Maintenant, du point de vue d'un développeur, voici plusieurs choses à avoir en tête en pensant au HTTPS :

* Pour le HTTPS, le serveur a besoin de "certificats" générés par une tierce partie.
    * Ces certificats sont en fait acquis auprès de la tierce partie, et non "générés".
* Les certificats ont une durée de vie.
    * Ils expirent.
    * Puis ils doivent être renouvelés et acquis à nouveau auprès de la tierce partie.

Il est intégré à Let's Encrypt. Ainsi, il peut gérer toutes les parties HTTPS, y compris l'acquisition et le renouvellement des certificats.

Il est également intégré à Docker. Ainsi, vous pouvez déclarer vos domaines dans les configurations de chaque application et faire en sorte qu'elles lisent ces configurations, génèrent les certificats HTTPS et servent via HTTPS à votre application automatiquement, sans nécessiter aucune modification de leurs configurations.

    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) {

    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 {

 *
 *  * 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

 * `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

* Traefik (que também pode gerenciar a renovação de certificados)
* Caddy (que também pode gerenciar a renovação de certificados)
* Nginx
* HAProxy

## Let's Encrypt

Antes de Let's Encrypt, esses **certificados HTTPS** eram vendidos por terceiros confiáveis.

O processo de aquisição de um desses certificados costumava ser complicado, exigia bastante papelada e os certificados eram bastante caros.

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();

    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)