gnu.java.security.sig.rsa

Class RSAPSSSignature

Implemented Interfaces:
Cloneable, ISignature

public class RSAPSSSignature
extends BaseSignature

The RSA-PSS signature scheme is a public-key encryption scheme combining the RSA algorithm with the Probabilistic Signature Scheme (PSS) encoding method.

The inventors of RSA are Ronald L. Rivest, Adi Shamir, and Leonard Adleman, while the inventors of the PSS encoding method are Mihir Bellare and Phillip Rogaway. During efforts to adopt RSA-PSS into the P1363a standards effort, certain adaptations to the original version of RSA-PSS were made by Mihir Bellare and Phillip Rogaway and also by Burt Kaliski (the editor of IEEE P1363a) to facilitate implementation and integration into existing protocols.

References:

  1. RSA-PSS Signature Scheme with Appendix, part B.
    Primitive specification and supporting documentation.
    Jakob Jonsson and Burt Kaliski.

Field Summary

Fields inherited from class gnu.java.security.sig.BaseSignature

md, privateKey, publicKey, schemeName

Fields inherited from interface gnu.java.security.sig.ISignature

SIGNER_KEY, SOURCE_OF_RANDOMNESS, VERIFIER_KEY

Constructor Summary

RSAPSSSignature()
Default 0-arguments constructor.
RSAPSSSignature(IMessageDigest md, int sLen)
RSAPSSSignature(String mdName)
Constructs an instance of this object using the designated message digest algorithm as its underlying hash function, and having 0-octet salt.
RSAPSSSignature(String mdName, int sLen)
Constructs an instance of this object using the designated message digest algorithm as its underlying hash function.

Method Summary

Object
clone()
This method may be called to create a new copy of the Object.
protected Object
generateSignature()
protected void
setupForSigning(PrivateKey k)
protected void
setupForVerification(PublicKey k)
protected boolean
verifySignature(Object sig)

Methods inherited from class gnu.java.security.sig.BaseSignature

clone, generateSignature, init, name, nextRandomBytes, setupForSigning, setupForVerification, setupSign, setupVerify, sign, update, update, verify, verifySignature

Methods inherited from class java.lang.Object

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

Constructor Details

RSAPSSSignature

public RSAPSSSignature()
Default 0-arguments constructor. Uses SHA-1 as the default hash and a 0-octet salt.

RSAPSSSignature

public RSAPSSSignature(IMessageDigest md,
                       int sLen)

RSAPSSSignature

public RSAPSSSignature(String mdName)
Constructs an instance of this object using the designated message digest algorithm as its underlying hash function, and having 0-octet salt.
Parameters:
mdName - the canonical name of the underlying hash function.

RSAPSSSignature

public RSAPSSSignature(String mdName,
                       int sLen)
Constructs an instance of this object using the designated message digest algorithm as its underlying hash function.
Parameters:
mdName - the canonical name of the underlying hash function.
sLen - the desired length in octets of the salt to use for encoding / decoding signatures.

Method Details

clone

public Object clone()
This method may be called to create a new copy of the Object. The typical behavior is as follows:
  • o == o.clone() is false
  • o.getClass() == o.clone().getClass() is true
  • o.equals(o) is true

However, these are not strict requirements, and may be violated if necessary. Of the three requirements, the last is the most commonly violated, particularly if the subclass does not override Object.equals(Object).

If the Object you call clone() on does not implement Cloneable (which is a placeholder interface), then a CloneNotSupportedException is thrown. Notice that Object does not implement Cloneable; this method exists as a convenience for subclasses that do.

Object's implementation of clone allocates space for the new Object using the correct class, without calling any constructors, and then fills in all of the new field values with the old field values. Thus, it is a shallow copy. However, subclasses are permitted to make a deep copy.

All array types implement Cloneable, and override this method as follows (it should never fail):

 public Object clone()
 {
   try
     {
       super.clone();
     }
   catch (CloneNotSupportedException e)
     {
       throw new InternalError(e.getMessage());
     }
 }
 
Specified by:
clone in interface ISignature
Overrides:
clone in interface BaseSignature
Returns:
a copy of the Object
See Also:
Cloneable

generateSignature

protected Object generateSignature()
            throws IllegalStateException
Overrides:
generateSignature in interface BaseSignature

setupForSigning

protected void setupForSigning(PrivateKey k)
            throws IllegalArgumentException
Overrides:
setupForSigning in interface BaseSignature

setupForVerification

protected void setupForVerification(PublicKey k)
            throws IllegalArgumentException
Overrides:
setupForVerification in interface BaseSignature

verifySignature

protected boolean verifySignature(Object sig)
            throws IllegalStateException
Overrides:
verifySignature in interface BaseSignature

RSAPSSSignature.java -- Copyright (C) 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.