Abi Rajan resources on SCJA Module 6

Java Security Architecture

With the two tier architecture the code was distributed through floppy disks or Compact disc (CD). The source came from the trusted source and no intervention has possibly had occurred. For example the software was loaded by the IS / IT department to the user department. The software was transported manually through a CD.

With the emergence of the three tier architecture the main advantage of three tier architecture over the two tier architecture was the software deployment was made easy. In three tier architecture the client was thin, calling the business logic in the middle tier. The deployment of the software was also through the internet. When the client tier was developed using applets, the client computer downloaded the appropriate classes at run time from the server.

Various methods were evolved to access the latest classes from the server each and every time the client is executed. This had an advantage over its predecessor two tier architecture where every change in the software application needed the software portion to be installed in each computers in the client base. This advantage of easy deployment in the three tier architecture came with an disadvantage that is the security of the application and the client computers which execute the code downloaded through the Internet.

Various scenarios where security is of importance in the three tier architecture.

When the client is an applet. The referenced classes are downloaded from the server. The downloaded code may be tampered which involves a security risk. Once the downloaded code is given access to access the local computer system it may do some thing which is not supposed to do. The applet may send information about the client computer to a remote computer.

The classes are downloaded through the internet to a local drive. The client uses the classes in the local drive. Even though at run time the classes are loaded from the local drive, the code was downloaded through the internet. The client do not know exactly what the code in the classes will do. May be it may paint a login screen which it is supposed to do. In the background it may open a socket connection to another computer in the Internet then open a sensitive file from the local drive and transfer the file content.

• Send information about the client computer to a remote computer.
• Send sensitive file information to a remote computer.
• Modify, replace or delete files in the client computer.
• Impersonate as somebody who is trusted.
• Not allowing the network to do its work.

Before Java the language did not take the security into consideration. The security was considered when implementing. The application did take of the security issues.

Java security includes two aspects:

Provide the Java platform (primarily through JDK) as a secure, ready-built platform on which to run Java-enabled applications in a secure fashion.

Provide security tools and services implemented in the Java programming language that enable a wider range of security-sensitive applications, for example, in the enterprise world.

In normal world firewall is a wall which do not allow the fire to spread to the near by areas. In computer terms firewall is in between the corporate network and the Internet. The firewall protect the data, files and the network inside the corporate network from the outside world. The firewall is a combination of software and hardware. The firewall can range from a simple program to a sophisticated network of computers and software.

The original security model is known as the sandbox model. The essence of the sandbox model is that local code is trusted to have full access to vital system resources (such as the file system) while downloaded remote code (an applet) is not trusted and can access only the limited resources provided inside the sandbox. JDK 1.1 introduced the concept of a "signed applet", as illustrated by the figure below. In that release, a correctly digitally signed applet is treated as if it is trusted local code if the signature key is recognized as trusted by the end system that receives the applet. Signed applets, together with their signatures, are delivered in the JAR (Java Archive) format. In JDK 1.1, unsigned applets still run in the sandbox.

Fine-grained access control.

Easily configurable security policy.

Easily extensible access control structure.

Extension of security checks to all Java programs, including applications as well as applets.

SSL:

SSL

Firewall :

A firewall is a system or group of systems enforces an access control policy between two networks.

Security Management

DMZ solutions

Shared solutions

Dedicated solutions

Digital Signatures and JAR files: