Frank Jennings

When I was casually examining my server log few months back, I noticed something was going off beam. To my horror, the primary server crashed, unable to take the load. Usually, I don't get that much traffic. Months later, I realized that I was the victim of a DDOS attack. Being a hacker type myself, I tried to investigate where I failed in my system administration. And I started learning Raw Socket programming, in an effort to understand how powerful it is under Linux. To my surprise, I realized any lamer can build up Raw Socket applications and can effectively misuse this wonderful trait . I'd like to share some of the interesting Raw Socket exploits. Don't ever try this! All along I was wondering if I could spoof my IP address and perform a SYN Flood attack on a server using C with my Linux box (2.4.1), as I found out that the hackers spoofed their source IP and ... (more)

Frank's Java Code Stack #1 Working with Cipher Streams

(October 11, 2002) - Often it is necessary to encrypt confidential messages and send them across a stream for better Data veracity. With JCE, you can encrypt streams of data and decrypt them using public/private key pair or using a single signature key file. The technique involves associating a Cipher object to Input or Output Stream. Please note that JCE is different from JSA and you need Java Cryptography Extension APIs to work with this example. JDK 1.4 comes with JCE APIs. Let's create a simple program, which initializes a KeyGenerator class, instantiates a Cipher Object usin... (more)

Accessing MBeans Through the Jini Service

Network systems based on service discovery can provide a consistent view of their distributed components even during changing network conditions. The ability of a system to heal itself during a network catastrophe, including architectural change and system breakdown, will help the system to realign its content traversal route intelligently and swiftly. This ability can be obtained from various healing strategies like failure detection, consistency maintenance, and distributed service activation techniques. A complete understanding of the interactions among self-healing strategies ... (more)

Signing or Sealing?

Tell me one good reason why anyone would despise dynamic class loading in Java. Chances are that no one will. Neither did I, until I reached a point where I could not contain my despair seeing it being much used and abused. RMI is an inherent evil. Say that to a group of Java programmers and try staying there a while. These guys have developed extremely flexible and robust network applications exploiting the clout of dynamic class loading. Well RMI is good as an optimal distributed solution, but invoking runtime instances from an arbitrary VM of different security context may compr... (more)

Method Processing with Dynamic Proxies

(April 24, 2003) - While designing Enterprise frameworks, you ought to be very cautious about exposing runtime instances of classes encompassing secure transaction or management core, outlining Intellectual Property of the enterprise. Often it is required to create a proxy wrapper around objects so method-invoke requests can be pre-processed before being associated with the original instance. Very few Java developers are accustomed to abstract their management objects by creating dynamic proxy wrappers. java.lang.reflect.Proxy class provides methods for creating dynamic proxy cla... (more)