javax.crypto.spec

Class RC2ParameterSpec

Implemented Interfaces:
AlgorithmParameterSpec

public class RC2ParameterSpec
extends Object
implements AlgorithmParameterSpec

A wrapper for parameters for the RC2 block cipher ("RC" means either "Rivest Cipher" or "Ron's Code", depending upon who you ask and when).
Since:
1.4

Constructor Summary

RC2ParameterSpec(int effectiveKeyBits)
Create RC2 parameters without an IV.
RC2ParameterSpec(int effectiveKeyBits, byte[] iv)
Create RC2 parameters with an IV.
RC2ParameterSpec(int effectiveKeyBits, byte[] iv, int offset)
Create RC2 parameters with an IV.

Method Summary

boolean
equals(Object o)
Determine whether this Object is semantically equal to another Object.
int
getEffectiveKeyBits()
Get the number of effective key bits.
byte[]
getIV()
Return the initialization vector, or null if none was specified.
int
hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

RC2ParameterSpec

public RC2ParameterSpec(int effectiveKeyBits)
Create RC2 parameters without an IV.
Parameters:
effectiveKeyBits - The number of effective key bits.

RC2ParameterSpec

public RC2ParameterSpec(int effectiveKeyBits,
                        byte[] iv)
Create RC2 parameters with an IV.
Parameters:
effectiveKeyBits - The number of effective key bits.
iv - The IV; the first eight bytes of this array are used.

RC2ParameterSpec

public RC2ParameterSpec(int effectiveKeyBits,
                        byte[] iv,
                        int offset)
Create RC2 parameters with an IV.
Parameters:
effectiveKeyBits - The number of effective key bits.
iv - The IV; the first eight bytes of this array after offset are used.
offset - From whence to start in the array.

Method Details

equals

public boolean equals(Object o)
Determine whether this Object is semantically equal to another Object.

There are some fairly strict requirements on this method which subclasses must follow:

  • It must be transitive. If a.equals(b) and b.equals(c), then a.equals(c) must be true as well.
  • It must be symmetric. a.equals(b) and b.equals(a) must have the same value.
  • It must be reflexive. a.equals(a) must always be true.
  • It must be consistent. Whichever value a.equals(b) returns on the first invocation must be the value returned on all later invocations.
  • a.equals(null) must be false.
  • It must be consistent with hashCode(). That is, a.equals(b) must imply a.hashCode() == b.hashCode(). The reverse is not true; two objects that are not equal may have the same hashcode, but that has the potential to harm hashing performance.

This is typically overridden to throw a ClassCastException if the argument is not comparable to the class performing the comparison, but that is not a requirement. It is legal for a.equals(b) to be true even though a.getClass() != b.getClass(). Also, it is typical to never cause a NullPointerException.

In general, the Collections API (java.util) use the equals method rather than the == operator to compare objects. However, IdentityHashMap is an exception to this rule, for its own good reasons.

The default implementation returns this == o.

Overrides:
equals in interface Object
Parameters:
Returns:
whether this Object is semantically equal to another

getEffectiveKeyBits

public int getEffectiveKeyBits()
Get the number of effective key bits.
Returns:
The numer of effective key bits.

getIV

public byte[] getIV()
Return the initialization vector, or null if none was specified.
Returns:
The IV, or null.

hashCode

public int hashCode()
Get a value that represents this Object, as uniquely as possible within the confines of an int.

There are some requirements on this method which subclasses must follow:

  • Semantic equality implies identical hashcodes. In other words, if a.equals(b) is true, then a.hashCode() == b.hashCode() must be as well. However, the reverse is not necessarily true, and two objects may have the same hashcode without being equal.
  • It must be consistent. Whichever value o.hashCode() returns on the first invocation must be the value returned on all later invocations as long as the object exists. Notice, however, that the result of hashCode may change between separate executions of a Virtual Machine, because it is not invoked on the same object.

Notice that since hashCode is used in Hashtable and other hashing classes, a poor implementation will degrade the performance of hashing (so don't blindly implement it as returning a constant!). Also, if calculating the hash is time-consuming, a class may consider caching the results.

The default implementation returns System.identityHashCode(this)

Overrides:
hashCode in interface Object
Returns:
the hash code for this Object

RC2ParameterSpec.java -- Wrapper for RC2 parameters. Copyright (C) 2004 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.