Of course there was. You can clean-room reverse-engineer the hardware. This is what is done daily by Libdragon maintainers for supplying an open source SDK for Nintendo 64 with zero proprietary code in it.

way back in the before times... Open Source projects went to great lengths to make sure they didn't use anything that could 'taint' the code (eg Samba )

I think the DeCSS stuff wasn't used till it had been publicly leaked and was considered 'common knowlege' or some such to prevent lawsuits

Not quite. There was nobody holding back on sharing for legal reasons, and it didn't prevent lawsuits.

The LiViD mailing list was full of people trying to get DVDs working with Linux, and they were already quite far into it. Derek Fawcus had already written the drive authentication code (so the drive would allow the host to read most disc sectors).

A piracy group, DrinkOrDie, reverse engineered the Xing DVD player for Windows and released DoD DVD Speed Ripper (no source code).

MoRE (Masters of Reverse Engineering) also reverse engineered the Xing DVD player and released DeCSS (no source code).

MoRE consisted of "mdx", "the nomad" and Jon Lech Johansen. "the nomad" reverse engineered the Xing DVD player. "mdx" used them to write a decrypter. Jon made a GUI frontend.

Prior to DeCSS's release, someone sent Derek Fawcus the decryption code. And he got around to playing with it, and was going to publish it on the LiViD list.

But before he did, DeCSS came out, and also its source code leaked, and Fawcus noticed his own code was in it (the drive authentication code), stripped of his credit. He complained about this and Johansen got in touch, and ultimately he allowed DeCSS to use his code under a non-GPL license.

Then, famously, Norway's "economic crime" unit brought criminal charges against Johansen. Ultimately, they concluded that Johansen himself hadn't infringed anything, because it was Derek Fawcus, "the nomad" and "mdx" who did that, and they're not Norwegian.

So, with that in mind:

- the LiViD mailing list would almost certainly have developed a DVD solution for Linux, not caring about clean room implementation, if DeCSS had not beaten them to the punch

- the fame DeCSS got also brought the angry litigators (though eventually justice prevailed)

I'll end on a quote from Derek Fawcus:

https://web.archive.org/web/20001202051300/http://livid.on.o...

> Something that may be of interest to people in the states is that I've had an offer of help to produce a specification of the algorithm - from which a third party could produce an implementation. i.e. proper clean room approach. This doesn't really matter from my point of view (or in my opinion most Europeans) but may be of use to the Yanks.

How could one ever prove that a solution was clean-room? For example I would consider the oman leak to taint all development of N64 in existence. Even if someone didn't personally look at it, they most certainly got information from someone else that did.

I don’t understand if this question is legal or morale/technical. I will answer to the latter, from the point of view of a prospective user of the library that wants to make their own mind around this.

Its quite easy to prove that libdragon was fully clean roomed. There are thousands of proofs like the git history showing incremental evolution and discovery, the various hardware testsuites being developed in parallel to it, the Ares emulator also improving its accuracy as things are being discovered over the past 4-5 years. At the same time, the n64brew wiki has also evolved to provide a source of independently verified, trustable hardware details.

Plus there are tens of thousands of Discord log messages where development has incrementally happened.

This is completely different from eg romhack-related efforts like Nintendo microcode evolutions where the authors explicitly acknowledge to have used the leaks to study and understand the original commented source code.

Instead, libdragon microcode has evolved from scratch, as clearly visible from the git history, discovering things a bit at a time, writing fuzzy tests to observe corner case behaviors, down to even creating a custom RSP programming language.

I believe all of this will be apparent to anybody approaching the codebase and studying it.

Lawyers, discovery, and a courtroom. The reason clean room works out is due to various lawsuits on the topic as a matter of law.

The Wikipedia article on clean room reverse engineering has all the examples that came to my mind and then some. https://en.wikipedia.org/wiki/Clean-room_design

> Lawyers, discovery, and a courtroom

In other words, money that these people don't have. The legal system is not a solution for these kinds of problems, nor it is affirmative defense. Anything that makes the defendant bear the burden of raising and proving that their actions didn't foul any legal requirement, is basically killing any project, even when using your "solution".

To me this still means "there IS no way". You can get sued and convince a judge you didn't do it, sure, but that's not necessarily 100% accurate, and also probably extremely unlikely to happen anyway in most cases. And you'd be surprised how easy it is to fake evidence with no way to prove otherwise. Plus all that still requires going to court.

Generally one has two sets of developers, one doing the RE work, and one doing the new implementation, and the only way you allow them to communicate is through documentation of the reverse engineered implementation. Should this go to court, you can walk each member of each group in to testify, and show off the stacks of documentation produced in the process.

That might convince a judge, sure, although it's still possible to fake the evidence... but I would argue the vast majority of people who claim to have clean-room RE'd something absolutely did not go through anything close to this process.

I don't know anything about the majority of developers, and I think sweeping claims about any group require strong evidence, which seems lacking. But there are plenty of examples of companies that followed such a process, and succeeded in court: https://en.wikipedia.org/wiki/Clean-room_design#Examples

> I would argue

With what evidence?

I think when someone fails to produce any evidence of a clean-room process being followed when they claim it's clean-room, is probably a good indicator. Yea you can call that "trust me bro" if you want, I won't be upset.