How do I sign a Java applet for use in a browser?

java browser applet certificate self-signed

61,014

Solution 1

Perhaps it's because you're opening some .class files outside the jar file?

That way it may not display the warning. I tried doing it that way but it still showed me the certificate warning and for a simple case it actually prevented me from accessing a class from the JAR with the separated class.

Maybe your specific setup or file organization causes that behavior. If you can layout that in more detail we could help better (or rather, try putting all those .class files in yet another signed Jar and add it to the archive"..., anotherJar.jar").

Solution 2

3 easy steps

keytool -genkey -keystore myKeyStore -alias me
keytool -selfcert -keystore myKeyStore -alias me
jarsigner -keystore myKeyStore jarfile.jar me

Solution 3

First, I'd suggest getting a valid code signing certificate. You can get a free cert from Thawte. Although generally these certs are used for S/MIME, they are also valid for code signing.

The second option is to import your self signed cert into the cacert file of the JRE which your browser is invoking.

The next thing to check is to make sure your browser is running your latest jar. One way to do this is to always increment your version number. The other option is for you to clear your Java applet cache. I usually clear my browser's cache as well, but this shouldn't be needed.

Solution 4

You mentioned:

When I open that html file, I never get the security confirmation dialog box...

Are you opening the file from your local file system, or via a URL to a web server hosting the HTML file and applet jar(s)? That could be why you get no warning.

Solution 5

Here is a way to sign your jars and then check to see that all the class files are signed with your keystore.

#!/bin/bash
KEYSTORE=/home/user/NetBeansProjects/sign/keystore
FILES=`find /home/user/NetBeansProjects/Project/dist/ -name "*.jar"`
for f in $FILES; 
   do echo password |  /usr/bin/jarsigner -keystore $KEYSTORE -verbose $f myself;
   echo "Signed $f"; 
  /usr/bin/jarsigner -verify -verbose -certs $f | grep X.509 | sort -u;
done

View more solutions

61,014

Author by

user107312

Updated on January 02, 2020

Comments

user107312 over 4 years
I'm trying to deploy a Java applet on my website. I also need to sign it, because I need to access the clipboard. I've followed all the signing tutorials I could find but have not had any success. Here is what I've done so far:
- Wrote an applet in NetBeans. It runs fine in the applet viewer.
- Made a .jar file out of it.
- Created a certificate by doing this:
```
keytool -genkey -keyalg rsa -alias myKeyName
keytool -export -alias myKeyName -file myCertName.crt
```
- Signed it wtih jarsigner like this:
```
jarsigner "C:\my path\myJar.jar" myKeyName
```
- Made an html file containing this:
```
<html>
  <body>
<applet code="my/path/name/myApplet.class" archive="../dist/myJar.jar"/>
  </body>
</html>
```
When I open that html file, I never get the security confirmation dialog box (and thus get the "java.security.AccessControlException: access denied" error). This happens on all browsers.

Am I missing a step?
user107312 about 15 years

I'm opening from my local system. Are you saying that the security dialog will not show up if it's opened locally? If this is true, is there any way to get it to appear locally? It would make testing my project much much easier. Meanwhile, I'll go try it out on the web server to see if this is the problem.
user107312 about 15 years

It's still not working, when accessed from the web server. I only need my .class files, .jar file, and .html file, right? Do I need any files related to the certificates?
user107312 about 15 years

I fixed it. The problem was that my jar files weren't being compiled in the same way that I was referencing the class files. It works now. Thanks!
user unknown almost 13 years

-keystore myKeyStore is even optional, isn't it? I got my applet signed, that way, but my Clipboardproblem remains. However the best appletsigning (jarsigning) - tutorial I found on the web. :)