Alek

x86/MASM32, C++, Reversing, and Nostalgia

[Alek @alekasm0]

@ModernVintageG Assuming you're using an API layer like DirectX or OpenGL? Lighting looks really nice.

[Alek @alekasm0]

@lazygamereviews Sorry to hear that man, can't imagine what you folks are going through.

[Alek @alekasm0]

@didyouknowgamin @hard4games I'm going to watch the whole thing, but I better see SimCopter.

[Alek @alekasm0]

@RetroWorldExpo @lazygamereviews Oh dang this is really close to me

[Alek @alekasm0]

@lazygamereviews Cahoots is amazing; he made a lot of great mods for Streets/Copter.

[Alek @alekasm0]

@LordEnum Yeah they experimented with that a bit in SafeDisc 1 as part of the checks. They had an int3 thats supposed to be caught as an exception by the program - with a debugger attached it just catches the exception and crashes. Sounds like a couple of new tricks hah!

[Alek @alekasm0]

Still on SafeDisc DRM cracking. Since the EXE is essentially the same thing as the DLL, I wrote my own ICD loader that does the same thing as SafeDisc (SetThreadContext injection). Still working on finishing the DPLAYERX bypass - had to rewrite reloc table used in decryption.

[Alek @alekasm0]

@LordEnum All that use the ICD, since the bypass involves injecting DPLAYERX, setting up the shared memory region, and then decrypting the ICD. I know they stopped using the ICD at some point, but I'm sure it's probably similar? You mean SafeDisc 4.6? Didn't know it went that far!

[Alek @alekasm0]

@LordEnum Thanks I've been working on a complete bypass for many months and it's quite complicated. This includes decryption of the .txt section, setting up the shared memory regions, performing the injection, passing the hash checks in the dll, etc. Hopefully I finish soon.

[Alek @alekasm0]

@lazygamereviews LAN Multiplayer works without any modification, you should definitely get some footage!

[Alek @alekasm0]

@lazygamereviews Oh yeah, now we're talking.

[Alek @alekasm0]

I was able to get the SafeDisc v1 DRM wrapper executable to decrypt with breakpoints, modifications, and without the kernel driver. Very soon you'll be able to bypass any SafeDisc v1 DRM by just specifying the .exe file to my analyzer. https://t.co/I0FNSP5h90

[Alek @alekasm0]

One of my favorite tricks from SafeDisc; rewrote it in C for those who are unfamiliar with x86. Apparently this works on 64-bit too?

[Alek @alekasm0]

In other words, an encrypted executable segment is xor'd 32 times with a rolling key - then xor'd again with an existing decrypted executable segment (assuming to check for modifications).

[Alek @alekasm0]

I've been working on removing SafeDisc DRM from Jane's F18. Besides the anti-disassembly, anti-debugging, and kernel level drivers that I've bypassed - I decided to hand-convert their 2-stage decryption from assembly. The following is how you decrypt 8 bytes.

[Alek @alekasm0]

In case anyone is interested in dumping ROMs from hardware, I wrote a little article on where to get started. https://t.co/3XZRdUfuVI

I show a demo of ripping printer firmware, but I'd like to start saving ROM data off old GPUs/Mobos.

https://t.co/M3cZZ9qYby

[Alek @alekasm0]

@itstheshadsy It's actually going to get way worse because modern games are much more likely to have online functionality (ie multiplayer, Steam API integration) - or some sort of intrusive DRM. In my case, it will be hard to retain definitive versions of games. Nice read!

[Alek @alekasm0]

@NPCxGOD It really boils down to time, I have a bunch of projects I'm working on so whenever I get around to it really.

[Alek @alekasm0]

Wrote a little article on setting up and using the LicheeRV Dock RISC-V board with UART only. I'm pretty interested in RISC-V and it may take over the RaspberryPi (and clones) ecosystem in the near future.

https://t.co/LjFXAu3LUN

[Alek @alekasm0]

Working on a CD-ROM patch Jane's FA-18, which uses SafeDisc DRM. It appears most bypasses go after the driver which gets installed directly, this is problematic because the driver apparently doesn't work with modern Windows and has vulnerabilities. Sanitizing the entire game...