I have my own hexdump file utility (Windows & Linux version both got). The problem is, I don't know yet how to create a hex editor.

The file reading and writing part is OK to me. The hex conversion is OK to me as well.

Just that I don't understand what is the form control to edit each of the hex values, and also that one to edit the ASCII string.



I can't put text box there, because when user delete a character, its adjacent character isn't shifted.
And I am not sure whether to put multiple "form control" for each hex bytes or not.

Does anyone plan to write a hex editor in the future? Do you know how to do it? Not necessarily in C#.

if existing tool is good enough to complete all the tasks,
no plan to create similar tools which is almost never used again.

p/s : just download some working hex editor if needed.





This post has been edited by flashang: Sep 11 2022, 11:15 AM

I am thinking of MaskedTextBox (an enhanced text box control) but it is still not perfect.

And I am not commercializing my hex editor, it is just fun learning how to do it.

I use Visual Studio built-in hex editor, by the way.

Thanks for your reply.

I try to analyse how hex editor work, and required "module" :

1. open file, and display 2 areas : hex / ascii (for non-display character, you may need to use some symbol).

2. allow user to edit (insert / overwrite) on ascii area, and update changes on hex area.
* this should be similar to normal text editor.
* this could be improved to accept special non-display character.

3. allow user to edit (insert / overwrite) on hex area, and update changes on ascii area.
* the challenge should be how to handle hex input.

4. save.

What would be nice is a hex editor that can output something like this, that matches bytes against structures.

https://n0.lol/sk_buff.png (created by netspooky).

I've yet to find a hex editor that can display data like this. The image is just some internal notes when netspooky is analyzing some Linux kernel structures.

A big bonus would be something that can properly support ASN.1 PER.

This post has been edited by junyian: Sep 11 2022, 06:08 PM

Nice diagram.

For that kind of hex editor to work, maybe can first open a file in binary mode, and then let user to import a C header file, such as winnt.h (or in the diagram, skbuff.h), so that the hex editor can do the mapping.

I am totally new to "Abstract Syntax Notation One", according to Wikipedia, it is broadly used in telecommunication (your job industry ) and computer networking, such as cryptography (your hobby ).

Or a self-created header file. It's useful when dealing with common file formats, like PE, ELF, PNG, etc., or custom ones.

Yup, ASN.1 is used in many industries There are a few types of encodings. If I remember correctly, cryto typically uses BER. Telecommunications typically uses PER, which is a little bit painful.
ASN.1 is simply an encoding format though. There is the ASN.1 notation that defines how data is stored, a bit like C header files.
Here's a taste of how it looks like.