La primera parte de la comunicación es solo para establecer la conexión entre el cliente y el servidor y decidir las claves criptográficas que usarán, etc.

<img src="/img/deployment/https/https02.drawio.svg">

Esta interacción entre el cliente y el servidor para establecer la conexión TLS se llama **handshake TLS**.

### TLS con Extensión SNI { #tls-with-sni-extension }

public final class CurrentDateHeader {
  private final OkHttpClient client = new OkHttpClient.Builder()
      .addInterceptor(new CurrentDateInterceptor())
      .build();

  public void run() throws Exception {
    Request request = new Request.Builder()
        .url("https://publicobject.com/helloworld.txt")
        .build();

    try (Response response = client.newCall(request).execute()) {

import okhttp3.RequestBody;
import okhttp3.Response;

public final class PostString {
  public static final MediaType MEDIA_TYPE_MARKDOWN
      = MediaType.get("text/x-markdown; charset=utf-8");

  private final OkHttpClient client = new OkHttpClient();

  public void run() throws Exception {
    String postBody = ""
        + "Releases\n"
        + "--------\n"
        + "\n"
        + " * _1.0_ May 6, 2013\n"

import okhttp3.Request
import okhttp3.RequestBody.Companion.asRequestBody
import okio.Path.Companion.toPath
import okio.buffer
import okio.fakefilesystem.FakeFileSystem

class PostPath {
  private val client = OkHttpClient()
  private val fileSystem = FakeFileSystem()
  val path = "test.json".toPath()

  fun run() {
    fileSystem.write(path) {
      writeUtf8("{}")
    }

    val request =
      Request

### Proxy Forwarded Header'ları Nasıl Çalışır { #how-proxy-forwarded-headers-work }

**Proxy**'nin, client ile **application server** arasında forwarded header'ları nasıl eklediğini gösteren görsel bir temsil:

```mermaid
sequenceDiagram
    participant Client
    participant Proxy as Proxy/Load Balancer
    participant Server as FastAPI Server

    Client->>Proxy: HTTPS Request<br/>Host: mysuperapp.com<br/>Path: /items

/* jcifs smb client library in Java
 * Copyright (C) 2002  "Michael B. Allen" <jcifs at samba dot org>
 *                   "Eric Glass" <jcifs at samba dot org>
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *

 */
package okhttp3.recipes.kt

import java.io.IOException
import okhttp3.CertificatePinner
import okhttp3.OkHttpClient
import okhttp3.Request

class CertificatePinning {
  private val client =
    OkHttpClient
      .Builder()
      .certificatePinner(
        CertificatePinner
          .Builder()
          .add("publicobject.com", "sha256/Vjs8r4z+80wjNcr1YKepWQboSIRi63WsWXhIMN+eWys=")

Voici une représentation visuelle de la façon dont le **proxy** ajoute des en‑têtes transférés entre le client et le **serveur d'application** :

```mermaid
sequenceDiagram
    participant Client
    participant Proxy as Proxy/Load Balancer
    participant Server as FastAPI Server

    Client->>Proxy: HTTPS Request<br/>Host: mysuperapp.com<br/>Path: /items

    Note over Proxy: Proxy adds forwarded headers

@router.get("/users/{id}")
def read_user(segment: str, id: str):
    return {"segment": segment, "id": id}


app.include_router(router, prefix="/{segment}")


client = TestClient(app)


def test_get():
    response = client.get("/seg/users/foo")
    assert response.status_code == 200, response.text

async def a():
    pass  # pragma: no cover


@app.get("/b", responses={500: {"description": "Error", "model": Error}})
async def b():
    pass  # pragma: no cover


client = TestClient(app)


def test_openapi_schema():
    response = client.get("/openapi.json")
    assert response.status_code == 200, response.text
    assert response.json() == snapshot(
        {
            "openapi": "3.1.0",