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Using Ghidra to Reverse Engineer Super Monkey Ball for GameCube
- 2pEXgD0fZ5cF 6y agoCan anybody recommend some good resources and/or books (or some kind of roadmap) to get into practical reverse engineering "starting from zero" (as in: a person with general higher level programming experience)?
- ackbar03 6y agoMy 2 cents is do some CTF questions. PicoCTF's are good for beginners, they have a good progression in difficulty. And once your more or less proficient then just crack some software. Find something old, like protected by purchasing key or whatever, and on the simpler side, don't go straight for photoshop or whatever. Its gonna take a long time but even if you don't succeed you'll get a much better feel for it in the process. Best way to learn is by doing, thats my experience anyways.
- _joel 6y agoThere's places like https://crackmes.one/ https://crackmes.one/ too
- walls 6y ago'Practical Malware Analysis' was required reading for all RE candidates at my previous job. It's very windows focused but teaches skills that are (somewhat) easily transferable.
- elitepleb 6y agohttps://beginners.re/ https://beginners.re/
- blinkingled 6y agoI think the author made these available for free in the past but now they are paywalled. (Nothing wrong with that at all, just thought it would help others trying to find the download on the site.)
- coldpie 6y agoHey, article author here. I'm not very good at this stuff, it's just applying knowledge I've picked up over my career working in systems-level programming and various little game hacking projects. The one thing I'd say is a real pre-requisite is to learn C. And I mean really learn C: pointers, including arithmetic and aliasing; memory allocation; stack vs heap; statics and globals. C is the lingua franca of this environment, and learning C will give you a good window into what the compiler is doing to turn your code into what's actually running on the CPU. It's also good to understand how computers actually work. I strongly recommend the book "Code" by Charles Petzold (Microsoft Press, be wary of counterfeits and don't buy from Amazon). It starts literally from scratch. Like, light bulbs with electricity and a switch. Then it builds on that to create a fundamental CPU, and then shows how to go from there into the real CPUs used today, including an introduction to assembly language and machine code. It's a fantastic book if you ever want to do anything low-level on a computer. Once you've got C and a basic level of understanding of assembly/machine code, I think you're ready to do something real. Start simple. The NES runs on a 6502, which is 8-bit, has three registers and only a handful of opcodes, and is single-threaded. In the past I've used FCEUX-DSP's debugger features[1], but I think these days most people use Mesen. You can use the same basic techniques I did in these articles: scan memory for the values you want (the player's score or life count; the player character's velocity), then set watch points to find the code that modifies them, then go understand what that code is doing and change it to do what you want. Give yourself infinite lives or a crazy high jump in Super Mario Bros or something. From there you can move on to more modern CPUs and such, but the complexity goes _way_ up once you move on from environments where most stuff was actually written in ASM or very simple C without fancy compilers. I was very relieved to see how readable Super Monkey Ball's disassembly actually was. [1] My first real game RE project was dumping PNG pictures of the levels in M.C. Kids for NES, for comparison on TCRF: https://gitlab.com/mcmapper/mcmapper/-/blob/master/main.c https://gitlab.com/mcmapper/mcmapper/-/blob/master/main.c https://tcrf.net/Proto:M.C._Kids https://tcrf.net/Proto:M.C._Kids
- samwestdev 6y agoThe book "Code" is by Petzold Charles
- JohnCurran 6y agoThis gets asked a fair bit. Here's an HN link tree you can follow to get you started: https://news.ycombinator.com/item?id=26296951 https://news.ycombinator.com/item?id=26296951
- dilDDoS 6y agoHackTheBox (hackthebox.eu) has some great reverse engineering challenges that you can learn a lot from, and have a clear difficulty progression. The non-retired challenges are all free with a basic account, but if you're starting from scratch, it might be beneficial to try out a premium account to access retired challenges (and their associated write-ups).
- bumbada 6y agoFor learning programming I always recommend that you have a specific project in mind, so instead of following a book, you follow your project's needs and use books as a reference. I learned (intel x86)assembly from joining a cracking group when I was adolescent, it was my first programming language. Nothing beats being taught by masters of the craft and competing and contributing as a team. Today I teach kids ARM assembly using microcontrollers like arduino unos or nanos and controlling a motor or servo, then I add more and more complexity like explaining klipper architecture, so they learn c and python. With kids, the social part is very important, and making real things that move and react on the real world too. I suspect is of great help for adults too. It is probably too dull to learn assembler today, on your own (alone) on a powerful computer. With a microcontroller you have a machine that is so constrained in resources that you really need to use c or assembly. HN has very good resources about assembly, you can search them on google "hacker news assembly" or "hacker news reverse engineer", use zotero to aggregate the links.
- pluc 6y agois your answer to "how do I learn to reverse-engineer things" to learn Assembly? If so why?
- secondcoming 6y agoBecause if you're dumping binaries, or attaching to running processes, you'll be looking at assembly code.
- pjc50 6y agoWell, the assembly is literally all you have, so you're not going to make much progress otherwise..
- barbecue_sauce 6y agoPretty sure that's the whole basis of reverse engineering.
- deleted 6y ago[deleted]
- NtGuy25 6y agoAs someone else said. Practical Malware Analysis is great. The ghidra book by Eagle is also decent as well. The best thing for RE learning though is to use Visual Studio to write a few programs. From the debugger view you can use the assembly, and see what your program ends up in. You also want to think about it as the programmer. You have a MASSIVE program. You want to see where it creates files. You know that on windows, it HAS to go through CreateFile, or at least NTcreatefile function or system call. So you can watch for these, or look where they are called in Ghidra. Now you can mark all the functions in the chain using xrefs (What references this) and then get all the functions that use createfile out of the way! And lastly, as a programmer, you know the apis. So think of what cases someone would use printf for example. There's not many. You know by the use of printf, there's some sort of logging at that location. If they use openfile. You have a good idea that all the code surrounding that call is going to be about the file being opened. TL;DR. Start from api calls, and work backwards. Use your knowledge as a dev for what these api calls are used for. And walk that call chain and mark. Eventually every function is mapped.
- Cloudef 6y agoGet a debugger and disassembler. Read their manual.
- jhatemyjob 6y agopokered or pokecrystal
- yomansat 6y agoThis series, for reverse engineering a multi-player game that's meant to be hacked: https://www.youtube.com/watch?v=RDZnlcnmPUA&list=PLhixgUqwRTjzzBeFSHXrw9DnQtssdAwgG&ab_channel=LiveOverflow https://www.youtube.com/watch?v=RDZnlcnmPUA&list=PLhixgUqwRT...
- 0x003 6y agoCrackmes are how I got into it. crackmes.one has a bunch of good ones. I whipped up a quick and easy one here for you you can run it if you want but it doesn't need to be run (generally don't run random executables you download off the internet) just load it in ghidra/radare/<decompiler of choice> and figure it out. it's just about finding the main entry point of the program and following the flow. https://filebin.net/h4kp7s0z04kqa5om https://filebin.net/h4kp7s0z04kqa5om
- amatecha 6y agonice. my recent discovery of "CTFs" made that challenge trivial haha! th@nk5 ;) Will check out this site though, that sounds interesting indeed.
- hatsunearu 6y agohttps://microcorruption.com/ https://microcorruption.com/ pretty easy and fun, there is a difficulty wall after a few stages though. but once you get there, you might be able to get through it with some general deduction skills.
- imwillofficial 6y agoI'd love to learn this skill, but unsure where to get started.
- samwestdev 6y agoI'd love to do something like this for various NES games. Can Ghidra hook up to some NES emulators?
- mikepurvis 6y agoI expect you'll have a tougher time there because NES games were written directly in assembler, so there won't be the characteristic patterns that a decompiler can use to recognize particular control flows— I believe C wasn't really standard until the N64 era, which was part of what made high-level emulation (see: UltraHLE) possible. On the other hand, hand-authored assembly is easier to read directly, because, of course, it was written and read in that form originally anyway!
- bluesign 6y agoStill bankswitching etc will cause a lot of problems for disassembler. Best option for NES is to use emulator debugger for sure.
- tom_ 6y agoGhidra didn't do a great job of 6502 when I tried using it a couple of years ago, due to poor support for a couple of the 6502's addressing modes, but maybe it's improved? This Github bug summarises the problem I was having with it: https://github.com/NationalSecurityAgency/ghidra/issues/201 https://github.com/NationalSecurityAgency/ghidra/issues/201
- g051051 6y agoThe version 9.2 release notes mention improvements to the 6502 processor specification: > Many improvements and bug fixes have been made to existing processor specifications: ARM, AARCH64, AVR8, CRC16C, PIC24/30, SH2, SH4, TriCore, X86, XGATE, 6502, 68K, 6805, M6809, 8051, and others. Perhaps it's better for your use case now?
- jhatemyjob 6y agoyou dont need Ghidra for that
- bluesign 6y agoNice reversing article for GameCube, but I think original scoring is much better. It is preventing you to play same easy levels over and over again, and as fast as possible bringing you to your skill level. Very good adaptive difficulty, it is actually punishing players for choosing to play easy levels behind theirs skill level, keeping game constant challenge. PS: haven’t played the game, assuming later levels are more difficult
- o_p 6y agoI really hope Ghidra becomes the standard in reverse engineering, but the good old IDA with decompilers is just too good for now
- brokenmachine 6y agoYes but ghidra is (much) cheaper.
- Cloudef 6y agoI actually like using radare2 the most. (It can also use ghidras decompiler)
- jeofken 6y agoI wonder if anyone has any reading resources for reversing old DOS programs written in fortran - namely SCORE, the music notation program, still unparalleled in productivity, beauty, and preciseness, but with a dead author and no source code.
- tralarpa 6y agoInteresting... (I sometimes do reverse engineering for fun and I am always looking for new challenges). I see there is a DOS version and a Windows version. I suppose you talk about the DOS version? (SCOR4)
- jeofken 6y agoYes, I’m talking about the dos version, SCOR4.exe, as the windows version is a buggy beta release where the author died before being able to get it stable. Plus keyboard use is more efficient than mouse.
- monksy 6y agoI miss the game Super Monkey Ball. That was one of those games that was supper approachable, and easily competitive with friends in the same room. They have released something for the ps4 but I haven't opened the box yet. Also, this makes me want to get out the https://www.cs.virginia.edu/~cr4bd/3330/F2018/bomblab.html https://www.cs.virginia.edu/~cr4bd/3330/F2018/bomblab.html lab and try the disassembler he's using.
- dimator 6y agoIt really was a highly enjoyable game, both 1p and with a party. I'm pretty sure it was the only thing we needed 4 controllers for :) The speed runs for that game are mind melting, if you're into watching those.
- G4E 6y agoThere was MTP Target, a clone with penguin which had a pretty active community circa 2008[1][2] I loved this game. It had an IRC server included so you could chat while in game, a forumboard, and a pretty diverse community. The gameplay was simple to learn but difficult to master, with a lot of fun for everyones. Sadly, it was open-source but not so much. The sole developer never opened up the source of the server, and even the client's were not keep up to date, so it was impossible to play elsewhere than the official server. The sole developer had a little revenue stream by selling premium account (which enabled the possibility to use custom skins and access to a private server) and never accepted to let the community fix bugs or host other servers. There was quiet a bit of friction and drama between him and some members of the community, and in the end he prefered letting the game die than giving it to the community. [1] http://web.archive.org/web/20111028123349/http://www.mtp-target.org/mt/mt_screenshots.php http://web.archive.org/web/20111028123349/http://www.mtp-tar... [2] http://web.archive.org/web/20110310131659/https://www.mtp-target.org/ http://web.archive.org/web/20110310131659/https://www.mtp-ta... [3] https://fr.m.wikipedia.org/wiki/Mtp_Target https://fr.m.wikipedia.org/wiki/Mtp_Target
- PEJOE 6y agoI've seen bomblab, etc, at a couple of universities. Does anyone know the history of these exercises? I saw them at CMU as well. Really cool that these are used across several great programs.
- bombcar 6y agoI wonder if Dolphin lets you load a "cheatsheet" or something where you can tell it to modify certain values in memory after loading from the ISO - so you don't have to modify the original source ISO at all.
- Deathmax 6y agoThat's what cheat codes allow you to do. The Dolphin wiki documents various "enhancements" you can apply with cheat codes (https://wiki.dolphin-emu.org/index.php?title=The_Legend_of_Zelda:_Skyward_Sword#Enhancements https://wiki.dolphin-emu.org/index.php?title=The_Legend_of_Z... as an example).
- bombcar 6y agoThat is awesome - reminds me of “overlays” used to modify code from back in the DOS days.
- dmix 6y agoI find it funny that their goal is to make the game technically harder to make it a better game in general - by reducing the points you get - incentivizing you to explore the other levels mores. Instead of your typical game hacks that make it easier or add cool things. Even though I get this is just a tutorial.
- letitbeirie 6y agoThe craziest thing about Super Monkey Ball to me is that F-Zero GX runs on the same engine, just sped way up.
- complexplane 6y agoI'm actually from a Super Monkey Ball 2 hacking community which, among other things, has been working on a Ghidra decompilation for a bit over a year now. We collaborate on a shared Ghidra server and have tons of stuff labelled and annotated at this point! As an example, here's a full decompilation of the camera code which runs after the ball passes through the goal: https://cdn.discordapp.com/attachments/463221047471374337/797664337282990080/unknown.png https://cdn.discordapp.com/attachments/463221047471374337/79... We also have the ability to inject C++ directly into the game for modding. I'm also the author of ApeSphere, a practice mod for SMB2 with features like savestates: https://github.com/complexplane/apesphere https://github.com/complexplane/apesphere . Take a look at rel/savestate.cpp for a taste of what we can do.
- guitarbill 6y agodo you have any tips for setting up a shared Ghidra server? the user management especially seemed scary, and has kept me from setting one up in the past.
- chillee 6y agoHaha, since he didn't mention it, this guy (complexplane), is also the WR holder in super monkey ball 2: https://www.speedrun.com/supermonkeyball2 https://www.speedrun.com/supermonkeyball2
- electro_blah 6y agoprobably cheated.
- uglycoyote 6y agoHow is it that the decompiled camera code has interesting variable names and even comments? I was expecting it to look more like the decompiled code from this article... With made-up and uninformative variable names. You mentioned collaborating on annotating the decompiled code. Is the linked code something created manually based on the "raw" results of the decompilation? Or does the toolset allow you to annotate memory addresses etc in such a way that when you invoke the decompilation it uses the nice names automatically?
- jimbob45 6y agoRookie question: is there anything IDA Pro does that Ghidra does not?
- saagarjha 6y agoIDA Pro tends to have somewhat better disassembly/decompilation for the things it supports well.