Clever Cup

How to design an API

2011-03-24T08:15:00.000-07:00

While watching some google tech talks I found this video. Really good one.

Encrypting using PGP (GnuPG) and Java

2011-03-16T06:28:00.000-07:00

So I was required to encrypt some files in a bpm process using GNUPPGP. There are not too many libraries out there that makes this and are for free. So after some googling I found this site http://www.cryptix.org/ . Very cool !!!!

After I download this two links

Cryptix OpenPGP	snapshot	2005/04/18	cryptix-openpgp-20050418-snap.zip
Cryptix JCE	snapshot	2005/03/28	cryptix-jce-20050328-snap.zip

I create I simple Helper that will simplify the final user to use them.

My helper looks like this

First register the Crypto :

private static final String OPEN_PGP = "OpenPGP";
static {
//**********************************************************************
// Dynamically register both the Cryptix JCE and Cryptix OpenPGP
// providers.
//**********************************************************************
java.security.Security.addProvider(new CryptixCrypto());
java.security.Security.addProvider(new CryptixOpenPGP());
}

Second create a simple helper method that accepts a byte[] or Binary in BPM and returns the encrypted byte[].

public static byte[] encryptFile(File publicKey, byte[] contentToEncrypt) {
//**********************************************************************
// First read the key.
//**********************************************************************
KeyBundle publicBob = null;
FileInputStream in = null;

try {
MessageFactory mf = MessageFactory.getInstance(OPEN_PGP);
in = new FileInputStream(publicKey);
Collection msgs = mf.generateMessages(in);
KeyBundleMessage kbm = (KeyBundleMessage) msgs.iterator().next();
publicBob = kbm.getKeyBundle();
} catch (IOException ioe) {
throw new RuntimeException("IOException... You did remember to run the " + "GenerateAndWriteKey example first, right?", ioe);
} catch (NoSuchAlgorithmException nsae) {
nsae.printStackTrace();
throw new RuntimeException("Cannot find the OpenPGP MessageFactory. " + "This usually means that the Cryptix OpenPGP provider is not " + "installed correctly.", nsae);
} catch (MessageException me) {
me.printStackTrace();
throw new RuntimeException("Reading keybundle failed.", me);
} finally {
if (in != null)
try {
in.close();
} catch (IOException e) {
//ignore this exception!!!
}
}

//**********************************************************************
// The actual stream encryption.
//**********************************************************************
BufferedInputStream bin = null;
LiteralMessageOutputStream literalMessageOutputStream = null;
try {
ByteArrayOutputStream encryptedFileOutputStream = new ByteArrayOutputStream();
literalMessageOutputStream = LiteralMessageOutputStream.getInstance(OPEN_PGP);
EncryptedMessageOutputStream encryptedMessage = EncryptedMessageOutputStream.getInstance(OPEN_PGP);
SecureRandom sr = new SecureRandom();
literalMessageOutputStream.init(encryptedMessage, sr); // Literal writes to Encrypted
encryptedMessage.init(encryptedFileOutputStream, sr); // Encrypted writes to file
encryptedMessage.addRecipient(publicBob);
//
literalMessageOutputStream.write(contentToEncrypt);
return encryptedFileOutputStream.toByteArray();

} catch (NoSuchAlgorithmException nsae) {
throw new RuntimeException("Cannot find OpenPGP implementation." +
" This usually means that the Cryptix OpenPGP provider is not " +
"installed correctly.", nsae);
} catch (MessageStreamException me) {
throw new RuntimeException("Streaming the message failed.", me);
} catch (IOException ioe) {
throw new RuntimeException("IO error.", ioe);
} finally {
if (bin != null) {
try {
bin.close();
} catch (IOException e) {
//ignore error
}
}
if (literalMessageOutputStream != null) {
try {
literalMessageOutputStream.close();
} catch (IOException e) {
//ignore error
}
}
}
}

Issues I found


java.security.InvalidKeyException: Illegal key size

Solution replace the security files

Suppose you are using jdk15. Go to http://java.sun.com/javase/downloads/index_jdk5.jsp
Go to the Other Downloads section and click on download link next to "Java Cryptography Extension (JCE) Unlimited Strength Jurisdiction Policy Files 5.0"
Download jce_policy-1_5_0.zip and extract it in to a directory.
You will find local_policy.jar and US_export_policy.jar files there in the extracted directory. Copy these two files to $JAVA_HOME/jre/lib/security directory. (These files will already be there. you may replace them)

Oracle ALBPM Performance Monitoring

2011-03-14T12:45:00.000-07:00

Currently I'm working at credit suisse as a BPM Consultant and I will like to create a tool to monitor the performance of the engine. This must show :

DB usage
JMS usage
Prepare statement pool

In order to implement this I will try to connect with JMX to the Weblogic server. Let see if I can...
Links :

Weblogic JMX Documentation

First item: Connect to the JMX weblogic Server

My First approach was to use an external (Failed)

The external resource of bpm is too old and does not allow me to connect to Weblogic 10

Second approach Is to create my Java Library and catalog it as a Java Component (Succedded)

I can not connect to the server using JMX from outside , for security reasons, but I do can connect using the local connection. That is why I use


private MBeanServer getMBeanServer() throws NamingException {
 MBeanServer server;
 InitialContext ctx = new InitialContext();
 server = (MBeanServer) ctx.lookup("java:comp/env/jmx/runtime");
 return server;
}

So this is how I will get my connection to the Weblogic MBeanServer access. Things I need to take care of :

This method need to be runs on server since I like to monitor the engine I need to get the MBeanServer from the engine not PAPI

So in order to finish this I create my library with only one class and catalog it


import javax.management.MBeanServer;
import javax.management.ObjectName;
import javax.naming.InitialContext;
import javax.naming.NamingException;

public class JMXMonitor {


 public static void main(String[] args) throws Exception {


 }

 public Object invokeMBeanMethod(String mBeanName, String methodName, Object[] args, String[] signature) throws Exception {
     MBeanServer mBeanServer = getMBeanServer();
     ObjectName name = new ObjectName(mBeanName);
     return mBeanServer.invoke(name, methodName, args, signature);
 }

 public Object getMBeanAttributeValue(String mBeanName, String attributeName) throws Exception {
     MBeanServer server = getMBeanServer();
     ObjectName name = new ObjectName(mBeanName);
     return server.getAttribute(name, attributeName);
 }

 private MBeanServer getMBeanServer() throws NamingException {
     MBeanServer server;
     InitialContext ctx = new InitialContext();
     server = (MBeanServer) ctx.lookup("java:comp/env/jmx/runtime");
     return server;
 }
}

So once I can get the this done I have 50% of the problem resolved.

Start up

2011-03-14T12:35:00.000-07:00

I'm starting this blog with the purpose of writing Ideas... what ever goes trough my mind... ;)