Signing VJ++ applets
If you have developed applets using VJ++ and have a desire to sign and CAB
(add a cabinet file and place a digital signature within that file) the applets,
there are a number of options available to make that happen. While several
vendors offer solutions for CAB-ing applets, Microsoft has created a completely
"nonstandard" CAB system that produces archives that are 40 percent
smaller than JAR files. A downloadable tool called Dubuild, which is part of Microsoft's
Java SDK, employs this
system.
Despite the obvious advantage of smaller file elements—especially those
transferred over the Internet—these Dubuild-created files are compatible only
with applications specifically designed to handle the Microsoft format.
Employing this standard sacrifices a certain level of portability. If Sun did
not completely control the Java standards, perhaps all of the vendors would be
creating smaller archives!
At any rate, Daniel Griscom's overview of Code
Signing for Java Applets
is a good place to start searching for the archiving and signing tools you'll
need. For platform or vendor-specific information, the following two links can
be of use:
Netscape's Java API developer page
Microsoft's Java Security Overview
Editor's note
The June 14, 2001 Java TechMail, "Writing objects to files,"
included a code snippet which contained a typographical error. The code line
localObj = (object)test;
should have read
localObj = (Object)test;
We apologize for any inconvenience this may have caused.