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ptolemy.actor.lib.security
Class CryptographyActor

java.lang.Object
  extended by ptolemy.kernel.util.NamedObj
      extended by ptolemy.kernel.InstantiableNamedObj
          extended by ptolemy.kernel.Entity
              extended by ptolemy.kernel.ComponentEntity
                  extended by ptolemy.actor.AtomicActor
                      extended by ptolemy.actor.TypedAtomicActor
                          extended by ptolemy.actor.lib.security.CryptographyActor
All Implemented Interfaces:
java.io.Serializable, java.lang.Cloneable, Actor, Executable, FiringsRecordable, Initializable, TypedActor, Changeable, Debuggable, DebugListener, Derivable, Instantiable, ModelErrorHandler, MoMLExportable, Moveable, Nameable
Direct Known Subclasses:
CipherActor
public abstract class CryptographyActor
extends TypedAtomicActor

A base class for cryptographic actors.

Cryptographic actors are actors that perform encryption or decryption or generate signatures of data.

Actors extending this class take in an unsigned byte array at the input, process the data based on the algorithm parameter and send an unsigned byte array to the output. The algorithms that maybe implemented are limited those that are implemented by "providers" following the Java Cryptography Extension (JCE) specifications and installed on the machine being run. If a provider specific instance of an algorithm is needed, the provider may be specified in the provider parameter. The keySize also allows implementations of algorithms using various key sizes.

Concrete actors derived from this base class must include a _process(byte[]) method that processes the data appropriately. The _process() method is called by CryptographyActor.fire(). This class takes care of basic initialization of the algorithm and provider parameters for use by the subclasses.

This actor relies on the Java Cryptography Architecture (JCA) and Java Cryptography Extension (JCE).
Information about JCA can be found at http://java.sun.com/j2se/1.4.2/docs/guide/security/CryptoSpec.html.
Information about JCE can be found at http://java.sun.com/products/jce/.
The Java 1.2 security tutorial can be found at http://java.sun.com/docs/books/tutorial/security1.2/index.html
Another Java security tutorial can be found at http://developer.java.sun.com/developer/onlineTraining/Security/Fundamentals/index.html

Since:
Ptolemy II 4.0
Version:
$Id: CryptographyActor.java 57040 2010-01-27 20:52:32Z cxh $
Author:
Christopher Hylands Brooks, Contributor: Rakesh Reddy
See Also:
Serialized Form
Accepted Rating:
Yellow (cxh)
Proposed Rating:
Green (cxh)

Nested Class Summary
 
Nested classes/interfaces inherited from class ptolemy.kernel.Entity
Entity.ContainedObjectsIterator
 
Field Summary
protected  java.lang.String _algorithm
          The name of the algorithm to be used.
protected  int _keySize
          The key size to be used when processing information.
protected  java.lang.String _provider
          The provider to be used for a provider specific implementation.
 StringParameter algorithm
          Specify the algorithm to be used to process data.
 TypedIOPort input
          The input port.
 Parameter keySize
          Specify the size of the key to be created.
 TypedIOPort output
          The output port.
 StringParameter provider
          Specify a provider for the given algorithm.
 
Fields inherited from class ptolemy.actor.AtomicActor
_actorFiringListeners, _initializables, _notifyingActorFiring, _stopRequested
 
Fields inherited from class ptolemy.kernel.util.NamedObj
_changeListeners, _changeLock, _changeRequests, _debugging, _debugListeners, _elementName, _isPersistent, _verbose, _workspace, ATTRIBUTES, CLASSNAME, COMPLETE, CONTENTS, DEEP, FULLNAME, LINKS
 
Fields inherited from interface ptolemy.actor.Executable
COMPLETED, NOT_READY, STOP_ITERATING
 
Constructor Summary
CryptographyActor(CompositeEntity container, java.lang.String name)
          Construct an actor with the given container and name.
 
Method Summary
protected abstract  byte[] _process(byte[] dataBytes)
          Process the input data based on parameter specifications.
 void attributeChanged(Attribute attribute)
          Override the base class to reinitialize the state if the algorithm, keySize, or provider parameter is changed.
 void fire()
          Read data from the from the input and process the data based on the algorithm, and provider by calling _process(byte []).
 
Methods inherited from class ptolemy.actor.TypedAtomicActor
_addPort, _fireAt, _fireAt, attributeTypeChanged, clone, newPort, typeConstraintList, typeConstraints
 
Methods inherited from class ptolemy.actor.AtomicActor
_actorFiring, _actorFiring, addActorFiringListener, addInitializable, clone, connectionsChanged, createReceivers, declareDelayDependency, getCausalityInterface, getDirector, getExecutiveDirector, getManager, initialize, inputPortList, isFireFunctional, isStrict, iterate, newReceiver, outputPortList, postfire, prefire, preinitialize, pruneDependencies, recordFiring, removeActorFiringListener, removeDependency, removeInitializable, setContainer, stop, stopFire, terminate, wrapup
 
Methods inherited from class ptolemy.kernel.ComponentEntity
_adjustDeferrals, _checkContainer, _getContainedObject, _propagateExistence, getContainer, instantiate, isAtomic, isOpaque, moveDown, moveToFirst, moveToIndex, moveToLast, moveUp, propagateExistence, setName
 
Methods inherited from class ptolemy.kernel.Entity
_description, _exportMoMLContents, _removePort, _validateSettables, connectedPortList, connectedPorts, containedObjectsIterator, getAttribute, getPort, getPorts, linkedRelationList, linkedRelations, portList, removeAllPorts, setClassDefinition, uniqueName
 
Methods inherited from class ptolemy.kernel.InstantiableNamedObj
_setParent, exportMoML, getChildren, getElementName, getParent, getPrototypeList, isClassDefinition, isWithinClassDefinition
 
Methods inherited from class ptolemy.kernel.util.NamedObj
_addAttribute, _adjustOverride, _attachText, _cloneFixAttributeFields, _debug, _debug, _debug, _debug, _debug, _getIndentPrefix, _isMoMLSuppressed, _markContentsDerived, _propagateValue, _recordDecoratedAttributes, _removeAttribute, _splitName, _stripNumericSuffix, addChangeListener, addDebugListener, attributeList, attributeList, deepContains, depthInHierarchy, description, description, event, executeChangeRequests, exportMoML, exportMoML, exportMoML, exportMoML, exportMoMLPlain, getAttribute, getAttributes, getChangeListeners, getClassName, getDecoratorAttribute, getDecoratorAttributes, getDerivedLevel, getDerivedList, getDisplayName, getFullName, getModelErrorHandler, getName, getName, getSource, handleModelError, isDeferringChangeRequests, isOverridden, isPersistent, lazyContainedObjectsIterator, message, propagateValue, propagateValues, removeChangeListener, removeDebugListener, requestChange, setClassName, setDeferringChangeRequests, setDerivedLevel, setDisplayName, setModelErrorHandler, setPersistent, setSource, sortContainedObjects, toplevel, toString, validateSettables, workspace
 
Methods inherited from class java.lang.Object
equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface ptolemy.actor.Actor
createReceivers, getCausalityInterface, getDirector, getExecutiveDirector, getManager, inputPortList, newReceiver, outputPortList
 
Methods inherited from interface ptolemy.actor.Executable
isFireFunctional, isStrict, iterate, postfire, prefire, stop, stopFire, terminate
 
Methods inherited from interface ptolemy.actor.Initializable
addInitializable, initialize, preinitialize, removeInitializable, wrapup
 
Methods inherited from interface ptolemy.kernel.util.Nameable
description, getContainer, getDisplayName, getFullName, getName, getName, setName
 
Methods inherited from interface ptolemy.kernel.util.Derivable
getDerivedLevel, getDerivedList, propagateValue
 

Field Detail

algorithm

public StringParameter algorithm
Specify the algorithm to be used to process data. The algorithm is specified as a string. The algorithms are limited to those implemented by providers using the Java JCE which are found on the Java virtual machine. The initial default is the first value returned by java.security.Security.getAlgorithms();

input

public TypedIOPort input
The input port. The type of this port is unsigned byte array. Data is read in on this port, processed by the _process() method during fire() and passed to the output port.

keySize

public Parameter keySize
Specify the size of the key to be created. The key size is an integer value representing the number of bits in the key. The initial default depends on the algorithm that is selected, not all algorithms use keySize. In addition, only certain keySizes may work with certain algorithms, see the documentation for the algorithm you are using.

DSA is the most common algorithm that uses keySize, the Sun documentation says: "The length, in bits, of the modulus p. This must range from 512 to 1024, and must be a multiple of 64. The default keysize is 1024." Refer to http://java.sun.com/j2se/1.4.2/docs/guide/security/CryptoSpec.html#AppB for a list of possible key sizes for certain algorithms. The initial default is 1024.

output

public TypedIOPort output
The output port. The type of this port is unsigned byte array. This port sends out the processed data received from the input port.

provider

public StringParameter provider
Specify a provider for the given algorithm. The default value is "SystemDefault" which allows the system to choose the provider based on the JCE architecture.

_algorithm

protected java.lang.String _algorithm
The name of the algorithm to be used.

_keySize

protected int _keySize
The key size to be used when processing information.

_provider

protected java.lang.String _provider
The provider to be used for a provider specific implementation.

Constructor Detail

CryptographyActor

public CryptographyActor(CompositeEntity container,
                         java.lang.String name)
                  throws NameDuplicationException,
                         IllegalActionException
Construct an actor with the given container and name. The Java virtual machine is queried for algorithm and provider choices and these choices are added to the appropriate parameters.

Parameters:
container - The container.
name - The name of this actor.
Throws:
IllegalActionException - If the actor cannot be contained by the proposed container.
NameDuplicationException - If the container already has an actor with this name.
Method Detail

attributeChanged

public void attributeChanged(Attribute attribute)
                      throws IllegalActionException
Override the base class to reinitialize the state if the algorithm, keySize, or provider parameter is changed.

Overrides:
attributeChanged in class NamedObj
Parameters:
attribute - The attribute that changed.
Throws:
IllegalActionException - Not thrown in this base class.

fire

public void fire()
          throws IllegalActionException
Read data from the from the input and process the data based on the algorithm, and provider by calling _process(byte []). The transformed data is then sent to the output port.

Specified by:
fire in interface Executable
Overrides:
fire in class AtomicActor
Throws:
IllegalActionException - If thrown by the base class or if there is a problem processing the data.

_process

protected abstract byte[] _process(byte[] dataBytes)
                            throws IllegalActionException
Process the input data based on parameter specifications. Subclasses should process the data using one of the signature or cipher classes provided in the JCA or JCE.

Parameters:
dataBytes - The data to be processed.
Returns:
The processed data.
Throws:
IllegalActionException - Not thrown in this base class
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