/* ISignature.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. */ package gnu.java.security.sig; import java.util.Map; /** * The visible methods of every signature-with-appendix scheme. *
* The Handbook of Applied Cryptography (HAC), by A. Menezes & al. states: * "Digital signature schemes which require the message as input to the * verification algorithm are called digital signature schemes with appendix. * ... They rely on cryptographic hash functions rather than customised * redundancy functions, and are less prone to existential forgery attacks." *
* References: *
buffer
of the first byte
* to consider.
* @param length the number of bytes in buffer
starting from
* the byte at index offset
to digest.
* @throws IllegalStateException if this instance was not setup for signature
* generation/verification.
*/
void update(byte[] buffer, int offset, int length)
throws IllegalStateException;
/**
* Terminates a signature generation phase by digesting and processing the
* context of the underlying message digest algorithm instance.
*
* @return a {@link Object} representing the native output of the signature
* scheme implementation.
* @throws IllegalStateException if this instance was not setup for signature
* generation.
*/
Object sign() throws IllegalStateException;
/**
* Terminates a signature verification phase by digesting and processing the
* context of the underlying message digest algorithm instance.
*
* @param signature a native signature object previously generated by an
* invocation of the sign()
method.
* @return true
iff the outpout of the verification phase
* confirms that the designated signature object has been generated
* using the corresponding public key of the recepient.
* @throws IllegalStateException if this instance was not setup for signature
* verification.
*/
boolean verify(Object signature) throws IllegalStateException;
/**
* Returns a clone copy of this instance.
*
* @return a clone copy of this instance.
*/
Object clone();
}