/* AlgorithmParametersSpi.java --- Algorithm Parameters SPI
   Copyright (C) 1999 Free Software Foundation, Inc.

This file is part of GNU Classpath.

GNU Classpath is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Classpath 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 for more details.

You should have received a copy of the GNU General Public License
along with GNU Classpath; see the file COPYING.  If not, write to the
Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
02111-1307 USA.

As a special exception, if you link this library with other files to
produce an executable, this library does not by itself cause the
resulting executable to be covered by the GNU General Public License.
This exception does not however invalidate any other reasons why the
executable file might be covered by the GNU General Public License. */

package java.security;
import java.security.spec.InvalidParameterSpecException;
import java.security.spec.AlgorithmParameterSpec;
import java.io.IOException;

/**
   AlgorithmParametersSpi is the Service Provider Interface
   for the Algorithm Parameters class. This class is used
   to manage the algorithm parameters.

   @since JDK 1.2
   @author Mark Benvenuto
 */
public abstract class AlgorithmParametersSpi
{
  /**
     Creates a new instance of AlgorithmParametersSpi
   */
  public AlgorithmParametersSpi()
  {
  }

  /**
     Initializes the engine with the specified 
     AlgorithmParameterSpec class.

     @param paramSpec A AlgorithmParameterSpec to initialize with

     @throws InvalidParameterSpecException For an inapporiate ParameterSpec class
   */
  protected abstract void engineInit(AlgorithmParameterSpec paramSpec) throws
    InvalidParameterSpecException;

  /**
     Initializes the engine with the specified 
     parameters stored in the byte array and decodes them
     according to the ASN.1 specification. If the ASN.1
     specification exists then it succeeds or else it throws
     IOException.

     @param params Parameters to initialize with

     @throws IOException Decoding Error
   */
  protected abstract void engineInit(byte[]params) throws IOException;

  /**
     Initializes the engine with the specified 
     parameters stored in the byte array and decodes them
     according to the specified decoding specification. 
     If format is null, then it is decoded using the ASN.1 
     specification if it exists or else it throws
     IOException.

     @param params Parameters to initialize with
     @param format Name of decoding format to use

     @throws IOException Decoding Error
   */
  protected abstract void engineInit(byte[]params,
				     String format) throws IOException;


  /**
     Returns a specification of this AlgorithmParameters object.
     paramSpec identifies the class to return the AlgortihmParameters
     in. 

     @param paramSpec Class to return AlgorithmParameters in

     @return the parameter specification

     @throws InvalidParameterSpecException if the paramSpec is an invalid parameter class
   */
  protected abstract AlgorithmParameterSpec engineGetParameterSpec(Class
								   paramSpec)
    throws InvalidParameterSpecException;


  /**
     Returns the parameters in the default encoding format. 
     The primary encoding format is ASN.1 format if it exists
     for the specified type.

     @return byte array representing the parameters
   */
  protected abstract byte[] engineGetEncoded() throws IOException;


  /**
     Returns the parameters in the specified encoding format. 
     If <code>format</code> is <code>null</code> then the 
     primary encoding format is used, the ASN.1 format, 
     if it exists for the specified type.

     @return byte array representing the parameters
   */
  protected abstract byte[] engineGetEncoded(String format) throws
    IOException;

  /**
     Returns a string describing the parameters in the 
     AlgorithmParametersSpi class.

     @return A string representing the format of the parameters.
   */
  protected abstract String engineToString();
}