gt:                 if (debug != null && Debug.isOn("handshake")) {
context: /*
   * Copyright (c) 1996, 2012, Oracle and/or its affiliates. All rights reserved.
   * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   *
   * This code is free software; you can redistribute it and/or modify it
   * under the terms of the GNU General Public License version 2 only, as
   * published by the Free Software Foundation.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * This code is distributed in the hope that it will be useful, but WITHOUT
   * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
   * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
   * version 2 for more details (a copy is included in the LICENSE file that
   * accompanied this code).
   *
   * You should have received a copy of the GNU General Public License version
   * 2 along with this work; if not, write to the Free Software Foundation,
   * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
   *
   * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  
  package sun.security.ssl;
  
  import java.io.*;
  import java.security.*;
  
  import javax.crypto.*;
  
  import javax.net.ssl.*;
  
  import sun.security.internal.spec.TlsRsaPremasterSecretParameterSpec;
  import sun.security.util.KeyLength;
  
  /**
   * This is the client key exchange message (CLIENT --> SERVER) used with
   * all RSA key exchanges; it holds the RSA-encrypted pre-master secret.
   *
   * The message is encrypted using PKCS #1 block type 02 encryption with the
   * server's public key.  The padding and resulting message size is a function
   * of this server's public key modulus size, but the pre-master secret is
   * always exactly 48 bytes.
   *
   */
  final class RSAClientKeyExchange extends HandshakeMessage {
  
      /**
       * The TLS spec says that the version in the RSA premaster secret must
       * be the maximum version supported by the client (i.e. the version it
       * requested in its client hello version). However, we (and other
       * implementations) used to send the active negotiated version. The
       * system property below allows to toggle the behavior.
       */
      private final static String PROP_NAME =
                                  "com.sun.net.ssl.rsaPreMasterSecretFix";
  
      /*
       * Default is "false" (old behavior) for compatibility reasons in
       * SSLv3/TLSv1.  Later protocols (TLSv1.1+) do not use this property.
       */
      private final static boolean rsaPreMasterSecretFix =
                                  Debug.getBooleanProperty(PROP_NAME, false);
  
      /*
       * The following field values were encrypted with the server's public
       * key (or temp key from server key exchange msg) and are presented
       * here in DECRYPTED form.
       */
      private ProtocolVersion protocolVersion; // preMaster [0,1]
      SecretKey preMaster;
      private byte[] encrypted;           // same size as public modulus
  
      /*
       * Client randomly creates a pre-master secret and encrypts it
       * using the server's RSA public key; only the server can decrypt
       * it, using its RSA private key.  Result is the same size as the
       * server's public key, and uses PKCS #1 block format 02.
       */
      RSAClientKeyExchange(ProtocolVersion protocolVersion,
              ProtocolVersion maxVersion,
              SecureRandom generator, PublicKey publicKey) throws IOException {
          if (publicKey.getAlgorithm().equals("RSA") == false) {
              throw new SSLKeyException("Public key not of type RSA");
          }
          this.protocolVersion = protocolVersion;
  
          int major, minor;
  
          if (rsaPreMasterSecretFix || maxVersion.v >= ProtocolVersion.TLS11.v) {
              major = maxVersion.major;
              minor = maxVersion.minor;
          } else {
              major = protocolVersion.major;
              minor = protocolVersion.minor;
          }
  
          try {
              String s = ((protocolVersion.v >= ProtocolVersion.TLS12.v) ?
                  "SunTls12RsaPremasterSecret" : "SunTlsRsaPremasterSecret");
              KeyGenerator kg = JsseJce.getKeyGenerator(s);
              kg.init(new TlsRsaPremasterSecretParameterSpec(major, minor),
                      generator);
              preMaster = kg.generateKey();
  
              Cipher cipher = JsseJce.getCipher(JsseJce.CIPHER_RSA_PKCS1);
              cipher.init(Cipher.WRAP_MODE, publicKey, generator);
              encrypted = cipher.wrap(preMaster);
          } catch (GeneralSecurityException e) {
              throw (SSLKeyException)new SSLKeyException
                                  ("RSA premaster secret error").initCause(e);
          }
      }
  
      /*
       * Server gets the PKCS #1 (block format 02) data, decrypts
       * it with its private key.
       */
      RSAClientKeyExchange(ProtocolVersion currentVersion,
              ProtocolVersion maxVersion,
              SecureRandom generator, HandshakeInStream input,
              int messageSize, PrivateKey privateKey) throws IOException {
  
          if (privateKey.getAlgorithm().equals("RSA") == false) {
              throw new SSLKeyException("Private key not of type RSA");
          }
  
          if (currentVersion.v >= ProtocolVersion.TLS10.v) {
              encrypted = input.getBytes16();
          } else {
              encrypted = new byte [messageSize];
              if (input.read(encrypted) != messageSize) {
                  throw new SSLProtocolException
                          ("SSL: read PreMasterSecret: short read");
              }
          }
  
          try {
              Cipher cipher = JsseJce.getCipher(JsseJce.CIPHER_RSA_PKCS1);
              cipher.init(Cipher.UNWRAP_MODE, privateKey);
              preMaster = (SecretKey)cipher.unwrap(encrypted,
                                  "TlsRsaPremasterSecret", Cipher.SECRET_KEY);
  
              // polish the premaster secret
              preMaster = polishPreMasterSecretKey(currentVersion, maxVersion,
                                                  generator, preMaster, null);
          } catch (Exception e) {
              // polish the premaster secret
              preMaster =
                      polishPreMasterSecretKey(currentVersion, maxVersion,
                                                  generator, null, e);
          }
      }
  
      /**
       * To avoid vulnerabilities described by section 7.4.7.1, RFC 5246,
       * treating incorrectly formatted message blocks and/or mismatched
       * version numbers in a manner indistinguishable from correctly
       * formatted RSA blocks.
       *
       * RFC 5246 describes the approach as :
       *
       *  1. Generate a string R of 46 random bytes
       *
       *  2. Decrypt the message to recover the plaintext M
       *
       *  3. If the PKCS#1 padding is not correct, or the length of message
       *     M is not exactly 48 bytes:
       *        pre_master_secret = ClientHello.client_version || R
       *     else If ClientHello.client_version <= TLS 1.0, and version
       *     number check is explicitly disabled:
       *        pre_master_secret = M
       *     else:
       *        pre_master_secret = ClientHello.client_version || M[2..47]
       */
      private SecretKey polishPreMasterSecretKey(ProtocolVersion currentVersion,
              ProtocolVersion clientHelloVersion, SecureRandom generator,
              SecretKey secretKey, Exception failoverException) {
  
          this.protocolVersion = clientHelloVersion;
  
          if (failoverException == null && secretKey != null) {
              // check the length
              byte[] encoded = secretKey.getEncoded();
              if (encoded == null) {      // unable to get the encoded key
                  if (debug != null && Debug.isOn("handshake")) {
                      System.out.println(
                          "unable to get the plaintext of the premaster secret");
                  }
  
                  int keySize = KeyLength.getKeySize(secretKey);
                  if (keySize > 0 && keySize != 384) {       // 384 = 48 * 8
                      if (debug != null && Debug.isOn("handshake")) {
                          System.out.println(
                              "incorrect length of premaster secret: " +
                              (keySize/8));
                      }
  
                      return generateDummySecret(clientHelloVersion);
                  }
  
                  // The key size is exactly 48 bytes or not accessible.
                  //
                  // Conservatively, pass the checking to master secret
                  // calculation.
                  return secretKey;
              } else if (encoded.length == 48) {
                  // check the version
                  if (clientHelloVersion.major == encoded[0] &&
                      clientHelloVersion.minor == encoded[1]) {
  
                      return secretKey;
                  } else if (clientHelloVersion.v <= ProtocolVersion.TLS10.v &&
                             currentVersion.major == encoded[0] &&
                             currentVersion.minor == encoded[1]) {
                      /*
                       * For compatibility, we maintain the behavior that the
                       * version in pre_master_secret can be the negotiated
                       * version for TLS v1.0 and SSL v3.0.
                       */
                      this.protocolVersion = currentVersion;
                      return secretKey;
                  }
  
  