content: /*
   * Copyright (c) 1998, 2013, 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
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   */
  
  package java.security;
  
  /**
   * This class defines the <i>Service Provider Interface</i> (<b>SPI</b>)
   * for the {@code SecureRandom} class.
   * All the abstract methods in this class must be implemented by each
   * service provider who wishes to supply the implementation
   * of a cryptographically strong pseudo-random number generator.
   *
   *
   * @see SecureRandom
   * @since 1.2
   */
  
  public abstract class SecureRandomSpi implements java.io.Serializable {
  
      private static final long serialVersionUID = -2991854161009191830L;
  
      /**
       * Reseeds this random object. The given seed supplements, rather than
       * replaces, the existing seed. Thus, repeated calls are guaranteed
       * never to reduce randomness.
       *
       * @param seed the seed.
       */
      protected abstract void engineSetSeed(byte[] seed);
  
      /**
       * Generates a user-specified number of random bytes.
       *
       * <p> If a call to {@code engineSetSeed} had not occurred previously,
       * the first call to this method forces this SecureRandom implementation
       * to seed itself.  This self-seeding will not occur if
       * {@code engineSetSeed} was previously called.
       *
       * @param bytes the array to be filled in with random bytes.
       */
      protected abstract void engineNextBytes(byte[] bytes);
  
      /**
       * Returns the given number of seed bytes.  This call may be used to
       * seed other random number generators.
       *
       * @param numBytes the number of seed bytes to generate.
       *
       * @return the seed bytes.
       */
       protected abstract byte[] engineGenerateSeed(int numBytes);
  }
  