mirror of git://gcc.gnu.org/git/gcc.git
				
				
				
			
		
			
				
	
	
		
			361 lines
		
	
	
		
			9.9 KiB
		
	
	
	
		
			Java
		
	
	
	
			
		
		
	
	
			361 lines
		
	
	
		
			9.9 KiB
		
	
	
	
		
			Java
		
	
	
	
| /* SecureRandom.java --- Secure Random class implmentation
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|    Copyright (C) 1999, 2001 Free Software Foundation, Inc.
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| 
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| This file is part of GNU Classpath.
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| 
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| GNU Classpath is free software; you can redistribute it and/or modify
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| it under the terms of the GNU General Public License as published by
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| the Free Software Foundation; either version 2, or (at your option)
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| any later version.
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| 
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| GNU Classpath is distributed in the hope that it will be useful, but
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| WITHOUT ANY WARRANTY; without even the implied warranty of
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| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
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| General Public License for more details.
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| 
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| You should have received a copy of the GNU General Public License
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| along with GNU Classpath; see the file COPYING.  If not, write to the
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| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
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| 02111-1307 USA.
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| 
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| As a special exception, if you link this library with other files to
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| produce an executable, this library does not by itself cause the
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| resulting executable to be covered by the GNU General Public License.
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| This exception does not however invalidate any other reasons why the
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| executable file might be covered by the GNU General Public License. */
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| 
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| package java.security;
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| import java.io.Serializable;
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| import java.util.Random;
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| import java.util.Enumeration;
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| 
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| /**
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|    SecureRandom is the class interface for using SecureRandom
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|    providers. It provides an interface to the SecureRandomSpi
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|    engine so that programmers can generate pseudo-random numbers.
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| 
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|    @author Mark Benvenuto <ivymccough@worldnet.att.net>
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|  */
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| public class SecureRandom extends Random
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| {
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|   //Serialized Field
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|   long counter = 0;		//Serialized
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|   MessageDigest digest = null;
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|   Provider provider = null;
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|   byte[] randomBytes = null;	//Always null
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|   int randomBytesUsed = 0;
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|   SecureRandomSpi secureRandomSpi = null;
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|   byte[] state = null;
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| 
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|   /**
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|      Default constructor for SecureRandom. It constructs a 
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|      new SecureRandom by instantating the first SecureRandom 
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|      algorithm in the default security provier. 
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| 
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|      It is not seeded and should be seeded using setSeed or else
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|      on the first call to getnextBytes it will force a seed.
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| 
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|      It is maintained for backwards compatibility and programs
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|      should use getInstance.
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|    */
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|   public SecureRandom()
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|   {
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|     Provider p[] = Security.getProviders();
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| 
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|     //Format of Key: SecureRandom.algname
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|     String key;
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| 
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|     String classname = null;
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|     int i, flag = 0;
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|     Enumeration e;
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|     for (i = 0; i < p.length; i++)
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|       {
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| 	e = p[i].propertyNames();
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| 	while (e.hasMoreElements())
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| 	  {
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| 	    key = (String) e.nextElement();
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| 	    if (key.startsWith("SecureRandom."))
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| 	      if ((classname = p[i].getProperty(key)) != null)
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| 		break;
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| 	  }
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| 	if (classname != null)
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| 	    break;
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|       }
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| 
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|     //if( classname == null)
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|     //  throw new NoSuchAlgorithmException();
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| 
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|     try
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|       {
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| 	this.secureRandomSpi =
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| 	  (SecureRandomSpi) Class.forName(classname).newInstance();
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| 
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| 	//s.algorithm = algorithm;
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| 	this.provider = p[i];
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|       }
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|     catch (ClassNotFoundException cnfe)
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|       {
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| 	//throw new NoSuchAlgorithmException("Class not found");
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|       }
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|     catch (InstantiationException ie)
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|       {
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| 	//throw new NoSuchAlgorithmException("Class instantiation failed");
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|       }
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|     catch (IllegalAccessException iae)
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|       {
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| 	//throw new NoSuchAlgorithmException("Illegal Access");
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|       }
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|   }
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| 
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|   /**
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|      A constructor for SecureRandom. It constructs a new 
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|      SecureRandom by instantating the first SecureRandom algorithm 
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|      in the default security provier. 
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| 
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|      It is seeded with the passed function and is useful if the user
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|      has access to hardware random device (like a radiation detector).
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| 
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|      It is maintained for backwards compatibility and programs
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|      should use getInstance.
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| 
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|      @param seed Seed bytes for class
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|    */
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|   public SecureRandom(byte[] seed)
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|   {
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|     this();
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|     setSeed(seed);
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|   }
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| 
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|   /**
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|      A constructor for SecureRandom. It constructs a new 
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|      SecureRandom using the specified SecureRandomSpi from
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|      the specified security provier. 
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| 
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|      @param secureRandomSpi A SecureRandomSpi class
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|      @param provider A Provider class
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|    */
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|   protected SecureRandom(SecureRandomSpi secureRandomSpi, Provider provider)
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|   {
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|     this.secureRandomSpi = secureRandomSpi;
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|     this.provider = provider;
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|   }
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| 
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|   /**
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|      Returns an instance of a SecureRandom. It creates the class
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|      for the specified algorithm if it exists from a provider.
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| 
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|      @param algorithm A SecureRandom algorithm to use
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| 
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|      @return Returns a new SecureRandom implmenting the chosen algorithm
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| 
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|      @throws NoSuchAlgorithmException if the algorithm cannot be found
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|    */
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|   public static SecureRandom getInstance(String algorithm) throws
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|     NoSuchAlgorithmException
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|   {
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|     Provider p[] = Security.getProviders();
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| 
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|     //Format of Key: SecureRandom.algname
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|     StringBuffer key = new StringBuffer("SecureRandom.");
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|     key.append(algorithm);
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| 
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|     String classname = null;
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|     int i;
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|     for (i = 0; i < p.length; i++)
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|       {
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| 	if ((classname = p[i].getProperty(key.toString())) != null)
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| 	  break;
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|       }
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| 
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|     if (classname == null)
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|         throw new NoSuchAlgorithmException();
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| 
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|     try
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|       {
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| 	return new SecureRandom((SecureRandomSpi) Class.forName(classname).
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| 				newInstance(), p[i]);
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|       }
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|     catch (ClassNotFoundException cnfe)
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|       {
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| 	throw new NoSuchAlgorithmException("Class not found");
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|       }
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|     catch (InstantiationException ie)
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|       {
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| 	throw new NoSuchAlgorithmException("Class instantiation failed");
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|       }
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|     catch (IllegalAccessException iae)
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|       {
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| 	throw new NoSuchAlgorithmException("Illegal Access");
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|       }
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| 
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|   }
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| 
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|   /**
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|      Returns an instance of a SecureRandom. It creates the class
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|      for the specified algorithm from the specified provider.
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| 
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|      @param algorithm A SecureRandom algorithm to use
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|      @param provider A security provider to use
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| 
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|      @return Returns a new SecureRandom implmenting the chosen algorithm
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| 
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|      @throws NoSuchAlgorithmException if the algorithm cannot be found
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|      @throws NoSuchProviderException if the provider cannot be found
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|    */
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|   public static SecureRandom getInstance(String algorithm,
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| 					 String provider) throws
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|     NoSuchAlgorithmException, NoSuchProviderException
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|   {
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|     Provider p = Security.getProvider(provider);
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|     if (p == null)
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|       throw new NoSuchProviderException();
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| 
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|     //Format of Key: SecureRandom.algName
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|     StringBuffer key = new StringBuffer("SecureRandom.");
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|     key.append(algorithm);
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| 
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|     String classname = p.getProperty(key.toString());
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|     if (classname == null)
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|       throw new NoSuchAlgorithmException();
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| 
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|     try
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|       {
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| 	return new SecureRandom((SecureRandomSpi) Class.forName(classname).
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| 				newInstance(), p);
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|       }
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|     catch (ClassNotFoundException cnfe)
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|       {
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| 	throw new NoSuchAlgorithmException("Class not found");
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|       }
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|     catch (InstantiationException ie)
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|       {
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| 	throw new NoSuchAlgorithmException("Class instantiation failed");
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|       }
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|     catch (IllegalAccessException iae)
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|       {
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| 	throw new NoSuchAlgorithmException("Illegal Access");
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|       }
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| 
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|   }
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| 
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|   /**
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|      Returns the provider being used by the current SecureRandom class.
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| 
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|      @return The provider from which this SecureRandom was attained
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|    */
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|   public final Provider getProvider()
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|   {
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|     return provider;
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|   }
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| 
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|   /**
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|      Seeds the SecureRandom. The class is re-seeded for each call and 
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|      each seed builds on the previous seed so as not to weaken security.
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| 
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|      @param seed seed bytes to seed with
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|    */
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|   public void setSeed(byte[] seed)
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|   {
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|     secureRandomSpi.engineSetSeed(seed);
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|   }
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| 
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|   /**
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|      Seeds the SecureRandom. The class is re-seeded for each call and 
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|      each seed builds on the previous seed so as not to weaken security.
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| 
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|      @param seed 8 seed bytes to seed with
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|    */
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|   public void setSeed(long seed)
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|   {
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|     // This particular setSeed will be called by Random.Random(), via
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|     // our own constructor, before secureRandomSpi is initialized.  In
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|     // this case we can't call a method on secureRandomSpi, and we
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|     // definitely don't want to throw a NullPointerException.
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|     // Therefore we test.
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|     if (secureRandomSpi != null)
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|       {
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|         byte tmp[] = { (byte) (0xff & (seed >> 56)),
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| 		       (byte) (0xff & (seed >> 48)),
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| 		       (byte) (0xff & (seed >> 40)),
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| 		       (byte) (0xff & (seed >> 32)),
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| 		       (byte) (0xff & (seed >> 24)),
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| 		       (byte) (0xff & (seed >> 16)),
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| 		       (byte) (0xff & (seed >> 8)),
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| 		       (byte) (0xff & seed)
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| 	};
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| 	secureRandomSpi.engineSetSeed(tmp);
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|       }
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|   }
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| 
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|   /**
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|      Generates a user specified number of bytes. This function
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|      is the basis for all the random functions.
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| 
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|      @param bytes array to store generated bytes in
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|    */
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|   public void nextBytes(byte[] bytes)
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|   {
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|     randomBytesUsed += bytes.length;
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|     counter++;
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|     secureRandomSpi.engineNextBytes(bytes);
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|   }
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| 
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|   /**
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|      Generates an integer containing the user specified
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|      number of random bits. It is right justified and padded
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|      with zeros.
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| 
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|      @param numBits number of random bits to get, 0 <= numBits <= 32;
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| 
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|      @return the random bits
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|    */
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|   protected final int next(int numBits)
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|   {
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|     if (numBits == 0)
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|       return 0;
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| 
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|     byte tmp[] = new byte[numBits / 8 + (1 * (numBits % 8))];
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| 
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|     secureRandomSpi.engineNextBytes(tmp);
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|     randomBytesUsed += tmp.length;
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|     counter++;
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| 
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|     int ret = 0;
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| 
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|     for (int i = 0; i < tmp.length; i++)
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|       ret |= tmp[i] << (8 * i);
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| 
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|     return ret;
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|   }
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| 
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|   /**
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|      Returns the given number of seed bytes. This method is
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|      maintained only for backwards capability. 
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| 
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|      @param numBytes number of seed bytes to get
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| 
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|      @return an array containing the seed bytes
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|    */
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|   public static byte[] getSeed(int numBytes)
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|   {
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|     byte tmp[] = new byte[numBytes];
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| 
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|     new Random().nextBytes(tmp);
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|     return tmp;
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|     //return secureRandomSpi.engineGenerateSeed( numBytes );
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|   }
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| 
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|   /**
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|      Returns the specified number of seed bytes.
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| 
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|      @param numBytes number of seed bytes to get
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| 
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|      @return an array containing the seed bytes
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|    */
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|   public byte[] generateSeed(int numBytes)
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|   {
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|     return secureRandomSpi.engineGenerateSeed(numBytes);
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|   }
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| 
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| }
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