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This is a well written, in depth analysis of the system. Why do you think the packets are encrypted?

by reidjs 3y ago

PawBer 3y ago
The LAN code is probably the same code as the online multiplayer.
- ClassyJacket 3y ago
  Halo 1 on original Xbox does not have online multiplayer. It launched before Xbox Live did.
  - msk-lywenn 3y ago
    They were probably already working on it
    - rafark 3y ago
      The game was actually close to ship without multiplayer, it was an afterthought. Some devs have talked about this (iirc, Marty O’Donnell was one of them).
      - notnaut 3y ago
        I’ve heard this was also the case for Goldeneye on the N64
        ravenstine 3y ago
        Goldeneye is one of the best case studies for why companies should give their engineers room to experiment. If I remember correctly, the multiplayer mode was originally a side project of one of the engineers and was added near the end of development. This isn't to say the campaign mode isn't good, but the ability for boys to play a shooter game against each other on the same console is what made that game.
      - thomastjeffery 3y ago
        The game being an FPS was an afterthought, too. Originally, they were working on an RTS.
        monocasa 3y ago
        I wouldn't call it an afterthought per se, more a pivot with a lot of work. It was already an FPS when it was shown off at MacWorld'99.
  - monocasa 3y ago
    As someone who's written replacement backend Xbox Live server infra, I can confirm that system link is very nearly the same base protocol set as is used by Live. They must have had that nailed down pretty close to launch, and were mainly working on support services that live needs but system link doesn't up until Live actually launched.
zootboy 3y ago
Probably for the reason the author speculates about in the article: > For example, would it not be cool if there was a game with a stack buffer overflow bug that allowed us to run arbitrary code remotely? That could potentially enable us to softmod an Xbox over the network, without the need of any special hardware.
nhellman 3y ago
Thanks, I was initially surprised that they were encrypted but I can speculate on a few potential reasons: - The Xbox was designed to be able to play online via Xbox Live (e.g. with Halo 2 that came out later in 2004), and they might have simply reused the network stack for System Link over LAN. I looked a little bit at Halo 2 system link, it uses the same system calls from the kernel but the protocol seems to be more complicated (e.g. the IV is never sent in plaintext, the two consoles derive it somehow). I haven't looked at Xbox Live, but Halo 2 could potentially use the same for System Link and Xbox Live. - The Xbox also really tried to lock down its security in order to prevent game piracy and homebrew games. This might have been another attempt to reduce the attack surface. - They also might have just wanted to keep their game protocols secret for trade secrets or simply avoiding scrutiny. In this case, we were able to create a kind of cheat, which they might have also wanted to avoid. Even though it is rarely an issue at LAN parties, it might have simply looked bad for the brand.
- monocasa 3y ago
  From what I've heard from microsofties over beers, it was really the second one. They didn't expect developers to write network code in ~2001 that didn't have memory safety vulnerabilities and wanted a barrier there between simple overflows and system security.
  - mywittyname 3y ago
    Makes total sense, especially recalling the zeitgeist of the era. IIRC, this was during the height of worms which propagated via vulnerabilities in code that handles network traffic.
  - willis936 3y ago
    The child in me from 20 years ago dreams of a software tool downloaded from a questionable website that jailbroke an xbox just by putting in the IP address.
    - monocasa 3y ago
      I hear that; I wish I was cool enough back in the day to release a tool on xbins. I'll have to settle for retro computing.
rasz 3y ago
There are cheats for certain online games that just listen to traffic. Sometimes games use bad encryption (static key) and cheats decrypt on the fly.

This is a well written, in depth analysis of the system. Why do you think the packets are encrypted?

by reidjs 3y ago

This is a well written, in depth analysis of the system. Why do you think the packets are encrypted?

PawBer 3y ago

The LAN code is probably the same code as the online multiplayer.

ClassyJacket 3y ago
Halo 1 on original Xbox does not have online multiplayer. It launched before Xbox Live did.
- msk-lywenn 3y ago
  They were probably already working on it
  - rafark 3y ago
    The game was actually close to ship without multiplayer, it was an afterthought. Some devs have talked about this (iirc, Marty O’Donnell was one of them).
    - notnaut 3y ago
      I’ve heard this was also the case for Goldeneye on the N64
      - ravenstine 3y ago
        Goldeneye is one of the best case studies for why companies should give their engineers room to experiment. If I remember correctly, the multiplayer mode was originally a side project of one of the engineers and was added near the end of development. This isn't to say the campaign mode isn't good, but the ability for boys to play a shooter game against each other on the same console is what made that game.
    - thomastjeffery 3y ago
      The game being an FPS was an afterthought, too. Originally, they were working on an RTS.
      - monocasa 3y ago
        I wouldn't call it an afterthought per se, more a pivot with a lot of work. It was already an FPS when it was shown off at MacWorld'99.
- monocasa 3y ago
  As someone who's written replacement backend Xbox Live server infra, I can confirm that system link is very nearly the same base protocol set as is used by Live. They must have had that nailed down pretty close to launch, and were mainly working on support services that live needs but system link doesn't up until Live actually launched.

zootboy 3y ago

Probably for the reason the author speculates about in the article: > For example, would it not be cool if there was a game with a stack buffer overflow bug that allowed us to run arbitrary code remotely? That could potentially enable us to softmod an Xbox over the network, without the need of any special hardware.

nhellman 3y ago

Thanks, I was initially surprised that they were encrypted but I can speculate on a few potential reasons: - The Xbox was designed to be able to play online via Xbox Live (e.g. with Halo 2 that came out later in 2004), and they might have simply reused the network stack for System Link over LAN. I looked a little bit at Halo 2 system link, it uses the same system calls from the kernel but the protocol seems to be more complicated (e.g. the IV is never sent in plaintext, the two consoles derive it somehow). I haven't looked at Xbox Live, but Halo 2 could potentially use the same for System Link and Xbox Live. - The Xbox also really tried to lock down its security in order to prevent game piracy and homebrew games. This might have been another attempt to reduce the attack surface. - They also might have just wanted to keep their game protocols secret for trade secrets or simply avoiding scrutiny. In this case, we were able to create a kind of cheat, which they might have also wanted to avoid. Even though it is rarely an issue at LAN parties, it might have simply looked bad for the brand.

monocasa 3y ago
From what I've heard from microsofties over beers, it was really the second one. They didn't expect developers to write network code in ~2001 that didn't have memory safety vulnerabilities and wanted a barrier there between simple overflows and system security.
- mywittyname 3y ago
  Makes total sense, especially recalling the zeitgeist of the era. IIRC, this was during the height of worms which propagated via vulnerabilities in code that handles network traffic.
- willis936 3y ago
  The child in me from 20 years ago dreams of a software tool downloaded from a questionable website that jailbroke an xbox just by putting in the IP address.
  - monocasa 3y ago
    I hear that; I wish I was cool enough back in the day to release a tool on xbins. I'll have to settle for retro computing.

rasz 3y ago

There are cheats for certain online games that just listen to traffic. Sometimes games use bad encryption (static key) and cheats decrypt on the fly.