Os domínios são verificados com segurança e os certificados são gerados automaticamente. Isso também permite automatizar a renovação desses certificados.

* Traefik (que también puede manejar la renovación de certificados)
* Caddy (que también puede manejar la renovación de certificados)
* Nginx
* HAProxy

## Let's Encrypt { #lets-encrypt }

Antes de Let's Encrypt, estos **certificados HTTPS** eran vendidos por terceros.

El proceso para adquirir uno de estos certificados solía ser complicado, requerir bastante papeleo y los certificados eran bastante costosos.

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 domains are securely verified and the certificates are generated automatically. This also allows automating the renewal of these certificates.

     * 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

            |    certificate: ${CertificatePinner.pin(cert)}
            |    DN: ${cert.subjectDN.name}
            |    subjectAltNames: ${OkHostnameVerifier.allSubjectAltNames(cert)}
            """.trimMargin(),
          )
        } else {
          throw SSLPeerUnverifiedException(
            "Hostname ${address.url.host} not verified (no certificates)",
          )
        }
      }

    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)

 * [okhttp-stats](https://github.com/flipkart-incubator/okhttp-stats): Get stats like average network speed.
 * [okhttp-system-keystore](https://github.com/charleskorn/okhttp-system-keystore): Use trusted certificates from the operating system keystore (Keychain on macOS, Certificate Store on Windows).
 * ⬜️ [Okio](https://github.com/square/okio/): A modern I/O API for Java.

And there has to be something in charge of **renewing the HTTPS certificates**, it could be the same component or it could be something different.

### Example Tools for HTTPS { #example-tools-for-https }

Some of the tools you could use as a TLS Termination Proxy are:

* Traefik
    * Automatically handles certificates renewals ✨
* Caddy
    * Automatically handles certificates renewals ✨
* Nginx

Auf diese Weise könnte der TLS-Terminierungsproxy HTTPS und Zertifikate für **mehrere Domains**, für mehrere Anwendungen, verarbeiten und die Requests dann jeweils an die richtige Anwendung weiterleiten.

### Verlängerung des Zertifikats { #certificate-renewal }

Irgendwann in der Zukunft würde jedes Zertifikat **ablaufen** (etwa 3 Monate nach dem Erwerb).