| /* GnuDHPublicKey.java -- |
| Copyright (C) 2003, 2006 Free Software Foundation, Inc. |
| |
| This file is a 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 of the License, 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; if not, write to the Free Software |
| Foundation, Inc., 51 Franklin St, 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.key.dh; |
| |
| import gnu.java.security.Registry; |
| import gnu.java.security.action.GetPropertyAction; |
| import gnu.java.security.key.IKeyPairCodec; |
| |
| import java.math.BigInteger; |
| import java.security.AccessController; |
| |
| import javax.crypto.interfaces.DHPublicKey; |
| |
| /** |
| * An implementation of the Diffie-Hellman public key. |
| * <p> |
| * Reference: |
| * <ol> |
| * <li><a href="http://www.ietf.org/rfc/rfc2631.txt">Diffie-Hellman Key |
| * Agreement Method</a><br> |
| * Eric Rescorla.</li> |
| * </ol> |
| */ |
| public class GnuDHPublicKey |
| extends GnuDHKey |
| implements DHPublicKey |
| { |
| private BigInteger y; |
| /** String representation of this key. Cached for speed. */ |
| private transient String str; |
| |
| /** |
| * Convenience constructor. Calls the constructor with five arguments passing |
| * {@link Registry#RAW_ENCODING_ID} as the value of its first argument. |
| * |
| * @param q a prime divisor of p-1. |
| * @param p the public prime. |
| * @param g the generator of the group. |
| * @param y the public value y. |
| */ |
| public GnuDHPublicKey(BigInteger q, BigInteger p, BigInteger g, BigInteger y) |
| { |
| this(Registry.RAW_ENCODING_ID, q, p, g, y); |
| } |
| |
| /** |
| * Constructs a new instance of <code>GnuDHPublicKey</code> given the |
| * designated parameters. |
| * |
| * @param preferredFormat the identifier of the encoding format to use by |
| * default when externalizing the key. |
| * @param q a prime divisor of p-1. |
| * @param p the public prime. |
| * @param g the generator of the group. |
| * @param y the public value y. |
| */ |
| public GnuDHPublicKey(int preferredFormat, BigInteger q, BigInteger p, |
| BigInteger g, BigInteger y) |
| { |
| super(preferredFormat == Registry.ASN1_ENCODING_ID ? Registry.X509_ENCODING_ID |
| : preferredFormat, |
| q, p, g); |
| this.y = y; |
| } |
| |
| /** |
| * A class method that takes the output of the <code>encodePublicKey()</code> |
| * method of a DH keypair codec object (an instance implementing |
| * {@link IKeyPairCodec} for DSS keys, and re-constructs an instance of this |
| * object. |
| * |
| * @param k the contents of a previously encoded instance of this object. |
| * @exception ArrayIndexOutOfBoundsException if there is not enough bytes, in |
| * <code>k</code>, to represent a valid encoding of an |
| * instance of this object. |
| * @exception IllegalArgumentException if the byte sequence does not represent |
| * a valid encoding of an instance of this object. |
| */ |
| public static GnuDHPublicKey valueOf(byte[] k) |
| { |
| // try RAW codec |
| if (k[0] == Registry.MAGIC_RAW_DH_PUBLIC_KEY[0]) |
| try |
| { |
| return (GnuDHPublicKey) new DHKeyPairRawCodec().decodePublicKey(k); |
| } |
| catch (IllegalArgumentException ignored) |
| { |
| } |
| // try X.509 codec |
| return (GnuDHPublicKey) new DHKeyPairX509Codec().decodePublicKey(k); |
| } |
| |
| public BigInteger getY() |
| { |
| return y; |
| } |
| |
| /** |
| * Returns the encoded form of this public key according to the designated |
| * format. |
| * |
| * @param format the desired format identifier of the resulting encoding. |
| * @return the byte sequence encoding this key according to the designated |
| * format. |
| * @exception IllegalArgumentException if the format is not supported. |
| */ |
| public byte[] getEncoded(int format) |
| { |
| byte[] result; |
| switch (format) |
| { |
| case IKeyPairCodec.RAW_FORMAT: |
| result = new DHKeyPairRawCodec().encodePublicKey(this); |
| break; |
| case IKeyPairCodec.X509_FORMAT: |
| result = new DHKeyPairX509Codec().encodePublicKey(this); |
| break; |
| default: |
| throw new IllegalArgumentException("Unsupported encoding format: " |
| + format); |
| } |
| return result; |
| } |
| |
| /** |
| * Returns <code>true</code> if the designated object is an instance of |
| * {@link DHPublicKey} and has the same parameter values as this one. |
| * |
| * @param obj the other non-null DH key to compare to. |
| * @return <code>true</code> if the designated object is of the same type |
| * and value as this one. |
| */ |
| public boolean equals(Object obj) |
| { |
| if (obj == null) |
| return false; |
| |
| if (! (obj instanceof DHPublicKey)) |
| return false; |
| |
| DHPublicKey that = (DHPublicKey) obj; |
| return super.equals(that) && y.equals(that.getY()); |
| } |
| |
| public String toString() |
| { |
| if (str == null) |
| { |
| String ls = (String) AccessController.doPrivileged |
| (new GetPropertyAction("line.separator")); |
| str = new StringBuilder(this.getClass().getName()).append("(") |
| .append(super.toString()).append(",").append(ls) |
| .append("y=0x").append(y.toString(16)).append(ls) |
| .append(")") |
| .toString(); |
| } |
| return str; |
| } |
| } |