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Diffstat (limited to 'libjava/classpath/gnu/javax/crypto/key/dh/GnuDHPublicKey.java')
| -rw-r--r-- | libjava/classpath/gnu/javax/crypto/key/dh/GnuDHPublicKey.java | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/libjava/classpath/gnu/javax/crypto/key/dh/GnuDHPublicKey.java b/libjava/classpath/gnu/javax/crypto/key/dh/GnuDHPublicKey.java new file mode 100644 index 00000000000..56516c9d0ea --- /dev/null +++ b/libjava/classpath/gnu/javax/crypto/key/dh/GnuDHPublicKey.java @@ -0,0 +1,194 @@ +/* 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.key.IKeyPairCodec; + +import java.math.BigInteger; + +import javax.crypto.interfaces.DHPublicKey; + +/** + * <p>An implementation of the Diffie-Hellman public key.</p> + * + * <p>Reference:</p> + * <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 +{ + + // Constants and variables + // ------------------------------------------------------------------------- + + private BigInteger y; + + // Constructor(s) + // ------------------------------------------------------------------------- + + /** + * 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; + } + + // Class methods + // ------------------------------------------------------------------------- + + /** + * <p>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.</p> + * + * @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); + } + + // Instance methods + // ------------------------------------------------------------------------- + + // javax.crypto.interfaces.DHPublicKey interface implementation ------------ + + public BigInteger getY() + { + return y; + } + + // other methods ----------------------------------------------------------- + + /** + * <p>Returns the encoded form of this public key according to the designated + * format.</p> + * + * @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()); + } +} |
