Yeah it sounds pretty wild already with some kind of, like, door knock mechanism using certificates? So you can’t scan for it. And some reverse engineering countermeasures.
Like everyone else, I have to wonder what libraries have been compromised in a way that nobody has noticed yet.
Very annoying - the apparent author of the backdoor was in communication with me over several weeks trying to get xz 5.6.x added to Fedora 40 & 41 because of it’s “great new features”. We even worked with him to fix the valgrind issue (which it turns out now was caused by the backdoor he had added). We had to race last night to fix the problem after an inadvertent break of the embargo.
He has been part of the xz project for 2 years, adding all sorts of binary test files, and to be honest with this level of sophistication I would be suspicious of even older versions of xz until proven otherwise.
Damn. I would love to see a full post mortem on this compromise.
Very cool. Easily my favorite use for 3d printing.
Related, I think there are several sets of files for various RC cars I have run across. Would be kind of fun to download a whole (RC) car :)
You probably want to look for books on reverse engineering. And a book on assembly for your CPU.
I learned assembly language for VAX-11 (this was like 30+ years ago) in a CS class. We also learned 6502 assembly in a computer engineering class. Neither book would help you. You want a book specific to whatever CPU you’re using.
Now, I never took it, but friends in college took a CS Compilers course where they learned the basics of writing a compiler. But that’s not what you’re talking about though it might help.
Trying to understand what a program does is reverse engineering. And a tool like IDA Pro would help you understand subroutines, variables, flow, library calls, and so on.
A debugger will be invaluable for seeing a program execute one instruction at a time.
You would need to know the assembly language for your CPU. And it would help to become familiar with certain patterns. I haven’t done much assembly (but I have done assembly on a few different CPUs) nor much reverse engineering so I’m not sure I can lend a whole lot of insight there.
As you learn assembly instructions, you will start to understand how loops, subroutines, if/then/else, and other things are accomplished for your CPU.
For example, if/then/else and loops are often accomplished with conditional branching. The conditions are based on CPU flags (bits in the Status Register) that are set by a comparison instruction. You’ll start to recognize how if/then/else and loops and other things are commonly implemented in assembly (without necessarily having to study the compiler; it will be obvious without knowing anything but assembly).
Another example might be how C structs are implemented. Some CPUs provide convenient memory addressing modes for structs, some don’t. Nearly all I am familiar with provide a convenient way to reference arrays with a simple index.
Subroutines are jumps to a set location and at the end of that code is a return instruction. Usually registers have to be saved when jumping and restored when returning. Arguments to the subroutines are pushed on to the stack either by value or by reference. Return value is provided through some convention (machines with lots of registers might always use one particular one for return).
I guess bottom line, learn assembly for your particular CPU, then take a crack at using a debugger and disassembler / reverse engineering tool.
I’m not entirely sure I follow why that is needed to learn how to do branching in forth but I only vaguely remember that language. Maybe if I did it would be more clear.
Anyway I hope this helps at least a little.
As the other commenter said, you want to learn about programming principles. Like, low coupling or don’t repeat yourself.
How long is your longest program? What would you say is a typical length?
You say your code is “bad” – in what ways? For example:
I guess if you are unlikely to go back and change it, or understand how it works, then sure. And yeah that happens.
I write scripts and utilities like that. Modularity is overkill although I do toss in a comment or two to give a hint to future me, just in case.
Although tbf, I took plenty of CS classes and some of the instructors beat best practices into our heads… So writing sloppy, arcane, spaghetti code causes me to flinch…
How in …? Holy shit. I am so in awe of those writers. Now I gotta go back and rewatch all of TNG. Some day I will get all the references… Could take decades.
That’s kickass, way to go! Online learning is the way to go. I have a hard time learning stuff directly from a book (ADHD may be why idk). Something about the structure and pace and external motivation of a course does the trick for me. That’s how I learned AngularJS, anyway. All kinds of stuff you can do with Java: Desktop apps, web apps, etc etc.
My first thought is various utilities on my Linux systems.
It does look interesting—because it is boring—as one of the blog entries talks about. :)
The goal seems to be stability and simplicity. A language with few features that remains mostly unchanged for the long term, to write simpler programs that can be counted on to do what they’re supposed to for the long term.
I like it. I will have to give this a whirl.
Dumb question: what qualifications are needed to do medical research?
I can probably manage PQ (potato quality)
John McClane, his feet sliced
It sounds like he couldn’t get a break, couldn’t find a home, never found the key to success, and likely felt this job was the wrong type.
We can’t help ourselves.
Murder She Wrote is awesome. It’s a lot of fun seeing familiar faces on shows like that. Especially if it is before they hit it big.
For years, in fact.
Did someone say “dino nuggies”??
Shopping for what?
I have a feeling there are a lot of busy people trying to answer that question, now. Yikes.