gnu.java.security.hash
Class Sha160
- Cloneable, IMessageDigest
The Secure Hash Algorithm (SHA-1) is required for use with the Digital
Signature Algorithm (DSA) as specified in the Digital Signature Standard
(DSS) and whenever a secure hash algorithm is required for federal
applications. For a message of length less than 2^64 bits, the SHA-1
produces a 160-bit condensed representation of the message called a message
digest. The message digest is used during generation of a signature for the
message. The SHA-1 is also used to compute a message digest for the received
version of the message during the process of verifying the signature. Any
change to the message in transit will, with very high probability, result in
a different message digest, and the signature will fail to verify.
The SHA-1 is designed to have the following properties: it is
computationally infeasible to find a message which corresponds to a given
message digest, or to find two different messages which produce the same
message digest.
References:
- SECURE HASH
STANDARD
Federal Information, Processing Standards Publication 180-1, 1995 April 17.
Sha160() - Trivial 0-arguments constructor.
|
static int[] | G(int hh0, int hh1, int hh2, int hh3, int hh4, byte[] in, int offset)
|
Object | clone() - This method may be called to create a new copy of the
Object.
|
protected byte[] | getResult() - Constructs the result from the contents of the current context.
|
protected byte[] | padBuffer() - Returns the byte array to use as padding before completing a hash
operation.
|
protected void | resetContext() - Resets the instance for future re-use.
|
boolean | selfTest()
|
protected void | transform(byte[] in, int offset) - The block digest transformation per se.
|
blockSize , clone , digest , getResult , hashSize , name , padBuffer , reset , resetContext , selfTest , transform , update , update , update |
clone , equals , extends Object> getClass , finalize , hashCode , notify , notifyAll , toString , wait , wait , wait |
Sha160
public Sha160()
Trivial 0-arguments constructor.
G
public static final int[] G(int hh0,
int hh1,
int hh2,
int hh3,
int hh4,
byte[] in,
int offset)
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 falseo.getClass() == o.clone().getClass()
is trueo.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());
}
}
- clone in interface IMessageDigest
- clone in interface BaseHash
getResult
protected byte[] getResult()
Constructs the result from the contents of the current context.
- getResult in interface BaseHash
- the output of the completed hash operation.
padBuffer
protected byte[] padBuffer()
Returns the byte array to use as padding before completing a hash
operation.
- padBuffer in interface BaseHash
- the bytes to pad the remaining bytes in the buffer before
completing a hash operation.
transform
protected void transform(byte[] in,
int offset)
The block digest transformation per se.
- transform in interface BaseHash
in
- the blockSize long block, as an array of bytes to digest.offset
- the index where the data to digest is located within the
input buffer.
Sha160.java --
Copyright (C) 2001, 2002, 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.