edu.vt.middleware.crypt.digest
Class DigestAlgorithm

java.lang.Object
  edu.vt.middleware.crypt.AbstractAlgorithm
      edu.vt.middleware.crypt.AbstractRandomizableAlgorithm
          edu.vt.middleware.crypt.digest.DigestAlgorithm

All Implemented Interfaces:

Algorithm, Randomizable

Direct Known Subclasses:

MD2, MD4, MD5, RipeMD128, RipeMD160, RipeMD256, RipeMD320, SHA1, SHA256, SHA384, SHA512, Tiger, Whirlpool

public class DigestAlgorithm
extends AbstractRandomizableAlgorithm

DigestAlgorithm provides message digest operations.

Version:

$Revision: 84 $

Author:

Middleware Services

Field Summary

static int	CHUNK_SIZE Chunk size used in stream-based digestion.
protected org.bouncycastle.crypto.Digest	digest Digest instance used for digest computation.
protected byte[]	salt Random data used to initialize digest.

Fields inherited from class edu.vt.middleware.crypt.AbstractRandomizableAlgorithm

randomByteSize

Fields inherited from class edu.vt.middleware.crypt.AbstractAlgorithm

algorithm, logger, randomProvider

Constructor Summary

protected

DigestAlgorithm(org.bouncycastle.crypto.Digest d) Creates a new digest algorithm that uses the given Digest for digest computation.

Method Summary

byte[]	digest(byte[] input) Computes the digest for the given data in a single operation.
String	digest(byte[] input, Converter converter) Computes the digest for the given data in a single operation and passes the resulting digest bytes through the given converter to produce text output.
byte[]	digest(InputStream in) Computes the digest for all the data in the stream by reading data and hashing it in chunks.
String	digest(InputStream in, Converter converter) Computes the digest for all the data in the stream by reading data and hashing it in chunks.
org.bouncycastle.crypto.Digest	getDigest() Gets the underlying object that performs digest computation.
byte[]	getRandomSalt() Gets a random salt in the amount specified by AbstractRandomizableAlgorithm.getRandomByteSize().
static DigestAlgorithm	newInstance(String algorithm) Creates a new digest algorithm instance from its name, e.g.
protected void	setDigest(org.bouncycastle.crypto.Digest d) Sets the internal object responsible for digest computation.
void	setSalt(byte[] randomBytes) Sets the salt used to randomize the digest prior to digestion.

Methods inherited from class edu.vt.middleware.crypt.AbstractRandomizableAlgorithm

getRandomByteSize, setRandomByteSize

Methods inherited from class edu.vt.middleware.crypt.AbstractAlgorithm

getAlgorithm, getRandomData, setRandomProvider, toString

Methods inherited from class java.lang.Object

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

Field Detail

CHUNK_SIZE

public static final int CHUNK_SIZE

Chunk size used in stream-based digestion.

See Also:

Constant Field Values

digest

protected org.bouncycastle.crypto.Digest digest

Digest instance used for digest computation.

salt

protected byte[] salt

Random data used to initialize digest.

Constructor Detail

DigestAlgorithm

protected DigestAlgorithm(org.bouncycastle.crypto.Digest d)

Creates a new digest algorithm that uses the given Digest for digest computation.

Parameters:

d - Used for digest computation.

Method Detail

newInstance

public static DigestAlgorithm newInstance(String algorithm)

Creates a new digest algorithm instance from its name, e.g. SHA-1 for a SHA1 digest.

Parameters:

algorithm - Name of a message digest algorithm.

Returns:

Digest algorithm instance that provides the requested algorithm.

setDigest

protected void setDigest(org.bouncycastle.crypto.Digest d)

Sets the internal object responsible for digest computation.

Parameters:

d - Used for digest computation.

setSalt

public void setSalt(byte[] randomBytes)

Sets the salt used to randomize the digest prior to digestion.

Parameters:

randomBytes - Random data to initialize digest.

getRandomSalt

public byte[] getRandomSalt()

Gets a random salt in the amount specified by AbstractRandomizableAlgorithm.getRandomByteSize().

Returns:

Random salt.

getDigest

public org.bouncycastle.crypto.Digest getDigest()

Gets the underlying object that performs digest computation.

Returns:

Digest instance.

digest

public byte[] digest(byte[] input)

Computes the digest for the given data in a single operation.

Parameters:

input - Data to be digested.

Returns:

Message digest as byte array.

digest

public String digest(byte[] input,
                     Converter converter)

Computes the digest for the given data in a single operation and passes the resulting digest bytes through the given converter to produce text output.

Parameters:

input - Data to be digested.

converter - Converts digest bytes to some string representation, e.g Base-64 encoded text.

Returns:

String representation of digest as provided by the converter.

digest

public byte[] digest(InputStream in)
              throws IOException

Computes the digest for all the data in the stream by reading data and hashing it in chunks.

Parameters:

in - Input stream containing data to be digested.

Returns:

Message digest as byte array.

Throws:

IOException - On input stream read errors.

digest

public String digest(InputStream in,
                     Converter converter)
              throws IOException

Computes the digest for all the data in the stream by reading data and hashing it in chunks. The output is converted to a string representation by the given converter.

Parameters:

in - Input stream containing data to be digested.

converter - Converts digest bytes to some string representation, e.g Base-64 encoded text.

Returns:

String representation of digest as provided by the converter.

Throws:

IOException - On input stream read errors.