throw IllegalArgumentException("failed to decode certificate", nsee)
  } catch (iae: IllegalArgumentException) {
    throw IllegalArgumentException("failed to decode certificate", iae)
  } catch (e: GeneralSecurityException) {
    throw IllegalArgumentException("failed to decode certificate", e)
  }
}

/**
 * Returns the certificate encoded in [PEM format][rfc_7468].
 *
 * [rfc_7468]: https://tools.ietf.org/html/rfc7468
 */

     * certificate can sign other certificates (but those certificates cannot themselves sign
     * certificates). Set this to 1 so this certificate can sign intermediate certificates that can
     * themselves sign certificates. Add one for each additional layer of intermediates to permit.
     */
    fun certificateAuthority(maxIntermediateCas: Int) =
      apply {

    val data = CertificateAdapters.certificate.toDer(this)
    try {
      val certificateFactory = CertificateFactory.getInstance("X.509")
      val certificates = certificateFactory.generateCertificates(Buffer().write(data).inputStream())
      return certificates.single() as X509Certificate
    } catch (e: NoSuchElementException) {
      throw IllegalArgumentException("failed to decode certificate", e)
    } catch (e: IllegalArgumentException) {

 *
 *  * The client's handshake certificates must have a [held certificate][HeldCertificate] (a
 *    certificate and its private key). The client must also have a (possibly-empty) chain of
 *    intermediate certificates to establish trust from a root certificate to the client's
 *    certificate. The root certificate is not included in this chain.
 *  * The server's handshake certificates must include a set of trusted root certificates. They

    assertThat(cleaner.clean(certificates, "hostname")).isEqualTo(certificates)
    assertThat(cleaner.clean(certificates.subList(0, 9), "hostname")).isEqualTo(
      certificates,
    )
  }

  @Test
  fun chainTooLong() {
    val heldCertificates = chainOfLength(11)
    val certificates: MutableList<Certificate> = ArrayList()
    for (heldCertificate in heldCertificates) {
      certificates.add(heldCertificate.certificate)

to generate a trusted root certificate, an intermediate certificate, and a server certificate.
We use `certificateAuthority(int)` to create certificates that can sign other certificates. The
int specifies how many intermediate certificates are allowed beneath it in the chain.

```java
HeldCertificate rootCertificate = new HeldCertificate.Builder()
    .certificateAuthority(1)
    .build();

 * the License.
 */
package okhttp3

import java.security.Principal
import java.security.cert.Certificate
import javax.net.ssl.SSLPeerUnverifiedException
import javax.net.ssl.SSLSession
import javax.net.ssl.SSLSessionContext
import javax.security.cert.X509Certificate

class FakeSSLSession(
  vararg val certificates: Certificate,
) : SSLSession {
  override fun getApplicationBufferSize(): Int = throw UnsupportedOperationException()

 * `api.publicobject.com` are valid if either A's or B's certificate is in the chain.
 *
 * ## Warning: Certificate Pinning is Dangerous!
 *
 * Pinning certificates limits your server team's abilities to update their TLS certificates. By
 * pinning certificates, you take on additional operational complexity and limit your ability to
 * migrate between certificate authorities. Do not use certificate pinning without the blessing of

        .addTrustedCertificate(comodoRsaCertificationAuthority)
        // Uncomment if standard certificates are also required.
        // .addPlatformTrustedCertificates()
        .build()
    client =
      OkHttpClient
        .Builder()
        .sslSocketFactory(certificates.sslSocketFactory(), certificates.trustManager)
        .build()
  }

  fun run() {
    showUrl("https://squareup.com/robots.txt")

 * certificate.
 *
 * Use of the chain cleaner is necessary to omit unexpected certificates that aren't relevant to
 * the TLS handshake and to extract the trusted CA certificate for the benefit of certificate
 * pinning.
 */
abstract class CertificateChainCleaner {
  @Throws(SSLPeerUnverifiedException::class)
  abstract fun clean(
    chain: List<Certificate>,