To read an InputStream directly to a byte array you can do something like this:

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FileConnector fconn = (FileConnector)Connector.open("testfile.txt");
InputStream inStream = fconn.openInputStream();
byte[] byteData = IOUtilities.streamToBytes(inStream);

I started releasing commercial applications on BlackBerry App World and yesterday was the first time I used the Dynamic Licensing model.  I devised a solution based on Google App Engine and this post shows how this can be achieved and also includes sample source code for other developers in a similar situation.  Dynamic Licensing provides a mechanism for granting activation codes to user who purchase applications.  The system works like this:

App World Flow

As with almost all commercial, downloadable applications, online purchase and activation codes have become the norm.  The end-user pays for the product, downloads it and waits for an activation code to be sent to his email address.  Once he receives the code, he enters it into the app and he can begin using it.  This is straightforward if the developer sells the app on his own store that is hosted on his own server.  If he is to sell it on other stores, however, things become tricky.  Usually, well established stores like MobiHand and others have a mechanism that allows a developer to interface with their storefront for various purposes.  One of these instances is when activation codes are involved.  In cases like these, here is a quick run-down of how the purchase flow works:

1. End-user visits Online Store
2. End-user buys app from the Online Store
3. Online Store contacts the Developer Server (using an HTTP POST request) with end-user specific details
4. Developer Server generates the activation key
5. Developer Server responds to the Online Store POST request with an activation key
6. Online Store then presents this activation key to the End-user

It is the Developer’s responsibility to get his activation server up and running to ensure steps 3-5 are completed.  Sometimes this can be a painful task; especially after you’ve spent a few grueling weeks in developing your latest and greatest application.  My solution is to setup a free account on Google App Engine to host my activation server routines there.  Why bother you ask?  Here are some advantages that I can see:

1. App Engine is free and can easily be converted to a paid model (reasonably priced) based only on usage of resources
2. App Engine offers Java so its more likely to be familiar to a BlackBerry developer
3. No administrative overhead with setting up a server or maintaining it
4. It’s cool if you like to get into “Cloud Computing”
5. It’s very easy to move off Google App Engine and onto your own server when you’re ready because of the standardized modules

I’m not going to talk you through how to get an account, sign-up, etc.  Google has tons of docs and tutorials on how to do so.  I’ll assume you’ve already got your App Engine and know how to deploy apps on it.  What we’re going to create is a servlet and optionally, some classes to help us persist the incoming information to the app engine database.  If you’re using Eclipse with the Google App Engine plugin, then creating a project is simple.  On Eclipse simply click File->New->Project and then choose Web Application Project under the Google folder.  By default, a new project will be created with a servlet having the “doGet” method.  This method handles only HTTP GET requests.  You also need to create your own “doPost” method.  This is usually because stores including App World will POST the data to your URL.  What I do is just swap the doGet with doPost.

I then write my routines to handle the incoming request.  I usually capture all relevant information, extract some key parameters, use it to generate my activation key and provide a response.  For the sake of simplifying things.  Here is the code for my servlet that captures information from BlackBerry App World, generates the Activation Code and responds with that code:

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package net.zenconsult.keyserver;
 
import java.io.IOException;
 
import javax.jdo.PersistenceManager;
import javax.servlet.http.HttpServlet;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
 
import net.zenconsult.codec.binary.Hex;
 
 
@SuppressWarnings("serial")
public class KeyServerServlet extends HttpServlet {
	public void doPost(HttpServletRequest req, HttpServletResponse resp)
			throws IOException {
		// The RIM POST Format:
		// PIN=12341234&email=customeremail@email.com&product=product&version=1.2&transactionid=123&test=false
 
		String PIN = req.getParameter("PIN");
		String email = req.getParameter("email");
		String product = req.getParameter("product");
		String version = req.getParameter("version");
		String transactionId = req.getParameter("transactionid");
		String test = req.getParameter("test");
		String verify = req.getParameter("verify");
 
		//Init vlaues
		if(email == null)
		{
			email = "";
		}
		if(product == null)
		{
			product = "";
		}
		if(version == null)
		{
			version = "";	
		}
		if(transactionId == null)
		{
			transactionId = "";
		}
		if(test == null)
		{
			test = "true";
		}
 
		// I realize using String.matches is taboo, but I did it anyway.  Feel free to change it
		// Since you can also pass your own parameters, I am passing the "verify" parameter; security by obscurity, I know, 
		// but when using App Engine, your Servlet is publicly accessible, so...
 
		if((PIN.matches("\\p{XDigit}{8}")) && (verify != null) && (verify.equalsIgnoreCase("bbappworld")) )
		{
			// This is my own Key Generation Routine
			KeyGen kg = new KeyGen(PIN);
			String hexString = new String(Hex.encodeHex(kg.genKey()));
 
			String Key = hexString.toUpperCase();
			if(test.equals("false"))
			{
				PersistenceManager pm = PMF.get().getPersistenceManager();
				Entry entry = new Entry(email, product, version, transactionId);
				pm.makePersistent(entry);
				pm.close();
			}
			resp.setContentType("text/plain");
			resp.getWriter().println("key="+Key);
		}
 
 
	}
}

If you paste the code above into your Eclipse, you will run into some errors.  These are the typical ones and how they can be fixed:

1. The KeyGen Class isn’t available.  This is my own KeyGen routine for generating Activation Keys.  It takes the BlackBerry PIN as an argument and does some magic on it.  You have to write this one yourself.
2. The Hex Class isn’t available.  In my case, I wanted to work with Hex strings and convert them back and forth.  I looked up the source to the Apache Commons Codec project and copied across the source code for the Hex class and all its dependencies into my own project.  You do not need to use it, but if you do, then I advise you to look at the Apache Commons Project.
3. The PMF class is missing.  This class is used if you want to Persist or store data. The PMF class source code is standard and Google App Engine has the sample code for it here.  If you need it, I’ve attached the code later on in this post.

As far as I recall this is what you will need to address.  Now, lets move onto storing the incoming data on the database.  I store each request in a class called an Entry.  Thus, each POST request to my servlet will be checked and if it isn’t tagged as a test, then it will be stored to the database.  The Entry object is marked as persistable and this makes it easy to store in the App Engine datastore.  Here is the code for the Entry object:

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package net.zenconsult.keyserver;
 
import java.util.Date;
 
import javax.jdo.annotations.IdGeneratorStrategy;
import javax.jdo.annotations.IdentityType;
import javax.jdo.annotations.PersistenceCapable;
import javax.jdo.annotations.Persistent;
import javax.jdo.annotations.PrimaryKey;
 
import com.google.appengine.api.datastore.Key;
 
 
 
@PersistenceCapable(identityType = IdentityType.APPLICATION)
public class Entry 
{
	@PrimaryKey
    @Persistent(valueStrategy = IdGeneratorStrategy.IDENTITY)
    private Key key;
 
	@Persistent
	private String email;
 
	@Persistent
	private String product;
 
	@Persistent
	private String version;
 
	@Persistent
	private String transactionId;
 
	@Persistent
	private Date creationDate;
 
	public Entry(String email, String product, String version, String transactionId)
	{
		setEmail(email);
		setProduct(product);
		setVersion(version);
		setTransactionId(transactionId);
		setCreationDate(new Date());
	}
 
	/**
	 * @param key the key to set
	 */
	public void setKey(Key key) {
		this.key = key;
	}
 
	/**
	 * @return the key
	 */
	public Key getKey() {
		return key;
	}
 
	/**
	 * @param email the email to set
	 */
	public void setEmail(String email) {
		this.email = email;
	}
 
	/**
	 * @return the email
	 */
	public String getEmail() {
		return email;
	}
 
	/**
	 * @param product the product to set
	 */
	public void setProduct(String product) {
		this.product = product;
	}
 
	/**
	 * @return the product
	 */
	public String getProduct() {
		return product;
	}
 
	/**
	 * @param version the version to set
	 */
	public void setVersion(String version) {
		this.version = version;
	}
 
	/**
	 * @return the version
	 */
	public String getVersion() {
		return version;
	}
 
	/**
	 * @param transactionId the transactionId to set
	 */
	public void setTransactionId(String transactionId) {
		this.transactionId = transactionId;
	}
 
	/**
	 * @return the transactionId
	 */
	public String getTransactionId() {
		return transactionId;
	}
 
	/**
	 * @param creationDate the creationDate to set
	 */
	public void setCreationDate(Date creationDate) {
		this.creationDate = creationDate;
	}
 
	/**
	 * @return the creationDate
	 */
	public Date getCreationDate() {
		return creationDate;
	}
 
 
}

Once you get this up and running, you have about the simplest mechanism for working with Dynamic Licensing with not only BlackBerry App World, but other stores as well.  You can, of course, make this as grandiose as you wish; that part is left as an exercise.  I’m just giving you a point to start at.

[Call Attribute: upto 4 characters][Date or Time: upto 6 characters]

Some examples of these are:

(W) 9:58p
(W2)11:22p
(H) 01/09

You will see in example 2 above, that all 10 characters are used up.  After I figured this out, the rest was pretty straightforward.  Here is the source code to my Field called PhoneNumberListField.

import net.rim.device.api.ui.DrawStyle;
import net.rim.device.api.ui.Graphics;
import net.rim.device.api.ui.component.ListField;
import net.rim.device.api.ui.component.ObjectListField;
 
public class PhoneNumberListField extends ObjectListField
{
 
	public PhoneNumberListField()
        {
     	    super();
        }
 
	public PhoneNumberListField(long style)
        {
     	    super(style);
        }
 
        public void drawListRow(ListField listField, Graphics graphics,
        		int index, int y, int width)
        {
 
        	String tmpCol1 = (String) this.get(listField, index);
        	String col1 = tmpCol1.substring(0, (tmpCol1.length() - 10));
        	String col2 = tmpCol1.substring(tmpCol1.length()-10);
 
        	int col2Size = this.getFont().getAdvance(col2);
                int col1Size = width - col2Size;
 
        	int col1Start = 0;
        	int col2Start = (width - col2Size);
 
        	graphics.drawText(col1, col1Start, y, DrawStyle.ELLIPSIS, col1Size);
 
        	graphics.drawText(col2, col2Start, y, DrawStyle.HDEFAULT, col2Size);
 
        }
 
}

How to implement

You first create an array of Strings.  This array can contain phone numbers or a combination of First Name, Last Name together with the phone attribute like (W), (H) for Work and Home numbers respectively.  The last field will be the date or time.  I check the time of the call to see if it is older than 24 hours.  If it is, I use the date.  The format for the time is “h:mma” and for date it is “MM/dd”.  You can format these using SimpleDateFormat.

The full list of BlackBerry Attributes are represented as follows:

Home: (H)
Work: (W)
Mobile: (M)
Pager: (P)
Fax: (F)
Other: (O)
Work2: (W2)
Home2: (H2)

The attribute constants can be found in the BlackBerryContact Interface.  A typical array of mine would look like this:

String[] numList = {“Sheran Gunasekera (W) 09/09”, “Scott Mosier (M) 9:39a”,
“Kevin Smith (M)10:39p”, “+12120031337     10:04p};

Then, if I want to place this field on my MainScreen, I do this:

PhoneNumberListField numbers = new PhoneNumberListField();
numbers.setEmptyString(“*** No Calls Yet ***”, DrawStyle.HCENTER);
numbers.set(numList);
add(numbers);

This is what it looks like:

PhoneNumberListField

Towards the very end of the installation, I received some error messages. They looked something like this:

An error occurred while collecting items to be installed
  No repository found containing: net.rim.eide/osgi.bundle/1.0.0.67
  No repository found containing: net.rim.eide.bootstrapper/osgi.bundle/1.0.0.67
  No repository found containing: net.rim.eide.preprocessing.hook/osgi.bundle/1.0.0.67

Quite annoying since it took me a long time to download the JDE ZIP file thanks to a slow Internet connection.  After a little bit of digging, I figured out that the three components I was missing were indeed not in the ZIP file that I had downloaded.  So rather than downloading the whole new ZIP file again, I thought I’d try another approach.

I went into the Eclipse Software Updates menu: Help->Software Updates and added the update site “http://www.blackberry.com/go/eclipseUpdate”.  I then refreshed the repository and looked for Plugin verison 5.0.0, highlighted the relevant checkboxes and clicked install.  Sure enough, Eclipse dutifully fetched the three missing bundles from RIM’s update site and finished off my installation.  I’m playing with OS 5.0 as I write this.

Finally, after looking into the django.core.handlers.wsgi module, I figured out how to send errors to the wsgi.errors setting and subsequently send errors to your Apache2 Error.log file.

I started off with my views.py as follows:

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from django.http import HttpResponse
from django.shortcuts import render_to_response, get_object_or_404
from myapp.models import F
 
def index(request):
    c = {}
    return render_to_response('myapp/index.html',c)
 
def detail(request, name):
    n = F.objects.get(name=name)
    c = {'name': n.fof}
    return render_to_response('myapp/detail.html',c)

If I needed to write to the Error.log file, I would have to change the code thusly:

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from django.http import HttpResponse
from django.shortcuts import render_to_response, get_object_or_404
from myapp.models import F
 
def index(request):
    c = {}
    print >> request.environ['wsgi.errors'],"Teh Errorist!"
    return render_to_response('myapp/index.html',c)
 
def detail(request, name):
    n = F.objects.get(name=name)
    c = {'name': n.fof}
    return render_to_response('myapp/detail.html',c)

The change is in line 7

I felt really stupid, because the solution was so straightforward.  I felt even more stupid that I couldn’t find any documentation out there.  Either way, I’m pleased that my app works, and in case someone else out there is searching for how to achieve this, then the above is how to do it.

I’ll leave you to work out why this is useful; alternatively you can also read my “Memory Card Forensics” post. Here is how I installed CarvFS:

Downloaded the source packages for CarvFS, libcarvpath, libewf and fuse. They can be found here:

CarvFS 0.2.1
libcarvpath 0.1.4
libewf-beta-20061223
fuse 2.6.5

There’s no specific order, but make sure that libewf, fuse and libcarvpath are installed before CarvFS.

I believe fuse should already be running as a kernel module in 7.04, so the kernel module will not be built.

Then, once you install CarvFS, you’re pretty much ready to go. I had one problem when I ran carvfs I received a library not found error for libfuse.so.2. The library itself was in /usr/local/lib, but there was no entry in /etc/ld.so.conf. So I added the entry and ran ldconfig and all was well.

How will you test CarvFS? First, you will need either a raw ‘dd’ image or an EWF image. libewf will install a tool called ‘ewfacquire’ which you can use to make EWF images. Here is an excerpt of one of my sessions:


sheran@azazel:~/Personal/research$ ewfacquire /dev/sdb1
ewfacquire 20061223 (libewf 20061223, zlib 1.2.3, libcrypto 0.9.8)
Information about acquiry required, please provide the necessary input
Image path and filename without extension: usbdisk
Case number: 1923
Description: USB Disk
Evidence number: 12
Examiner name: Sheran
Notes: 64Mb USB Disk used for Forensics tests
Media type (fixed, removable) [fixed]: removable
Use compression (none, fast, best) [none]: best
Use EWF file format (smart, ftk, encase1, encase2, encase3, encase4, encase5, linen5, ewfx) [encase5]:
Start to acquire at offset (0 >= value >= 65135616) [0]:
Amount of bytes to acquire (0 >= value >= 65135616) [65135616]:
Evidence segment file size in kbytes (2^10) (1440 >= value >= 2097152) [665600]:
The amount of sectors to read at once (64, 128, 256, 512, 1024, 2048, 4096) [64]: 512
The amount of sectors to be used as error granularity (1 >= value >= 512) [64]:
The amount of retries when a read error occurs (0 >= value >= 255) [2]:
Wipe sectors on read error (mimic EnCase like behavior) (yes, no) [yes]:
...
...
...
...

It goes on to acquire an EWF image of my 64Mb USB Disk.

The next step would be to mount it. Create a mount point for it first. I use /mnt/carvfs.


sheran@azazel:~/Personal/research$ sudo carvfs /mnt/carvfs ewf usbdisk.E01 /mnt/carvfs/fad545a8c4c86973eb0ae33da06e9c80
sheran@azazel:~/Personal/research$


Now that the image is mounted, switch to the root prompt (I wasted some time on this one) and then go into the mounted image:


root@azazel:/mnt/carvfs/fad545a8c4c86973eb0ae33da06e9c80# ls -alrt
total 63617
-rw-rw-rw- 1 root root 2545 1970-01-01 04:00 README
-r--r--r-- 1 root root 1397 1970-01-01 04:00 ocfa.xml
-r--r--r-- 1 root root 65135616 1970-01-01 04:00 CarvFS.crv
d--x--x--x 3 root root 0 1970-01-01 04:00 CarvFS
drwxr-xr-x 3 root root 0 1970-01-01 04:00 .
drwxr-xr-x 5 root root 4096 2007-06-18 17:43 ..

I then ran a strings on the first 512 bytes like so:

root@azazel:/mnt/carvfs/fad545a8c4c86973eb0ae33da06e9c80# strings CarvFS/0:512.crv
MSDOS5.0
NO NAME FAT32 3
f`f;F
fXfXfXfX
NTLDR
Remove disks or other media.
Disk error
Press any key to restart
root@azazel:/mnt/carvfs/fad545a8c4c86973eb0ae33da06e9c80#

That’s about it.

I know my instructions probably suck big time, but I didn’t want to waste too much time in actually telling you how to do some of the other things. Anyway, if you’re sniffing around CarvFS you probably know how to do most of the stuff anyway. If, however, you still want to know stepwise details, drop me a comment or mail me.

Till then.