I have an application and posted to Cydia recently. It has been cracked by someone else and posted it in torrent sites. I have a binary checksum verification mechanism inside and they were able to create a new checksum file based on the changes they have made to the binary. They have edited two functions and decompiled it and posted it to torrents.
I saw that it's possible to see the actual implementation of functions and classes. But in order to edit the functions they have to find the address of that function and edit it via HEX EDITOR. I don’t want to make it "unhackable", but I really want to find out how they hack.
How can I edit a function in an iOS binary and re-compile it? For example I have a following method in one of my classes.
- (id) getSomething {
return #"Something";
}
I want to edit the return value of this function. Is that possible?
Usually, you don't "re-compile" it. Just feed the file to IDA, look for strings, function calls or whatever you are looking for and then use a hex editor or similar to edit the file on assembly level. In most cases it's enough to simply change a conditional jump into an unconditional jump or a nop (no operation). If you want to change return values, you have to put a little more effort into it, but in my experience you either edit the char sequence right inside the binary file, if it's specified as a constant or initial value - or you just write a completely new function and "copy" the assembler code of it into the original file. You just have to make sure your new function does not take more space than the original - or everything's getting a lot more complex.
I hope that's what you were asking for, otherwise just tell us which app you are talking about and we can look deeper into it :)
Related
I want to make a small "library" to be used by my future maxima scripts, but I am not quite sure on how to proceed (I use wxMaxima). Maxima's documentation covers the save(), load() and loadFile() functions, yet does not provide examples. Therefore, I am not sure whether I am using the proper/best way or not. My current solution, which is based on this post, stores my library in the *.lisp format.
As a simple example, let's say that my library defines the cosSin(x) function. I open a new session and define this function as
(%i0) cosSin(x) := cos(x) * sin(x);
I then save it to a lisp file located in the /tmp/ directory.
(%i1) save("/tmp/lib.lisp");
I then open a new instance of maxima and load the library
(%i0) loadfile("/tmp/lib.lisp");
The cosSin(x) is now defined and can be called
(%i1) cosSin(%pi/4)
(%o1) 1/2
However, I noticed that a substantial number of the libraries shipped with maxima are of *.mac format: the /usr/share/maxima/5.37.2/share/ directory contains 428 *.mac files and 516 *.lisp files. Is it a better format? How would I generate such files?
More generally, what are the different ways a library can be saved and loaded? What is the recommended approach?
Usually people put the functions they need in a file name something.mac and then load("something.mac"); loads the functions into Maxima.
A file can contain any number of functions. A file can load other files, so if you have somethingA.mac and somethingB.mac, then you can have another file that just says load("somethingA.mac"); load("somethingB.mac");.
One can also create Lisp files and load them too, but it is not required to write functions in Lisp.
Unless you are specifically interested in writing Lisp functions, my advice is to write your functions in the Maxima language and put them in a file, using an ordinary text editor. Also, I recommend that you don't use save to save the functions to a file as Lisp code; just type the functions into a file, as Maxima code, with a plain text editor.
Take a look at the files in share to get a feeling for how other people have gone about it. I am looking right now at share/contrib/ggf.mac and I see it has a lengthy comment header describing its purpose -- such comments are always a good idea.
For principiants, like me,
Menu Edit:configure:Startup commands
Copy all the functions you have verified in the first box (this will write your wxmaxima-init.mac in the location indicated below)
Restart Wxmaxima.
Now you can access the functions whitout any load() command
I know my question is rather generic (and it looks like "please do all of my work for me"), so let me make it somewhat clearer: I'm - more or less - a COBOL beginner, the only thing I've done with it so far was a small FastCGI application for a single-serving page, just to have done something with it.
Now I'm considering to write a small file server in GnuCOBOL so I have something real to work with. I tend to learn new languages by writing stuff in them. While I do have an idea about how to read and process a specific file now, I still could need a clue about how I can collect and handle a specified directory's contents.
Sadly, the system calls C$LIST-DIRECTORY,x"91" function 69, CBL_DIR_SCAN_START and its sibling methods are still on the GnuCOBOL Wish List, so I can't just adapt existing solutions from the commercial COBOLs. I'm somewhat lost here.
call "system" using "dir /b > fileslist.txt" end-call
And then read in the listing file ...
I like using .fsi signature files to control visibility. However, if I have both Foo.fsi and Foo.fs files in my solution, and #load "Foo.fs" in a script, it doesn't seem like the corresponding signature file gets used. If I do:
#load "Foo.fsi"
#load "Foo.fs"
... then the desired visibility control happens. Is this the recommended way to achieve this, or is there a better way to do it? In a perfect world, one would like to see the signature file automatically loaded, too.
Not a final answer, but a better way.
From reading Expert F# 4.0 one can do
#load "Foo.fsi" "Foo.fs" "Foo.fsx"
All three loads are on one line.
TL;DR
The link to the book is via WolrdCat just put in a zip code and it will show you locations near there where the book can be found.
Hi I use interop to call C# code in Delphi.
C# code has a binary and in Delphi 5 Menu: Project-->Import Type Library
Click Add to add the tlb file: XXXX.tlb
Unit dir name: input the path where the delphi XXX_TLB.pas file is generated.
If the C# dll, tlb and delphi XXX_TLB.pas has already been there. Now I add one more function in C# code and hope Delphi can call this function as well. I need to recompile c# and regenerate delphi XXX_TLB.pas file. But by following the above steps, I see the newly generated XXX_TLB.pas includes my newly added function, but looks like the functions order in XXX_TLB.pas is totally different from before.
For example, in my C# binary I have function:
func1();
func2();
func3();
func4();//newly added
In the old XXX_TLB.pas, the function order is:
func1();
func2();
func3();
Now XXX_TLB.pas is like this:
func1();
func3();
func4();
func2();
The XXX_TLB.pas can still be used, looks like no functionality difference, but when I check in to tfs, I see it changes a lot from pervious version. Is there a way to keep this new XXX_TLB.pas the same order as before but add my function as well? How to do that? Thanks!
You cannot hope to keep the changes to a minimum unless you start writing the .pas file yourself. That sounds like a worse option.
Probably what is happening is that you have changed version of either one of your compilers since the last time you imported. Otherwise one would expect minimal differences.
Just check it in with a comment stating which versions of compiler and .ocx/.dll were used.
You can't, as far as I know.
I most cases, I'm able to consider them as a sort of "black box" anyway, and only occasionally have to peek in them to find a specific declaration.
I'm working in a Delphi IDE expert and I wonder if it's possible add new items to the code completion combobox displayed by the Delphi IDE when the user press CtrlSpace
UPDATE:
What I need is add items to the code completion list based in a specified type.
example suppose which I have a type called TMytype, what I want to do is add addional items to the code completion list when the user type a variable of the type TMytype
check this image
I found your question somewhat confusing but if you are in search of credible source on "Custom Live Templates" and the like on Delphi, head to the blog of Cary Jensen here.
Edit:
Looking forward to further improvement of the scope of the question, I suggest here another direction to explore:
Source code manipulation using IOTAEditor, IOTASourceEditor, IOTAEditReader and the like
Some Parsing for sanity check prior to apply any modification.
Adoption of Client DataSet as a format to store data (It's serializable) to simplify the coding of IDE editors.
Perhaps I haven't fully grasped the extent of what you are asking here, but you can add templates simply by going to 'View|Templates' from the Delphi IDE. This then opens a template viewer. Press the '+' icon. It opens a template1.xml document which you can then edit so create your new item.
If you wish to do this programatically, just add an xml file (of the same format) to the ..\RAD Studio\code_templates folder.