Java tutorial
/* * Copyright (c) 2003, 2018, 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 javax.crypto.spec; import java.math.BigInteger; import java.security.spec.AlgorithmParameterSpec; import java.security.spec.MGF1ParameterSpec; /** * This class specifies the set of parameters used with OAEP Padding, * as defined in the * <a href="https://tools.ietf.org/rfc/rfc8017.txt">PKCS#1 v2.2</a> standard. * * Its ASN.1 definition in PKCS#1 standard is described below: * <pre> * RSAES-OAEP-params ::= SEQUENCE { * hashAlgorithm [0] HashAlgorithm DEFAULT sha1, * maskGenAlgorithm [1] MaskGenAlgorithm DEFAULT mgf1SHA1, * pSourceAlgorithm [2] PSourceAlgorithm DEFAULT pSpecifiedEmpty * } * </pre> * where * <pre> * HashAlgorithm ::= AlgorithmIdentifier { * {OAEP-PSSDigestAlgorithms} * } * MaskGenAlgorithm ::= AlgorithmIdentifier { {PKCS1MGFAlgorithms} } * PSourceAlgorithm ::= AlgorithmIdentifier { * {PKCS1PSourceAlgorithms} * } * * 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 }| * { OID id-sha512-224 PARAMETERS NULL }| * { OID id-sha512-256 PARAMETERS NULL }, * ... -- Allows for future expansion -- * } * PKCS1MGFAlgorithms ALGORITHM-IDENTIFIER ::= { * { OID id-mgf1 PARAMETERS HashAlgorithm }, * ... -- Allows for future expansion -- * } * PKCS1PSourceAlgorithms ALGORITHM-IDENTIFIER ::= { * { OID id-pSpecified PARAMETERS EncodingParameters }, * ... -- Allows for future expansion -- * } * EncodingParameters ::= OCTET STRING(SIZE(0..MAX)) * </pre> * <p>Note: the OAEPParameterSpec.DEFAULT uses the following: * <pre> * message digest -- "SHA-1" * mask generation function (mgf) -- "MGF1" * parameters for mgf -- MGF1ParameterSpec.SHA1 * source of encoding input -- PSource.PSpecified.DEFAULT * </pre> * * @see java.security.spec.MGF1ParameterSpec * @see PSource * * @author Valerie Peng * * @since 1.5 */ public class OAEPParameterSpec implements AlgorithmParameterSpec { private String mdName = "SHA-1"; private String mgfName = "MGF1"; private AlgorithmParameterSpec mgfSpec = MGF1ParameterSpec.SHA1; private PSource pSrc = PSource.PSpecified.DEFAULT; /** * The OAEP parameter set with all default values. */ public static final OAEPParameterSpec DEFAULT = new OAEPParameterSpec(); /** * Constructs a parameter set for OAEP padding as defined in * the PKCS #1 standard using the default values. */ private OAEPParameterSpec() { } /** * Constructs a parameter set for OAEP padding as defined in * the PKCS #1 standard using the specified message digest * algorithm <code>mdName</code>, mask generation function * algorithm <code>mgfName</code>, parameters for the mask * generation function <code>mgfSpec</code>, and source of * the encoding input P <code>pSrc</code>. * * @param mdName the algorithm name for the message digest. * @param mgfName the algorithm name for the mask generation * function. * @param mgfSpec the parameters for the mask generation function. * If null is specified, null will be returned by getMGFParameters(). * @param pSrc the source of the encoding input P. * @exception NullPointerException if <code>mdName</code>, * <code>mgfName</code>, or <code>pSrc</code> is null. */ public OAEPParameterSpec(String mdName, String mgfName, AlgorithmParameterSpec mgfSpec, PSource pSrc) { if (mdName == null) { throw new NullPointerException("digest algorithm is null"); } if (mgfName == null) { throw new NullPointerException("mask generation function " + "algorithm is null"); } if (pSrc == null) { throw new NullPointerException("source of the encoding input " + "is null"); } this.mdName = mdName; this.mgfName = mgfName; this.mgfSpec = mgfSpec; this.pSrc = pSrc; } /** * Returns the message digest algorithm name. * * @return the message digest algorithm name. */ public String getDigestAlgorithm() { return mdName; } /** * Returns the mask generation function algorithm name. * * @return the mask generation function algorithm name. */ public String getMGFAlgorithm() { return mgfName; } /** * Returns the parameters for the mask generation function. * * @return the parameters for the mask generation function. */ public AlgorithmParameterSpec getMGFParameters() { return mgfSpec; } /** * Returns the source of encoding input P. * * @return the source of encoding input P. */ public PSource getPSource() { return pSrc; } }