I recently started learning reversing again, and I encountered a problem using my OllyDBG. When debugging an EXE which has buttons that every button does a different thing, I can't seem to find a way to follow a specific button's code.
For example: I have a KeygenMe with 3 buttons: "Login", "About", "Exit".
I want OllyDbg to follow what happens when I press the "Login" button.
How do I do that? I know it is possible as I've done it before.
You can follow a button by asking for olly to stop when the program returns from a funcion.
Do this:
Start debugging your KeygenMe.
Focus on ollydbg window and press Ctrol+F9
Focus on the KeygenMe and click on the button.
Olly will stop on the return of the button function.
Some times olly may stop a little bit far from where you want to go like in user32.dll, so you'll need to trace back your way.
you can do this using two tectiques(that i know):
(Use one after you landed on the return)
Use trace back:
Run your program normally and then hit trace over Ctrol+F11
Then go back using - (Minus Key from numeric keyboard)
or Use Breakpoints
Put breakpoints till you find from were this function is called
Using Right click on the code find the references for the struction that you find on the first step.
keep doint step 1 and 2 till you find your function
(i use both but some times the first one don't work)
The way described above I think is the general one,and it should work on the majority of cases. However, if you already know in which compiler the app was built, you can use a specific approach for it and eventually you can reach faster and more precise what you are looking for.
Supposing the worse case that your exe wasn't built with .NET and you can't decompile it easily. There are some tricks.
For instance Delphi/C++ builder apps make a table in the binary with public object event and addresses, it is extremely easy to decode it, in fact there are some Olly scripts to do that.
On the other hand, if it was made with Visual C using MFC or something like that you can easily reach it if you know how MFC is called.
I am using perl tray from activestate and have a question. I am wanting to make some type of ui or way for a user to set "Settings" on my application. These settings can just be written / read from a text file that is stored on the users computer.
The part I am not understanding though is how to go about making a ui. The only thing i can think of is showing a local perl page that runs on their computer to write to the file. However, I'm not sure how i could get perl to run in the browser when only using perltray.
Any suggestions?
PerlTray is an odd duck. It has an implicit event loop that kicks in after you either fall off the end of your program or after your 1st call to exit(). This makes it incompatible with most other common GUI event loops or most mini-server techniques that operate in the same process & thread.
2 possibilities come to mind:
Most Likely you'll have success spawning a thread or process that creates a traditional perl GUI or a mini-server hosting your configuration web-app. I'd probably pick Tkx, but that's just my preference.
I have a suspicion that the Event Loop used by Win32::GUI may actually be compatible with the event loop in PerlTray, but some experimentation would be required to verify that. I generally avoid Win32::GUI because it's not platform independent, but if you're using PerlTray, you're tied to Windows anyway...
Imagine a 3-dim putty - a polyhedron which every facet is a putty shell.
A few Qs:
1. Is there already such a thing?
2. How can I easily implement a cube/polyhedron that rotates freely, so that on each facet - I can decide what to show (for example, a putty shell). I really don't want to dwell on the graphics part, unless I have to. So any easily prepared graphic would be nice, as long as it supports my requirement. Can openGL help me? JOGL? HTML5? (I don't mind it being in a browser)
Really weird question, not even sure it belongs here, but seems fun anyway...
Have a look here : http://www.jukie.net/bart/blog/popenRWE
So I'd say : start a bash instance with this variant of popen which handles both writes and reads, use the pipes for input and output, forward keyboard strokes to input, and render the output in OpenGL, probably in a rendertexture.
Repeat for each side...
Not html5 or jogl, though. Plain old C or C++.
Compiz's Desktop Cube and six fullscreen Xterms.
I recenty stumbled upon some files described as "HTML Applications" on my Win XP machine.
What are they?
Who would ever use them? Why do I have like 2 or 3 of them on my PC?
How do they generally work? I mean hey - HTML is for adding formatting to text - HTML Applications? What the? Microsoft?
HTAs are good for things like VB scripts that you want an interface for other than MsgBox or a console window.
Since it's HTML, you can use buttons, text areas, check boxes, etc to show information to the user and get input from them, and use CSS to style it all. Since HTAs run on the local machine, you have access to everything you can do with VBScript for computation and file access, WMI for system management, program automation with COM objects, data access with ADO, and so on.
I once wrote an HTA that installs, updates, and compares Word templates on a user's machine from a common folder. The user can see their template folder next to the common folder to know if they are up to date, and hit the Update button if not.
Another one manages and verifies the installation of a program on a user's computer, copying over the exe if necessary, making sure registry entries are set correctly, putting a shortcut on the desktop, letting the user test and see the results of the installation, and so on. It also logs all of this info to a common place for me to check on.
One of my biggest HTA projects was a Project Manager system. The interface showed me all of the Excel, Word or Access projects I had going on. It would open the selected project in its particular environment, and showed me all of the pieces of it. It allowed me to import and export code modules from a common library using VBE automation (the Visual Basic Editor COM interface).
I'm about to put one together to show current and "dead" printer drivers on a user's machine. With me coaching them over the phone, they will run the HTA which will list all of the installed printers. They will put a check mark next to the ones they want to keep, then hit a button to delete all of the others. Fairly easy for them, and saves me from going to each and every PC to fix this.
Many of these kinds of things only make sense in a Windows environment, but you can write some pretty general purpose stuff with it too. Anything you can express in VBScript or JScript (JavaScript) and want an HTML/CSS front on is a good candidate for an HTA. I also even wrote a basic network chat system in it at one point.
There are lots of little HTAs around for converting data from one format to another, say converting comma separated data to columnar, or adding or removing various kinds of formatting like quote-printable escape codes, converting hex formatted text into plain text, and on and on. Copy text into one input text area, check a few options and press the Go button, then copy the converted data from the output text area. One I wrote was an SQL formatter. It would take SQL code and wrap it up as either a VB or Delphi string, and also
go from wrapped back to plain SQL code, with basic indenting and "pretty printing" to clean it up.
I don't do as much with HTAs as I used to, but still think they are a pretty cool technology for the kinds of jobs that fit in that niche.
See here for Introduction to HTML Applications (HTAs).
What are your opinions on developing for the command line first, then adding a GUI on after the fact by simply calling the command line methods?
eg.
W:\ todo AddTask "meeting with John, re: login peer review" "John's office" "2008-08-22" "14:00"
loads todo.exe and calls a function called AddTask that does some validation and throws the meeting in a database.
Eventually you add in a screen for this:
============================================================
Event: [meeting with John, re: login peer review]
Location: [John's office]
Date: [Fri. Aug. 22, 2008]
Time: [ 2:00 PM]
[Clear] [Submit]
============================================================
When you click submit, it calls the same AddTask function.
Is this considered:
a good way to code
just for the newbies
horrendous!.
Addendum:
I'm noticing a trend here for "shared library called by both the GUI and CLI executables." Is there some compelling reason why they would have to be separated, other than maybe the size of the binaries themselves?
Why not just call the same executable in different ways:
"todo /G" when you want the full-on graphical interface
"todo /I" for an interactive prompt within todo.exe (scripting, etc)
plain old "todo <function>" when you just want to do one thing and be done with it.
Addendum 2:
It was mentioned that "the way [I've] described things, you [would] need to spawn an executable every time the GUI needs to do something."
Again, this wasn't my intent. When I mentioned that the example GUI called "the same AddTask function," I didn't mean the GUI called the command line program each time. I agree that would be totally nasty. I had intended (see first addendum) that this all be held in a single executable, since it was a tiny example, but I don't think my phrasing necessarily precluded a shared library.
Also, I'd like to thank all of you for your input. This is something that keeps popping back in my mind and I appreciate the wisdom of your experience.
I would go with building a library with a command line application that links to it. Afterwards, you can create a GUI that links to the same library. Calling a command line from a GUI spawns external processes for each command and is more disruptive to the OS.
Also, with a library you can easily do unit tests for the functionality.
But even as long as your functional code is separate from your command line interpreter, then you can just re-use the source for a GUI without having the two kinds at once to perform an operation.
Put the shared functionality in a library, then write a command-line and a GUI front-end for it. That way your layer transition isn't tied to the command-line.
(Also, this way adds another security concern: shouldn't the GUI first have to make sure it's the RIGHT todo.exe that is being called?)
Joel wrote an article contrasting this ("unix-style") development to the GUI first ("Windows-style") method a few years back. He called it Biculturalism.
I think on Windows it will become normal (if it hasn't already) to wrap your logic into .NET assemblies, which you can then access from both a GUI and a PowerShell provider. That way you get the best of both worlds.
My technique for programming backend functionality first without having the need for an explicit UI (especially when the UI isn't my job yet, e.g., I'm desigining a web application that is still in the design phase) is to write unit tests.
That way I don't even need to write a console application to mock the output of my backend code -- it's all in the tests, and unlike your console app I don't have to throw the code for the tests away because they still are useful later.
I think it depends on what type of application you are developing. Designing for the command line puts you on the fast track to what Alan Cooper refers to as "Implementation Model" in The Inmates are Running the Asylum. The result is a user interface that is unintuitive and difficult to use.
37signals also advocates designing your user interface first in Getting Real. Remember, for all intents and purposes, in the majority of applications, the user interface is the program. The back end code is just there to support it.
It's probably better to start with a command line first to make sure you have the functionality correct. If your main users can't (or won't) use the command line then you can add a GUI on top of your work.
This will make your app better suited for scripting as well as limiting the amount of upfront Bikeshedding so you can get to the actual solution faster.
If you plan to keep your command-line version of your app then I don't see a problem with doing it this way - it's not time wasted. You'll still end up coding the main functionality of your app for the command-line and so you'll have a large chunk of the work done.
I don't see working this way as being a barrier to a nice UI - you've still got the time to add one and make is usable etc.
I guess this way of working would only really work if you intend for your finished app to have both command-line and GUI variants. It's easy enough to mock a UI and build your functionality into that and then beautify the UI later.
Agree with Stu: your base functionality should be in a library that is called from the command-line and GUI code. Calling the executable from the UI is unnecessary overhead at runtime.
#jcarrascal
I don't see why this has to make the GUI "bad?"
My thought would be that it would force you to think about what the "business" logic actually needs to accomplish, without worrying too much about things being pretty. Once you know what it should/can do, you can build your interface around that in whatever way makes the most sense.
Side note: Not to start a separate topic, but what is the preferred way to address answers to/comments on your questions? I considered both this, and editing the question itself.
I did exactly this on one tool I wrote, and it worked great. The end result is a scriptable tool that can also be used via a GUI.
I do agree with the sentiment that you should ensure the GUI is easy and intuitive to use, so it might be wise to even develop both at the same time... a little command line feature followed by a GUI wrapper to ensure you are doing things intuitively.
If you are true to implementing both equally, the result is an app that can be used in an automated manner, which I think is very powerful for power users.
I usually start with a class library and a separate, really crappy and basic GUI. As the Command Line involves parsing the Command Line, I feel like i'm adding a lot of unneccessary overhead.
As a Bonus, this gives an MVC-like approach, as all the "real" code is in a Class Library. Of course, at a later stage, Refactoring the library together with a real GUI into one EXE is also an option.
If you do your development right, then it should be relatively easy to switch to a GUI later on in the project. The problem is that it's kinda difficult to get it right.
Kinda depends on your goal for the program, but yeah i do this from time to time - it's quicker to code, easier to debug, and easier to write quick and dirty test cases for. And so long as i structure my code properly, i can go back and tack on a GUI later without too much work.
To those suggesting that this technique will result in horrible, unusable UIs: You're right. Writing a command-line utility is a terrible way to design a GUI. Take note, everyone out there thinking of writing a UI that isn't a CLUI - don't prototype it as a CLUI.
But, if you're writing new code that does not itself depend on a UI, then go for it.
A better approach might be to develop the logic as a lib with a well defined API and, at the dev stage, no interface (or a hard coded interface) then you can wright the CLI or GUI later
I would not do this for a couple of reasons.
Design:
A GUI and a CLI are two different interfaces used to access an underlying implementation. They are generally used for different purposes (GUI is for a live user, CLI is usually accessed by scripting) and can often have different requirements. Coupling the two together is not a wise choice and is bound to cause you trouble down the road.
Performance:
The way you've described things, you need to spawn an executable every time the GUI needs to d o something. This is just plain ugly.
The right way to do this is to put the implementation in a library that's called by both the CLI and the GUI.
John Gruber had a good post about the concept of adding a GUI to a program not designed for one: Ronco Spray-On Usability
Summary: It doesn't work. If usability isn't designed into an application from the beginning, adding it later is more work than anyone is willing to do.
#Maudite
The command-line app will check params up front and the GUI won't - but they'll still be checking the same params and inputting them into some generic worker functions.
Still the same goal. I don't see the command-line version affecting the quality of the GUI one.
Do a program that you expose as a web-service. then do the gui and command line to call the same web service. This approach also allows you to make a web-gui, and also to provide the functionality as SaaS to extranet partners, and/or to better secure the business logic.
This also allows your program to more easily participate in a SOA environement.
For the web-service, don't go overboard. do yaml or xml-rpc. Keep it simple.
In addition to what Stu said, having a shared library will allow you to use it from web applications as well. Or even from an IDE plugin.
There are several reasons why doing it this way is not a good idea. A lot of them have been mentioned, so I'll just stick with one specific point.
Command-line tools are usually not interactive at all, while GUI's are. This is a fundamental difference. This is for example painful for long-running tasks.
Your command-line tool will at best print out some kind of progress information - newlines, a textual progress bar, a bunch of output, ... Any kind of error it can only output to the console.
Now you want to slap a GUI on top of that, what do you do ? Parse the output of your long-running command line tool ? Scan for WARNING and ERROR in that output to throw up a dialog box ?
At best, most UI's built this way throw up a pulsating busy bar for as long as the command runs, then show you a success or failure dialog when the command exits. Sadly, this is how a lot of UNIX GUI programs are thrown together, making it a terrible user experience.
Most repliers here are correct in saying that you should probably abstract the actual functionality of your program into a library, then write a command-line interface and the GUI at the same time for it. All your business logic should be in your library, and either UI (yes, a command line is a UI) should only do whatever is necessary to interface between your business logic and your UI.
A command line is too poor a UI to make sure you develop your library good enough for GUI use later. You should start with both from the get-go, or start with the GUI programming. It's easy to add a command line interface to a library developed for a GUI, but it's a lot harder the other way around, precisely because of all the interactive features the GUI will need (reporting, progress, error dialogs, i18n, ...)
Command line tools generate less events then GUI apps and usually check all the params before starting. This will limit your gui because for a gui, it could make more sense to ask for the params as your program works or afterwards.
If you don't care about the GUI then don't worry about it. If the end result will be a gui, make the gui first, then do the command line version. Or you could work on both at the same time.
--Massive edit--
After spending some time on my current project, I feel as though I have come full circle from my previous answer. I think it is better to do the command line first and then wrap a gui on it. If you need to, I think you can make a great gui afterwards. By doing the command line first, you get all of the arguments down first so there is no surprises (until the requirements change) when you are doing the UI/UX.
That is exactly one of my most important realizations about coding and I wish more people would take such approach.
Just one minor clarification: The GUI should not be a wrapper around the command line. Instead one should be able to drive the core of the program from either a GUI or a command line. At least at the beginning and just basic operations.
When is this a great idea?
When you want to make sure that your domain implementation is independent of the GUI framework. You want to code around the framework not into the framework
When is this a bad idea?
When you are sure your framework will never die