Re-signing modified .jar files to play movie in Panasonic BD-35

[badflame]

I have one problem with PANASONIC BD-35 when I modify a .jar file.

For example, the text of "audios" for audio selection of the movie. When I playback the BD, it works well, but when I show the menu all text of the modified .jar file not appears (it's empty).

When I playback in the PC or another Blu-ray reproducer (I tested it in Samsung) works well and I can see the new texts in the menu of the modified .jar file.

I have read by Internet that this is a concrete problem of four models of PANASONIC (included my BD-35), and that the solution is, after modified .jar fiel, re-sign it.

And this is my problem, I don't know how to resign the modified .jar files.

It's exists one tuturial that says about to make a ISO of the blu-ray folder, insert the ISO in DAEMON TOOLS and decrypt it again with AnyDVD HD. (versions previous to 6.8.0.0 because 6.8.0.0 doesn't fix java in unprotected discs anymore) .

I tried it and AnyDVD not make new CERTIFICATE content (it keeps the same) and .jar files are not re-signed.

¿Can someone help me?

Thanks a lot.

[Baldrick]

How do you modify the jar?

I'm pretty sure you must reauthor some way but have not seen anything simple if you just want to adjust the menu, extras, etc.

[badflame]

In fact it's quite simple. The steps to modify a .jar file are:

1) open the .jar with 7zip

2) extract the file that you want modify

3) edit the file with one hex editor

4) injecting the edited file in the .jar with 7zip (overwriting the original file)

This is the way for edit text menu in JAVA Blu-ray. But just a few players (included my PANASONIC BD-35) don't reads the edited file when the original Blu-ray has the .jar files signed in the CERTIFICATE folder (because not all JAVA Blu-ray has the .jar files signed).

So, in this precise case is necessary to re-signing the modified .jar files (creating a new CERTIFICATE files). And this is my question HOW TO DO IT?

[nic2k4]

So, in this precise case is necessary to re-signing the modified .jar files (creating a new CERTIFICATE files). And this is my question HOW TO DO IT?

Certificates are issued by a signing authority, you would need their private key to generate a new certificate that would be compatible with your player's public key. The only solution I can see is stripping the certificate from the file, that also implies you would have to edit the navigation file to remove any reference to the certificate for that .jar.

[badflame]

Interesting.

Well, is something like AnyDVD does when ripping Blu-ray first time.

I know that since the JAVA console (installing SKD on your computer) you can sign jar generating a key (because it seems that any key is valid). But I have no knowledge of JAVA and it seems very complex. I would need a software that automates this process.


This option that you talk, about stripping manually the certificate and all the navigation references, could be one good option. Any idea where to start?

Thanks.

[nic2k4]

My guess would be here.

[badflame]

Thanks for reply but that thread only talks about which blu-ray players reads or not unsigned .jar files, but not give solutions

[5x9ir]

Hey guys, I'de been looking for a tool to re-sign jar files besides anydvd hd < 6.8 and after signing an entire bluray using the hdcookbook tools and not having it work on my hardware player I was getting frustrated.
I'm not sure why it didn't work as I was replacing all the certificate files app.discroot.crt bu.discroot.crt and id.bdmv.
All I can think is I was messing something up somewhere along the way but I didn't have a software based player that enforced certificates so the process of testing each change was too tedius to continue.
I reached out to the author of xreveal and he was able to put together an adhoc tool that you can use to sign jar files of discs ripped using xreveal or anydvdhd.
I am not 100% certain, but it might work on rips from other tools.
I just don't know if it is merely using the app.discroot.crt certificate to do the signing, or if it relies on the same root ca (which is perhaps embedded in the anydvd/xreveal programs?).

The requirement is that you have a JAR file with a META-INF folder that contains MANIFEST.MF SIG-BD00.SF and SIG-BD00.RSA.
It appears that the tool updates all files, and perhaps uses the existing fields in the SIG-BD00.RSA along with those from the app.discroot.crt.
The generated JAR files worked perfectly on my hardware player.

He has uploaded the tool to https://xreveal.com/download/signbdj.exe
And the invocation is the following.
"signbdj.exe app.discroot.crt 44444.jar"
If you are looking for this feature I suggest you also check out xreveal and also offer support for the author of this great free tool!

One other note on modifying jar class files.
I found that using RECAF 4 was very good.
Recompiled files don't work as they target JAVA version 8.0 language specification.
For whatever reason my hardware player could only recognize java version 3.0.
As such you need to make changes using JAVA assembly then save the file and export.
This preserves the JAVA version 3.0.
RECAF has a bunch of tools to translate JAVA into JAVA ASM which you can then copy into the assembly listing so it makes it pretty easy.