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View Full Version : bpx bug in WKTVBDE 1.4 found+fixed+tutorial :)


0xf0001
January 21st, 2004, 20:09
hi there!

I am currently looking at a kinda famous "old" protection that deals with pcode and therefor started using the WKTVBDEbug. since this protection uses an OCX i shortly ran into this bug when debugging this OCX (yes, i try the hardcore approach on this gggg)

so why not put on top of beeing somehow in the very dark with this topic - come to the conclusion that i have NO tool that does what I need. cause also WKTVBDE that would be it has such an annoying limitation that you cannot BPX into an address that you can not currently doubleclick in your small code window.

that is very bad, because you can always start from the beginning and not just jmp where you already were. you have to trace it everytime. kinda new game new luck thing ggg

fortunately WKTVBDE was very gently written for reversing and it turned out to be quite easy to change the thing:

when you <ctrl-e> and enter an address for your breakpoint and it has 8 characters (the OCX for sure ALWAYS has) the last character will be cut off (lowest nibble) but hey you get an extra "0" in front of it (highest nibble)
making from my input eg 1100eebf -> 01100eeb. ups.

i have written also a short tutorial about how to patch it that i think fits quite good for a newbie/beginners "reversing" tutorial - since it is very basic.

have phun!

greetz, da 0xf001

dELTA
January 21st, 2004, 20:56
Hehe, nice work.

JMI
January 21st, 2004, 22:04
Always happy to see more tools for p-code. There are not alot of them out there.

Regards,

disavowed
January 21st, 2004, 22:34
very simple patch, but i'm really glad you went to the effort of writing it up and posting it here. nice work!

0xf0001
January 21st, 2004, 23:05
thank you people for the positive feedback!

yes, i was also curious that it was _so_ simple.
and so it came in to my mind why not write it down and people can have 2 values out of it.
first the people like me that want to do something very specific and sit in front of a general tool that gives them everything, but suddenly a limitation comes up that brings everything to fall. and i remember the pain when you just have to accept that you cant go further although you got the full taste of it and it helped me personally a lot.
second i talked a little in a general approach how can you do such thing? you see you need not be scared of a lowlevel tool like a debugger. and that everything breaks down to simple questions and there is no magic. ok this is a very easy case. and so you get a taste and maybe want to understand more and more ....
finally you have to do the work yourself gggg and feel a little like the experts.
so i think could be a good starting point although its so simple.
it is not to impress or so - and i say it is easy but my intention was to maybe put it to any beginners or newbies tut collection. you can read out names of tools, types of tools and so on. and that it could be maybe good to have an api reference and so on. small peaces that should make them happy who search for it

thx, 0xf001