystoreFile", v -> certificate.setCertificateKeystoreFile(v));
                    doSetupServerConfig(logger, props, "certificateKeystorePassword", v -> certificate.setCertificateKeystorePassword(v));

     * a line containing the cipher suite. Next is the length of the peer certificate chain. These
     * certificates are base64-encoded and appear each on their own line. The next line contains the
     * length of the local certificate chain. These certificates are also base64-encoded and appear
     * each on their own line. A length of -1 is used to encode a null array. The last line is

  /**
   * Configure the server to [want client auth][SSLSocket.setWantClientAuth]. If the
   * client presents a certificate that is [trusted][TrustManager] the handshake will
   * proceed normally. The connection will also proceed normally if the client presents no
   * certificate at all! But if the client presents an untrusted certificate the handshake
   * will fail and no connection will be established.
   */
  public fun requestClientAuth() {

        .build()
    val handshakeCertificates =
      HandshakeCertificates
        .Builder()
        .heldCertificate(heldCertificate)
        .addTrustedCertificate(heldCertificate.certificate)
        .build()

    client =
      client
        .newBuilder()
        .sslSocketFactory(
          handshakeCertificates.sslSocketFactory(),
          handshakeCertificates.trustManager,