content: /*
   * Copyright (c) 2001, 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.spec;
  
  import java.math.BigInteger;
  import java.security.spec.MGF1ParameterSpec;
  
  /**
   * This class specifies a parameter spec for RSA-PSS signature scheme,
   * as defined in the
   * <a href="http://www.ietf.org/rfc/rfc3447.txt">PKCS#1 v2.1</a>
   * standard.
   *
   * <p>Its ASN.1 definition in PKCS#1 standard is described below:
   * <pre>
   * RSASSA-PSS-params ::= SEQUENCE {
   *   hashAlgorithm      [0] OAEP-PSSDigestAlgorithms  DEFAULT sha1,
   *   maskGenAlgorithm   [1] PKCS1MGFAlgorithms  DEFAULT mgf1SHA1,
   *   saltLength         [2] INTEGER  DEFAULT 20,
   *   trailerField       [3] INTEGER  DEFAULT 1
   * }
   * </pre>
   * where
   * <pre>
   * OAEP-PSSDigestAlgorithms    ALGORITHM-IDENTIFIER ::= {
   *   { OID id-sha1 PARAMETERS NULL   }|
   *   { OID id-sha224 PARAMETERS NULL   }|
   *   { OID id-sha256 PARAMETERS NULL }|
   *   { OID id-sha384 PARAMETERS NULL }|
   *   { OID id-sha512 PARAMETERS NULL },
   *   ...  -- Allows for future expansion --
   * }
   *
   * PKCS1MGFAlgorithms    ALGORITHM-IDENTIFIER ::= {
   *   { OID id-mgf1 PARAMETERS OAEP-PSSDigestAlgorithms },
   *   ...  -- Allows for future expansion --
   * }
   * </pre>
   * <p>Note: the PSSParameterSpec.DEFAULT uses the following:
   *     message digest  -- "SHA-1"
   *     mask generation function (mgf) -- "MGF1"
   *     parameters for mgf -- MGF1ParameterSpec.SHA1
   *     SaltLength   -- 20
   *     TrailerField -- 1
   *
   * @see MGF1ParameterSpec
   * @see AlgorithmParameterSpec
   * @see java.security.Signature
   *
   * @author Valerie Peng
   *
   *
   * @since 1.4
   */
  
  public class PSSParameterSpec implements AlgorithmParameterSpec {
  
      private String mdName = "SHA-1";
      private String mgfName = "MGF1";
      private AlgorithmParameterSpec mgfSpec = MGF1ParameterSpec.SHA1;
      private int saltLen = 20;
      private int trailerField = 1;
  
      /**
       * The PSS parameter set with all default values.
       * @since 1.5
       */
      public static final PSSParameterSpec DEFAULT = new PSSParameterSpec();
  
      /**
       * Constructs a new {@code PSSParameterSpec} as defined in
       * the PKCS #1 standard using the default values.
       */
      private PSSParameterSpec() {
      }
  
      /**
       * Creates a new {@code PSSParameterSpec} as defined in
       * the PKCS #1 standard using the specified message digest,
       * mask generation function, parameters for mask generation
       * function, salt length, and trailer field values.
       *
       * @param mdName the algorithm name of the hash function.
       * @param mgfName the algorithm name of the mask generation
       * function.
       * @param mgfSpec the parameters for the mask generation
       * function. If null is specified, null will be returned by
       * getMGFParameters().
       * @param saltLen the length of salt.
       * @param trailerField the value of the trailer field.
       * @exception NullPointerException if {@code mdName},
       * or {@code mgfName} is null.
       * @exception IllegalArgumentException if {@code saltLen}
       * or {@code trailerField} is less than 0.
       * @since 1.5
       */
      public PSSParameterSpec(String mdName, String mgfName,
                              AlgorithmParameterSpec mgfSpec,
                              int saltLen, int trailerField) {
          if (mdName == null) {
              throw new NullPointerException("digest algorithm is null");
          }
          if (mgfName == null) {
              throw new NullPointerException("mask generation function " +
                                             "algorithm is null");
          }
          if (saltLen < 0) {
              throw new IllegalArgumentException("negative saltLen value: " +
                                                 saltLen);
          }
          if (trailerField < 0) {
              throw new IllegalArgumentException("negative trailerField: " +
                                                 trailerField);
          }
          this.mdName = mdName;
          this.mgfName = mgfName;
          this.mgfSpec = mgfSpec;
          this.saltLen = saltLen;
          this.trailerField = trailerField;
      }
  
      /**
       * Creates a new {@code PSSParameterSpec}
       * using the specified salt length and other default values as
       * defined in PKCS#1.
       *
       * @param saltLen the length of salt in bits to be used in PKCS#1
       * PSS encoding.
       * @exception IllegalArgumentException if {@code saltLen} is
       * less than 0.
       */
      public PSSParameterSpec(int saltLen) {
          if (saltLen < 0) {
              throw new IllegalArgumentException("negative saltLen value: " +
                                                 saltLen);
          }
          this.saltLen = saltLen;
      }
  
      /**
       * Returns the message digest algorithm name.
       *
       * @return the message digest algorithm name.
       * @since 1.5
       */
      public String getDigestAlgorithm() {
          return mdName;
      }
  
      /**
       * Returns the mask generation function algorithm name.
       *
       * @return the mask generation function algorithm name.
       *
       * @since 1.5
       */
      public String getMGFAlgorithm() {
          return mgfName;
      }
  
      /**
       * Returns the parameters for the mask generation function.
       *
       * @return the parameters for the mask generation function.
       * @since 1.5
       */
      public AlgorithmParameterSpec getMGFParameters() {
          return mgfSpec;
      }
  
      /**
       * Returns the salt length in bits.
       *
       * @return the salt length.
       */
      public int getSaltLength() {
          return saltLen;
      }
  
      /**
       * Returns the value for the trailer field, i.e. bc in PKCS#1 v2.1.
       *
       * @return the value for the trailer field, i.e. bc in PKCS#1 v2.1.
       * @since 1.5
       */
      public int getTrailerField() {
          return trailerField;
      }
  }
  