edu.vt.middleware.password
Class AbstractDigester

java.lang.Object
  edu.vt.middleware.password.AbstractDigester

Direct Known Subclasses:

HistoryRule, SourceRule

public abstract class AbstractDigester
extends Object

Provides common implementation for password rules that use a digest.

Version:

$Revision: 2704 $ $Date: 2013-04-24 17:30:32 -0400 (Wed, 24 Apr 2013) $

Author:

Middleware Services

Field Summary

protected edu.vt.middleware.crypt.util.Converter	converter Converter to use in conjunction with the digest.
protected edu.vt.middleware.crypt.digest.DigestAlgorithm	digest Digest object to use if comparing hashed passwords.

Constructor Summary

AbstractDigester()

Method Summary

protected byte[]	addSalt(byte[] data, byte[] salt) Concatenates the supplied salt to the supplied data.
protected byte[]	extractSalt(byte[] hash, int length) Extracts a salt from the end of the supplied hash.
protected boolean	matches(String undigested, String reference) Determines whether an undigested password matches a (possibly digested) reference value.
void	setDigest(String algorithm, edu.vt.middleware.crypt.util.Converter conv) This will set the supplied digest algorithm to be used when password comparison are made.

Methods inherited from class java.lang.Object

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

Field Detail

digest

protected edu.vt.middleware.crypt.digest.DigestAlgorithm digest

Digest object to use if comparing hashed passwords.

converter

protected edu.vt.middleware.crypt.util.Converter converter

Converter to use in conjunction with the digest.

Constructor Detail

AbstractDigester

public AbstractDigester()

Method Detail

setDigest

public void setDigest(String algorithm,
                      edu.vt.middleware.crypt.util.Converter conv)

This will set the supplied digest algorithm to be used when password comparison are made. Useful if you need to compare password which are in a hashed form. See DigestAlgorithm.

Parameters:

algorithm - to use for hashing

conv - to convert bytes to string

matches

protected boolean matches(String undigested,
                          String reference)

Determines whether an undigested password matches a (possibly digested) reference value.

Parameters:

undigested - candidate clear text password.

reference - reference password (possibly digested).

Returns:

true if passwords match, false otherwise.

extractSalt

protected byte[] extractSalt(byte[] hash,
                             int length)

Extracts a salt from the end of the supplied hash.

Parameters:

hash - to read salt from

length - of the salt to extract

Returns:

salt bytes

addSalt

protected byte[] addSalt(byte[] data,
                         byte[] salt)

Concatenates the supplied salt to the supplied data.

Parameters:

data - to concatenate salt to

salt - to concatenate

Returns:

new byte array of concatenated data