org.jgroups.protocols
Class ENCRYPT

java.lang.Object
  extended byorg.jgroups.stack.Protocol
      extended byorg.jgroups.protocols.ENCRYPT

public class ENCRYPT
extends Protocol

ENCRYPT layer. Encrypt and decrypt the group communication in JGroups The file can be used in two ways:

Each message is identified as encrypted with a specific encryption header which identifies the type of encrypt header and an MD5 digest that identifies the version of the key being used to encrypt/decrypt the messages.

Option 1


This is the simplest option and can be used by simply inserting the Encryption layer at any point in the JGroup stack - it will encrypt all Events of a type MSG that have a non-null message buffer. The format of the entry in this form is:
<ENCRYPT key_store_name="defaultStore.keystore" store_password="changeit" alias="myKey"/>
An example bare-bones.xml file showing the keystore version can be found in the conf ina file called EncryptKeyStore.xml - along with a defaultStore.keystore file.
In order to use the Encrypt layer in this manner it is necessary to have the secretKey already generated in a keystore file. The directory containing the keystore file must be on the application's classpath. You cannot create a SecretKey keystore file using the keytool application shipped with the JDK. A java file called KeyStoreGenerator is included in the demo package that can be used from the command line (or IDE) to generate a suitable keystore.

Option 2


This option is suited to an application that does not ship with a known key but instead it is generated and distributed by the controller. The secret key is first generated by the Controller (in JGroup terms). When a view change occurs a peer will request the secret key by sending a key request with its own public key. The controller encrypts the secret key with this key and sends it back to the peer who then decrypts it and installs the key as its own secret key.
All encryption and decryption of Messages is done using this key. When a peer receives a view change that shows a different keyserver it will repeat this process - the view change event also trigger the encrypt layer to queue up and down messages until the new key is installed. The previous keys are retained so that messages sent before the view change that are queued can be decrypted if the key is different.
An example EncryptNoKeyStore.xml is included in the conf file as a guide.


Note: the current version does not support the concept of perfect forward encryption (PFE) which means that if a peer leaves the group the keys are re-generated preventing the departed peer from decrypting future messages if it chooses to listen in on the group. This is not included as it really requires a suitable authentication scheme as well to make this feature useful as there is nothing to stop the peer rejoining and receiving the new key. A future release will address this issue.

Author:
Steve Woodcock

Nested Class Summary
static class ENCRYPT.EncryptHeader
           
 
Field Summary
 
Fields inherited from class org.jgroups.stack.Protocol
down_handler, down_prot, down_queue, down_thread, down_thread_prio, log, observer, props, stack, stats, trace, up_handler, up_prot, up_queue, up_thread, up_thread_prio, warn
 
Constructor Summary
ENCRYPT()
           
 
Method Summary
 void down(Event evt)
          An event is to be sent down the stack.
protected  java.lang.String getAsymAlgorithm()
           
protected  javax.crypto.Cipher getAsymCipher()
           
protected  int getAsymInit()
           
protected  java.lang.String getAsymProvider()
           
protected  javax.crypto.SecretKey getDesKey()
           
protected  Address getKeyServerAddr()
           
protected  java.lang.String getKeyStoreName()
           
protected  java.security.KeyPair getKpair()
           
protected  Address getLocal_addr()
           
 java.lang.String getName()
           
protected  java.security.PublicKey getServerPubKey()
           
protected  java.lang.String getSymAlgorithm()
           
protected  javax.crypto.Cipher getSymDecodingCipher()
           
protected  javax.crypto.Cipher getSymEncodingCipher()
           
protected  int getSymInit()
           
protected  java.lang.String getSymProvider()
           
 void init()
          Called after instance has been created (null constructor) and before protocol is started.
 void initKeyPair()
          Generates the public/private key pair from the init params
 void initSymKey()
          Used to initialise the symmetric key if none is supplied in a keystore.
 void reset()
          Just remove if you don't need to reset any state
protected  void setKeyServerAddr(Address keyServerAddr)
           
protected  void setLocal_addr(Address local_addr)
           
 boolean setProperties(java.util.Properties props)
          Configures the protocol initially.
 void up(Event evt)
          An event was received from the layer below.
 
Methods inherited from class org.jgroups.stack.Protocol
destroy, downThreadEnabled, dumpStats, enableStats, getDownProtocol, getDownQueue, getProperties, getUpProtocol, getUpQueue, handleSpecialDownEvent, isTrace, isWarn, passDown, passUp, printStats, providedDownServices, providedUpServices, receiveDownEvent, receiveUpEvent, requiredDownServices, requiredUpServices, resetStats, setDownProtocol, setObserver, setPropertiesInternal, setProtocolStack, setTrace, setUpProtocol, setWarn, start, startDownHandler, startUpHandler, statsEnabled, stop, stopInternal, upThreadEnabled
 
Methods inherited from class java.lang.Object
clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
 

Constructor Detail

ENCRYPT

public ENCRYPT()
Method Detail

getName

public java.lang.String getName()
Specified by:
getName in class Protocol

setProperties

public boolean setProperties(java.util.Properties props)
Description copied from class: Protocol
Configures the protocol initially. A configuration string consists of name=value items, separated by a ';' (semicolon), e.g.:
 "loopback=false;unicast_inport=4444"
 

Overrides:
setProperties in class Protocol

init

public void init()
          throws java.lang.Exception
Description copied from class: Protocol
Called after instance has been created (null constructor) and before protocol is started. Properties are already set. Other protocols are not yet connected and events cannot yet be sent.

Overrides:
init in class Protocol
Throws:
java.lang.Exception - Thrown if protocol cannot be initialized successfully. This will cause the ProtocolStack to fail, so the channel constructor will throw an exception

initSymKey

public void initSymKey()
                throws java.lang.Exception
Used to initialise the symmetric key if none is supplied in a keystore.

Throws:
java.lang.Exception

initKeyPair

public void initKeyPair()
                 throws java.lang.Exception
Generates the public/private key pair from the init params

Throws:
java.lang.Exception

reset

public void reset()
Just remove if you don't need to reset any state


up

public void up(Event evt)
Description copied from class: Protocol
An event was received from the layer below. Usually the current layer will want to examine the event type and - depending on its type - perform some computation (e.g. removing headers from a MSG event type, or updating the internal membership list when receiving a VIEW_CHANGE event). Finally the event is either a) discarded, or b) an event is sent down the stack using passDown() or c) the event (or another event) is sent up the stack using passUp().

Overrides:
up in class Protocol

down

public void down(Event evt)
Description copied from class: Protocol
An event is to be sent down the stack. The layer may want to examine its type and perform some action on it, depending on the event's type. If the event is a message MSG, then the layer may need to add a header to it (or do nothing at all) before sending it down the stack using passDown(). In case of a GET_ADDRESS event (which tries to retrieve the stack's address from one of the bottom layers), the layer may need to send a new response event back up the stack using passUp().

Overrides:
down in class Protocol

getAsymInit

protected int getAsymInit()
Returns:
Returns the asymInit.

getAsymProvider

protected java.lang.String getAsymProvider()
Returns:
Returns the asymProvider.

getDesKey

protected javax.crypto.SecretKey getDesKey()
Returns:
Returns the desKey.

getKpair

protected java.security.KeyPair getKpair()
Returns:
Returns the kpair.

getAsymCipher

protected javax.crypto.Cipher getAsymCipher()
Returns:
Returns the asymCipher.

getServerPubKey

protected java.security.PublicKey getServerPubKey()
Returns:
Returns the serverPubKey.

getSymAlgorithm

protected java.lang.String getSymAlgorithm()
Returns:
Returns the symAlgorithm.

getSymInit

protected int getSymInit()
Returns:
Returns the symInit.

getSymProvider

protected java.lang.String getSymProvider()
Returns:
Returns the symProvider.

getAsymAlgorithm

protected java.lang.String getAsymAlgorithm()
Returns:
Returns the asymAlgorithm.

getKeyStoreName

protected java.lang.String getKeyStoreName()
Returns:
Returns the keyStoreName.

getSymDecodingCipher

protected javax.crypto.Cipher getSymDecodingCipher()
Returns:
Returns the symDecodingCipher.

getSymEncodingCipher

protected javax.crypto.Cipher getSymEncodingCipher()
Returns:
Returns the symEncodingCipher.

getLocal_addr

protected Address getLocal_addr()
Returns:
Returns the local_addr.

setLocal_addr

protected void setLocal_addr(Address local_addr)
Parameters:
local_addr - The local_addr to set.

getKeyServerAddr

protected Address getKeyServerAddr()
Returns:
Returns the keyServerAddr.

setKeyServerAddr

protected void setKeyServerAddr(Address keyServerAddr)
Parameters:
keyServerAddr - The keyServerAddr to set.


Copyright ? 1998-2005 Bela Ban. All Rights Reserved.