[ndiscussion]

If you use the Signal app from the app stores, and communicate with the server, you are using 100% closed source software.

They could easily add a backdoor in the client despite the fact that it's "open source", because no one builds it from source.

[mdaniel]

"No one" is a bit harsh; I even helped a poster in r/Signal set up a CircleCI build for the repo in order to show that it's not oppressively hard, just tedious (as with all things CI/CD)

The Signal android build now uses some PKCS11 machinery that requires patching out to build without using a smartcard, but otherwise it works as expected.

I dove into this darkness while trying to fix the borked MMS handling on Visible (a Verizon MVNO), and is the reason I'm generally with you: if someone can't build the project, then it's not effectively open source, IMHO, because I lose my "right to repair"

[Caligatio]

By this standard, there is practically nothing that qualifies as open source. Compile something yourself? Well can you really trust your compiler unless you compiled it? How do you compile your compiler without a compiler? Obviously this is possible but no one does it; therefore no software is truly open source.

[ndiscussion]

I disagree that these are on the same level - compiling something yourself, or having something compiled by ie the Arch Linux maintainers requires a number of people to comply.

The app store is a single point of failure with huge reach.

[morelisp]

Are Signal's Android builds no longer reproducible?

[ndiscussion]

It looks like they are, but there might be a minor issue in verifying the content: https://github.com/signalapp/Signal-Android/issues/10476

But despite best efforts by the community to verify builds, Google and Apple can be forced to upload a malicious app to a particular user, meaning they aren't using the same app at all.