"application/vnd.micrografx.igx",
				"application/vnd.mif",
				"application/vnd.mindjet.mindmanager",
				"application/vnd.minisoft-hp3000-save",
				"application/vnd.mitsubishi.misty-guard.trustweb",
				"application/vnd.mobius.daf",
				"application/vnd.mobius.dis",
				"application/vnd.mobius.mbk",
				"application/vnd.mobius.mqy",
				"application/vnd.mobius.msl",
				"application/vnd.mobius.plc",

        assertEquals("192.168.1.100", rateLimitHelper.getClientIp(request));
    }

    @Test
    public void test_getClientIp_xForwardedFor_trustedProxy() {
        // 127.0.0.1 is configured as a trusted proxy by default
        final MockletHttpServletRequest request = getMockRequest();
        request.setRemoteAddr("127.0.0.1");
        request.addHeader("X-Forwarded-For", "203.0.113.50, 70.41.3.18, 150.172.238.178");

   *
   *
   * The victim's gets a non-CA certificate signed by a CA, and pins the CA root and/or
   * intermediate. This is business as usual.
   *
   * ```
   *   pinnedRoot (trusted by CertificatePinner)
   *     -> pinnedIntermediate (trusted by CertificatePinner)
   *       -> realVictim
   * ```
   *
   * The attacker compromises a CA. They take the public key from an intermediate certificate

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

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) {

 * called certificate authorities (CAs).
 *
 * Browsers and other HTTP clients need a set of trusted root certificates to authenticate their
 * peers. Sets of root certificates are managed by either the HTTP client (like Firefox), or the
 * host platform (like Android). In July 2018 Android had 134 trusted root certificates for its HTTP
 * clients to trust.
 *

* 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!**

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

import okhttp3.internal.toCanonicalHost
import okio.ByteString
import okio.ByteString.Companion.decodeBase64
import okio.ByteString.Companion.toByteString

/**
 * Constrains which certificates are trusted. Pinning certificates defends against attacks on
 * certificate authorities. It also prevents connections through man-in-the-middle certificate
 * authorities either known or unknown to the application's user.