On Sun, Feb 01, 2026 at 05:09:48PM +0000, David Howells wrote: > Mihai-Drosi Câju <[email protected]> wrote: > > > > The current signature-based module integrity checking has some drawbacks > > in combination with reproducible builds. Either the module signing key > > is generated at build time, which makes the build unreproducible, or a > > static signing key is used, which precludes rebuilds by third parties > > and makes the whole build and packaging process much more complicated. > > There is another issue too: If you have a static private key that you use to > sign modules (and probably other things), someone will likely give you a GPL > request to get it. > > One advantage of using a transient key every build and deleting it after is > that no one has the key. > > One other thing to remember: security is *meant* to get in the way. That's > the whole point of it. > > However, IANAL. > > David
It sounds like hash-based module authentication is just better, then. If the full set of authentic modules is known at kernel build time, then signatures are unnecessary to verify their authenticity: a list of hashes built into the kernel image is perfectly sufficient. (This patchset actually gets a little fancy and makes it a Merkle tree root. But it could be simplified to just a list of hashes.) With that being the case, why is there still effort being put into adding more features to module signing? I would think efforts should be focused on hash-based module authentication, i.e. this patchset. - Eric
