/*
 * Copyright (c) 2018, 2020, 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 sun.security.rsa;

import java.io.*;
import sun.security.util.*;
import sun.security.x509.*;
import java.security.AlgorithmParametersSpi;
import java.security.NoSuchAlgorithmException;
import java.security.spec.AlgorithmParameterSpec;
import java.security.spec.InvalidParameterSpecException;
import java.security.spec.MGF1ParameterSpec;
import java.security.spec.PSSParameterSpec;
import static java.security.spec.PSSParameterSpec.DEFAULT;

This class implements the PSS parameters used with the RSA signatures in PSS padding. Here is its ASN.1 definition: RSASSA-PSS-params ::= SEQUENCE { hashAlgorithm [0] HashAlgorithm DEFAULT sha1, maskGenAlgorithm [1] MaskGenAlgorithm DEFAULT mgf1SHA1, saltLength [2] INTEGER DEFAULT 20 trailerField [3] TrailerField DEFAULT trailerFieldBC }
Author:Valerie Peng
/** * This class implements the PSS parameters used with the RSA * signatures in PSS padding. Here is its ASN.1 definition: * RSASSA-PSS-params ::= SEQUENCE { * hashAlgorithm [0] HashAlgorithm DEFAULT sha1, * maskGenAlgorithm [1] MaskGenAlgorithm DEFAULT mgf1SHA1, * saltLength [2] INTEGER DEFAULT 20 * trailerField [3] TrailerField DEFAULT trailerFieldBC * } * * @author Valerie Peng * */
public final class PSSParameters extends AlgorithmParametersSpi { private PSSParameterSpec spec; public PSSParameters() { } @Override protected void engineInit(AlgorithmParameterSpec paramSpec) throws InvalidParameterSpecException { if (!(paramSpec instanceof PSSParameterSpec)) { throw new InvalidParameterSpecException ("Inappropriate parameter specification"); } PSSParameterSpec spec = (PSSParameterSpec) paramSpec; String mgfName = spec.getMGFAlgorithm(); if (!spec.getMGFAlgorithm().equalsIgnoreCase("MGF1")) { throw new InvalidParameterSpecException("Unsupported mgf " + mgfName + "; MGF1 only"); } AlgorithmParameterSpec mgfSpec = spec.getMGFParameters(); if (!(mgfSpec instanceof MGF1ParameterSpec)) { throw new InvalidParameterSpecException("Inappropriate mgf " + "parameters; non-null MGF1ParameterSpec only"); } this.spec = spec; } @Override protected void engineInit(byte[] encoded) throws IOException { // first initialize with the DEFAULT values before // retrieving from the encoding bytes String mdName = DEFAULT.getDigestAlgorithm(); MGF1ParameterSpec mgfSpec = (MGF1ParameterSpec) DEFAULT.getMGFParameters(); int saltLength = DEFAULT.getSaltLength(); int trailerField = DEFAULT.getTrailerField(); DerInputStream der = new DerInputStream(encoded); DerValue[] datum = der.getSequence(4); for (DerValue d : datum) { if (d.isContextSpecific((byte) 0x00)) { // hash algid mdName = AlgorithmId.parse (d.data.getDerValue()).getName(); } else if (d.isContextSpecific((byte) 0x01)) { // mgf algid AlgorithmId val = AlgorithmId.parse(d.data.getDerValue()); if (!val.getOID().equals(AlgorithmId.MGF1_oid)) { throw new IOException("Only MGF1 mgf is supported"); } AlgorithmId params = AlgorithmId.parse( new DerValue(val.getEncodedParams())); String mgfDigestName = params.getName(); switch (mgfDigestName) { case "SHA-1": mgfSpec = MGF1ParameterSpec.SHA1; break; case "SHA-224": mgfSpec = MGF1ParameterSpec.SHA224; break; case "SHA-256": mgfSpec = MGF1ParameterSpec.SHA256; break; case "SHA-384": mgfSpec = MGF1ParameterSpec.SHA384; break; case "SHA-512": mgfSpec = MGF1ParameterSpec.SHA512; break; case "SHA-512/224": mgfSpec = MGF1ParameterSpec.SHA512_224; break; case "SHA-512/256": mgfSpec = MGF1ParameterSpec.SHA512_256; break; case "SHA3-224": mgfSpec = MGF1ParameterSpec.SHA3_224; break; case "SHA3-256": mgfSpec = MGF1ParameterSpec.SHA3_256; break; case "SHA3-384": mgfSpec = MGF1ParameterSpec.SHA3_384; break; case "SHA3-512": mgfSpec = MGF1ParameterSpec.SHA3_512; break; default: throw new IOException ("Unrecognized message digest algorithm " + mgfDigestName); } } else if (d.isContextSpecific((byte) 0x02)) { // salt length saltLength = d.data.getDerValue().getInteger(); if (saltLength < 0) { throw new IOException("Negative value for saltLength"); } } else if (d.isContextSpecific((byte) 0x03)) { // trailer field trailerField = d.data.getDerValue().getInteger(); if (trailerField != 1) { throw new IOException("Unsupported trailerField value " + trailerField); } } else { throw new IOException("Invalid encoded PSSParameters"); } } this.spec = new PSSParameterSpec(mdName, "MGF1", mgfSpec, saltLength, trailerField); } @Override protected void engineInit(byte[] encoded, String decodingMethod) throws IOException { if ((decodingMethod != null) && (!decodingMethod.equalsIgnoreCase("ASN.1"))) { throw new IllegalArgumentException("Only support ASN.1 format"); } engineInit(encoded); } @Override protected <T extends AlgorithmParameterSpec> T engineGetParameterSpec(Class<T> paramSpec) throws InvalidParameterSpecException { if (PSSParameterSpec.class.isAssignableFrom(paramSpec)) { return paramSpec.cast(spec); } else { throw new InvalidParameterSpecException ("Inappropriate parameter specification"); } } @Override protected byte[] engineGetEncoded() throws IOException { return getEncoded(spec); } @Override protected byte[] engineGetEncoded(String encMethod) throws IOException { if ((encMethod != null) && (!encMethod.equalsIgnoreCase("ASN.1"))) { throw new IllegalArgumentException("Only support ASN.1 format"); } return engineGetEncoded(); } @Override protected String engineToString() { return spec.toString(); }
Returns the encoding of a PSSParameterSpec object. This method is used in this class and AlgorithmId.
Params:
  • spec – a PSSParameterSpec object
Throws:
  • IOException – if the name of a MessageDigest or MaskGenAlgorithm is unsupported
Returns:its DER encoding
/** * Returns the encoding of a {@link PSSParameterSpec} object. This method * is used in this class and {@link AlgorithmId}. * * @param spec a {@code PSSParameterSpec} object * @return its DER encoding * @throws IOException if the name of a MessageDigest or MaskGenAlgorithm * is unsupported */
public static byte[] getEncoded(PSSParameterSpec spec) throws IOException { AlgorithmParameterSpec mgfSpec = spec.getMGFParameters(); if (!(mgfSpec instanceof MGF1ParameterSpec)) { throw new IOException("Cannot encode " + mgfSpec); } MGF1ParameterSpec mgf1Spec = (MGF1ParameterSpec)mgfSpec; DerOutputStream tmp = new DerOutputStream(); DerOutputStream tmp2, tmp3; // MD AlgorithmId mdAlgId; try { mdAlgId = AlgorithmId.get(spec.getDigestAlgorithm()); } catch (NoSuchAlgorithmException nsae) { throw new IOException("AlgorithmId " + spec.getDigestAlgorithm() + " impl not found"); } if (!mdAlgId.getOID().equals(AlgorithmId.SHA_oid)) { tmp2 = new DerOutputStream(); mdAlgId.derEncode(tmp2); tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte) 0), tmp2); } // MGF AlgorithmId mgfDigestId; try { mgfDigestId = AlgorithmId.get(mgf1Spec.getDigestAlgorithm()); } catch (NoSuchAlgorithmException nase) { throw new IOException("AlgorithmId " + mgf1Spec.getDigestAlgorithm() + " impl not found"); } if (!mgfDigestId.getOID().equals(AlgorithmId.SHA_oid)) { tmp2 = new DerOutputStream(); tmp2.putOID(AlgorithmId.MGF1_oid); mgfDigestId.encode(tmp2); tmp3 = new DerOutputStream(); tmp3.write(DerValue.tag_Sequence, tmp2); tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte) 1), tmp3); } // SaltLength if (spec.getSaltLength() != 20) { tmp2 = new DerOutputStream(); tmp2.putInteger(spec.getSaltLength()); tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte) 2), tmp2); } // TrailerField if (spec.getTrailerField() != PSSParameterSpec.TRAILER_FIELD_BC) { tmp2 = new DerOutputStream(); tmp2.putInteger(spec.getTrailerField()); tmp.write(DerValue.createTag(DerValue.TAG_CONTEXT, true, (byte) 3), tmp2); } // Put all together under a SEQUENCE tag DerOutputStream out = new DerOutputStream(); out.write(DerValue.tag_Sequence, tmp); return out.toByteArray(); } }