repackaged/okhttp/src/main/java/com/android/okhttp/ConnectionSpec.java - platform/external/okhttp - Git at Google

 /* GENERATED SOURCE. DO NOT MODIFY. */
 /*
  * Copyright (C) 2014 Square, Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License");
  * you may not use this file except in compliance with the License.
  * You may obtain a copy of the License at
  *
  *      http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS,
  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  * See the License for the specific language governing permissions and
  * limitations under the License.
  */
 package com.android.okhttp;

 import com.android.okhttp.internal.Util;
 import java.util.Arrays;
 import java.util.List;
 import javax.net.ssl.SSLSocket;

 import static com.android.okhttp.internal.Util.concat;
 import static com.android.okhttp.internal.Util.contains;

 /**
  * Specifies configuration for the socket connection that HTTP traffic travels through. For {@code
  * https:} URLs, this includes the TLS version and cipher suites to use when negotiating a secure
  * connection.
  *
  * <p>The TLS versions configured in a connection spec are only be used if they are also enabled in
  * the SSL socket. For example, if an SSL socket does not have TLS 1.2 enabled, it will not be used
  * even if it is present on the connection spec. The same policy also applies to cipher suites.
  *
  * <p>Use {@link Builder#allEnabledTlsVersions()} and {@link Builder#allEnabledCipherSuites} to
  * defer all feature selection to the underlying SSL socket.
  * @hide This class is not part of the Android public SDK API
  */
 public final class ConnectionSpec {

   // This is a subset of the cipher suites supported in Chrome 46, current as of 2015-11-05.
   // All of these suites are available on Android 5.0; earlier releases support a subset of
   // these suites. https://github.com/square/okhttp/issues/330
   private static final CipherSuite[] APPROVED_CIPHER_SUITES = new CipherSuite[] {
       CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
       CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
       CipherSuite.TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,

       // Note that the following cipher suites are all on HTTP/2's bad cipher suites list. We'll
       // continue to include them until better suites are commonly available. For example, none
       // of the better cipher suites listed above shipped with Android 4.4 or Java 7.
       CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
       CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
       CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
       CipherSuite.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
       CipherSuite.TLS_DHE_RSA_WITH_AES_128_CBC_SHA,
       CipherSuite.TLS_DHE_RSA_WITH_AES_256_CBC_SHA,
       CipherSuite.TLS_RSA_WITH_AES_128_GCM_SHA256,
       CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA,
       CipherSuite.TLS_RSA_WITH_AES_256_CBC_SHA,
       CipherSuite.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
   };

   /** A modern TLS connection with extensions like SNI and ALPN available. */
   public static final ConnectionSpec MODERN_TLS = new Builder(true)
       .cipherSuites(APPROVED_CIPHER_SUITES)
       .tlsVersions(TlsVersion.TLS_1_2, TlsVersion.TLS_1_1, TlsVersion.TLS_1_0)
       .supportsTlsExtensions(true)
       .build();

   /** A backwards-compatible fallback connection for interop with obsolete servers. */
   public static final ConnectionSpec COMPATIBLE_TLS = new Builder(MODERN_TLS)
       .tlsVersions(TlsVersion.TLS_1_0)
       .supportsTlsExtensions(true)
       .build();

   /** Unencrypted, unauthenticated connections for {@code http:} URLs. */
   public static final ConnectionSpec CLEARTEXT = new Builder(false).build();

   private final boolean tls;
   private final boolean supportsTlsExtensions;
   private final String[] cipherSuites;
   private final String[] tlsVersions;

   private ConnectionSpec(Builder builder) {
     this.tls = builder.tls;
     this.cipherSuites = builder.cipherSuites;
     this.tlsVersions = builder.tlsVersions;
     this.supportsTlsExtensions = builder.supportsTlsExtensions;
   }

   public boolean isTls() {
     return tls;
   }

   /**
    * Returns the cipher suites to use for a connection. Returns {@code null} if all of the SSL
    * socket's enabled cipher suites should be used.
    */
   public List<CipherSuite> cipherSuites() {
     if (cipherSuites == null) return null;

     CipherSuite[] result = new CipherSuite[cipherSuites.length];
     for (int i = 0; i < cipherSuites.length; i++) {
       result[i] = CipherSuite.forJavaName(cipherSuites[i]);
     }
     return Util.immutableList(result);
   }

   /**
    * Returns the TLS versions to use when negotiating a connection. Returns {@code null} if all of
    * the SSL socket's enabled TLS versions should be used.
    */
   public List<TlsVersion> tlsVersions() {
     if (tlsVersions == null) return null;

     TlsVersion[] result = new TlsVersion[tlsVersions.length];
     for (int i = 0; i < tlsVersions.length; i++) {
       result[i] = TlsVersion.forJavaName(tlsVersions[i]);
     }
     return Util.immutableList(result);
   }

   public boolean supportsTlsExtensions() {
     return supportsTlsExtensions;
   }

   /** Applies this spec to {@code sslSocket}. */
   void apply(SSLSocket sslSocket, boolean isFallback) {
     ConnectionSpec specToApply = supportedSpec(sslSocket, isFallback);

     if (specToApply.tlsVersions != null) {
       sslSocket.setEnabledProtocols(specToApply.tlsVersions);
     }
     if (specToApply.cipherSuites != null) {
       sslSocket.setEnabledCipherSuites(specToApply.cipherSuites);
     }
   }

   /**
    * Returns a copy of this that omits cipher suites and TLS versions not enabled by {@code
    * sslSocket}.
    */
   private ConnectionSpec supportedSpec(SSLSocket sslSocket, boolean isFallback) {
     String[] cipherSuitesIntersection = cipherSuites != null
         ? Util.intersect(String.class, cipherSuites, sslSocket.getEnabledCipherSuites())
         : sslSocket.getEnabledCipherSuites();
     String[] tlsVersionsIntersection = tlsVersions != null
         ? Util.intersect(String.class, tlsVersions, sslSocket.getEnabledProtocols())
         : sslSocket.getEnabledProtocols();

     // In accordance with https://tools.ietf.org/html/draft-ietf-tls-downgrade-scsv-00
     // the SCSV cipher is added to signal that a protocol fallback has taken place.
     if (isFallback && contains(sslSocket.getSupportedCipherSuites(), "TLS_FALLBACK_SCSV")) {
       cipherSuitesIntersection = concat(cipherSuitesIntersection, "TLS_FALLBACK_SCSV");
     }

     return new Builder(this)
         .cipherSuites(cipherSuitesIntersection)
         .tlsVersions(tlsVersionsIntersection)
         .build();
   }

   /**
    * Returns {@code true} if the socket, as currently configured, supports this connection spec.
    * In order for a socket to be compatible the enabled cipher suites and protocols must intersect.
    *
    * <p>For cipher suites, at least one of the {@link #cipherSuites() required cipher suites} must
    * match the socket's enabled cipher suites. If there are no required cipher suites the socket
    * must have at least one cipher suite enabled.
    *
    * <p>For protocols, at least one of the {@link #tlsVersions() required protocols} must match the
    * socket's enabled protocols.
    */
   public boolean isCompatible(SSLSocket socket) {
     if (!tls) {
       return false;
     }

     if (tlsVersions != null
         && !nonEmptyIntersection(tlsVersions, socket.getEnabledProtocols())) {
       return false;
     }

     if (cipherSuites != null
         && !nonEmptyIntersection(cipherSuites, socket.getEnabledCipherSuites())) {
       return false;
     }

     return true;
   }

   /**
    * An N*M intersection that terminates if any intersection is found. The sizes of both
    * arguments are assumed to be so small, and the likelihood of an intersection so great, that it
    * is not worth the CPU cost of sorting or the memory cost of hashing.
    */
   private static boolean nonEmptyIntersection(String[] a, String[] b) {
     if (a == null || b == null || a.length == 0 || b.length == 0) {
       return false;
     }
     for (String toFind : a) {
       if (contains(b, toFind)) {
         return true;
       }
     }
     return false;
   }

   @Override public boolean equals(Object other) {
     if (!(other instanceof ConnectionSpec)) return false;
     if (other == this) return true;

     ConnectionSpec that = (ConnectionSpec) other;
     if (this.tls != that.tls) return false;

     if (tls) {
       if (!Arrays.equals(this.cipherSuites, that.cipherSuites)) return false;
       if (!Arrays.equals(this.tlsVersions, that.tlsVersions)) return false;
       if (this.supportsTlsExtensions != that.supportsTlsExtensions) return false;
     }

     return true;
   }

   @Override public int hashCode() {
     int result = 17;
     if (tls) {
       result = 31 * result + Arrays.hashCode(cipherSuites);
       result = 31 * result + Arrays.hashCode(tlsVersions);
       result = 31 * result + (supportsTlsExtensions ? 0 : 1);
     }
     return result;
   }

   @Override public String toString() {
     if (!tls) {
       return "ConnectionSpec()";
     }

     String cipherSuitesString = cipherSuites != null ? cipherSuites().toString() : "[all enabled]";
     String tlsVersionsString = tlsVersions != null ? tlsVersions().toString() : "[all enabled]";
     return "ConnectionSpec("
         + "cipherSuites=" + cipherSuitesString
         + ", tlsVersions=" + tlsVersionsString
         + ", supportsTlsExtensions=" + supportsTlsExtensions
         + ")";
   }

   /**
    * @hide This class is not part of the Android public SDK API
    */
   public static final class Builder {
     private boolean tls;
     private String[] cipherSuites;
     private String[] tlsVersions;
     private boolean supportsTlsExtensions;

     Builder(boolean tls) {
       this.tls = tls;
     }

     public Builder(ConnectionSpec connectionSpec) {
       this.tls = connectionSpec.tls;
       this.cipherSuites = connectionSpec.cipherSuites;
       this.tlsVersions = connectionSpec.tlsVersions;
       this.supportsTlsExtensions = connectionSpec.supportsTlsExtensions;
     }

     public Builder allEnabledCipherSuites() {
       if (!tls) throw new IllegalStateException("no cipher suites for cleartext connections");
       this.cipherSuites = null;
       return this;
     }

     public Builder cipherSuites(CipherSuite... cipherSuites) {
       if (!tls) throw new IllegalStateException("no cipher suites for cleartext connections");

       String[] strings = new String[cipherSuites.length];
       for (int i = 0; i < cipherSuites.length; i++) {
         strings[i] = cipherSuites[i].javaName;
       }
       return cipherSuites(strings);
     }

     public Builder cipherSuites(String... cipherSuites) {
       if (!tls) throw new IllegalStateException("no cipher suites for cleartext connections");

       if (cipherSuites.length == 0) {
         throw new IllegalArgumentException("At least one cipher suite is required");
       }

       this.cipherSuites = cipherSuites.clone(); // Defensive copy.
       return this;
     }

     public Builder allEnabledTlsVersions() {
       if (!tls) throw new IllegalStateException("no TLS versions for cleartext connections");
       this.tlsVersions = null;
       return this;
     }

     public Builder tlsVersions(TlsVersion... tlsVersions) {
       if (!tls) throw new IllegalStateException("no TLS versions for cleartext connections");

       String[] strings = new String[tlsVersions.length];
       for (int i = 0; i < tlsVersions.length; i++) {
         strings[i] = tlsVersions[i].javaName;
       }

       return tlsVersions(strings);
     }

     public Builder tlsVersions(String... tlsVersions) {
       if (!tls) throw new IllegalStateException("no TLS versions for cleartext connections");

       if (tlsVersions.length == 0) {
         throw new IllegalArgumentException("At least one TLS version is required");
       }

       this.tlsVersions = tlsVersions.clone(); // Defensive copy.
       return this;
     }

     public Builder supportsTlsExtensions(boolean supportsTlsExtensions) {
       if (!tls) throw new IllegalStateException("no TLS extensions for cleartext connections");
       this.supportsTlsExtensions = supportsTlsExtensions;
       return this;
     }

     public ConnectionSpec build() {
       return new ConnectionSpec(this);
     }
   }
 }
	/* GENERATED SOURCE. DO NOT MODIFY. */
	/*
	* Copyright (C) 2014 Square, Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License");
	* you may not use this file except in compliance with the License.
	* You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/
	package com.android.okhttp;

	import com.android.okhttp.internal.Util;
	import java.util.Arrays;
	import java.util.List;
	import javax.net.ssl.SSLSocket;

	import static com.android.okhttp.internal.Util.concat;
	import static com.android.okhttp.internal.Util.contains;

	/**
	* Specifies configuration for the socket connection that HTTP traffic travels through. For {@code
	* https:} URLs, this includes the TLS version and cipher suites to use when negotiating a secure
	* connection.
	*
	* <p>The TLS versions configured in a connection spec are only be used if they are also enabled in
	* the SSL socket. For example, if an SSL socket does not have TLS 1.2 enabled, it will not be used
	* even if it is present on the connection spec. The same policy also applies to cipher suites.
	*
	* <p>Use {@link Builder#allEnabledTlsVersions()} and {@link Builder#allEnabledCipherSuites} to
	* defer all feature selection to the underlying SSL socket.
	* @hide This class is not part of the Android public SDK API
	*/
	public final class ConnectionSpec {

	// This is a subset of the cipher suites supported in Chrome 46, current as of 2015-11-05.
	// All of these suites are available on Android 5.0; earlier releases support a subset of
	// these suites. https://github.com/square/okhttp/issues/330
	private static final CipherSuite[] APPROVED_CIPHER_SUITES = new CipherSuite[] {
	CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,
	CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,
	CipherSuite.TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,

	// Note that the following cipher suites are all on HTTP/2's bad cipher suites list. We'll
	// continue to include them until better suites are commonly available. For example, none
	// of the better cipher suites listed above shipped with Android 4.4 or Java 7.
	CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,
	CipherSuite.TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,
	CipherSuite.TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,
	CipherSuite.TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,
	CipherSuite.TLS_DHE_RSA_WITH_AES_128_CBC_SHA,
	CipherSuite.TLS_DHE_RSA_WITH_AES_256_CBC_SHA,
	CipherSuite.TLS_RSA_WITH_AES_128_GCM_SHA256,
	CipherSuite.TLS_RSA_WITH_AES_128_CBC_SHA,
	CipherSuite.TLS_RSA_WITH_AES_256_CBC_SHA,
	CipherSuite.TLS_RSA_WITH_3DES_EDE_CBC_SHA,
	};

	/** A modern TLS connection with extensions like SNI and ALPN available. */
	public static final ConnectionSpec MODERN_TLS = new Builder(true)
	.cipherSuites(APPROVED_CIPHER_SUITES)
	.tlsVersions(TlsVersion.TLS_1_2, TlsVersion.TLS_1_1, TlsVersion.TLS_1_0)
	.supportsTlsExtensions(true)
	.build();

	/** A backwards-compatible fallback connection for interop with obsolete servers. */
	public static final ConnectionSpec COMPATIBLE_TLS = new Builder(MODERN_TLS)
	.tlsVersions(TlsVersion.TLS_1_0)
	.supportsTlsExtensions(true)
	.build();

	/** Unencrypted, unauthenticated connections for {@code http:} URLs. */
	public static final ConnectionSpec CLEARTEXT = new Builder(false).build();

	private final boolean tls;
	private final boolean supportsTlsExtensions;
	private final String[] cipherSuites;
	private final String[] tlsVersions;

	private ConnectionSpec(Builder builder) {
	this.tls = builder.tls;
	this.cipherSuites = builder.cipherSuites;
	this.tlsVersions = builder.tlsVersions;
	this.supportsTlsExtensions = builder.supportsTlsExtensions;
	}

	public boolean isTls() {
	return tls;
	}

	/**
	* Returns the cipher suites to use for a connection. Returns {@code null} if all of the SSL
	* socket's enabled cipher suites should be used.
	*/
	public List<CipherSuite> cipherSuites() {
	if (cipherSuites == null) return null;

	CipherSuite[] result = new CipherSuite[cipherSuites.length];
	for (int i = 0; i < cipherSuites.length; i++) {
	result[i] = CipherSuite.forJavaName(cipherSuites[i]);
	}
	return Util.immutableList(result);
	}

	/**
	* Returns the TLS versions to use when negotiating a connection. Returns {@code null} if all of
	* the SSL socket's enabled TLS versions should be used.
	*/
	public List<TlsVersion> tlsVersions() {
	if (tlsVersions == null) return null;

	TlsVersion[] result = new TlsVersion[tlsVersions.length];
	for (int i = 0; i < tlsVersions.length; i++) {
	result[i] = TlsVersion.forJavaName(tlsVersions[i]);
	}
	return Util.immutableList(result);
	}

	public boolean supportsTlsExtensions() {
	return supportsTlsExtensions;
	}

	/** Applies this spec to {@code sslSocket}. */
	void apply(SSLSocket sslSocket, boolean isFallback) {
	ConnectionSpec specToApply = supportedSpec(sslSocket, isFallback);

	if (specToApply.tlsVersions != null) {
	sslSocket.setEnabledProtocols(specToApply.tlsVersions);
	}
	if (specToApply.cipherSuites != null) {
	sslSocket.setEnabledCipherSuites(specToApply.cipherSuites);
	}
	}

	/**
	* Returns a copy of this that omits cipher suites and TLS versions not enabled by {@code
	* sslSocket}.
	*/
	private ConnectionSpec supportedSpec(SSLSocket sslSocket, boolean isFallback) {
	String[] cipherSuitesIntersection = cipherSuites != null
	? Util.intersect(String.class, cipherSuites, sslSocket.getEnabledCipherSuites())
	: sslSocket.getEnabledCipherSuites();
	String[] tlsVersionsIntersection = tlsVersions != null
	? Util.intersect(String.class, tlsVersions, sslSocket.getEnabledProtocols())
	: sslSocket.getEnabledProtocols();

	// In accordance with https://tools.ietf.org/html/draft-ietf-tls-downgrade-scsv-00
	// the SCSV cipher is added to signal that a protocol fallback has taken place.
	if (isFallback && contains(sslSocket.getSupportedCipherSuites(), "TLS_FALLBACK_SCSV")) {
	cipherSuitesIntersection = concat(cipherSuitesIntersection, "TLS_FALLBACK_SCSV");
	}

	return new Builder(this)
	.cipherSuites(cipherSuitesIntersection)
	.tlsVersions(tlsVersionsIntersection)
	.build();
	}

	/**
	* Returns {@code true} if the socket, as currently configured, supports this connection spec.
	* In order for a socket to be compatible the enabled cipher suites and protocols must intersect.
	*
	* <p>For cipher suites, at least one of the {@link #cipherSuites() required cipher suites} must
	* match the socket's enabled cipher suites. If there are no required cipher suites the socket
	* must have at least one cipher suite enabled.
	*
	* <p>For protocols, at least one of the {@link #tlsVersions() required protocols} must match the
	* socket's enabled protocols.
	*/
	public boolean isCompatible(SSLSocket socket) {
	if (!tls) {
	return false;
	}

	if (tlsVersions != null
	&& !nonEmptyIntersection(tlsVersions, socket.getEnabledProtocols())) {
	return false;
	}

	if (cipherSuites != null
	&& !nonEmptyIntersection(cipherSuites, socket.getEnabledCipherSuites())) {
	return false;
	}

	return true;
	}

	/**
	* An N*M intersection that terminates if any intersection is found. The sizes of both
	* arguments are assumed to be so small, and the likelihood of an intersection so great, that it
	* is not worth the CPU cost of sorting or the memory cost of hashing.
	*/
	private static boolean nonEmptyIntersection(String[] a, String[] b) {
	if (a == null \|\| b == null \|\| a.length == 0 \|\| b.length == 0) {
	return false;
	}
	for (String toFind : a) {
	if (contains(b, toFind)) {
	return true;
	}
	}
	return false;
	}

	@Override public boolean equals(Object other) {
	if (!(other instanceof ConnectionSpec)) return false;
	if (other == this) return true;

	ConnectionSpec that = (ConnectionSpec) other;
	if (this.tls != that.tls) return false;

	if (tls) {
	if (!Arrays.equals(this.cipherSuites, that.cipherSuites)) return false;
	if (!Arrays.equals(this.tlsVersions, that.tlsVersions)) return false;
	if (this.supportsTlsExtensions != that.supportsTlsExtensions) return false;
	}

	return true;
	}

	@Override public int hashCode() {
	int result = 17;
	if (tls) {
	result = 31 * result + Arrays.hashCode(cipherSuites);
	result = 31 * result + Arrays.hashCode(tlsVersions);
	result = 31 * result + (supportsTlsExtensions ? 0 : 1);
	}
	return result;
	}

	@Override public String toString() {
	if (!tls) {
	return "ConnectionSpec()";
	}

	String cipherSuitesString = cipherSuites != null ? cipherSuites().toString() : "[all enabled]";
	String tlsVersionsString = tlsVersions != null ? tlsVersions().toString() : "[all enabled]";
	return "ConnectionSpec("
	+ "cipherSuites=" + cipherSuitesString
	+ ", tlsVersions=" + tlsVersionsString
	+ ", supportsTlsExtensions=" + supportsTlsExtensions
	+ ")";
	}

	/**
	* @hide This class is not part of the Android public SDK API
	*/
	public static final class Builder {
	private boolean tls;
	private String[] cipherSuites;
	private String[] tlsVersions;
	private boolean supportsTlsExtensions;

	Builder(boolean tls) {
	this.tls = tls;
	}

	public Builder(ConnectionSpec connectionSpec) {
	this.tls = connectionSpec.tls;
	this.cipherSuites = connectionSpec.cipherSuites;
	this.tlsVersions = connectionSpec.tlsVersions;
	this.supportsTlsExtensions = connectionSpec.supportsTlsExtensions;
	}

	public Builder allEnabledCipherSuites() {
	if (!tls) throw new IllegalStateException("no cipher suites for cleartext connections");
	this.cipherSuites = null;
	return this;
	}

	public Builder cipherSuites(CipherSuite... cipherSuites) {
	if (!tls) throw new IllegalStateException("no cipher suites for cleartext connections");

	String[] strings = new String[cipherSuites.length];
	for (int i = 0; i < cipherSuites.length; i++) {
	strings[i] = cipherSuites[i].javaName;
	}
	return cipherSuites(strings);
	}

	public Builder cipherSuites(String... cipherSuites) {
	if (!tls) throw new IllegalStateException("no cipher suites for cleartext connections");

	if (cipherSuites.length == 0) {
	throw new IllegalArgumentException("At least one cipher suite is required");
	}

	this.cipherSuites = cipherSuites.clone(); // Defensive copy.
	return this;
	}

	public Builder allEnabledTlsVersions() {
	if (!tls) throw new IllegalStateException("no TLS versions for cleartext connections");
	this.tlsVersions = null;
	return this;
	}

	public Builder tlsVersions(TlsVersion... tlsVersions) {
	if (!tls) throw new IllegalStateException("no TLS versions for cleartext connections");

	String[] strings = new String[tlsVersions.length];
	for (int i = 0; i < tlsVersions.length; i++) {
	strings[i] = tlsVersions[i].javaName;
	}

	return tlsVersions(strings);
	}

	public Builder tlsVersions(String... tlsVersions) {
	if (!tls) throw new IllegalStateException("no TLS versions for cleartext connections");

	if (tlsVersions.length == 0) {
	throw new IllegalArgumentException("At least one TLS version is required");
	}

	this.tlsVersions = tlsVersions.clone(); // Defensive copy.
	return this;
	}

	public Builder supportsTlsExtensions(boolean supportsTlsExtensions) {
	if (!tls) throw new IllegalStateException("no TLS extensions for cleartext connections");
	this.supportsTlsExtensions = supportsTlsExtensions;
	return this;
	}

	public ConnectionSpec build() {
	return new ConnectionSpec(this);
	}
	}
	}