Attempting to remove OSS licenses is why coldcard firmware became vulnerable

TLDR: coldcard decided to move from open source licensing to a "source available" license that would prevent people from forking their firmware to make competing products. This meant they needed to replace GPL license crypto libraries, it is this refactoring that created the opportunity for them to screw up. Because of their corporate greed that decided to do this rather than continuing to build features on top of true OSS licenses.

Body of tweet:

Regarding the Coldcard entropy bug – many folks are explaining what happened but I wanted to take a minute to explain why it may have happened.

It's a disastrous situation and our heart goes out to all the Bitcoiners affected.

Here's a timeline of events:

On July 28 2020: @FOUNDATION announced our first Passport hardware wallet and noted that we were building on Coldcard firmware which at the time was GPLv3 licensed (FOSS license).

On July 30 2020: NVK publicly said he regretted choosing GPL because Coldcard now had a “clone” and that they would change things in future updates. https://x.com/nvk/status/128

8860345864527874

On November 18 2020: Coldcard added its MIT + Commons Clause license, prohibiting commercial products substantially derived from the software.

https://github.com/Coldcard/firmw

are/commit/b6b9191145d37fbb6d754597350653141596dd12

On January 8, 2021: Coldcard firmware 3.2.1 formally announced, “License changed from GPL to MIT+CC on files for which the GPL doesn’t apply.” CC is the "Commons Clause" license addendum which is "source available" instead of FOSS.

On March 1, 2021: The “First pass w/ libNgU” commit removed the GPL

@Trezor-derived crypto libraries and replaced them with libNgU. That same 120-file commit changed seed generation code. libNgU was licensed with a novel “Licensed for Bitcoin Only” license.

On March 17, 2021: Version 4.0.0 announced that all crypto and BIP39 code had been replaced and that the “last remaining GPL code” was removed. https://blog.coinkite.com/version-4.0.0-

released/

https://github.com/Coldcard/firmw

are/blob/b18723dddb6d751c39978e4364b56b2414f68b47/releases/ChangeLog.md#L12

Our best understanding right now is that the entropy bug was collateral damage from this major overhaul of the codebase.

To be clear, this overhaul was not solely about licensing. Coldcard also cited technical goals including adopting Bitcoin Core’s libsecp256k1, faster AES and SHA implementations, and reproducible builds.

But the timeline establishes two things:

(1) Foundation’s launch was the obvious impetus for Coldcard’s licensing change, and

(2) removing the remaining GPL code was an explicit goal of the subsequent v4 rewrite.

We don't know by how much the licensing pressure affected the scope or timeline of the rewrite. All we can determine is that the entropy bug was introduced inside the same 120-file commit that removed the old GPL code dependencies.