Thaqnks speedo.

Question, you say I can hardcode my server's certificate in the applet.  How
exactly do I do that?  Do I include the certificate in the jar file, and
read it from there?  Since this is the same certificate that is used to sign
the jar file, can it be used to verify the applet has not been modified?  If
so, how?  It doesn't seem very secure since presumably the embedded
certificate could be used to sign a modified version of the applet.  In
other words, wouldn't a cracker be able to extract the certificate and use
it for whatever evil purpose he wants?

Perhaps a different approach.

What attacks is the following vulnerable to, and how do I defend against
them?

1) User using his web browser uses https to open my login page and logs in.

2) If the login is successful, the user gets to a welcome page, again using
https, and this has a link to a page containing  my applet and the protocol
used is https.  On the server side, this page is generated by a servlet, and
there will be an item in web.xml forcing all access to this page to be
through https.

2a) I assume the applet itself will be sent to the client browser over an
SSL/TLS socket.  I also assume that the applet is signed, so the browser
will not run it if it has been modified in transit in an attempted man in
the middle attack.

Question: I see, in the Postgres documentation, I can use OpenSSL to create
self signed certificates, and that I can place such a certificate into a
file called "root.crt" into the data directory.  It says that when this is
done, the server will request a client certificate.  If the attempt to
connect is from an applet, where will it get this certificate?  Can it use
the certificate that was used to sign it?  I will, of course, be using JDBC
to connect to the server (whether from a servlet or an applet).  Where, in
JDBC, do I look for instructions on how to use it to make a connection to
the server using https (i.e. what class and what function do I use)?

Is there a way to ensure that the jar file containing the applet is neither
cached nor modified on the client machine?

Question:  Can an applet create a digest of the jar file in which it was
sent to the client browser, and then send that digest to the server for
comparison with the digest of the jar file as it exists on the server?  And
can the browser be prohibited from caching the jar file containing the
applet?  Would that enable the server to ensure that the applet had not been
modified either on the client machine or between the client and server?

I am torn between having the client interact with a database through a
servlet or directly with the database running on the same machine as the
application server.  I am also torn between using an applet or an
application launched using webstart (again having both configured so they're
not cached on the client machine).  In either case, the applet/application
is very small, so sending them over the network will not impose a
significant wait time.  Regardless of whether I use an applet or
application, it will not need to access the client hardware, and can quite
happily function within the original sandbox security model to which Java
applets were originally confined.  I neither need nor want access to the
clients' hardware!

Is it not a significant hole in java security if I can not verify, from my
server, that the applet or application trying to connect to my server is in
fact the same code I signed?

Thanks,

Ted