| /* DHParametersGenerator.java -- JCE Adapter for a generator of DH parameters |
| 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.javax.crypto.jce.GnuCrypto; |
| import gnu.javax.crypto.key.dh.GnuDHKeyPairGenerator; |
| import gnu.javax.crypto.key.dh.RFC2631; |
| |
| import java.math.BigInteger; |
| import java.security.AlgorithmParameterGeneratorSpi; |
| import java.security.AlgorithmParameters; |
| import java.security.InvalidAlgorithmParameterException; |
| import java.security.InvalidParameterException; |
| import java.security.NoSuchAlgorithmException; |
| import java.security.Provider; |
| import java.security.SecureRandom; |
| import java.security.spec.AlgorithmParameterSpec; |
| import java.security.spec.InvalidParameterSpecException; |
| |
| import javax.crypto.spec.DHGenParameterSpec; |
| import javax.crypto.spec.DHParameterSpec; |
| |
| /** |
| * A JCE Adapter for a generator of DH parameters. |
| */ |
| public class DHParametersGenerator |
| extends AlgorithmParameterGeneratorSpi |
| { |
| private static final Provider GNU_CRYPTO = new GnuCrypto(); |
| |
| /** Size of the prime (public) modulus in bits. */ |
| private int modulusSize = -1; |
| |
| /** Size of the prime (private) modulus in bits. */ |
| private int exponentSize = -1; |
| |
| /** User specified source of randomness. */ |
| private SecureRandom rnd; |
| |
| /** Our concrete DH parameters generator. */ |
| private RFC2631 rfc2631; |
| |
| |
| protected void engineInit(int size, SecureRandom random) |
| { |
| if ((size % 256) != 0 || size < GnuDHKeyPairGenerator.DEFAULT_PRIME_SIZE) |
| throw new InvalidParameterException("Prime modulus (p) size (in bits) " |
| + "MUST be a multiple of 256, and " |
| + "greater than or equal to 1024"); |
| this.modulusSize = size; |
| this.rnd = random; |
| } |
| |
| protected void engineInit(AlgorithmParameterSpec spec, SecureRandom random) |
| throws InvalidAlgorithmParameterException |
| { |
| if (spec instanceof DHParameterSpec) |
| { |
| DHParameterSpec dhSpec = (DHParameterSpec) spec; |
| BigInteger p = dhSpec.getP(); |
| int size = p.bitLength(); |
| this.engineInit(size, random); |
| } |
| else if (spec instanceof DHGenParameterSpec) |
| { |
| DHGenParameterSpec dhSpec = (DHGenParameterSpec) spec; |
| int size = dhSpec.getPrimeSize(); |
| this.engineInit(size, random); |
| exponentSize = dhSpec.getExponentSize(); |
| |
| if ((exponentSize % 8) != 0 |
| || exponentSize < GnuDHKeyPairGenerator.DEFAULT_EXPONENT_SIZE) |
| throw new InvalidParameterException("Random exponent size (in bits) " |
| + "MUST be a multiple of 8, and " |
| + "greater than or equal to " |
| + GnuDHKeyPairGenerator.DEFAULT_EXPONENT_SIZE); |
| if (exponentSize > modulusSize) |
| throw new InvalidParameterException("Random exponent size (in bits) " |
| + "MUST be less than that of the " |
| + "public prime modulus (p)"); |
| } |
| |
| throw new InvalidAlgorithmParameterException("Wrong AlgorithmParameterSpec type: " |
| + spec.getClass().getName()); |
| } |
| |
| protected AlgorithmParameters engineGenerateParameters() |
| { |
| if (modulusSize < 1) |
| modulusSize = GnuDHKeyPairGenerator.DEFAULT_PRIME_SIZE; |
| |
| if (exponentSize < 1) |
| exponentSize = GnuDHKeyPairGenerator.DEFAULT_EXPONENT_SIZE; |
| |
| rfc2631 = new RFC2631(exponentSize, modulusSize, rnd); |
| BigInteger[] params = rfc2631.generateParameters(); |
| BigInteger p = params[RFC2631.DH_PARAMS_P]; |
| BigInteger g = params[RFC2631.DH_PARAMS_G]; |
| int l = params[RFC2631.DH_PARAMS_Q].bitLength(); |
| DHParameterSpec spec = new DHParameterSpec(p, g, l); |
| AlgorithmParameters result = null; |
| try |
| { |
| result = AlgorithmParameters.getInstance(Registry.DH_KPG, GNU_CRYPTO); |
| result.init(spec); |
| } |
| catch (NoSuchAlgorithmException ignore) |
| { |
| } |
| catch (InvalidParameterSpecException ignore) |
| { |
| } |
| return result; |
| } |
| } |