assertThat(it.protocol).isEqualTo(Protocol.HTTP_2)
      assertThat(it.handshake!!.tlsVersion).isEqualTo(TlsVersion.TLS_1_3)
    }

    client.connectionPool.evictAll()
    assertEquals(0, client.connectionPool.connectionCount())

    client.newCall(request).execute().use {
      assertThat(it.protocol).isEqualTo(Protocol.HTTP_2)
      assertThat(it.handshake!!.tlsVersion).isEqualTo(TlsVersion.TLS_1_3)
    }

    response.use {
      assertEquals(Protocol.HTTP_2, response.protocol)
      if (Build.VERSION.SDK_INT >= 29) {
        assertEquals(TlsVersion.TLS_1_3, response.handshake?.tlsVersion)
      } else {
        assertEquals(TlsVersion.TLS_1_2, response.handshake?.tlsVersion)
      }
      assertEquals(200, response.code)
      assertTrue(socketClass?.startsWith("com.android.org.conscrypt.") == true)
    }
  }

  @Test

    val request = Request(server.url("/"))

    val response = client.newCall(request).execute()

    response.use {
      assertEquals(200, response.code)
      assertEquals(TlsVersion.TLS_1_3, response.handshake?.tlsVersion)
      assertEquals(Protocol.HTTP_2, response.protocol)

      assertThat(response.exchangeAccessor!!.connectionAccessor.socket())
        .isInstanceOf<SSLSocketImpl>()
    }
  }

  @Test

        TlsVersion.TLS_1_3,
      ) // v1.2 on OpenJDK 8.
    val request1 = server.takeRequest()
    assertThat(tlsVersions).contains(request1.handshake?.tlsVersion)
    val request2 = server.takeRequest()
    assertThat(tlsVersions).contains(request2.handshake?.tlsVersion)
  }

  /**
   * Verify that we don't retry connections on certificate verification errors.
   *

<img src="/img/deployment/https/https01.drawio.svg">

### TLS-Handshake-Start { #tls-handshake-start }

Der Browser kommuniziert dann mit dieser IP-Adresse über **Port 443** (den HTTPS-Port).

<img src="/img/deployment/https/https01.drawio.svg">

### TLS Handshake Başlangıcı { #tls-handshake-start }

Tarayıcı daha sonra bu IP adresiyle **443 portu** (HTTPS portu) üzerinden iletişim kurar.

        .build();

    Call call = client.newCall(new Request.Builder()
        .url(server.url("/"))
        .build());
    Response response = call.execute();
    System.out.println(response.handshake().tlsVersion());
  }

  public static void main(String... args) throws Exception {
    new HttpsServer().run();
  }

    try (Response response = client.newCall(request).execute()) {
      assertTrue(response.code() == 200 || response.code() == 404);
      assertEquals(Protocol.HTTP_2, response.protocol());

      for (Certificate c: response.handshake().peerCertificates()) {
        X509Certificate x = (X509Certificate) c;
        System.out.println(x.getSubjectDN());
      }
    }
  }

    val request = Request.Builder().url("https://mozilla.org/robots.txt").build()

    client.newCall(request).execute().use {
      assertThat(it.protocol).isEqualTo(Protocol.HTTP_2)
      assertThat(it.handshake!!.tlsVersion).isEqualTo(TlsVersion.TLS_1_3)
    }
  }

        .build()

    client.newCall(request).execute().use { response ->
      if (!response.isSuccessful) throw IOException("Unexpected code $response")

      for (certificate in response.handshake!!.peerCertificates) {
        println(CertificatePinner.pin(certificate))
      }
    }
  }
}

fun main() {
  CertificatePinning().run()