View Single Post
  #1  
Old 07-23-2018, 19:38
java3ever java3ever is offline
Friend
 
Join Date: Jun 2017
Posts: 7
Rept. Given: 0
Rept. Rcvd 0 Times in 0 Posts
Thanks Given: 5
Thanks Rcvd at 0 Times in 0 Posts
java3ever Reputation: 0
FlexNet / FlexLM with Java

Hi,

I'm trying to understand how FlexNet works and of course find out the vendor keys.
Note: Application is based on short sign (-> no ECC!) and accepts HostID=ANY

Well, I've searched for the FlexNet routines inside the native executables but didn't found any.
The FlexNet routines seem to be implemented in Java.
I've found a class file (c.class) in one of the JARs, which contains the following lines:


Code:
  
private static final String a = "LMCOMSOL.opt";
private static final String b = "VENDOR LMCOMSOL";
private static final String c = "USER_BASED";
This looks pretty much like FlexNet stuff.

In this class file, there are two methods JD-GUI cannot decompile (it shows the byte code).
Do you think I should try to reverse engineer these two methods? I guess it's likely, that it contains the logic.

Also, has anyone ever dealt with Java based FlexNet? Are there any tricks to find out the vendor keys?

Cheers!


//EDIT:
Tried different decompiler for Java (CFR)
Error for method:
Code:
This method has failed to decompile.  [...]
org.benf.cfr.reader.util.ConfusedCFRException: Tried to end blocks [1[TRYBLOCK]], but top level block is 13[DOLOOP]
But it seems like there is only one method for which CFR fails.

//EDIT 2:
Oops.
CFR is able to decompile the methods JD cannot ("b"), however there is one method ("c") that JD can decompile but CFR not.

Last edited by java3ever; 07-23-2018 at 19:52.
Reply With Quote