import javax.net.ssl.SSLSession
import okhttp3.internal.toImmutableList

/**
 * A record of a TLS handshake. For HTTPS clients, the client is *local* and the remote server is
 * its *peer*.
 *
 * This value object describes a completed handshake. Use [ConnectionSpec] to set policy for new
 * handshakes.
 */
class Handshake internal constructor(
  /**

          // Produced ClientHello handshake message
          // Consuming ServerHello handshake message
          // Consuming server Certificate handshake message
          // Consuming server CertificateStatus handshake message
          // Found trusted certificate
          // Consuming ECDH ServerKeyExchange handshake message
          // Consuming ServerHelloDone handshake message

            address.url.host,
          )
        }
      this.handshake = handshake

      // Check that the certificate pinner is satisfied by the certificates presented.
      certificatePinner.check(address.url.host) {
        handshake.peerCertificates.map { it as X509Certificate }
      }

      // Success! Save the handshake and the ALPN protocol.
      val maybeProtocol =

import java.util.concurrent.Executors
import java.util.concurrent.Future
import javax.net.ServerSocketFactory
import javax.net.SocketFactory
import javax.net.ssl.SSLSocket
import okhttp3.Handshake
import okhttp3.Handshake.Companion.handshake
import okhttp3.TestUtil.threadFactory
import okhttp3.internal.closeQuietly
import okhttp3.testing.PlatformRule
import okio.ByteString.Companion.toByteString
import org.junit.jupiter.api.AfterEach

Call call = client.newCall(new Request.Builder()
    .url(server.url("/"))
    .build());
Response response = call.execute();
System.out.println(response.handshake().peerPrincipal());
RecordedRequest recordedRequest = server.takeRequest();
System.out.println(recordedRequest.getHandshake().peerPrincipal());
```

 * Keep whichever TCP connection succeeds first and cancel all the others.
 * Race TCP only. Only attempt a TLS handshake on the winning TCP connection.

    val formBody: FormBody = builder.build()
  }

  @Test
  fun handshake() {
    var handshake: Handshake =
      (localhost().sslSocketFactory().createSocket() as SSLSocket).session.handshake()
    val listOfCertificates: List<Certificate> = listOf()
    handshake =
      Handshake.get(
        TlsVersion.TLS_1_3,
        CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,

          .writeByte('\n'.code)

        if (url.isHttps && handshake != null) {
          sink.writeByte('\n'.code)
          sink.writeUtf8(handshake.cipherSuite.javaName).writeByte('\n'.code)
          writeCertList(sink, handshake.peerCertificates)
          writeCertList(sink, handshake.localCertificates)
          sink.writeUtf8(handshake.tlsVersion.javaName).writeByte('\n'.code)
        }
      }
    }

      when (expected) {
        is SSLHandshakeException -> {
          // On Android, the handshake fails before the certificate pinner runs.
          assertThat(expected.message!!).contains("Could not validate certificate")
        }

        is SSLPeerUnverifiedException -> {
          // On OpenJDK, the handshake succeeds but the certificate pinner fails.

    .build();
```

### Debugging TLS Handshake Failures

The TLS handshake requires clients and servers to share a common TLS version and cipher suite. This
depends on the JVM or Android version, OkHttp version, and web server configuration. If there is no
common cipher suite and TLS version, your call will fail like this:

```
Caused by: javax.net.ssl.SSLProtocolException: SSL handshake aborted: ssl=0x7f2719a89e80: