Author Topic: Assembly tutorial  (Read 10218 times)

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Offline iago

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Assembly tutorial
« on: March 13, 2007, 12:00:43 am »
So I was going to walk dlStevens through my standard assembly reference this weekend. Instead, I decided to write a guide that anybody can use. It's supposed to be a beginner's guide. Knowing C is a definite asset, and some programming experience is probably a requirement.

I've only made it to the first example so far, which is the Starcraft CDKey checker (when you're installing the game). The ultimate goal is to show some cracking, keygen-writing, some buffer overflow exploitation, and writing a hack for a game (very basic, for an old version, but that's beside the point). I pretty much want to cover all the cool stuff. If this goes well, I might extend it to do some other neat things, depending on what people want.

Plus, I finally get to use the domain name I bought a few months ago :)

http://www.skullsecurity.org/wiki
« Last Edit: March 13, 2007, 12:18:15 am by iago »

Offline Newby

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Re: Assembly tutorial
« Reply #1 on: March 13, 2007, 12:10:37 am »
That's awesome. :)
- Newby
http://www.x86labs.org

Quote
[17:32:45] * xar sets mode: -oooooooooo algorithm ban chris cipher newby stdio TehUser tnarongi|away vursed warz
[17:32:54] * xar sets mode: +o newby
[17:32:58] <xar> new rule
[17:33:02] <xar> me and newby rule all

I'd bet that you're currently bloated like a water ballon on a hot summer's day.

That analogy doesn't even make sense.  Why would a water balloon be especially bloated on a hot summer's day? For your sake, I hope there wasn't too much logic testing on your LSAT. 

Offline iago

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Re: Assembly tutorial
« Reply #2 on: March 13, 2007, 12:13:00 am »
I should mention, I've done absolutely no proofreading, anybody feel free to look for grammar/spelling mistakes and fix them.

Offline d&q

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Re: Assembly tutorial
« Reply #3 on: March 13, 2007, 01:06:58 pm »
I should mention, I've done absolutely no proofreading, anybody feel free to look for grammar/spelling mistakes and fix them.

I have been doing so, but I have not been able to create an account:
Code: [Select]
Fatal error: Call to undefined function mail() in /home/ron/skullsecurity/wiki/includes/UserMailer.php on line 152
Scratch that, I just cannot input an email address.  :'(
The writ of the founders must endure.

Offline MyndFyre

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Re: Assembly tutorial
« Reply #4 on: March 13, 2007, 02:31:03 pm »
Ooh! Can I write stuff about coding security practices?
I have a programming folder, and I have nothing of value there

Running with Code has a new home!

Our species really annoys me.

Offline Chavo

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Re: Assembly tutorial
« Reply #5 on: March 13, 2007, 04:31:07 pm »
IMO, making sure someone completely understands addressing needs to be understood before they jump into larger examples.

Offline iago

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Re: Assembly tutorial
« Reply #6 on: March 13, 2007, 05:59:34 pm »
I spent a good part of today working on it, especially the "stack" section and the examples. So if anybody wants to have a look, there's plenty more content there!

Oh and I realized the humor today on a site about x86 by x86.. :)

Ooh! Can I write stuff about coding security practices?
I've been aiming more from the taking-stuff-apart side, but of course the more content the better.

What did you have in mind, specifically? Could it be part of a section other than "Assembly", or does it still fit with that?

IMO, making sure someone completely understands addressing needs to be understood before they jump into larger examples.
How do you mean, exactly? I went over a little bit about memory in the first page, but not a whole lot. What, specifically, do you think I should talk about?

Keep in mind that this guide is for reading assembly, not writing it, so I didn't bother with a lot of the boring addressing stuff I learned back in school, only what I find I actually use. But I'm open to suggestions if you think there's anything specifically I ought to mention.

Offline iago

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Re: Assembly tutorial
« Reply #7 on: March 13, 2007, 08:56:38 pm »
I fixed it so that the image in the top-left corner randomly chooses an image from OSPAP and resizes it. :)

(Up till now, it was just a selection of static images)

Offline abc

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Re: Assembly tutorial
« Reply #8 on: March 13, 2007, 09:09:55 pm »
I LOVE IAGO!

Offline iago

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Re: Assembly tutorial
« Reply #9 on: March 13, 2007, 10:12:24 pm »
I LOVE IAGO!
It's encouragement like that that'll help me finish this :)


Also having nothing to do at work helps...

Offline Joe

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Re: Assembly tutorial
« Reply #10 on: March 13, 2007, 11:29:49 pm »
I LOVE IAGO!
It's encouragement like that that'll help me finish this :)


Also having nothing to do at work helps...


Well, in that case:

I LOVE iAGO!
I'd personally do as Joe suggests

You might be right about that, Joe.


Offline abc

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Re: Assembly tutorial
« Reply #11 on: March 14, 2007, 07:32:49 am »
I always thought I'd never understand ASM, but (seriously) since iago's tutorials I've *actually* understood quite a lot.

and I love it!

Offline Chavo

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Re: Assembly tutorial
« Reply #12 on: March 14, 2007, 02:48:43 pm »
How do you mean, exactly? I went over a little bit about memory in the first page, but not a whole lot. What, specifically, do you think I should talk about?

Keep in mind that this guide is for reading assembly, not writing it, so I didn't bother with a lot of the boring addressing stuff I learned back in school, only what I find I actually use. But I'm open to suggestions if you think there's anything specifically I ought to mention.
I suppose if you are just reading the code, its not as big of a deal but there is a huge difference between stack addressing / extended addressing / relative addressing / etc that can cause all kinds of problems if you don't know which to use when and how to figure out what the effective address of any given operand is.

Offline iago

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Re: Assembly tutorial
« Reply #13 on: March 14, 2007, 04:13:47 pm »
I suppose if you are just reading the code, its not as big of a deal but there is a huge difference between stack addressing / extended addressing / relative addressing / etc that can cause all kinds of problems if you don't know which to use when and how to figure out what the effective address of any given operand is.
Yeah, that's not terribly important. I go over relative addressing very briefly, in like one sentence, and I talk about the stack a lot. But I don't talk about any kind of variable storage other than the stack, because when you're reading assembly that's pretty much common sense.

Also, I don't know enough about addressing to confidently talk about that, either.

Offline Chavo

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Re: Assembly tutorial
« Reply #14 on: March 15, 2007, 02:20:51 pm »
Maybe I'll add something then when I have the time.