org.jasypt.util.digest
Class Digester

Object
  org.jasypt.util.digest.Digester

public final class Digester
extends Object

Utility class for creating digests without using a salt or iterating the hash function. This means that digests created by this class will be compatible (and equivalent) to the ones which could be created by the user by directly using a MessageDigest object.

This class can be thought of as convenience wrapper for MessageDigest, adding thread-safety and a more javabean-like interface to it. These two features enable a more adequate use from an IoC container like Spring.

This class internally holds a StandardByteDigester configured this way:

• Algorithm: MD5 by default, but configurable.
• Provider: Default JVM security provider, but configurable.
• Salt size: 0 bytes, no salt used.
• Iterations: 1, hash function will not be iterated.

This class is thread-safe

Since:

1.2 (class existed as org.jasypt.util.MessageDigester since 1.1)

Author:

Daniel Fernández

Field Summary

static String

DEFAULT_ALGORITHM MD5 will be the default algorithm to be used if none is specified.

Constructor Summary

Digester()
Creates a new instance of Digester.

Digester(String algorithm)
Creates a new instance of Digester, specifying the algorithm to be used.

Digester(String algorithm, Provider provider)
Creates a new instance of Digester, specifying the algorithm to be used.

Digester(String algorithm, String providerName)
Creates a new instance of Digester, specifying the algorithm to be used.

Method Summary

byte[]	digest(byte[] binary) Creates a digest.
void	setAlgorithm(String algorithm) Sets the algorithm to be used for digesting, like MD5 or SHA-1.
void	setProvider(Provider provider) Sets the security provider to be asked for the digest algorithm.
void	setProviderName(String providerName) Sets the name of the security provider to be asked for the digest algorithm.

Methods inherited from class Object

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

Field Detail

DEFAULT_ALGORITHM

public static final String DEFAULT_ALGORITHM

MD5 will be the default algorithm to be used if none is specified.

See Also:

Constant Field Values

Constructor Detail

Digester

public Digester()

Creates a new instance of Digester. It will use the default algorithm unless one is specified with setAlgorithm(String).

Digester

public Digester(String algorithm)

Creates a new instance of Digester, specifying the algorithm to be used.

Digester

public Digester(String algorithm,
                String providerName)

Creates a new instance of Digester, specifying the algorithm to be used.

Since:

1.3

Digester

public Digester(String algorithm,
                Provider provider)

Creates a new instance of Digester, specifying the algorithm to be used.

Since:

1.3

Method Detail

setAlgorithm

public void setAlgorithm(String algorithm)

Sets the algorithm to be used for digesting, like MD5 or SHA-1.

This algorithm has to be supported by your security infrastructure, and it should be allowed as an algorithm for creating java.security.MessageDigest instances.

If you are specifying a security provider with setProvider(Provider) or setProviderName(String), this algorithm should be supported by your specified provider.

If you are not specifying a provider, you will be able to use those algorithms provided by the default security provider of your JVM vendor. For valid names in the Sun JVM, see Java Cryptography Architecture API Specification & Reference.

Parameters:

algorithm - the name of the algorithm to be used.

Throws:

AlreadyInitializedException - if it has already been initialized, this is, if digest(byte[]) has been called at least once.

setProviderName

public void setProviderName(String providerName)

Sets the name of the security provider to be asked for the digest algorithm. This security provider has to be registered beforehand at the JVM security framework.

The provider can also be set with the setProvider(Provider) method, in which case it will not be necessary neither registering the provider beforehand, nor calling this setProviderName(String) method to specify a provider name.

Note that a call to setProvider(Provider) overrides any value set by this method.

If no provider name / provider is explicitly set, the default JVM provider will be used.

Parameters:

providerName - the name of the security provider to be asked for the digest algorithm.

Throws:

AlreadyInitializedException - if it has already been initialized, this is, if digest(byte[]) has been called at least once.

Since:

1.3

setProvider

public void setProvider(Provider provider)

Sets the security provider to be asked for the digest algorithm. The provider does not have to be registered at the security infrastructure beforehand, and its being used here will not result in it being registered.

If this method is called, calling setProviderName(String) becomes unnecessary.

If no provider name / provider is explicitly set, the default JVM provider will be used.

Parameters:

provider - the provider to be asked for the chosen algorithm

Throws:

AlreadyInitializedException - if it has already been initialized, this is, if digest(byte[]) has been called at least once.

Since:

1.3

digest

public byte[] digest(byte[] binary)

Creates a digest.

Parameters:

binary - the byte array to be digested.

Returns:

the resulting digest.

See Also:

StandardByteDigester.digest(byte[])