-----------------------

The above example uses a self-signed certificate. This is convenient for testing but not
representative of real-world HTTPS deployment. To get closer to that we can use `HeldCertificate`
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

              //    chain
              // We can only do this for Trusted, because Trusted implementations of cancel do
              // nothing but delegate to this method and do not permit user overrides.
              AbstractFuture<?> trusted = (AbstractFuture<?>) futureToPropagateTo;
              localValue = trusted.value();
              if (localValue == null | localValue instanceof DelegatingToFuture) {

* Caddy (that can also handle certificate renewals)
* Nginx
* HAProxy

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

Before Let's Encrypt, these **HTTPS certificates** were sold by trusted third parties.

The process to acquire one of these certificates used to be cumbersome, require quite some paperwork and the certificates were quite expensive.

But then **[Let's Encrypt](https://letsencrypt.org/)** was created.

Use [CertificatePinner](https://square.github.io/okhttp/5.x/okhttp/okhttp3/-certificate-pinner/) to restrict which certificates and certificate authorities are trusted. Certificate pinning increases security, but limits your server team’s abilities to update their TLS certificates. **Do not use certificate pinning without the blessing of your server’s TLS administrator!**

* the application is running locally (e.g. on `localhost`) or in an internal network
* and the application doesn't have any authentication, it expects that any request from the same network can be trusted.

## Example Attack { #example-attack }

Imagine you build a way to run a local AI agent.

It provides an API at

```
http://localhost:8000/v1/agents/multivac
```

There's also a frontend at

You can start FastAPI CLI with the *CLI Option* `--forwarded-allow-ips` and pass the IP addresses that should be trusted to read those forwarded headers.

If you set it to `--forwarded-allow-ips="*"` it would trust all the incoming IPs.

If your **server** is behind a trusted **proxy** and only the proxy talks to it, this would make it accept whatever is the IP of that **proxy**.

<div class="termy">

```console

 * They don't specify whether a specific proxy server should be used or how to authenticate with that proxy server.

## Previous tools { #previous-tools }

### [Django](https://www.djangoproject.com/) { #django }

It's the most popular Python framework and is widely trusted. It is used to build systems like Instagram.

    `EventSourceListener.onOpen()`.
 *  Fix: Enforce the max intermediates constraint when using pinned certificates with Conscrypt.
    This impacts Conscrypt when the server's presented certificates form both a trusted-but-unpinned
    chain and an untrusted-but-pinned chain.
 *  Upgrade: [Kotlin 1.6.10][kotlin_1_6_10].


## Version 5.0.0-alpha.3

_2021-11-22_

          this.routeDatabase = null
        }

        this.hostnameVerifier = hostnameVerifier
      }

    /**
     * Sets the certificate pinner that constrains which certificates are trusted. By default HTTPS
     * connections rely on only the [SSL socket factory][sslSocketFactory] to establish trust.
     * Pinning certificates avoids the need to trust certificate authorities.
     */