content: /*
   * Copyright (c) 1997, 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
   * or visit www.oracle.com if you need additional information or have any
   * questions.
   */
  
  package java.security;
  
  import java.io.*;
  import java.security.spec.AlgorithmParameterSpec;
  import java.security.spec.InvalidParameterSpecException;
  
  import sun.security.jca.Providers;
  
  /**
   * This class is used as an opaque representation of cryptographic parameters.
   *
   * <p>An {@code AlgorithmParameters} object for managing the parameters
   * for a particular algorithm can be obtained by
   * calling one of the {@code getInstance} factory methods
   * (static methods that return instances of a given class).
   *
   * <p>Once an {@code AlgorithmParameters} object is obtained, it must be
   * initialized via a call to {@code init}, using an appropriate parameter
   * specification or parameter encoding.
   *
   * <p>A transparent parameter specification is obtained from an
   * {@code AlgorithmParameters} object via a call to
   * {@code getParameterSpec}, and a byte encoding of the parameters is
   * obtained via a call to {@code getEncoded}.
   *
   * <p> Android provides the following <code>AlgorithmParameters</code> algorithms:
   * <table>
   *   <thead>
   *     <tr>
   *       <th>Algorithm</th>
   *       <th>Supported API Levels</th>
   *     </tr>
   *   </thead>
   *   <tbody>
   *     <tr>
   *       <td>AES</td>
   *       <td>1+</td>
   *     </tr>
   *     <tr>
   *       <td>BLOWFISH</td>
   *       <td>10+</td>
   *     </tr>
   *     <tr>
   *       <td>ChaCha20</td>
   *       <td>28+</td>
   *     </tr>
   *     <tr>
   *       <td>DES</td>
   *       <td>1+</td>
   *     </tr>
   *     <tr>
   *       <td>DESede</td>
   *       <td>1+</td>
   *     </tr>
   *     <tr>
   *       <td>DH</td>
   *       <td>1+</td>
   *     </tr>
   *     <tr>
   *       <td>DSA</td>
   *       <td>1+</td>
   *     </tr>
   *     <tr>
   *       <td>EC</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>GCM</td>
   *       <td>22+</td>
   *     </tr>
   *     <tr class="deprecated">
   *       <td>IES</td>
   *       <td>1-8</td>
   *     </tr>
   *     <tr>
   *       <td>OAEP</td>
   *       <td>1+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA1AndAES_128</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA1AndAES_256</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA224AndAES_128</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA224AndAES_256</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA256AndAES_128</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA256AndAES_256</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA384AndAES_128</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA384AndAES_256</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA512AndAES_128</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PBEwithHmacSHA512AndAES_256</td>
   *       <td>26+</td>
   *     </tr>
   *     <tr>
   *       <td>PKCS12PBE</td>
   *       <td>1+</td>
   *     </tr>
   *     <tr>
   *       <td>PSS</td>
   *       <td>1-8,24+</td>
   *     </tr>
   *   </tbody>
   * </table>
   *
   * These algorithms are described in the <a href=
   * "{@docRoot}/../technotes/guides/security/StandardNames.html#AlgorithmParameters">
   * AlgorithmParameters section</a> of the
   * Java Cryptography Architecture Standard Algorithm Name Documentation.
   *
   * @author Jan Luehe
   *
   *
   * @see AlgorithmParameterSpec
   * @see java.security.spec.DSAParameterSpec
   * @see KeyPairGenerator
   *
   * @since 1.2
   */
  
  public class AlgorithmParameters {
  
      // The provider
      private Provider provider;
  
      // The provider implementation (delegate)
      private AlgorithmParametersSpi paramSpi;
  
      // The algorithm
      private String algorithm;
  
      // Has this object been initialized?
      private boolean initialized = false;
  
      /**
       * Creates an AlgorithmParameters object.
       *
       * @param paramSpi the delegate
       * @param provider the provider
       * @param algorithm the algorithm
       */
      protected AlgorithmParameters(AlgorithmParametersSpi paramSpi,
                                    Provider provider, String algorithm)
      {
          this.paramSpi = paramSpi;
          this.provider = provider;
          this.algorithm = algorithm;
      }
  
      /**
       * Returns the name of the algorithm associated with this parameter object.
       *
       * @return the algorithm name.
       */
      public final String getAlgorithm() {
          return this.algorithm;
      }
  
      /**
       * Returns a parameter object for the specified algorithm.
       *
       * <p> This method traverses the list of registered security Providers,
       * starting with the most preferred Provider.
       * A new AlgorithmParameters object encapsulating the
       * AlgorithmParametersSpi implementation from the first
       * Provider that supports the specified algorithm is returned.
       *
       * <p> Note that the list of registered providers may be retrieved via
       * the {@link Security#getProviders() Security.getProviders()} method.
       *
       * <p> The returned parameter object must be initialized via a call to
       * {@code init}, using an appropriate parameter specification or
       * parameter encoding.
       *
       * @param algorithm the name of the algorithm requested.
       * See the AlgorithmParameters section in the <a href=
       * "{@docRoot}/../technotes/guides/security/StandardNames.html#AlgorithmParameters">
       * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
       * for information about standard algorithm names.
       *
       * @return the new parameter object.
       *
       * @exception NoSuchAlgorithmException if no Provider supports an
       *          AlgorithmParametersSpi implementation for the
       *          specified algorithm.
       *
       * @see Provider
       */
      public static AlgorithmParameters getInstance(String algorithm)
      throws NoSuchAlgorithmException {
          try {
              Object[] objs = Security.getImpl(algorithm, "AlgorithmParameters",
                                               (String)null);
              return new AlgorithmParameters((AlgorithmParametersSpi)objs[0],
                                             (Provider)objs[1],
                                             algorithm);
          } catch(NoSuchProviderException e) {
              throw new NoSuchAlgorithmException(algorithm + " not found");
          }
      }
  
      /**
       * Returns a parameter object for the specified algorithm.
       *
       * <p> A new AlgorithmParameters object encapsulating the
       * AlgorithmParametersSpi implementation from the specified provider
       * is returned.  The specified provider must be registered
       * in the security provider list.
       *
       * <p> Note that the list of registered providers may be retrieved via
       * the {@link Security#getProviders() Security.getProviders()} method.
       *
       * <p>The returned parameter object must be initialized via a call to
       * {@code init}, using an appropriate parameter specification or
       * parameter encoding.
       *
       * @param algorithm the name of the algorithm requested.
       * See the AlgorithmParameters section in the <a href=
       * "{@docRoot}/../technotes/guides/security/StandardNames.html#AlgorithmParameters">
       * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
       * for information about standard algorithm names.
       *
       * @param provider the name of the provider.
       *
       * @return the new parameter object.
       *
       * @exception NoSuchAlgorithmException if an AlgorithmParametersSpi
       *          implementation for the specified algorithm is not
       *          available from the specified provider.
       *
       * @exception NoSuchProviderException if the specified provider is not
       *          registered in the security provider list.
       *
       * @exception IllegalArgumentException if the provider name is null
       *          or empty.
       *
       * @see Provider
       */
      public static AlgorithmParameters getInstance(String algorithm,
                                                    String provider)
          throws NoSuchAlgorithmException, NoSuchProviderException
      {
          if (provider == null || provider.length() == 0)
              throw new IllegalArgumentException("missing provider");
          // Android-added: Check for Bouncy Castle deprecation
          Providers.checkBouncyCastleDeprecation(provider, "AlgorithmParameters", algorithm);
          Object[] objs = Security.getImpl(algorithm, "AlgorithmParameters",
                                           provider);
          return new AlgorithmParameters((AlgorithmParametersSpi)objs[0],
                                         (Provider)objs[1],
                                         algorithm);
      }
  
      /**
       * Returns a parameter object for the specified algorithm.
       *
       * <p> A new AlgorithmParameters object encapsulating the
       * AlgorithmParametersSpi implementation from the specified Provider
       * object is returned.  Note that the specified Provider object
       * does not have to be registered in the provider list.
       *
       * <p>The returned parameter object must be initialized via a call to
       * {@code init}, using an appropriate parameter specification or
       * parameter encoding.
       *
       * @param algorithm the name of the algorithm requested.
       * See the AlgorithmParameters section in the <a href=
       * "{@docRoot}/../technotes/guides/security/StandardNames.html#AlgorithmParameters">
       * Java Cryptography Architecture Standard Algorithm Name Documentation</a>
       * for information about standard algorithm names.
       *
       * @param provider the name of the provider.
       *
       * @return the new parameter object.
       *
       * @exception NoSuchAlgorithmException if an AlgorithmParameterGeneratorSpi
       *          implementation for the specified algorithm is not available
       *          from the specified Provider object.
       *
       * @exception IllegalArgumentException if the provider is null.
       *
       * @see Provider
       *
       * @since 1.4
       */
      public static AlgorithmParameters getInstance(String algorithm,
                                                    Provider provider)
          throws NoSuchAlgorithmException
      {
          if (provider == null)
              throw new IllegalArgumentException("missing provider");
          // Android-added: Check for Bouncy Castle deprecation
          Providers.checkBouncyCastleDeprecation(provider, "AlgorithmParameters", algorithm);
          Object[] objs = Security.getImpl(algorithm, "AlgorithmParameters",
                                           provider);
          return new AlgorithmParameters((AlgorithmParametersSpi)objs[0],
                                         (Provider)objs[1],
                                         algorithm);
      }
  
      /**
       * Returns the provider of this parameter object.
       *
       * @return the provider of this parameter object
       */
      public final Provider getProvider() {
          return this.provider;
      }
  
      /**
       * Initializes this parameter object using the parameters
       * specified in {@code paramSpec}.
       *
       * @param paramSpec the parameter specification.
       *
       * @exception InvalidParameterSpecException if the given parameter
       * specification is inappropriate for the initialization of this parameter
       * object, or if this parameter object has already been initialized.
       */
      public final void init(AlgorithmParameterSpec paramSpec)
          throws InvalidParameterSpecException
      {
          if (this.initialized)
              throw new InvalidParameterSpecException("already initialized");
          paramSpi.engineInit(paramSpec);
          this.initialized = true;
      }
  
      /**
       * Imports the specified parameters and decodes them according to the
       * primary decoding format for parameters. The primary decoding
       * format for parameters is ASN.1, if an ASN.1 specification for this type
       * of parameters exists.
       *
       * @param params the encoded parameters.
       *
       * @exception IOException on decoding errors, or if this parameter object
       * has already been initialized.
       */
      public final void init(byte[] params) throws IOException {
          if (this.initialized)
              throw new IOException("already initialized");
          paramSpi.engineInit(params);
          this.initialized = true;
      }
  
      /**
       * Imports the parameters from {@code params} and decodes them
       * according to the specified decoding scheme.
       * If {@code format} is null, the
       * primary decoding format for parameters is used. The primary decoding
       * format is ASN.1, if an ASN.1 specification for these parameters
       * exists.
       *
       * @param params the encoded parameters.
       *
       * @param format the name of the decoding scheme.
       *
       * @exception IOException on decoding errors, or if this parameter object
       * has already been initialized.
       */
      public final void init(byte[] params, String format) throws IOException {
          if (this.initialized)
              throw new IOException("already initialized");
          paramSpi.engineInit(params, format);
          this.initialized = true;
      }
  
      /**
       * Returns a (transparent) specification of this parameter object.
       * {@code paramSpec} identifies the specification class in which
       * the parameters should be returned. It could, for example, be
       * {@code DSAParameterSpec.class}, to indicate that the
       * parameters should be returned in an instance of the
       * {@code DSAParameterSpec} class.
       *
       * @param <T> the type of the parameter specification to be returrned
       * @param paramSpec the specification class in which
       * the parameters should be returned.
       *
       * @return the parameter specification.
       *
       * @exception InvalidParameterSpecException if the requested parameter
       * specification is inappropriate for this parameter object, or if this
       * parameter object has not been initialized.
       */
      public final <T extends AlgorithmParameterSpec>
          T getParameterSpec(Class<T> paramSpec)
          throws InvalidParameterSpecException
      {
          if (this.initialized == false) {
              throw new InvalidParameterSpecException("not initialized");
          }
          return paramSpi.engineGetParameterSpec(paramSpec);
      }
  
      /**
       * Returns the parameters in their primary encoding format.
       * The primary encoding format for parameters is ASN.1, if an ASN.1
       * specification for this type of parameters exists.
       *
       * @return the parameters encoded using their primary encoding format.
       *
       * @exception IOException on encoding errors, or if this parameter object
       * has not been initialized.
       */
      public final byte[] getEncoded() throws IOException
      {
          if (this.initialized == false) {
              throw new IOException("not initialized");
          }
          return paramSpi.engineGetEncoded();
      }
  
      /**
       * Returns the parameters encoded in the specified scheme.
       * If {@code format} is null, the
       * primary encoding format for parameters is used. The primary encoding
       * format is ASN.1, if an ASN.1 specification for these parameters
       * exists.
       *
       * @param format the name of the encoding format.
       *
       * @return the parameters encoded using the specified encoding scheme.
       *
       * @exception IOException on encoding errors, or if this parameter object
       * has not been initialized.
       */
      public final byte[] getEncoded(String format) throws IOException
      {
          if (this.initialized == false) {
              throw new IOException("not initialized");
          }
          return paramSpi.engineGetEncoded(format);
      }
  
      /**
       * Returns a formatted string describing the parameters.
       *
       * @return a formatted string describing the parameters, or null if this
       * parameter object has not been initialized.
       */
      public final String toString() {
          if (this.initialized == false) {
              return null;
          }
          return paramSpi.engineToString();
      }
  }
  