BaseHash (LSST CCS - OPC Driver 1.0.4 API)

java.lang.Object
- gnu.crypto.hash.BaseHash

All Implemented Interfaces:

IMessageDigest, Cloneable

Direct Known Subclasses:

MD4, MD5
```
public abstract class BaseHash
extends Object
implements IMessageDigest
```
A base abstract class to facilitate hash implementations.

Version:

$Revision: 1.8 $

Field Summary

Fields
Modifier and Type	Field and Description
`protected int`	`blockSize` The hash (inner) block size in bytes.
`protected byte[]`	`buffer` Temporary input buffer.
`protected long`	`count` Number of bytes processed so far.
`protected int`	`hashSize` The hash (output) size in bytes.
`protected String`	`name` The canonical name prefix of the hash.

Constructor Summary

Constructors
Modifier Constructor and Description

protected BaseHash(String name, int hashSize, int blockSize)
Trivial constructor for use by concrete subclasses.

Constructors
Modifier	Constructor and Description
`protected`	`BaseHash(String name, int hashSize, int blockSize)` Trivial constructor for use by concrete subclasses.

Method Summary

All Methods Instance Methods Abstract Methods Concrete Methods
Modifier and Type	Method and Description
`int`	`blockSize()` Returns the algorithm's (inner) block size in bytes.
`abstract Object`	`clone()` Returns a clone copy of this instance.
`byte[]`	`digest()` Completes the message digest by performing final operations such as padding and resetting the instance.
`protected abstract byte[]`	`getResult()` Constructs the result from the contents of the current context.
`int`	`hashSize()` Returns the output length in bytes of this message digest algorithm.
`String`	`name()` Returns the canonical name of this algorithm.
`protected abstract byte[]`	`padBuffer()` Returns the byte array to use as padding before completing a hash operation.
`void`	`reset()` Resets the current context of this instance clearing any eventually cached intermediary values.
`protected abstract void`	`resetContext()` Resets the instance for future re-use.
`abstract boolean`	`selfTest()` A basic test.
`protected abstract void`	`transform(byte[] in, int offset)` The block digest transformation per se.
`void`	`update(byte b)` Continues a message digest operation using the input byte.
`void`	`update(byte[] b, int offset, int len)` Continues a message digest operation, by filling the buffer, processing data in the algorithm's HASH_SIZE-bit block(s), updating the context and count, and buffering the remaining bytes in buffer for the next operation.

Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

- Field Detail
  - name
```
protected String name
```
    The canonical name prefix of the hash.
  - hashSize
```
protected int hashSize
```
    The hash (output) size in bytes.
  - blockSize
```
protected int blockSize
```
    The hash (inner) block size in bytes.
  - count
```
protected long count
```
    Number of bytes processed so far.
  - buffer
```
protected byte[] buffer
```
    Temporary input buffer.
- Constructor Detail
  - BaseHash
```
protected BaseHash(String name,
                   int hashSize,
                   int blockSize)
```
    Trivial constructor for use by concrete subclasses.
    
    Parameters:
    
    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.
- Method Detail
  - name
```
public String name()
```
    Description copied from interface: IMessageDigest
    
    Returns the canonical name of this algorithm.
    
    Specified by:
    
    name in interface IMessageDigest
    
    Returns:
    
    the canonical name of this instance.
  - hashSize
```
public int hashSize()
```
    Description copied from interface: IMessageDigest
    
    Returns the output length in bytes of this message digest algorithm.
    
    Specified by:
    
    hashSize in interface IMessageDigest
    
    Returns:
    
    the output length in bytes of this message digest algorithm.
  - blockSize
```
public int blockSize()
```
    Description copied from interface: IMessageDigest
    
    Returns the algorithm's (inner) block size in bytes.
    
    Specified by:
    
    blockSize in interface IMessageDigest
    
    Returns:
    
    the algorithm's inner block size in bytes.
  - update
```
public void update(byte b)
```
    Description copied from interface: IMessageDigest
    
    Continues a message digest operation using the input byte.
    
    Specified by:
    
    update in interface IMessageDigest
    
    Parameters:
    
    b - the input byte to digest.
  - update
```
public void update(byte[] b,
                   int offset,
                   int len)
```
    Description copied from interface: IMessageDigest
    
    Continues a message digest operation, by filling the buffer, processing data in the algorithm's HASH_SIZE-bit block(s), updating the context and count, and buffering the remaining bytes in buffer for the next operation.
    
    Specified by:
    
    update in interface IMessageDigest
    
    Parameters:
    
    b - the input block.
    
    offset - start of meaningful bytes in input block.
    
    len - number of bytes, in input block, to consider.
  - digest
```
public byte[] digest()
```
    Description copied from interface: IMessageDigest
    
    Completes the message digest by performing final operations such as padding and resetting the instance.
    
    Specified by:
    
    digest in interface IMessageDigest
    
    Returns:
    
    the array of bytes representing the hash value.
  - reset
```
public void reset()
```
    Description copied from interface: IMessageDigest
    
    Resets the current context of this instance clearing any eventually cached intermediary values.
    
    Specified by:
    
    reset in interface IMessageDigest
  - clone
```
public abstract Object clone()
```
    Description copied from interface: IMessageDigest
    
    Returns a clone copy of this instance.
    
    Specified by:
    
    clone in interface IMessageDigest
    
    Overrides:
    
    clone in class Object
    
    Returns:
    
    a clone copy of this instance.
  - selfTest
```
public abstract boolean selfTest()
```
    Description copied from interface: IMessageDigest
    
    A basic test. Ensures that the digest of a pre-determined message is equal to a known pre-computed value.
    
    Specified by:
    
    selfTest in interface IMessageDigest
    
    Returns:
    
    true if the implementation passes a basic self-test. Returns false otherwise.
  - padBuffer
```
protected abstract byte[] padBuffer()
```
    Returns the byte array to use as padding before completing a hash operation.
    
    Returns:
    
    the bytes to pad the remaining bytes in the buffer before completing a hash operation.
  - getResult
```
protected abstract byte[] getResult()
```
    Constructs the result from the contents of the current context.
    
    Returns:
    
    the output of the completed 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.
    
    Parameters:
    
    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.

Class BaseHash

Field Summary

Constructor Summary

Method Summary

Methods inherited from class java.lang.Object

Field Detail

name

hashSize

blockSize

count

buffer

Constructor Detail

BaseHash

Method Detail

name

hashSize

blockSize

update

update

digest

reset

clone

selfTest

padBuffer

getResult

resetContext

transform