Introduction to Return Oriented Programming
Source: Davee's Blog
This will be a small introduction into return oriented programming, commonly referred to as ROP. I've had a lot of experience with security measures (duh) but never really had any hands on experience with more modern security technologies such as non-executable stack/data (DEP, NX, XN, W^X) or Address Space Layout Randomisation (ASLR).
The non-executable stack isn't really limited to just the stack, anything that isn't code memory can't be executed. So as in PSP, you can't just jump to the savedata and have the day's work done. No, instead the only code executable is real code provided by the OS when binaries are loaded. This is a nice and funky way but ROP is the counter and tends to poop on this method.
PSVita Native Hack, c'mon devs!
Source: Davee's Blog
Just to start, congratulation to yifanlu for his excellent work on gaining the first vita native hack. I'd like to note that I'm just relaying information from a forum post by yifanlu and did not have any input on yifanlu's work, it's all his!
Also, if you're not a developer, please note that there is currently no way to run homebrew, colour your screen, download binaries, hack your device, make a milkshake from 10 miles away or such. This post is purely informational.
Continuing on, considering my audience gathers quite a few developers I think this post should complement the cause. So, if you don't know, vita dev yifanlu has been looking around for developers who are interested in developing native software on the vita. He is calling out for developers to help him develop an ELF loader.
I'm baaaack!
Source: Davee's Blog
Well, this place has been cleaned up a little bit and I can log back in again. You might of noticed that I've changed the theme, and you'll probably find out that I do this often!
Well this post is going summarise what the hell I've been doing since my last post in terms of development and perhaps you'll be disappointed. Follow the link and find out!
Kermit
Source: Davee's Blog
Turns out he's not just a green frog! So, I've been throwing this word around recently and it's probably about time I explain. Kermit, either a protocol or perhaps a funny name (see KIRK/SPOCK) is a communication interface for the PSP emu. Specifically it allows the PSP to talk to the host.
Now, I can tell there aren't as many developers here, so I'll try to simplify for the curious minds but this stuff is pretty complicated. I'll only explain the API in detail as the lower level still need a little bit of clearing up, but here goes.
PS Vita PSP HEN
Source: Davee's Blog
First thing first, huge thanks to Proxima and some1. They've provided key utilities and advice for this research. So, yeah, it was really only a matter of time till this kind of thing happened. Sony dont just emulate the userland process of a PSP game, they emulate the entire kernel albeit, a modified kernel. The PSP emu has limited access to hardware, with interfacing the hardware done via a Kermit module. Kermit is a old-timers transmission protocol, likely used to talk to the native Vita.
Can you crack it? + Solution
Source: Davee's Blog
Thanks to a facebook message from my dad yesterday, I was informed of this website: Can you Crack it?. So, promptly, I got onto the job and it was surprisingly easy and I imagine it will be for most people who can reverse engineer and has experience doing so.
Click read more to see how I did it, but I suggest you have a good attempt beforehand. It's a nice little reverse engineering exercise.
"Chronoswitch" Downgrader 5.0. Advanced 09g Support!
Source: Davee's Blog
As an ongoing project, me and some1 have been enhancing this downgrader from birth on the 6.31/6.35 firmwares. This multi-firmware downgrader allows you to install a lower (or higher) firmware without any fuss. No complex flash0 sharing, just running the firmware update.
However, there comes restriction with PSP models and compatible firmware. For example, a PSPgo cannot run 1.50 as there are no drivers for the system and the IPL format is incompatible. Much like this, the PSP 3000 09g is unable to install firmwares < 6.30 which removes it's ability to appreciate the flexibility of permanent custom firmware.
This is no longer the case.
Emma is not well :(
Source: Davee's Blog
It sucks, my beautiful girlfriend's fallen pretty ill and I want her to get real better soon. If you could spare some time I'd appreciate if you'd drop a comment. Hopefully she'll be up and running soon again!
She's suffering from some migraines and it's causing her a lot of pain. Leave something to help cheer her up, it'll mean a lot to me!
Love you Emma :D <3
Cheers guys.
Arduino projects.
Source: Davee's Blog
Well, I'm no beginner to electronics, but this is my first microcontroller that can directly interface them! So yeah, pretty cool, never messed with AVR in my life, always used PIC for my USB controller. So I've been messing around a bit and I've done some very basic stuff working with components here and there.
Read on to see the stuff I've done.
KIRK 0x10 Private Key
Source: Davee's Blog
The private key for the KIRK 0x10 functionality is known to be stored in a encrypted buffer of 0x20 bytes. Proxima discovered that the KIRK 0x10 operates as this:
Invocation:
u8 buffer[0x34]
u8 encryptedprivatekey[0x20] - the private key returned by KIRK 0xC must be AES encrypted somehow
u8 SHA1hashofmessagetosign[0x14]
memcpy(buffer,encryptedprivatekey,0x20)
memcpy(buffer+0x20,SHA1hashofmessagetosign,0x14)
sceUtilsBufferCopyWithRange(newsig,0x28,buffer,0x34,0x10);
newsig will have the r and s values for an ECDSA signature
This isn't that useful since it is not clear how to encrypt the private key to sign the message. There are some examples in IDStorage where a pre-encrypted private key and public key pair can be used, but no general cases yet.
A look at the TA-88v3 IPL Hash.
Source: Davee's Blog
First a huge thanks to Gusha for his huge support donating a lot of time for testing stuff on his TA-88v3, cheers mate! This post I'll describe what I have found out so far with the TA-88v3 and provide a model representing the security and operation of the TA-88v3 pre-IPL. Unfortunately, the hash has not been broken but this could be some useful information.
6.35 and 6.31 Downgrader
Source: Davee's Blog
Sony, being as sneaky as they are decided to do a rather interesting move. As researched by Coyotebean, Sony started enforcing using a public key method of verifying KIRK data and removing the ability to load the old types of data. As they did this, firmware 6.30+ cannot decrypt the updater and the PRX inside and therefore cannot use the index.dat spoofing to downgrade.
Arcanum.
Source: Davee's Blog
Now that 6.20 TN-A is out in the open, allow me to describe the kernel vulnerability used. Back in 5.70/6.00 Sony introduced a feature into the sceUtility_private library that allowed to set and unset a callback with kernel privileges.
sceUtility_private_2DC8380C // release (unset) power callback
These two functions are not normally imported so they require some special techniques such as syscall estimation to reach them in order to utilise their functionality.
Now, how does this kernel exploit work?
lolhax ep1: info and turtle love
Source: Davee's Blog
Well, finally decided that I'll update this blog... hopefully I'll remember to do so in the future also! Yep, life is busy just now, school, school, school so not much time for code or stuff. In the meantime, I guess all I can do is end this with a rather epic video. The romance of a turtle and a cat.
Interesting, huh?
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Wooooo! I have a blog!
Source: Davee's Blog
Hello everyone, this is my blog! After owning x-fusion for nearly four years, decided I should get a new domain, hence this blog.
I've never had a blog before, so bear with me whilst I get used to all this fancy software (currently using wordpress atm). Back to the point, I made this blog in order to share research and post stuff that interest me when I see them. I'm currently actively working on the PS3 and the PSP so no doubt I'll post some information regarding whatever I find.
In specifics, I am working on the PSPgo privately researching the firmware and the hardware for changes between the previous models. I am also actively working on the lv2 reverse-engineering of the PS3.
In other notes, I am ment to be playing at a music festival with my band on the 29th May, 2010. So, I'm looking forward to that. If you didn't know I play in a band called "Guide the Light". You should check us out, I mean we played with Pearl and the Puppets (who are really good and you should also check out).
Anyway, think I'mma finish off there, ran out of things to say.
- Davee 2010
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