Table of Contents
Advertisement
Introduction to Netscape Signing Tool
JAR Format and JAR Archives
The Java Archive (JAR) format is a set of conventions for associating digital
signatures, installer scripts, and other information with files in a directory. Signing
tools such as Netscape Signing Tool allow you to sign files using the JAR format
and package them as a single JAR file. JAR files are used by Communicator client
software to support automatic software installation, user-controlled access to local
system resources by Java applets, and other features that help address potential
security problems.
The JAR file type is a registered Internet MIME type based on the standard
cross-platform ZIP archive format. A JAR file functions as a digital envelope for a
compressed collection of files. The JAR file type is distinct from the JAR format,
which is simply a way of organizing information in a directory.
Because the JAR format doesn't require a digital signature to be stored physically
inside the file with which it is associated, JAR files are extremely flexible. You can
use Netscape Signing Tool to sign any files, including Java class files,
Communicator plug-ins, or any other kind of document or application. You can
also use version 1.1 and later versions of Netscape Signing Tool to sign inline
JavaScript scripts.
You must create a JAR file if you want to take advantage of Communicator's
SmartUpdate feature. Communicator can automatically locate, download, and
install components, plug-ins, and Java classes on a user's machine, thus freeing the
user from this chore. Automatic software installation also helps both software
developers who want to distribute software and updates over the Internet and
system administrators using Mission Control to manage a corporate intranet.
You don't need to know anything else about the JAR format to use Netscape
Signing Tool, which takes care of the details for you. For detailed information
about the JAR format, see The Jar Format at this URL:
http://developer.netscape.com/docs/manuals/signedobj/jarfile/index.
html
For detailed information about using the JAR Installation Manager to package your
software for use with SmartUpdate, see Using JAR Installation Manager for
SmartUpdate at this URL:
http://developer.netscape.com/docs/manuals/communicator/jarman/inde
x.htm
Chapter 13
Netscape Signing Tool
89
Advertisement
Table of Contents
