/* * 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 * PKCS#1 v2.1 * standard. * *
Its ASN.1 definition in PKCS#1 standard is described below: *
* 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 * } ** where *
* 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 -- * } **
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; } }