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Thread: FlexLm: Recracked the wheel

  1. #1

    Talking FlexLm: Recracked the wheel

    Hi guys
    I have recently given a medical application protected by flexlm, asked to crack
    since it's almost ten years that i wasn't doing such things, my knowledge was completely out of date, and i didn't know that flexlm is a comercial lie shit manager etc, thinking it's part of the software, so i cracked it on my own.
    there was a function with a reference to a string "lm_checkout(..." ending with following:
    005216AB  |.  83C4 0C       ADD     ESP, 0C
    005216AE  |>  8B45 E4       MOV     EAX, DWORD PTR SS:[EBP-1C]
    005216B1  |.  5F            POP     EDI
    005216B2  |.  8BE5          MOV     ESP, EBP
    005216B4  |.  5D            POP     EBP
    005216B5  \.  C3            RETN
    and it returned -8 or -10 when there was some problem with license, so i just patched the line 516AE from

    and it worked fine, however there was a lot of files with the exact same code, so i wrote a simple nodejs script to replace it inside all of them (guessed it right, i'm a web dev these days).
    all went fine, software installed and executed well, and I sent it to the guy who requested

    but some days later he called and said there's some third party component used by the software and it's not working..
    i checked it and it was written in java, and there i found a file: lmtools.exe
    and only then i realized (after some searching) that it's flexlm which is already soooooooo famous in reverse engineering communities

    i have decided that if i can generate some license, it's better than patching 39 files, and i will be sure that once done, there will be no more problems..
    to make it brief: I have extracted seed1 & seed2, generated vendor keys using lmkg3 and I used the only sdk that i could find over the web: 11.9
    but the license genrated is not working

    licenses are of the form:
    FEATURE xxx SA*_*d 1 30-mar-2015 uncounted **20hex chars** \
    i have no idea what ecc check is, but if i'm going to patch something, my own solution is better (disables the whole license checking).

    I have two versions of the software, one uses flexlm 10.8.5 and the other uses 11.5
    i have read somewhere that flexlm licenses are backward compatible, i want to test it with flexlm sdk 10.8 but i cant find it anywhere

    if someone have any tips, i'll be so happy to hear it,
    and if someone has sdk 10.8, i will be soooo happier to have it

    thanks in advance
    I promise that I have read the FAQ and tried to use the Search to answer my question.

  2. #2

    Anybody there?

    Is anybody here? Or is this forum dead??
    I promise that I have read the FAQ and tried to use the Search to answer my question.

  3. #3
    Founder FoxB's Avatar
    Join Date
    Mar 2002
    is good daemon and the license/servicekey generator's is ready many time ago

  4. #4
    Quote Originally Posted by arash16 View Post
    Is anybody here? Or is this forum dead??
    Many are not aware that the forum is up again

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