| /* DHParameters.java -- DH parameters DAO |
| Copyright (C) 2006 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.javax.crypto.jce.sig; |
| |
| import gnu.java.security.Registry; |
| import gnu.java.security.der.DER; |
| import gnu.java.security.der.DERReader; |
| import gnu.java.security.der.DERValue; |
| import gnu.java.security.der.DERWriter; |
| import gnu.java.security.util.DerUtil; |
| |
| import java.io.ByteArrayOutputStream; |
| import java.io.IOException; |
| import java.math.BigInteger; |
| import java.security.AlgorithmParametersSpi; |
| import java.security.spec.AlgorithmParameterSpec; |
| import java.security.spec.InvalidParameterSpecException; |
| import java.util.ArrayList; |
| |
| import javax.crypto.spec.DHGenParameterSpec; |
| import javax.crypto.spec.DHParameterSpec; |
| |
| /** |
| * A JCE-specific Data Access Object (DAO) for DH parameters. |
| */ |
| public class DHParameters |
| extends AlgorithmParametersSpi |
| { |
| /** The prime public modulus. */ |
| private BigInteger p; |
| |
| /** The generator. */ |
| private BigInteger g; |
| |
| /** A prime factor of p-1. */ |
| private BigInteger q; |
| |
| /** The (private) random exponent's size (in bits). */ |
| private int l; |
| |
| // default 0-arguments constructor |
| |
| protected void engineInit(AlgorithmParameterSpec spec) |
| throws InvalidParameterSpecException |
| { |
| if (! (spec instanceof DHParameterSpec)) |
| throw new InvalidParameterSpecException("Wrong AlgorithmParameterSpec type: " |
| + spec.getClass().getName()); |
| DHParameterSpec dhSpec = (DHParameterSpec) spec; |
| p = dhSpec.getP(); |
| g = dhSpec.getG(); |
| l = dhSpec.getL(); |
| } |
| |
| /** |
| * Decodes the set of DH parameters as per RFC-2459; i.e. the DER-encoded |
| * form of the following ASN.1 construct: |
| * |
| * <pre> |
| * DhParams ::= SEQUENCE { |
| * p INTEGER, -- odd prime, p=jq +1 |
| * g INTEGER, -- generator, g |
| * q INTEGER -- factor of p-1 |
| * } |
| * </pre> |
| */ |
| protected void engineInit(byte[] params) throws IOException |
| { |
| DERReader der = new DERReader(params); |
| |
| DERValue derParams = der.read(); |
| DerUtil.checkIsConstructed(derParams, "Wrong DH Parameters field"); |
| |
| DERValue val = der.read(); |
| DerUtil.checkIsBigInteger(val, "Wrong P field"); |
| p = (BigInteger) val.getValue(); |
| val = der.read(); |
| DerUtil.checkIsBigInteger(val, "Wrong G field"); |
| g = (BigInteger) val.getValue(); |
| val = der.read(); |
| DerUtil.checkIsBigInteger(val, "Wrong Q field"); |
| q = (BigInteger) val.getValue(); |
| l = q.bitLength(); |
| } |
| |
| protected void engineInit(byte[] params, String format) throws IOException |
| { |
| if (format != null) |
| { |
| format = format.trim(); |
| if (format.length() == 0) |
| throw new IOException("Format MUST NOT be an empty string"); |
| |
| if (! format.equalsIgnoreCase(Registry.ASN1_ENCODING_SHORT_NAME)) |
| throw new IOException("Unknown or unsupported format: " + format); |
| } |
| |
| engineInit(params); |
| } |
| |
| protected AlgorithmParameterSpec engineGetParameterSpec(Class paramSpec) |
| throws InvalidParameterSpecException |
| { |
| if (paramSpec.isAssignableFrom(DHParameterSpec.class)) |
| return new DHParameterSpec(p, g, l); |
| |
| if (paramSpec.isAssignableFrom(DHGenParameterSpec.class)) |
| return new DHGenParameterSpec(p.bitLength(), l); |
| |
| throw new InvalidParameterSpecException("Wrong AlgorithmParameterSpec type: " |
| + paramSpec.getName()); |
| } |
| |
| /** |
| * Encodes the set of DH parameters as per RFC-2459; i.e. as the DER-encoded |
| * form of the following ASN.1 construct: |
| * |
| * <pre> |
| * DhParams ::= SEQUENCE { |
| * p INTEGER, -- odd prime, p=jq +1 |
| * g INTEGER, -- generator, g |
| * q INTEGER -- factor of p-1 |
| * } |
| * </pre> |
| */ |
| protected byte[] engineGetEncoded() throws IOException |
| { |
| DERValue derP = new DERValue(DER.INTEGER, p); |
| DERValue derG = new DERValue(DER.INTEGER, g); |
| DERValue derQ = new DERValue(DER.INTEGER, q); |
| |
| ArrayList params = new ArrayList(3); |
| params.add(derP); |
| params.add(derG); |
| params.add(derQ); |
| DERValue derParams = new DERValue(DER.CONSTRUCTED | DER.SEQUENCE, params); |
| |
| ByteArrayOutputStream baos = new ByteArrayOutputStream(); |
| DERWriter.write(baos, derParams); |
| byte[] result = baos.toByteArray(); |
| |
| return result; |
| } |
| |
| protected byte[] engineGetEncoded(String format) throws IOException |
| { |
| if (format != null) |
| { |
| format = format.trim(); |
| if (format.length() == 0) |
| throw new IOException("Format MUST NOT be an empty string"); |
| |
| if (! format.equalsIgnoreCase(Registry.ASN1_ENCODING_SHORT_NAME)) |
| throw new IOException("Unknown or unsupported format: " + format); |
| } |
| |
| return engineGetEncoded(); |
| } |
| |
| protected String engineToString() |
| { |
| StringBuffer sb = new StringBuffer("p="); |
| if (p == null) |
| sb.append("???"); |
| else |
| sb.append("0x").append(p.toString(16)); |
| |
| sb.append(", g="); |
| if (g == null) |
| sb.append("???"); |
| else |
| sb.append("0x").append(g.toString(16)); |
| |
| sb.append(", q="); |
| if (q == null) |
| sb.append("???"); |
| else |
| sb.append("0x").append(q.toString(16)); |
| |
| sb.append(", l=").append(l); |
| |
| return sb.toString(); |
| } |
| } |