explain me this byte generation

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Teehee

Joined: 05 Aug 2009
Posts: 570
Location: Brazil

Teehee 22 Aug 2012, 22:48

This generates 4 bytes

Code:

use32
mov eax, [eax+ebx*2+0xF]  
8B 44 58 0F

This generates 7 bytes

Code:

use32
mov eax, [eax+ebx*2+0xFF]  
8B 84 58 FF 00 00 00

This generates 4 bytes

Code:

use32
mov eax, [eax+ebx*2+0xFFFFFFFF];
8B 44 58 FF

Why?
Thank you

_________________
Sorry if bad english.

22 Aug 2012, 22:48

revolution
When all else fails, read the source

Joined: 24 Aug 2004
Posts: 20451
Location: In your JS exploiting you and your system

revolution 22 Aug 2012, 23:34

8-bit signed values (-0x80 to 0x7f) have a short-form encoding. It is explained in the Intel and AMD manuals.

22 Aug 2012, 23:34

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