gnu.java.security.hash
Class BaseHash
- Cloneable, IMessageDigest
A base abstract class to facilitate hash implementations.
protected int | blockSize - The hash (inner) block size in bytes.
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protected byte[] | buffer - Temporary input buffer.
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protected long | count - Number of bytes processed so far.
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protected int | hashSize - The hash (output) size in bytes.
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protected String | name - The canonical name prefix of the hash.
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BaseHash(String name, int hashSize, int blockSize) - Trivial constructor for use by concrete subclasses.
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int | blockSize()
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abstract Object | clone() - This method may be called to create a new copy of the
Object.
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byte[] | digest()
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protected abstract byte[] | getResult() - Constructs the result from the contents of the current context.
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int | hashSize()
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String | name()
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protected abstract byte[] | padBuffer() - Returns the byte array to use as padding before completing a hash
operation.
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void | reset()
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protected abstract void | resetContext() - Resets the instance for future re-use.
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abstract boolean | selfTest()
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protected abstract void | transform(byte[] in, int offset) - The block digest transformation per se.
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void | update(byte b)
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void | update(byte[] b)
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void | update(byte[] b, int offset, int len)
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clone , equals , extends Object> getClass , finalize , hashCode , notify , notifyAll , toString , wait , wait , wait |
blockSize
protected int blockSize
The hash (inner) block size in bytes.
buffer
protected byte[] buffer
Temporary input buffer.
count
protected long count
Number of bytes processed so far.
hashSize
protected int hashSize
The hash (output) size in bytes.
name
protected String name
The canonical name prefix of the hash.
BaseHash
protected BaseHash(String name,
int hashSize,
int blockSize)
Trivial constructor for use by concrete subclasses.
name
- the canonical name prefix of this instance.hashSize
- the block size of the output in bytes.blockSize
- the block size of the internal transform.
clone
public abstract 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 Object
getResult
protected abstract byte[] getResult()
Constructs the result from the contents of the current context.
- the output of the completed hash operation.
padBuffer
protected abstract byte[] padBuffer()
Returns the byte array to use as padding before completing a hash
operation.
- the bytes to pad the remaining bytes in the buffer before
completing a hash operation.
resetContext
protected abstract void resetContext()
Resets the instance for future re-use.
transform
protected abstract void transform(byte[] in,
int offset)
The block digest transformation per se.
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.
BaseHash.java --
Copyright (C) 2001, 2002, 2006 Free Software Foundation, Inc.
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