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gnu.java.security.key.dss

Class DSSKey

Implemented Interfaces:
DSAKey, Key, Serializable
Known Direct Subclasses:
DSSPrivateKey, DSSPublicKey
public abstract class DSSKey
extends Object
implements Key, DSAKey
A base asbtract class for both public and private DSS (Digital Signature Standard) keys. It encapsulates the three DSS numbers: p, q and g.

According to the JDK, cryptographic Keys all have a format. The format used in this implementation is called Raw, and basically consists of the raw byte sequences of algorithm parameters. The exact order of the byte sequences and the implementation details are given in each of the relevant getEncoded() methods of each of the private and public keys.

IMPORTANT: Under certain circumstances (e.g. in an X.509 certificate with inherited AlgorithmIdentifier's parameters of a SubjectPublicKeyInfo element) these three MPIs may be null.

See Also:
DSSPrivateKey.getEncoded(int), DSSPublicKey.getEncoded(int)

Field Summary

protected int
defaultFormat
Identifier of the default encoding format to use when externalizing the key material.
protected BigInteger
g
g = h(p-1)/q mod p, where h is any integer with 1 < h < p - 1 such that h (p-1)/q mod p > 1 (g has order q mod p ).
protected BigInteger
p
A prime modulus, where 2L-1 < p < 2L for 512 <= L <= 1024 and L a multiple of 64.
protected BigInteger
q
A prime divisor of p - 1, where 2159 < q < 2160.

Fields inherited from interface java.security.Key

serialVersionUID

Constructor Summary

DSSKey(int defaultFormat, BigInteger p, BigInteger q, BigInteger g)
Trivial protected constructor.

Method Summary

boolean
equals(Object obj)
Returns true if the designated object is an instance of DSAKey and has the same DSS (Digital Signature Standard) parameter values as this one.
String
getAlgorithm()
byte[]
getEncoded()
Deprecated. see getEncoded(int).
abstract byte[]
getEncoded(int format)
String
getFormat()
DSAParams
getParams()
This method returns non-secret parameters of the DSA key
boolean
hasInheritedParameters()
String
toString()
Convert this Object to a human-readable String.

Methods inherited from class java.lang.Object

clone, equals, extends Object> getClass, finalize, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

defaultFormat

protected final int defaultFormat
Identifier of the default encoding format to use when externalizing the key material.

g

protected final BigInteger g
g = h(p-1)/q mod p, where h is any integer with 1 < h < p - 1 such that h (p-1)/q mod p > 1 (g has order q mod p ).

p

protected final BigInteger p
A prime modulus, where 2L-1 < p < 2L for 512 <= L <= 1024 and L a multiple of 64.

q

protected final BigInteger q
A prime divisor of p - 1, where 2159 < q < 2160.

Constructor Details

DSSKey

protected DSSKey(int defaultFormat,
                 BigInteger p,
                 BigInteger q,
                 BigInteger g)
Trivial protected constructor.
Parameters:
defaultFormat - the identifier of the encoding format to use by default when externalizing the key.
p - the DSS parameter p.
q - the DSS parameter q.
g - the DSS parameter g.

Method Details

equals

public boolean equals(Object obj)
Returns true if the designated object is an instance of DSAKey and has the same DSS (Digital Signature Standard) parameter values as this one.

Always returns false if the MPIs of this key are inherited. This may be the case when the key is re-constructed from an X.509 certificate with absent or NULL AlgorithmIdentifier's parameters field.

Overrides:
equals in interface Object
Parameters:
obj - the other non-null DSS key to compare to.
Returns:
true if the designated object is of the same type and value as this one.

getAlgorithm

public String getAlgorithm()
Specified by:
getAlgorithm in interface Key

getEncoded

public byte[] getEncoded()

Deprecated. see getEncoded(int).

Specified by:
getEncoded in interface Key

getEncoded

public abstract byte[] getEncoded(int format)

getFormat

public String getFormat()
Specified by:
getFormat in interface Key

getParams

public DSAParams getParams()
This method returns non-secret parameters of the DSA key
Specified by:
getParams in interface DSAKey
Returns:
The DSA parameters

hasInheritedParameters

public boolean hasInheritedParameters()
Returns:
true if p, q and g are all null. Returns false otherwise.

toString

public String toString()
Convert this Object to a human-readable String. There are no limits placed on how long this String should be or what it should contain. We suggest you make it as intuitive as possible to be able to place it into System.out.println() and such.

It is typical, but not required, to ensure that this method never completes abruptly with a RuntimeException.

This method will be called when performing string concatenation with this object. If the result is null, string concatenation will instead use "null".

The default implementation returns getClass().getName() + "@" + Integer.toHexString(hashCode()).

Overrides:
toString in interface Object
Returns:
the String representing this Object, which may be null
See Also:
getClass(), Object.hashCode(), Class.getName(), Integer.toHexString(int)
DSSKey.java -- Copyright 2001, 2002, 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.

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