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Hi,
Can someone assist me with how i might go about decompiling or viewing a dll, making changes to it and recompiling it? What tools can i use to do this?
I have tried copying some of the dlls from my device over to my local pc, however most of the time i get an "access violation" message.
Further, i realize i can use idlasm to disassemble .net files, but it seems most of the more interesting dlls and files may be standard c dlls. How can i take a look at the code in these and modify if wanted?
thanks much.
farseer: what level of experience do you have?
V
I'd like to think i am decent developer, but that may be in my own mind
However, i do not do a lot of "hacking", i.e., have not had the need to do much reverse engineering. I have been coding ground up apps for over 10 years however, uisng C++, Java, C#, VB, etc. You name the language, and i've probably done something in it .
vijay555 said:
farseer: what level of experience do you have?
V
Click to expand...
Click to collapse
was that the wrong answer?
farseer said:
I'd like to think i am decent developer, but that may be in my own mind
However, i do not do a lot of "hacking", i.e., have not had the need to do much reverse engineering. I have been coding ground up apps for over 10 years however, uisng C++, Java, C#, VB, etc. You name the language, and i've probably done something in it .
vijay555 said:
farseer: what level of experience do you have?
V
Click to expand...
Click to collapse
Click to expand...
Click to collapse
The correct answer should be "I know ARM assembler language, the structure of Win32 PE files, I know what is XIP DLL and why I cannot modify them directly, and I have read the WM5 source code".
In this case the process is simple - you decompile a DLL with IDA (www.datarescue.com), find the place you need, modify the code to suit your needs - and that is all. In most cases there is not enough place in DLL for your code, so you need to use virus-like techniques, my prefered method is to patch the code so that it loads my DLL and run it instead of original code. Or use some other hooking methods so that my code is executed instead of original.
Ah, thanks much, this was helpful. I do have a few follow up questions:
1. Is "Arm assembler" different than standard assembler? If so, any suggested readings?
2. There are some dlls that cannot be copied to my local pc (i get an access violation i believe). How does one extract an image of such dlls?
3. Where is the WM5 source code? and why would i need to read this to be able to hack/patch dlls?
thanks again.
mamaich said:
The correct answer should be "I know ARM assembler language, the structure of Win32 PE files, I know what is XIP DLL and why I cannot modify them directly, and I have read the WM5 source code".
In this case the process is simple - you decompile a DLL with IDA (www.datarescue.com), find the place you need, modify the code to suit your needs - and that is all. In most cases there is not enough place in DLL for your code, so you need to use virus-like techniques, my prefered method is to patch the code so that it loads my DLL and run it instead of original code. Or use some other hooking methods so that my code is executed instead of original.
Click to expand...
Click to collapse
Hi farseer!
I am nowhere near the level of mamaich or vijay555 but I have some experience in this and I believe I can give you some basic answers:
1. ARM is a different architecture then x86 processors and the assembler is different to accommodate it. There are some basic similarities like mov add and such, but even the registers are different (R0 - R15 if I am not mistaken). Sorry, I don't know any books on it, but if you google you will quickly find the list of commands with basic explanation.
2. Since the OS is in ROM you can't just copy and paste it's DLLs and EXEs. Look for ROM dumping tools on this forum, or already extracted images on the ftp. Keep in mind MS did some tricks to save memory and make it harder to get at the files, so like mamaich said, you need to learn about XIP and the ROM structure in general to understand whats going on.
3. Hmm... MS does have a program for sharing most of WM source code, but it's not for common people like us. (check out their site to see what I mean) I suspect there are other sources of getting the parts necessary to understand DLL hooking, but I have no idea what they might be.
Well that's my two cents until an expert can answer you. Hope this helps.
farseer: you gave a perfectly good answer IMHO, just needed to get an idea of what level to pitch a response without talking up or down to you!
It's well documented that I'm a self confessed newb to c++, and would say that your programming skills should certainly hold you in good stead. However, having a good knowledge of the Win32 API is certainly beneficial.
For decompiling, basically IDA. There is an IDA demo available on their website that should get you going, it's pretty much 100% functional other then it won't save, and closes itself (or crashes itself) after a reasonable, random period of time. IDA is "the daddy" for pretty much all mainstream reversing, although you could write your own decompiler/debugger.
Recompiling - that's a toughy. IDA won't permit recompiling on ARM AFAIK.
You'll have to hexedit into the target and patch directly. Otherwise you get into the exciting world of code injection, hooking etc, as Mamaich says.
For that area, read everything he's ever written, before you start reversing
Oh, and a helpful hint to all. Don't just read what Mamaich's written on this board, his posts on other boards are even more useful!
It's worth getting a good familiarity with reversing on x86 first, get used to how IDA works etc (and Soft Ice is very useful to give a good insight into x86, although AFAIK it's not available for WinCE). ARM assembler is different, but just grab a list of the opcodes and read through a few CPU developers' guides (online).
There are a number of tutorials on reversing ARM stuff online. In the usual places for that kind of stuff.
For getting access to the ROM files, easiest way is to grab a rom update file and decrypt it. Mamaich is once again your man, his romtools do the job. He also has a "live" rom grabber, that'll grab all the files/modules out of your running phone for your perusal.
Platform Builder is available free to give you (some) WinCE source code. Not all, but enough to give you years worth of reading.
V
Thanks all...very kind of you to respond in such detail. I look forward to dabbling a bit with IDA and some of mamaich tools. I suppose the first order of business is to do a lil more research and then just dive in! It's been a while since i wrote any assembly code (not since college!), but i am a bit excited at having an excuse to do so again.
thanks again.
Just remember that unless you really luck out and the developer left the symbol table intact, you're going to end up with garbage for the names of variables and subroutines.
I hate reading decompiled code.
Hello!
Does anyone of you know which dll's I have to use to get the following information:
- the net the sim card is booked in
- states of my GSM unit
- states of my telephone unit
Can anyone help me getting these information or tell me where I might find them?
Thank you very much in advance.
Monty
On Wm5, state and notification broker. No dlls required.
Please move your question to the development forum, for better responses :wink:
V
Sounds nice. But there's a problem: we do not only use WM 5 Pocket PCs. Many of our devices use Windows CE instead.
Do you know which P/Invoke I have to use?
If you're definitely not using WM5, but WinCE, then it's a hell of a lot more trouble. You need to use TAPI generally, this will give you answers to each of those queries.
I don't use Managed Code, so check out www.opennetcf.org/
If you're using Compact Framework, there may well be managed libraries to get access to this stuff easily.
Native Code ≡ Pain
V
I checked the library on opennetcf.org but it doesn't seem to be very useful. Is there any way to find out the functions compiled in the API dll's? I'm sure Microsoft offers a way to get the wanted information. But I cannot find it
Hi all,
I am really mad from this OBEX bluetooth thing, I have spent a month trying to add BT OBEX support in my program but ith no luck, I scanned the internet line by line and found almost nothing.
I found things on codeproject and experts-exchange, but not of much use and some did not work correctly.
I saw some programs that deal with obex developed in this forum like GSMBeam and maybe others.
Any one knows how to program BT OBEX for file exchange?? I need to only send a file!! any libraries for evc++? I am really tired now and this is my last place to save my project.
I hope I will find help here
Don't know if this works for you... give it a go..
To change the ability to receive files via Bluetooth (OBEX)
* The setting is at 'HKEY_LOCAL_MACHINE\Software\Microsoft\Obex'
* The 'IsEnabled' DWORD value should be set to '1' to enable OBEX and '0' to disable OBEX.
Hi,
The problem is not with my device, the registry settings are correct, but I need help for developing my BT Obex application, specifically, I need my application to be able to send files to other devices via bluetooth (just like resco explorer).
ANY HELP GUYS? ANY C++ LIBRARIES? ANYONE DID THAT BEFORE?
please shade some light if you can.
Thanks in advance
Aaaa... IC
U could try here... http://www.gatefold.co.uk/obex/
It's a test-ware for sending contacts and files by bluetooth and there's a source and compiles software that u could d/load 2 test...
Hope this helps
Hi,
Thanks for your help, but as I wrote in the first post, I need it for c++, I already have this library but unfortunately it is for .NET applications, not c++.
I need some help on c++
Thanks again.
Come on guys... provide something
Would this help you out?
And maybe this
Thanks _Nomad_ for your help.
But again, both links are dedicated to the .NET CF, but I am using eVC++, so they are not useful for me.
I need some thing to use in eVC++, not .NET.
Thanks anyway.
And Guys, if any body knows anything useful please let me know.
mohgdeisat said:
I need some thing to use in eVC++, not .NET.
Click to expand...
Click to collapse
Use the force luke...
search for "obexsquirt"
the result will lead you to a full functioning c++ source code for obex transfer over both bt and irda.
cheers
Yes, thanks.
Actually I have the book that introduced this sample but some code is missing in the book.
I found another code derived from obexsquirt sample, it works fine but the problem is that it fails to disconnect from the target device and the connection remains open, I tried to debug it but found nothing to correct, the code seems to be written correctly but I don't know why the problem arises.
Please try to see the code guys and tell me whatever you get:
Article:
http://www.developer.com/ws/palm/article.php/10946_3573636_3
Code sample:
http://www.developer.com/img/2005/12/Obex.zip
Thanks guys
Most of us are already aware that PPC and smartphone edition are similar enough to be mostly compatible in their apps across the platforms.
That is, with enough coaxing and the help of input simulators like SPHelper, I've managed to run almost any Pocket PC app on a smartphone device.
Well, until now.
I've officialy run into my first brick wall of sorts, and I'm hoping someone here can shed some light onto the situation.
Since the MS implementation of A2DP has quality issues, I'm trying to run MSI Blueplayer app ( found at http://cweb.msi.com.tw/program/support/download/dld/spt_dld_detail.php?UID=619&kind=8) on a smartphone.
Analyzing the cab, I extracted 4 .dll's that go in the \windows dir (msibtstk.dll, msibtapi.dll, CHS.dll and TW.dll), and two .exe program files that go in program files\msi\blueplayer (STLoader.exe, and MPOBCE.exe).
Now, normally its as simple as running the .exe, at least it always has been in the past.
However, every time I hit MPOBCE.exe, all I get is:
"Alert
Can't find MPOBCE or one of its components. Make sure the path and filename are correct and that all the required libraries are available."
Just to control this experiment, I copied the exact same files over to a PPC device and ran it to find that it DOES work.
Now, I've never encountered PPC specific code before- in fact, I didn't even know such a thing was possible. Has anyone see/heard of this sort of thing before?
Can someone help me take this apart and find out what makes it work on a PPC only? Perhaps a PPC-specific path (if there is such a thing)?
At this point, as much as I'd like to get this working, I'm just as much intellectually curious as to what would cause a program to only operate on a PPC installation.
Hello Dishe.
Your problem is simple: Certain DLLs that come built in Pocket PC version of windows mobile do not exist in the Smartphone version. An example is MFC DLLs.
What you need to do is get hold of 'dependency walker' which is a neat little app that MS incorporated in to VS 6 (though I understand it was written by an independent developer and should be available separately).
It will show you exactly which DLL files each exe is linked to. You then have to get a good copy (from a ROM dump) of the needed DLL and put it in windows directory.
Hope this helps.
That's a great idea. Thanks! I never heard of the dependency walker before, but it sounds like a perfect tool for this. I'll have to check it out on my office computer (I don't have VS 6 at home).
I wont be back in my office until wed., so if anyone had a bit of spare time, I'll attach the files here for someone to examine.
If anyone wants to look into it and tell me what dll's are required, I can get ahold of them from a healthy Pocket PC image.
Thanks!
This zip file has the two .exe's contained in the installation. I think only mpobce.exe is complaining about missing components, though.
Oops, apparently I should have checked first...
Dependency Walker is a free app. I downloaded it and tried it out.
It lists a bunch of .dll's, most of which I had on smartphone.
However, the two missing ones are:
mfcce300.dll
olece300.dll
Now, I'm not exactly sure what these do, so I need to look into it some more. Does anyone have any clue what these are for? If I copy them from a Pocket PC, will they operate on a smartphone?
Hi Dishe.
I guess I should have been more clear: Dependency Walker was written as freeware by an independent developer, but M$ liked it so much they decided to grab it for VS.
Any way, mfcce300.dll is MFC version for PPC (if you are not familiar with MFC, it's a collection of "ready code" that simplifies writing apps in c++)
It comes built in for PPCs but not for smartphones for some reason. If you have a good dump check that DLL with dep. walker as well, I am pretty sure it is linked to a few others.
olece300.dll - is a COM support dll. I won't even go there because I really hate COM (that's Component Object Model, not com port) and I am really not sure my self what the DLL does.
If you do get a good version of those two you should be able to get the app running.
levenum said:
Hi Dishe.
I guess I should have been more clear: Dependency Walker was written as freeware by an independent developer, but M$ liked it so much they decided to grab it for VS.
Any way, mfcce300.dll is MFC version for PPC (if you are not familiar with MFC, it's a collection of "ready code" that simplifies writing apps in c++)
It comes built in for PPCs but not for smartphones for some reason. If you have a good dump check that DLL with dep. walker as well, I am pretty sure it is linked to a few others.
olece300.dll - is a COM support dll. I won't even go there because I really hate COM (that's Component Object Model, not com port) and I am really not sure my self what the DLL does.
If you do get a good version of those two you should be able to get the app running.
Click to expand...
Click to collapse
Thanks for the help, I'm realizing there's a lot more to this I should have known before embarking on such a task. I've never had such a problem doing this before, I guess MFC isn't so popular!
Anyway, I need a good ROM dump, I haven't been able to aquire one. In the mean time I tried some files I found searching google... didn't expect it to work, but tried it anyway. Still complained of missing files- you're right, I'll bet MFC is calling more dll's as well that I need.
Perhaps there's hope...
You were right... I just needed more .dlls!
I found a whole series of .dlls required by mfcce300.dll that my smartphone was missing, so I put them all in the program directory and it opened!
Problem is, its not so stable... the files were pulled from a ce.net-4.1 set of files since I don't have access to a wm5 rom image.
One more thong I should have thought about earlier:
Some COM dlls, maybe even olece300.dll have a function called DllRegisterServer that writes them to registry as COM provider (under HKCR\CLSID).
Check to see if I am right using Dep. Walker and if so try to get regsvr32.exe or something similar for the PPC. (On a PC you use regsvr32 somedll.dll to register a COM server)
This may help with stability issue.
Not sure if I have worded this properly as I'm at the edge of my knowledge but I wish to call a function that I am assuming is in a DLL which is contained in ROM. I know the name of the DLL but how can I get a list of functions available from it when I cannot copy it onto my PC?
Many Thanks
Hi Tailor.
First, what function exactly are you looking for? There may be some documentation on it somewhere.
To browse a ROM dll you need to get a ROM dump. The simplest way for your purpose, provided you have a WM5 device is to search for TESTWM5.exe by mamiac on this forum. It will dump all files to your SD. They won't be workable for coding purposes, but still good enough to use dependency walker to get exported functions from DLLs.
Unfortunately that still won't tell you the parameters the function expects. only its name.
Hi Levenum and thanks for your reply.
Its a Sony Sat Nav Windows CE 4.2 device so unforunately theres not much chance of a ROM dump or documentation. Then unit is sold as a finished product and not intended for further developement.
I have installed TomTom instead of the poor app already installed and was trying to get access to the hardware buttons and Light sensor on the unit and then intended to use the TomTom SDK to recreate their functions.
The keys don't not trigger a key press event but their are DLL's called something like powerbutton.dll and navbutton.dll and so it's a fair guess that they could be used to trigger these events.
Obviously without knowing their exported functions I'm not going to get much further.
Any further thoughts ?
Many Thanks
How exactly are you trying to catch the key events?
For what you describe, you don't just need to know function names, you need to know with what parameters to call them so this is definitely not the way to go.
If you are coding with C++ search for info on SetWindowsHook. I am not sure of its implementation on CE, but this might be what you need.
I'm using VB.Net 2005
I'll have a look at SetWindowsHook, Thanks.
Any ideas for the light sensor, there's a test app that Sony have left on the device, it gives a reading from 0 to 100?
How are they likely to be reading this value?